Thesis Submitted by DR. TUAN CIN THANG (M.MAS-CANDIDATE)

APRIL 2025
ABSTRACT:

Introduction: Laparoscopic cholecystectomy has become gold standard because of its well-recognized minimal invasiveness and accelerated post-operative recovery. The most common use of energy sources in laparoscopic cholecystectomy are conventional electrosurgery and harmonic scalpel. However, the conventional electrosurgery produces excessive smoke and the intense collateral heat generation leading to tissue necrosis and subsequent perforation of gallbladder resulting in bile and stone spillage which will interfere with the laparoscopic view and leads to frequent instrument changes, and ultimately prolongs operating time. An advanced energy source, harmonic scalpel may provide the advantage of shorter operating time by reducing smoke and frequency of changing working instruments and provide bloodless dissection in GB bed. This study assesses whether the use of the expensive harmonic scalpel in laparoscopic cholecystectomy is justifiable.

Aim: To analyze the surgical outcomes of harmonic scalpel assisted versus conventional laparoscopic cholecystectomy.

Methods: This is a retrospective cohort study compared harmonic scalpel assisted laparoscopic cholecystectomy (HLC) and conventional laparoscopic cholecystectomy (CLC) in terms of surgical outcomes. Data of patients who underwent LC using either harmonic scalpel or monopolar diathermy were collected and categorized into two groups. In group A, harmonic scalpel was used for dissection and monopolar electrosurgery was used in group B. Outcome parameters analyzed were mean operation time, blood loss, bile duct injury, drain placement, conversion to open surgery, post-operative pain using visual analogue scale (VAS) scoring, nausea and vomiting, surgical site infection, need of ERCP, re-operation, length of hospital stay, mortality and cost per procedure (USD).

Results: The mean operative time was significantly shorter in the HLC group than the CLC group (38.2 5.5 min vs 46.8 6.2 min, p<0.0001). The mean intraoperative blood loss was also significantly lower in the HLC group (17.9 6.0ml vs36.4 7.9ml, p<0.00001). Furthermore, the HLC group showed significantly lower postoperative pain scores at all time points (p<0.00001). The duration of hospital stay was significantly shorter in HLC (1.4 0.6 days vs 2.3 0.7 days, p<0.0001). Nevertheless, the expense of cost per procedure was significantly higher in the HLC group ($300 50 vs $100 20, p<0.00001). Other parameters such as drain placement (15% vs 35%, p=0.273), bile duct injury (0% vs 10%, p=0.487), conversion to open surgery (0% vs 10%, p=0.487), postoperative nausea and vomiting (15%vs30%, p=0.451), need for ERCP (5% vs15%, p=0.605), re-operation (0%vs5%, p=1.000), SSI (10%vs20%, p=0.661) did not significantly differ between the groups.

Conclusion: In this study, apart from its high cost, HLC has significant advantages over CLC with respect to operating time, intraoperative blood loss, postoperative pain and length of hospital stay.

CHAPTER 1

INTRODUCTION

The first person to perform laparoscopic cholecystectomy was Professor Muhe of Boblingen, Germany. He performed the operation on September 12, 1985.1 It was popularized in the late 1980s by Mouret and Dubois in Europe and Reddick in the United States.2. Since then, laparoscopic cholecystectomy has undergone various developments. This includes the use of multiple techniques for coagulation during dissection. Now, laparoscopic cholecystectomy has replaced conventional open cholecystectomy and has become the gold standard.1 The reason may be its well-recognized minimal invasiveness and accelerated post-operative recovery. 3 Indications for cholecystectomy include cholecystitis (acute and chronic), biliary dyskinesia, adenomatous gallbladder polyps, gall stone diseases.4 The coagulation during dissection can be achieved by conventional electrocoagulation or the harmonic scalpel, which uses ultrasonic energy.1

CHAPTER 2

OBJECTIVES

General Objective

- To analyze the outcomes of harmonic scalpel assisted laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy

Specific Objectives

1. To compare demographic parameters in HLC and CLC groups

2. To compare intraoperative parameters such as operation time, intraoperative bleeding, bile duct injury, need of drain placement and conversion to open surgery between the two groups

3. To compare postoperative parameters such as pain using VAS scoring, nausea and vomiting, surgical site infection, need of ERCP intervention, reoperation, length of hospital stay in days, cost per procedure in USD, and mortality between the two groups

CHAPTER 3

LITERATURE REVIEW

3.1. Acute Cholecystitis (AC)

It is inflammation of gallbladder results from obstruction of the cystic duct, usually by a gallstone, followed by distension and subsequent chemical or bacterial inflammation of the gallbladder. People with acute cholecystitis usually have persistent right upper quadrant pain, anorexia, nausea, vomiting, and fever. About 95% of people with acute cholecystitis have gallstones (calculous cholecystitis) and 5% lack gallstones (acalculous cholecystitis). Severe acute cholecystitis may lead to necrosis of the gallbladder wall, known as gangrenous cholecystitis¹¹.

The incidence of acute cholecystitis among people with gallstones is unknown. The incidence of acute cholecystitis is about 20% among people with biliary colic. Biliary colic occurs in 1% to 4% of people with gallstones¹². About 20% of patients admitted to hospital for biliary tract disease have acute cholecystitis. Acute calculous cholecystitis is three times more common in women than in men up to the age of 50 years, and is about one and a half times more common in women than in men thereafter.¹¹

Acute calculous cholecystitis seems to be caused by obstruction of the cystic duct by a gallstone, or local mucosal erosion and inflammation caused by a stone, but cystic duct ligation alone does not produce acute cholecystitis in animal studies. The role of bacteria in the pathogenesis of acute cholecystitis is not clear; positive cultures of bile or gallbladder wall are found in 50% to 75% of cases.^13,14The cause of acute acalculous cholecystitis is uncertain and may be multifactorial, including increased susceptibility to bacterial colonization of static gallbladder bile.¹¹

3.2. Treatment

The treatment of AC is based on the disease severity, the presence of complications, and pre-existing conditions and comorbidities. Early LC represents the cornerstone in the treatment of AC, but, in some circumstances, when early LC is contraindicated, delayed surgery is performed. Medical treatment, especially the use of antibiotics, plays a crucial role. Sometimes, gallbladder drainage (GBD) may be indicated¹⁵. In difficult conditions, subtotal cholecystectomy may be necessary due to not reaching the critical view of safety, difficulty identification of the anatomical structures with risk of injury to nearby structures ¹⁶.

3.2.1. Medical Treatment

In the course of AC, patients should be kept on fasting and initiate antimicrobial therapy. General supportive care, such as fluid and electrolyte intravenous infusion, and possibly analgesic agent administration, are also mandatory ¹⁷.

In order to select a suitable empirical treatment, generally based on broad-spectrum antibiotics (e.g., penicillin, cephalosporins, fluoroquinolones), clinicians should consider drug pharmacokinetics and pharmacodynamics, local antibiogram, a history of antimicrobial use, allergic or adverse reactions, and renal and hepatic function. Importantly, the presence of a biliary–enteric anastomosis warrants anaerobic therapy (e.g., metronidazole) ¹⁸. A culture of bile and gallbladder tissue is suggested during cholecystectomy in case of emphysematous cholecystitis, gallbladder wall necrosis, or perforation ¹⁹. Once cultures and susceptibility test results are available, clinicians should discontinue antimicrobial therapy if no longer needed or switch to an antimicrobial agent that is specific for the isolated organism. The duration of antibiotic therapy depends on clinical features¹⁸.

3.2.2. Surgical Treatment

(a) Laparoscopic Cholecystectomy

The cornerstone of AC treatment is early LC. In particular, early LC performed within 72 hours should be the method of choice for the treatment of AC, because it is related to a shorter hospital stay, fewer perioperative complications, and reduced costs¹⁸.

(b) Gallbladder Drainage

GBD, also known as cholecystostomy, should be performed in all patients with severe AC in whom cholecystectomy is contraindicated. Moreover, GBD should also be considered in patients with moderate AC and a high surgical risk, particularly in case of an inadequate response to the medical treatment ¹⁵. Percutaneous transhepatic GBD, performed under ultrasound guidance, is the method of choice. In contrast, percutaneous GBD through the transperitoneal route is not recommended, because it is associated with a higher rate of complications, mainly bile leakage and biliary peritonitis²⁰

(c) Subtotal Cholecystectomy

Subtotal cholecystectomy is a bail-out procedure undertaken when facing difficult laparoscopic cholecystectomy due to not reaching the critical view of safety, inadequate identification of the anatomical structures involved and/or risk of injury ¹⁶.

The 2020 World Journal of Emergency Surgery guide for acute calculous cholecystitis recommends performing subtotal cholecystectomy in situations where it’s difficult to identify the anatomical structures needed or if there is a high risk of iatrogenic lesions²¹.

3.3. Energy Sources Used in Laparoscopic Cholecystectomy

In LC, the common energy sources used are electrosurgery and harmonic scalpel.

3.3.1. Electrosurgery

In electrosurgery, heat is generated in the tissue by the flow of radio frequency (RF) electric current. The RF energy can be applied to tissue by using either monopolar or bipolar tools. In monopolar electrosurgery, the electrical circuit is completed by the passage of current from the active electrode at the surgical site to the dispersive electrode (or the return electrode) attached to the body of the patient. The active electrode can be of any form (usually a point, hook or a blade) with sharp edges and/or blunt edges. The return electrode is usually a wide pad, attached to the skin of the patient, which disperses the heat and safely leads the current out of the body. The waveforms with different duty cycles can be used to produce four main effects inelectrosurgery namely, cutting, coagulation, desiccation and fulguration. To perform coagulation or desiccation, a lower duty cycle high voltage waveform is used but can also be performed with 100 % duty cycle lower voltage cutting waveform as well. Finally in fulguration, a lower duty cycle high voltage waveform is applied through the active electrode of a pointed monopolar electrosurgical tool tip in noncontact mode close to the tissues.

The current travelling through the body can interfere with any implanted medical devices such as pacemakers and defibrillators. Other mechanisms through which injuries can occur during electrosurgery include insulation failure, remote injury, direct and capacitive coupling.

Figure 1. Monopolar Diathermy Hook in Laparoscopic Cholecystectomy

Figure 1. Monopolar Diathermy Hook in Laparoscopic Cholecystectomy

3.3.1. Ultrasonic Energy

The basic working principle of ultrasonic surgical instruments such as ultrasonically activated scalpel (UAS) is to use the low frequency mechanical vibrations (ultrasonic energy in the range of 15–55 kHz) of the tool tips or the blades for tissue cutting and coagulation. The mechanical vibrations when transferred to the tissues on contact induces protein denaturation by breaking down the hydrogen bonds in tissues due to the internal cellular friction caused by the vibrations. The mechanical vibrations are produced by the piezoelectric transducers embedded in the tools which convert the applied electrical energy to mechanical vibrations which are then transferred to the active blades for cutting or coagulation. In general, the cutting and coagulation in UAS depends on various factors such as grip pressure, the shape and area of the blades in contact with the tissues and the power settings.

The major advantage of using UAS is that it produces less heat compared to other energy devices (temperature by harmonic scalpel, 80-100 compared to 200-300 for electrocoagulation) thereby reducing the risk of thermal injury. Due to lesser heat generation, charring and desiccation is also greatly reduced. Since no smoke is produced, except for the mist produced due to cavitation effect which dissipates much faster, UAS offers unobstructed view for endoscopic/ laparoscopic procedures. The UAS does not transmit active current in the tissues and thereby eliminate any risk of electric shock.

Not many complications were reported in the use of harmonic scalpel in laparoscopy. General disadvantages of ultrasonic devices include slower coagulation compared to electrosurgery, altering of the frequency or impedance of the surgical system itself due to blade fatigue, temperature elevation, excessive applied pressure, or improper use^22,23. Moreover, if the vibrating jaw directly touch bowel or blood vessels, it can be punctured²³.

3.4.1. Surgical Management of Cholecystitis

It can be done by open or laparoscopic approach. Nevertheless, Open cholecystectomy (OC) is being phased out in favor of laparoscopic cholecystectomy (LC) as a treatment for AC. From 0% in 1987 to 80% in 1992, the proportion of cholecystectomies done laparoscopically has increased. Due to the progress of laparoscopic technology, the growing competence and experience of surgeons, shorter hospital stays, and a shorter period for return to regular activities, open operations have been replaced by laparoscopic methods²⁴.

3.4.1. Laparoscopic Cholecystectomy

(a) Patient position

The patient is operated in the supine position with a steep head up and left tilt. This typical positioning of laparoscopic cholecystectomy should be achieved once the pneumoperitoneum has been established. The patient is then placed in reverse Trendelenburg’s position and rotated to the left to give maximal exposure to the right upper quadrant.

Figure 3: Patient Position in Laparoscopic Cholecystectomy

(b) Position of Surgical Team

The surgeon stands on the left side of the patient with camera holder-assistant. A scrub nurse and one assistant stand right to the patient and should hold the fundus grasping forceps.

Figure 4: Position of Surgical Team

(c) Steps of Procedure

Creation of Pneumoperitoneum and Port Insertion

After induction of general anesthesia, patient should be appropriately positioned. Nasogastric intubation is done for decompression of the stomach. Pneumoperitoneum can be established by a Closed or an Open technique.

1. Closed Access

In closed access technique, pneumoperitoneum is created by Veress needle. This is a blind technique and most commonly practiced way of access by surgeons and gynecologists worldwide.

2. Open Access

In this, there is a direct entry by open technique, without creating pneumoperitoneum and insufflator is connected once blunt trocar is inside the abdominal cavity under direct vision. There are various ways of open access like Hasson’s technique, Scandinavian technique and Fielding technique. Some surgeons and gynecologists practice blind trocar insertion without pneumoperitoneum. The incidence of injury due to this type of access is much higher.

(i) Introduction of Veress Needle

Veress needle should be held like a dart. At the time of insertion, there should be 45° of elevation angle. Elevation angle is angle between instrument and body of patient. To get an elevation angle of 45° the distal end of the Veress needle should be pointed toward anus. To prevent creation of preperitoneal slip of tip of Veress needle, it is necessary that Veress needle should be perpendicular to the abdominal wall. However, there is a fear of injury of great vessels or bowel if Veress needle is inserted perpendicular to the abdominal wall. To avoid both the difficulty (creation of preperitoneal space and injury to bowel or great vessels), the lower abdominal wall should be lifted in such a way that it should lie at 90° angle in relation to the Veress needle but in relation to the body of patient Veress needle will be at an angle of 45° pointed towards anus. Lifting of abdominal wall should be adequate so that the distance of abdominal wall from viscera should increase. At the time of entry of Veress needle surgeon can hear and feel two click sounds. The first click sound is due to rectus sheath and second click sound is due to puncture of peritoneum. Anterior and posterior rectus forms one sheath at the level of umbilicus, so there will be only one click for rectus. If any other area of abdominal wall is selected for access surgeon will get three click sounds. Once these two click sound is felt, surgeon should stop pushing Veress needle further inside and he should use various indicators such as needle movement test, irrigation test, aspiration test and hanging drop test to know how far he has accessed.

Figure 5: Holding of Veress Needle and Insertion

Once it is confirmed that Veress needle is inside the abdominal cavity the tubing of insufflator is attached and flow is started. The preset pressure ideally should be 12 mm Hg. In any circumstance, it should not be more than 18 mmHg.

(ii) Ports Insertion

The initial 1 mm stab puncture wound of skin for Veress needle should be extended to 11 mm. Surgeon should hold the trocar in proper way. Head of trocar should rest on thenar eminence, middle finger should encircle air inlet and index finger should point toward sharp end. After holding the trocar properly in hand, full thickness of abdominal wall should be lifted by fingers thenar and hypothenar muscles. After creation of pneumoperitoneum lifting of abdominal wall is difficult because it slips. To overcome this, it should be grasped to counter the pressure exerted by the tip of trocar.

Initially, angle of insertion for primary trocar should be perpendicular to abdominal wall but once surgeon feels giving way sensation, the trocar should be tilted to 60 to 70° angle. The entry of primary port can be confirmed by audible click for disposable trocar, whooshing sound for reusable trocar and loss of resistance for both types of trocars. Once the trocar entry in abdominal cavity is confirmed, cannula is stabilized with left hand and trocar is removed by right hand. After removing trocar, cannula is pushed slightly further inside the abdomen to prevent coming cannula in preperitoneal space with movement of abdominal wall with respiration. Once cannula is in place tubing of insufflator is attached and started to fill the CO2 at preset pressure. Then telescope is introduced and the abdominal cavity is explored for any obvious abnormalities. The secondary ports are then placed under direct visualization with the laparoscope. The surgeon places a 10mm trocar in the midline and left to the falciform ligament at the epigastrium. Two 5mm ports, one subcostal trocar in right upper quadrant and another one at lower, near the right anterior axillary line are inserted.

Figure 6: Ports Position in Laparoscopic Cholecystectomy

(iii) Exposure of Gallbladder and Cystic Pedicle

A grasper is used through the right lower 5mm trocar to grasp the gallbladder fundus and retract it up over the liver edge to expose the entire length of the gallbladder. If there are adhesions to the GB, they will need to be cleared using blunt and sharp dissection. With the entire GB visualized, a second grasper is inserted through the right upper quadrant trocar to grasp the GB infundibulum and retract it up and to the right to expose the triangle of Calot.

Figure 7: Calot’s Triangle

(iv) Dissection of Cystic Pedicle

The dissection should be started with anteromedial traction by left hand grasper placed on the anterior edge of Hartmann’s pouch. It will expose the posterior peritoneum. The peritoneum of the posterior leaf of the cystic pedicle is divided superficially as far back as the liver. Posterior leaf is better to dissect before anterior leaf because it is relatively less vascular and the bleeding if any, will not soil the anterior peritoneum, whereas if the anterior peritoneum is dissected first, it may make the dissection area of posterior peritoneum filled with blood making dissection of this area difficult.

Figure 8: Posterior Dissection of GB by Retracting Infundibulum Superomedially

Figure 9: Anterior Dissection of GB by Retracting Infundibulum Inferolaterally

Critical View of Safety: Anterior and posterior dissection continues with alternating inferolateral and superomedial retraction of the neck until the GB is dissected away from the liver, creating a ‘’window’’ crossed by two structures- cystic duct and artery. This is the ‘’critical view of safety (CVS)’’ that should be achieved prior to clipping or dividing any tubular structures. There is no need to dissect down to the cystic duct-CBD junction unless the cystic duct is very short. The cystic artery should be dissected in similar fashion. Calot’s node, or the cystic duct lymph node, is usually encountered adjacent and anterior to the artery and can be a useful landmark.

Figure 10: Strasburg’s Critical View of Safety

(v) Separation of Cystic Duct from Artery

Once the cystic duct is visualized, the dissector can be used to create a window in the triangle of Calot between the cystic duct and cystic artery. This window should be created high near the gallbladder-cystic duct junction to avoid injury to the common duct.

The separation of the cystic duct anteriorly from the cystic artery behind can be performed by a Maryland's grasper by gently opening the jaw of Maryland between the duct and artery. The opening of the jaw of Maryland dissector should be in the line of duct never at right angle to avoid injury of artery behind. Sufficient length of the cystic duct and artery on the gallbladder side should be skeletonized so that three clips can be applied

Figure 11: Cystic duct and Artery Skeletonized Up To GB

(vi) Clipping and Division of Cystic Duct and Cystic Artery

After isolating the cystic duct and artery, the clipper is introduced through the epigastric port and at least two clips are placed on the proximal side of the cystic duct. Care is taken not to place the clips too low because retraction can tent up the common bile duct or cause it to be obstructed. Another clip is placed on the gallbladder side of the cystic duct, leaving enough distance between the clips to divide it. In a similar fashion, clips are placed on the cystic artery, two proximally and one on the gallbladder side of the artery. The laparoscopic scissors or harmonic scalpel are then used through the epigastric port to divide the cystic duct and artery between the clips. Both the jaw of scissors should be under vision

Figure 12: Cutting Cystic Duct and Artery After Clipping

(vii) Dissection of GB from Liver Bed

The electrosurgical hook or harmonic scalpel is used with cautery through the epigastric port to dissect the gallbladder from the bed of the liver. Using a grasper, the gallbladder is first retracted right to expose and dissect the medial side of the attachment. The gallbladder is then retracted to the left and the lateral side is dissected. Using this back and forth action, the hook or harmonic scalpel is used to dissect the gallbladder off the bed from inferior to superior until it is 90 percent removed from the liver. Holding the remaining portion of the gallbladder attached to the liver, the dissection bed and the clipped structures are evaluated and any active bleeding is stopped using heal of the hook or harmonic scalpel. Gallbladder should be separated from the liver through the areolar tissue plane binding the gallbladder to the Glisson's capsule lining the liver bed. The actual separation can be performed with scissors with electrosurgical attachment or electrosurgical hook knife. Perforation of the gallbladder during its separation is a common complication which is encountered in 15 percent of cases. One should be careful at the time of dissection and if there is spillage of stone, each stone should be removed from the peritoneal cavity to avoid abscess formation in future.

Figure 13: Separation of GB From Liver Bed

(viii) Extraction of Gallbladder

The gallbladder is now freed from the liver and placed on top of the liver. The patient is returned to the supine position and the area of dissection and the upper right quadrant are irrigated and suctioned until clear. The gallbladder is extracted through the 11 mm epigastric operating port with the help of gallbladder extractor. Many surgeons use umbilical port for withdrawal of gallbladder. If gallbladder is removed through the umbilical port the laparoscope is placed through the epigastric port and the gallbladder is visualized on the dome of the liver. A large grasper with teeth is placed through the umbilical port and used to grasp the gallbladder along the edge of the clipped cystic duct stump. The gallbladder is then exteriorized through the umbilical incision where it is held into position with a clamp. First the neck of the gallbladder should be engaged in the cannula and then cannula will withdraw together with neck of gallbladder held within the jaw of gallbladder extractor. Once the port with the neck of the gallbladder is out, the neck is grasped with the help of a blunt hemostat and it should be pulled out with screwing. If gallbladder is of small size, it will come without much difficulty, otherwise small incision should be given over the neck of the gallbladder and suction irrigation instrument should be used to suck all the bile to facilitate easy withdrawal. Sometimes big stones will not allow easy passage of gallbladder and in these situations, ovum forceps should be inserted inside the lumen of gallbladder through the incision of its neck and all the stone should be crushed. When ovum forceps is used to remove the big stones from the gallbladder, care should be taken that gallbladder should be held loose to have room for forceps otherwise it will perforate and all the stone may spill out. Extraction inside a bag is recommended as a safeguard against stone loss and contamination of the exit wound.

Figure 14: Extraction of GB

(ix) Ending of the Operation

The instrument and then ports are removed. Telescope should be removed leaving gas valve of umbilical port open to let out all the gas. At the time of removing umbilical port, telescope should be again inserted and umbilical port should be removed over the telescope to prevent any entrapment of omentum. The wound is then closed with suture. Vicryl should be used for rectus and unabsorbable intradermal or stapler for skin. A single suture is used to close the umbilicus and upper midline fascial opening. Many laparoscopic surgeons routinely leave this fascial defect without ill defect. Some surgeons like to inject local anesthetic agent over port site to avoid postoperative pain. Sterile dressing over the wound should be applied.23

3.5. Studies Regarding Comparison of Surgical Outcomes of Harmonic Scalpel and Monopolar Diathermy Laparoscopic Cholecystectomy

The mean age for the group undergoing conventional LC was 46.6 years ± 11.39 years, ranging from 29 years to 65 years. The mean age for the HLC group was 40.25 years ± 14.85 years, ranging from 21 years to 73 years. This suggested that cholelithiasis was most common in the age group of 40-50 years (Rajnish et al, 2018)6. In Janssen et al. study, the mean age was 50 years( 18-82) in HLC group and 52 years (21-55) in CLC group showing that gallstone is most common in the age group between 50 and 60 years5. In Rajnish et al study, 25 (62.5%) were female and 15 (37.5%) were males and the gender ratio in both the groups was comparable. The sex ratio (male:female) was 14(23.3%) : 46(76.7%) in the study of Yehia et al.20199. In their studies, the prevalence of cholelithiasis was more common in females. The mean BMI was 25.5(18.7-43) in HLC group and 26.6(17.9-42.5) in the CLC group in the study of Janssen et al., 2003. In Rajnish et al. study, the mean BMI was 23.62±4.22 in CLC group and 23.55±4.75 in HLC group.

Yehia et al. conducted a prospective randomized study in 60 adult patients, presented with chronic calculus cholecystitis. Patients were divided randomly into 2 groups. Group A included 30 patients who underwent conventional laparoscopic cholecystectomy and group B included 30 patients who underwent laparoscopic cholecystectomy using harmonic scalpel (Ethicon Endo-Surgery).

The mean duration of surgery in the CLC group was 55.5±14.1 minutes, and in the HLC group was 46.8±14.3 minutes. The difference in the duration of surgery between the two groups was significant with p-value of 0.0249. Bessa et al. conducted a prospective study of 120 patients with gall bladder disease undergoing laparoscopic cholecystectomy. These patients were assigned either to the harmonic scalpel group (HS group = 60) or the clip and cautery group (C&C=60).The median operation time was statistically significantly shorter in the HS group than in the C&C group (32 vs. 40 minutes, respectively; P = 0.000)1. In 2014, Catena et al. had done a randomized controlled trial. A total of 42 patients were assigned randomly to either the harmonic scalpel group (H = 21) or the monopolar diathermy group (MD = 21). The intraoperative blood loss was significantly less in the harmonic scalpel group (91.1 ± 11.9 vs 166.6 cc ± 19.2, p<0.05). The conversion rate was also significantly less in the harmonic scalpel group(4.7% vs 33%, p<0.05)10. In the study of A.Zanghi et al., 121 patients in whom dissection and coagulation were performed using monopolar diathermy and 43 patients who were all treated with the harmonic scalpel ( Ethicon Endo-Surgery) as the sole instrument used in the whole procedure. The intraoperative volume blood loss was significantly more in the traditional group than in the harmonic scalpel group (29.32+14.21 vs. 12.41+8.22; p < 0.0001)4. In the study of Liao et al., a total of 198 patients were randomly allocated to LC with a Harmonic scalpel (experimental group, 117 patients) or conventional monopolar electrocautery (control group, 81 patients). The conversion to open cholecystectomy was required in 1 patient of the experimental group caused by common bile duct injury, whereas none of the patients from the control group underwent conversion (P >0.05)3. In the study of Rajnish et al, out of 40 patients, an intraperitoneal drain was kept in seven patients (17.5%). Six patients (30%) in the CLC group and four patients (20%) in the HLC group required an intraperitoneal drain. The difference was not significant (p = 0.716).

Postoperative pain scores studied in the Cengiz et al trial at the first and fourth hours of recovery are statistically lower in ultrasonic dissection group with p value of 0.04 and 0.004 respectively. Pain scores at 24 hours of recovery from Cengiz and Tsimoyiannis trials were combined with a lower estimate in the ultrasonic dissection group (p=0.00001)25. In the study of Rajnish et al., the mean VAS score on Day 0 for the CLC group was 4.55 ± 0.51 and that for HLC group was 4.65 ± 0.6, with p value of 0.59. The mean VAS score on Day 1 of surgery was 2.3 ± 0.8 in the CLC group and 2.25 ± 0.78 in HLC group, with p value of 0.84. The postoperative pain VAS score was not significant in their study. Kandil et al. had done a prospective randomized study of 140 patients undergoing laparoscopic cholecystectomy who were randomly assigned to either the diathermy group (n=70) or the harmonic scalpel group (n=70). The incidence of nausea and vomiting was higher in the diathermy group. But it did not show a significant difference (p>0.05)26. In the study of Sasi et al., there was no statistical difference in the number of patients who experienced a clinically significant postoperative nausea, nor was there a statistical difference in the number of patients who suffered from vomiting in the early postoperative period (P=0.65). No patients had subhepatic drains or postoperative bile leakage in the ultrasonic group (n=160), while in the electrocautery group (n=160), patients had bile observed in their subhepatic drains reported by Tsimoyiannis et al. In 2 patients, bile leakage was observed during the first 24 postoperative hours, while in the third patient, bile leakage continued for 6 days. In all, endoscopic retrograde cholangiopancreatography (ERCP) confirmed bile leakage from the gallbladder’s liver bed. There is no statistical difference between the 2 groups with regards to this outcome (P=0.19)27. In the study of Rajnish et al., a total of five (12.5%) patients had superficial SSI. None of the patients had deep SSI. Three patients (15%) in the CLC group had superficial SSI and two patients (10%) in the HLC group had superficial SSI. The SSI rates between the two groups were not significant (p = 1.000). In Sasi et al. study, port-site infections occurred in 2 patients in the ultrasonic group (3.3%) and in 3 others in the electrocautery group (5%). This outcome was not statistically significant(p>0.05).

In the study of Tsimoyiannis et al, the length of hospital stay was 1.9 ± 0.5 days in CLC group and 1.4 ± 0.2 days HLC group. The difference was statistically significant with p-value of 0.00527. However, in the study of A.Zanghi et al, the hospital stay was not significantly shorter in harmonic group (48.15+4.29 vs. 49.06+2.94 h, p > 0.05)4.

In a cost analysis by Westervelt28, the cost in an American hospital of a disposable LCS Harmonic scalpel blade tip is $330.00. This is compared with the combined cost of a disposable electrocautery shears and a clipper, which is $350.00. In Europe, Huscher et al29estimated the cost for a disposable LCS Harmonic scalpel to be lower compared with the combined cost for one scissors and one clipper (346.03 Euro vs. 397.67 Euro). However, the cost issue is relevant only on the assumption that disposable technology is used for monopolar electrocautery.

MATERIALS AND METHOD

4.1. Study Design

This is a hospital based retrospective cohort study.

4.2. Study Site

World Laparoscopic Hospital, Gurugrum, India.

4.3. Study Period

From 1 December, 2023 to 30 November, 2024

4.4. Study Population

All patients with gallbladder diseases underwent laparoscopic cholecystectomy by using either monopolar diathermy or harmonic scalpel in World Laparoscopic Hospital in the study period. Patients were selected based on the following inclusion and exclusion criteria.

4.5. Selection Criteria

4.5.1. Inclusion criteria

Age between 20 and 70 years
Physical status ASA class I or II
Diagnosis of simple acute or chronic cholecystitis
Cholelithiasis
Gallbladder polyps
Suitability for LC because of the presence of clinically significant symptoms
Prophylaxis of malignancy in high-risk patients
BMI <40 kg/m2

4.5.2. Exclusion criteria

Age <20 years and >70years
Pregnant or lactating women
BMI >40 kg/m2
ASA class III or IV
Complicated intrahepatic or extrahepatic bile duct stones
Complicated acute pancreatitis
Suspected gallbladder malignancy
History of previous open upper abdominal surgery

4.6. Data Collection

Preoperative, intraoperative and postoperative data from medical records, who underwent laparoscopic cholecystectomy using either harmonic scalpel or conventional monopolar diathermy in World Laparoscopic Hospital, were collected according to inclusion and exclusion criteria consecutively during the study period.

4.7. Sample Size Determination

4.7.1. Sample Size Calculation

Sample size calculated from the following formula.

n = (2×(Z_(1-α/2 )+Z_(1-β) )^2)/d^2

Z_(1-α/2) = z-score for the desired significance level (1.96 for a two-sided α=0.05)

Z_(1-β) = z-score for the desired power (0.84 for 80% power)

d = standardized effect size (Cohen’s d), where

d=∆/σ

∆ is the difference in means, and σ is the standard deviation

n = 20

4.8. Statistical Analysis

Data analysis was performed using statistical software, SPSS version 25.

4.8.1. Descriptive Statistics

Mean and Standard Deviation for continuous variables
Frequencies and percentages for categorical variables

4.8.2. Comparative Analysis

Independent t-test for continuous variables
Fisher’s Exact test for categorical variables

4.9. Detailed Procedure

Preoperative, intraoperative and postoperative data from medical records, who underwent laparoscopic cholecystectomy using either harmonic scalpel or conventional monopolar diathermy in World Laparoscopic Hospital, were collected according to inclusion and exclusion criteria consecutively during the study period. The sample was calculated as 20 in each group.

The demographic profiles in both groups were noted. The intraoperative parameters such as duration of surgery (skin to skin), amount of blood loss, presence or absence of injury to bile duct, drain placement and conversion to open surgery were noted in both groups. Postoperative pain was assessed using the visual analogue scale (VAS) score at 1,2,4,6 and 24 hours. Moreover, other postoperative parameters such as postoperative nausea, vomiting and need of ERCP, reoperation, duration of hospital stay, cost per procedure and mortality were recorded. At the time of discharge, during the first postoperative visit and at the 30th postoperative day, patients were examined for wound infection. After collecting the patient data, they were analyzed to compare the outcomes between the two groups.

RESULTS

5.1. Demographic Profiles

A total of 40 patients were enrolled in the study, 20 in harmonic scalpel LC and 20 in conventional LC. The demographic profiles of the two groups were comparable. The mean age for the group undergoing HLC (group A) was 43.3±11.22 years, ranging from 25 years to 62 years. The mean age for the CLC group (group B) was 44.75±10.85 years, ranging from 26 years to 64 years. This data suggests that gallstone is most common in the age group of 40-50 years. Out of the total 40 patients enrolled in the study, 29 (72.5%) were females and 11(27.5%) were males and the gender ratio in both groups was comparable. Both groups had a comparable body mass index (BMI) and distribution of various comorbidities in the study population. The American Society of Anesthesiologist (ASA) fitness category did not significantly differ between the two groups (Table-1).

Table 1: Comparison of Baseline Parameters Between the Groups

Parameters		Group A(n=20)	Group B(n=20)
Age (mean SD)		43.3 11.22	44.75 10.85
BMI (mean SD)		26.43 4.75	26.62 4.22
Sex	Male Female	6(30%) 14(70%)	5(25%) 15(75%)
Comorbidities	Diabetes Hypertension	8(40%) 5(25%)	5(25%) 15(75%)
ASA Category	ASA I ASA II	11(55%) 9(45%)	12(60%) 8(40%)

5.2. Intraoperative Parameters

The mean duration of surgery in the HLC group was 38.2±5.5 minutes and in CLC group was 46 ±6.2 minutes. The difference in the duration of surgery between the two groups was significant (p<0.0001). The intraoperative blood loss was significantly lower in HLC group than in the CLC group (17.4±6 ml vs 36.9± 7.9ml, p<0.00001). The need of drain placement was 3 (15%) in HLC group and 7(35%) in CLC group. There is no significant difference between the two groups (p =0.273). In the CLC group, there were two cases (10%) of bile duct injuries and both were converted to open surgery. In the HLC group, there were no cases of bile duct injury and conversion to open surgery. These occurrences were not significantly different (0%vs10%, p=0.487) for bile duct injury and (0%vs10%, p=0.487) for conversion to open surgery.

Table 2: Comparison of Intraoperative Parameters Between the Groups

	Group A(HLC)	Group B (CLC)	p-value
Mean operation time	38.2±5.5 min	46.8±6.2 min	<0.0001
Mean blood loss	17.9±6.0ml	36.4±7.9ml	<0.00001
Mean blood loss	3(15%)	7(35%)	0.273
Bile duct injury	0(0%)	2(10%)	0.487
Conversion to open surgery	0(0%)	2(10%)	0.487

5.3. Postoperative Parameters

All patients were given injectable analgesics in the immediate postoperative period and were given oral analgesics from the next day if the patient complained of pain. Pain assessment was done by using VAS at 1,2,4,6 and 24 hours in both groups. In HLC group, the mean VAS scores at postoperative 1,2,4,6, and 24 hours were 4.1±0.8, 3.5±0.7, 3.0±0.6, 2.6±0.5 and 2.2±0.5 respectively. In CLC group, the mean VAS scores at postoperative 1,2,4,6 and 24 hours were 5.3±1, 4.8±1.1, 4.4±1.0, 3.9±0.9 and 3.5±0.8 respectively. The harmonic scalpel group showed significantly lower pain scores at all time points.

Table 3: Comparison of Postoperative Pain Using VAS Score Between the Groups

Pain Score (VAS 0-10)	HLC	CLC	p-value
1 Hour	4.1±0.8	5.3±1.0	<0.001
2 Hours	3.5±0.7	4.8±1.1	<0.00001
4 Hours	3.0±0.6	4.4±1.0	<0.00001
6 Hours	2.6±0.5	3.9±0.9	<0.00001
24 Hours	2.2±0.5	3.5±0.8	<0.00001

There were 3(15%) in HLC and 6(30%) in CLC of postoperative nausea and vomiting and it was not significantly different (p= 0.451). In CLC group, 2(10%) of cases needed ERCP interventions due to CBD injuries and 1 (5%) patient for CBD stones while1(5%) case needed ERCP intervention for CBD stones in HLC group. This difference is not significant(p=0.605). Reoperation was done in 1(5%) patient due to progressive bile leakage in CLC group. The mean hospital stay (days) was significantly longer in CLC group (2.3±0.7 days vs 1.4±0.6 days, p<0.0001). A total of 6(15%) patients had superficial surgical site infection (SSI). None of patients had deep SSI. Four patients (20%) in the CLC group had superficial SSI and two patients (10%) in the HLC group had superficial SSI. Surgical site infection was not significantly different in the two groups(p=0.661). There was no mortality in both groups. The cost per procedure (USD) was $100±20 in CLC and $300±50 in HLC group. It was significantly higher in the HLC group (p<0.00001).

Table 4: Comparison of Postoperative Morbidities Between the Groups

	HLC Group	CLC Group	p-value
Nausea and Vomiting	3(15%)	6(30%)	0.451
Surgical Site Infection	2(10%)	4(20%)	0.661
Need for ERCP	1(5%)	3(15%)	0.605
Re-operation	0 (0%)	1(5%)	1.000
Length of Hospital Stay	1.4±0.6 days	2.3±0.7 days	<0.0001
Mortality	0 (0%)	0(0%)
Cost Per Procedure(USD)	$300±50	$100±20	<0.00001

DISCUSSION

In the study of Rajnish et al 2018, cholelithiasis was most common at the age of 40-50 years. In the current study, the mean age for the group undergoing HLC was 43.3±11.22 years, and the mean age for the CLC group was 44.75±10.85 years. It showed that cholelithiasis was most common in the age group of 40-50 years. Females were more susceptible to develope gallstone diseases in the study of Yehia et al.20199 showing male to female ratio to be 14(23.3%):46(76.7%). Rajnish et al.6 study also showed higher prevalence of cholelithiasis in female where 25 (62.5%) were females and 15 (37.5%) were males. In the current study, out of 40 patients undergoing laparoscopic cholecystectomy, 29 (72.5%) were females and 11(27.5%) were males showing that cholelithiasis was more common in females.

The terminology “clipless cholecystectomy” has been used in a few studies to indicate that the total operating procedure is carried out by using the harmonic scalpel including the division of the cystic artery and cystic duct6. In the present study, the harmonic scalpel was used for the dissection of Calot’s Triangle and the dissection of the GB from the GB fossa. The cystic duct and cystic artery were divided after clipping with conventional titanium clips.

In various studies done previously, there was a significant difference in the operating time between the harmonic and electrocautery groups. This can be explained by the fact that the harmonic scalpel is a multifunctional instrument26,30 . It replaces four instruments routinely used in conventional LC, namely, the dissector, clip applier, scissors, and electrosurgical hook/spatula. Hence, there is no need to change instruments repeatedly, and this saves time. Also, there is no smoke production while using the harmonic scalpel. This also saves time, as the camera lens need not be cleaned repeatedly and provides a clear operative field for the surgeon to work.

Operating time was significantly longer in the CLC group in the study conducted by Jain et al. (64.7 ± 13.74 vs. 50 ± 9.36; p = 0.001) and Kadil et al (61.88 ± 16.17 vs. 52.14 ± 9.8; p < 0.0001)6. In the study of Yehia et al, the mean duration of surgery in the CLC group was 55.5±14.1 minutes, and in the HLC group was 46.8±14.3 minutes. The difference in the duration of surgery between the two groups was significant with p-value of 0.0249. In the present study, it also showed a significant longer mean operation time in CLC group (46.8±6.2 min vs 38.2±5.5 min; p<0.0001). In the study of Catena et al, the intraoperative blood loss was significantly less in the harmonic scalpel group (91.1 ± 11.9 ml vs 166.6 ml ± 19.2, p<0.05). In the study of A.Zanghi et al, the intraoperative volume blood loss was significantly more in the traditional group than in the harmonic scalpel group (29.32±14.21ml vs. 12.41±8.22ml; p < 0.0001). In the current study, the mean blood loss was significantly more in the CLC group (17.4±6 ml vs 36.9± 7.9ml, p<0.00001). Bleeding from the liver bed is a commonly encountered problem that prolongs the operating time, as it takes time to control diffuse bleeding from the liver bed. Electrocautery with the ball tip is conventionally used to stop bleeding from the GB fossa; however, the crust formation and stickiness of electrocautery make the use of such an instrument difficult. The smoke emitted from the electrocautery also makes the operating field hazy and delays the identification of the bleeding point. A harmonic scalpel with a hook and ball dissector has the advantage of stopping the bleeding without producing smoke6. In the study of Rajnish et al, the need of intraperitoneal drain in both groups was not significant (p = 0.716). The occurrence of need of drain placement due to gallbladder perforation with stone spillage and suspicion of oozing from vessels was not significantly different in the current study (p=0.273). In the study of Liao et al, conversion to open cholecystectomy was required in one patient of the harmonic scalpel group caused by common bile duct injury, whereas none of the patients from the conventional group underwent conversion (P >0.05). Conversely in the current study, two patients in CLC group had bile duct injuries owing to difficulty identification of Calot’s triangle with dense adhesions. Both patients were converted to open surgery and primary repair with T-tube insertion was performed. In the HLC group, there was no bile duct injury and need of conversion to open surgery. However, these differences were not statistically significant, (0% vs10%, p=0.487) and (0%vs10%, p=0.487), respectively. LC using conventional monopolar electrocautery is well documented to be safe and associated with occasional iatrogenic injury, such as postoperative bleeding, bile duct damage and bowel perforation, mainly because of the effect of collateral energy from electrocauterization, in contrast to minimal energy transfer from ultrasonic vibration3.

Pain in the immediate post-operative period is mostly due to visceral irritation. In the CLC group, the effect spreads laterally up to 5mm as compared to 1.5 mm in ultrasonic shears. This leads to increased thermal damage and charring in surrounding tissues and nerve structures, leading to increased postoperative pain in the CLC group. Jain et al. noted that post-operative pain was significantly less in the harmonic shear group6. This is due to less release of inflammatory mediators, as there is less lateral tissue and nerve damage. Also, the duration of peritoneal distension is less due to the shorter surgery duration, thereby directly affecting the duration and degree of traction to vessels and nerve. Mahabaleshwar et al. also concluded that the postoperative pain is less in the harmonic scalpel group30. Post-operative pain scores after 24 hours were found to be significantly better in HCL by Kandil et al. as well (4.48 ± 1.89 vs. 3.12 ± 1.84; p = 0.001) 26. In this study, postoperative pain scores at 1,2,4,6 and 24 hours were significantly better in HLC group with p-value of <0.001, <0.00001, <0.00001, <0.00001 and <0.00001 respectively.

In Sasi et.al. study , postoperative nausea was significantly lower with ultrasonic dissection compared with electrocautery(p<0.05)25. However, Kandil et al study showed that the incidence of nausea and vomiting was higher in the diathermy group. But it did not show a significant difference (p>0.05). In the present study, occurrence of postoperative nausea and vomiting were not statistically different (p=0.451). In the Tsimoyiannis et al study, three patients needed ERCP for postoperative bile leakage from the gallbladder’s liver bed in the electrocautery group. But there is no statistical difference between the two groups with regards to this outcome (P=0.19). In the current study, three patients in CLC group needed ERCP for stent placement due to occurrence of symptomatic biloma presented after two weeks of operation. In HLC group, one patient required ERCP stent placement for symptomatic biloma presented after 10 days of surgery. After stent placement, all four patients were recovered well. Cholangiogram was taken after four weeks and there was no more bile leakage in all patients. So, stents removal was done in all patients. However, the need of ERCP in the two groups was not statistically significant (5%vs 15%, p=0.605). Meanwhile, one patient with CBD injury from the CLC group had progressive bile leakage with signs and symptoms of biliary peritonitis in the postoperative period and reoperation was done on fifth postoperative day. Roux-en-Y hepaticojejunostomy was performed and postoperative period was uneventful. The risk of SSI is less in laparoscopic procedures as compared to open surgeries, as the size of the incision is small. The risk of SSI depends on various factors, such as duration of surgery, spillage of bile, intra-abdominal collection due to postoperative bile leak, retrieval of GB through the port, presence of drain, and comorbidities such as diabetes6. In the study of Rajnish et al, three patients (15%) in the CLC group had superficial SSI and two patients (10%) in the HLC group had superficial SSI. The SSI rates between the two groups were not significant (p = 1.000). In Sasi et al. study, port-site infections occurred in two patients in the ultrasonic group (3.3%) and in 3 others in the electrocautery group (5%). This outcome was not statistically significant(p>0.05). In this study, two patients (10%) in the HLC group had superficial SSI and both of them were diabetics. Four patients (20%) in CLC group developed superficial SSI. Among them, three patients had diabetes and one patient had an intraperitoneal drain. The overall SSI was 15% and test was not significant (10%vs20%, p=0.661). There was no mortality in the study groups.

CONCLUSION

The primary objective of this study was to analyze surgical outcomes of harmonic scalpel laparoscopic cholecystectomy versus conventional monopolar diathermy laparoscopic cholecystectomy. The HLC group demonstrated significantly lower operative time, intraoperative blood loss, length of hospital stay, and postoperative pain scores compared to the CLC group. However, there were no significant differences between the two groups in terms of bile duct injury, conversion to open surgery and the need for drain placement. Postoperative outcomes such as nausea and vomiting, the need of ERCP intervention, surgical site infection, and reoperation rates were also comparable. Notably, HLC offered consistently lower pain scores across assessed time points. Despite these advantages, the primary limitation of HLC remains its higher cost, which poses a significant challenge, particularly in resource-limited settings and developing countries.