A comparative study of single incision versus conventional four incision
Thesis of SILS
SUBMITTED: BY DR NJEM J. MINER ROLL NO- TGOU/PG/2873/M. MAS/2014 J TO
Department Of Minimal Access Surgery, World Laparoscopy Hospital Centre, The Global Open University Of Nagaland , In Part Fulfilment Of The Requirements For The Award Of Masters Degree In Minimal Access Surgery August 2015
CERTIFICATION :
This study “A Comparative study of single incision versus conventional four incision laparoscopic cholecystectomy” was conducted under our supervision, we have also supervised the writing of the thesis.
Dr. J. S. Chowhan, MBBS, MS,F.MAS,PGDHHM
Coordinator -------------------------------------------------
Dr. (PROF.) R. K. Mishra, MBBS,MS,MWALS,MRCS,M MAS,F. MAS,D.MAS,FICRS,PHD
Professor and Head, Minimal Access Surgery, TGO University of the Nagaland and Medical Director
World Laparoscopy Hospital, X 100, Cyber City. DLF Phase II, Gurgaon, New Delhi, India
---------------------------------------------
Dr. NJEM JOSIAH MINER
C/O World laparoscopy Hospital, X 100,Cyber City. DLF Phase II , Gurgaon , New Delhi, India
DECLARATION:
I Dr. Njem Josiah Miner hereby declare that this thesis titled “A Comparative study of Single Incision Versus Conventional Four incision Laparoscopic Cholecystectomy” has not been submitted in candidature for any other degree.
Acknowledgement :
I would like to thank my supervisors Dr.(Prof.) R K Mishra and Dr. J S Chowhan and the entire staff of the World Laparoscopy Hospital Centre, of The Global Open University of Nagaland, for their tireless support and guide
.
M y appreciation also goes to Dr. Parveen Bhatia and the entire staff of the institute of Minimal Access, Metabolic and Bariatric Surgery, Sir Ganga Ram Hospital for offering me an opportunity to do my clinical posting and also to carry out this research in the institute. To Dr Arund Prasad and staff of the department of Minimal Access Surgery Apollo Hospital, you were very receptive during my clinical rotation and taught me practical approaches to minimal access surgery, thank you.
My gratitude also goes to the management of the Jos University Teaching Hospital who gave me the opportunity to train as a Cardiothoracic surgeon which served as a “stepping stone” to this “mile stone” in minimal access surgery. To my family, thank you for enduring my absence, your understanding has been sterling.
Dedicatiion :
I dedicate this thesis to Paul and Joanne my jewels.
Acronnyms:
SILC Single incision laparoscopic cholecystectomy
4PLC Four port laparoscopic cholecystectomy
NOTES Natural orifices transluminal endoscopic surgery
1.0 Stuctured Summary:
Laparoscopic cholecystectomy has traditionally been performed using multiple small incisions. Single incision laparoscopic cholecystectomy (SILC) has emerged as an alternative technique to improve cosmesis and minimize complications associated with multiple incisions. This study compared single incision laparoscopic cholecystectomy with conventional four incision laparoscopic cholecystectomy.
METHODOLOGY: All consecutive patients who had laparoscopic cholecystectomy for gall bladder disease at the Institute of Minimal Access, Metabolic and Bariatric Surgery, Sir Ganga Ram Hospital between January 2012 and October2014 were included in the study. Excluded were patients who were operated for malignant gall bladder disease, patients with mirizzi syndrome, patients with gall bladder perforation and patients who were in ASA 1V and V.
PRIMARY END POINTS: Length of hospital stay, analgesic requirements, complications and hospital visits.
RESULTS: Of the one hundred and twenty patients who had laparoscopic cholecystectomy at the institute of minimal access, metabolic and bariatric surgery, Sir Gan Garam Hospital, New Delhi, sixty one (50.4%) had conventional four port laparoscopic cholecystectomy (4PLC), while sixty (49.6%) had single incision laparoscopic cholecystectomy (SILC). The average age of the patients was 45.9+or – range 9 years to 85 years fo both groups. The average age for those who had SILC was 46.7+or-15 while that for those who had 4PLC was 45.2+or-14.The number of males who had SILC was 26(43.3%), while 34(56.7%) were females. Those who had conventional four port laparoscopic cholecystectomy had 31(50.8%) males and 34(56.7%) females. Indications for the operation were similar for the two groups (table 3). There was one conversion from SILC to 4PLC. This was a patient who had prior percutaneous drainage of gallbladder empyema in another hospital. None of the patients in the two groups was however, converted to open cholecystectomy. There was also no intraoperative complication or peri-operative mortality recorded in both groups of patients.
The average length of hospital stay including in-patient and out-patient surgeries was 23.93+or-9.8, range 4 hours to 48 hours for thosewho had SILC and 30.07+or-16, range 8 hours to 72 hours for patients who underwent 4PLC (P=0.014). After undergoing SILC, 90%(54 of 60) of patients went home within 24 hours, while 75% (46 of 61) of thosewho had 4PLC went home within 24 hours ( P=0.05). Patients in both groups had either paracetamol or a non steroidal anti-inflammatory agent (NSAID) as post operative analgesic. Only one (1.7%) patient who had SILC required an NSAID for post operative analgesia, while fifty nine (98.3%) had post operative pain relieve using only paracetamol. Four(6.6%) of patients who had 4PLC required an NSAID for post operative analgesia, while 57(93.4%) had only paracetamol for post operative analgesia (P=0.177), which was not statistically significant.
Conclusion: Single incicion laparoscopic cholecystectomy appears to offer prospects for shorter hospital and early return to work compaired to conventional four port laparoscopic surgery. Patients undergoing either SILC or 4PLC appear to have similar analgesic requirement. Extrapolating this to pain difference between the two surgical technique however, require caution. SILC as a surgical technique is however, feasible and promising for treatment of symptomatic cholelithiasis
Key Words: Single incision laparoscopic cholecystectomy, four incision laparoscopic cholecystectomy
2.1 Introduction: Laparoscopic cholecystectomy has become one of the most effective procedures for the treatment of gall bladder pathology.(1) This technique has induced tremendous revolution in the surgery of biliary sytem, mainly due to improved results compared to the open technique and its cosmetic advantages has further endeared in the heart of surgeons. (1,2) Since the first laparoscopic cholecystectomy (LC) by Muhe et al in 1985, conventional laparoscopic cholecystectomy (CLC) has become the gold standard for treating gall bladder disease.( 1,3,4,9,14) Conventional laparoscopic cholecystectomy is a safe established procedure and traditionally it is performed through three to four small incisions. (4,5,9,11) It is the commonest operation performed laparocopically world wide.(14)
A trend towards even more minimally invasive approaches has however, led to techniques of single incision and natural orifices transluminal endoscopic surgery (NOTES).(1,2,4,4,9) The first published report of single incision laparoscopic cholecystectomy was by Navarra in 1997 and since that time the idea of“ scarless” surgery has gained increasing popularity among patients as well as surgeons.(1,4,6) Single incision laparoscopic cholecystectomy is indeed a rapidly evolving technique that is complimenting conventional laparoscopic cholecystectomy in selected fields and patients.( 4) It is now considered by many as a bridge between traditional cholecystectomy and natural orifices transluminal endoscopic surgery.(2,4,5) Single incision laparoscopic cholecystectomy utilizes three ports through a single skin incision at the umbilicus and is being considered as a “no scar” surgery because the incision is placed within the umbilical scar.(4,7) It has gained increasing attention due to the potential to maximize the benefits of laparoscopic surgery.(8,11) The reported advantages of single incision laparoscopic cholecystectomy include less port operative pain and minimum or no narcotic analgesic requirements, shorter hospital stay, quicker return to work and better cosmesis as well as low complication rate and cost.(1,4,9,11)
Single incision laparoscopic cholecystectomy is feasible and promising method of cholecystectomy and it is possible to do this procedure without the use of special equipment (1,4,9) It is a safe and effective alternative to four incision laparoscopic cholecystectomy that provides surgeons with an alternative minimal access surgical option and the ability to hide the surgical incision within the umbilicus.( 4,9,10) It is predicted by some reports that it may become a standard approach to laparoscopic cholecystectomy.(1)
This procedure is however, not without drawbacks. Among the suggested disadvantages are prolonged operative time, high cost of special instruments, increased risk of operative complications and ergonomically disadvantageous to the surgeon. ( 1).
The main aim of this study is to compare single incision laparoscopic cholecystectomy with conventional four incisionlaparoscopic cholecystectomy in patients who had cholecystectomy for gall bladder disease. The specific objectives include finding out the advantages of SILC over conventional laparoscopic cholecystectomy, to evaluate any operative challenges inherent in single incision laparoscopic cholecystectomy as well as unveil a single center experience with both operative approaches.
3.1 Literature Review : Single-incision laparoscopic surgery (SILS) is a “new” method to perform “old” operations. Though SILS has been referred to by many names, for the sake of this study, any procedure done laparoscopically through one incision (regardless of the number of ports or working channels) will be considered SILS procedure. Laparoscopic cholecystectomy has traditionally been performed using multiple small incisions. Single incision laparoscopic cholecystectomy (SILC) has emerged as an alternative technique to improve cosmesis and minimize complications associated with multiple incisions. A trend towards even more minimally invasive approaches has however, led to techniques of single incision and natural orifices transluminal endoscopic surgery (NOTES).(1,2,4,4,9) The first published report of single incision laparoscopic cholecystectomy was by Navarra in 1997 and since that time the idea of“ scarless” surgery has gained increasing popularity among patients as well as surgeons.(1,4,6) Single incision laparoscopic cholecystectomy is indeed a rapidly evolving technique that is complimenting conventional laparoscopic cholecystectomy in selected fields and patients.( 4) It is now considered by many as a bridge between traditional cholecystectomy and natural orifices transluminal endoscopic surgery.(2,4,5) Single incision laparoscopic cholecystectomy utilizes three ports through a single skin incision at the umbilicus and is being considered as a “no scar” surgery because the incision is placed within the umbilical scar.(4,7) It has gained increasing attention due to the potential to maximize the benefits of laparoscopic surgery.(8,11) The reported advantages of single incision laparoscopic cholecystectomy include less port operative pain and minimum or no narcotic analgesic requirements, shorter hospital stay, quicker return to work and better cosmesis as well as low complication rate and cost.(1,4,9,11)
Single incision laparoscopic cholecystectomy is feasible and promising method of cholecystectomy and it is possible to do this procedure without the use of special equipment (1,4,9) It is a safe and effective alternative to four incision laparoscopic cholecystectomy that provides surgeons with an alternative minimal access surgical option and the ability to hide the surgical incision within the umbilicus.( 4,9,10) It is predicted by some reports that it may become a standard approach to laparoscopic cholecystectomy.(1) This procedure is however, not without drawbacks. Among the suggested disadvantages are prolonged operative time, high cost of special instruments, increased risk of operative complications and ergonomically disadvantageous to the surgeon. ( 1).
3.11 The Evolution Of Single Incision Laparoscopic : The advent of SILS was in the field of gynecology. Wheeless reported on the first 4000 cases of SILS tubal ligation in 1969.4,16 The procedure was done using an offset eyepiece and a 5-mm working port to introduce instruments to perform the procedure. They reported that healing was “so satisfactory that no scar was grossly visible.” Since then, SILS tubal ligation has become the standard of care for elective female sterilization. 16The first application of SILS in general surgery was a SILS appendectomy by Pelosi in 1992 in 25 patients.2,5,16 That same year, D’Alessio described a technique for appendectomy in pediatric patients in which a special port was used at the umbilicus to allow the surgeon to bring the appendix out through the umbilicus to perform an extracorporeal appendectomy. 4 In this study, of the 166 patients enrolled, 19% required additional trocars to assist in the operation, and 4% required conversion to an open operation. When the operation was able to be completed with a single port, the mean operative time was 35 minutes with a 7-day return to normal activity, compared with 10 days for those that required additional trocars. The technique showed promise. 16
3.12 The Evolution Of Single Incision Laparoscopic Surgery For Cholecystectomy: The first reports of SILS cholecystectomy came in 1997 in a letter to the editor in the British Journal of Surgery by Navarra.2,4,5,16 In 30 patients two 10-mm ports were placed side-by-side with a small skin bridge between them. The surgeon placed multiple transabdominal sutures through the gallbladder to manipulate it. Once the gallbladder was able to be removed the small skin bridge was transected and the gallbladder was removed via this common incision. This was a technical paper with minimal results reported. In 1999, Piskun reported on 10 patients on whom he performed a SILS cholecystectomy by placing two 5-mm trocars through a common umbilical incision and using transabdominal sutures to manipulate the gallbladder.16 The fascial bridge between the two trocars was then joined and the specimen extracted through this single umbilical incision. Since that time, sporadic reports of SILS cholecystectomy have been reported under various names. Various terms cited in the literature for single-incision laparoscopic surgery). With the introduction of natural orifice transluminal endoscopic surgery (NOTES), there has been renewed interest in SILS procedures. SILS can be differentiated from NOTES in the fact that NOTES is performed with no incision on the abdominal wall, rather the incision is made through another organ (stomach, vagina, rectum) in order to perform a laparoscopic operation.
3.13 Current Literature Review: Current literature is composed primarily of the experiences of various surgeons using the SILS technique. These are mainly case reports or case series. Nearly every operation imaginable has been reported using SILS techniques Similar to the controversy surrounding laparoscopic appendectomy versus open appendectomy, there is little data comparing SILS procedures to their traditional laparoscopic counterparts.7,8,16 Indeed there is no evidence that SILS is any better than current standard laparoscopic procedures other than the obvious cosmetic results.16 Some worries about SILS surgery include the possible increase in pain because of larger fascial incisions needed to place the large ports into the abdomen and increased risk of umbilical hernia formation. 7,16 Navarra performed a randomized study of traditional laparoscopic cholecystectomy to their singleincision technique as described above.10,16 They found longer operative times with the SILS procedure with no difference in postoperative pain or cost and a higher rate of umbilical herniation. It should be noted, however, that in this study the fascial defect required to remove the gallbladder was 2.5 cm, because of the use of two 10-mm ports (a 5-mm clip applier was not available during the study period). Early results from a current study, which is designed to compare SILS and conventional cholecystectomy, have shown no differences in operative time, postoperative pain, and blood loss. 16The only advantage seen has been in cosmesis. In this study 68% of patients would have opted for a SILS cholecystectomy if they had to have the operation done again. It should be noted that this is a preliminary study that has only enrolled 25 of the 200 patients needed to complete the study.8,16 A recent study presented at the Society of American Gastrointestinal and Endoscopic Surgeons found no difference in total operating room cost, charges to the patient, and hospital charges when comparing SILS cholecystectomy to standard cholecystectomy.11 Further randomized studies are needed to determine if SILS is any better than conventional laparoscopic surgery. This review of literature shows that there is a paucity of quality data comparing SILS to its counterpart. The studies we have do not reveal any significant advantage to SILS over standard laparoscopic techniques thus far, except with respect to cosmesis.
4.1 Methodology:
4.12 Study Design: In this retrospective cross sectional study, after institutional clearance, data obtained from hospital records of patients who had laparoscopic cholecystectomy for gall bladder disease was analyzed.
4.13 Study Area: This study will be carried out at the Institute of Minimal Access, Metabolic and Bariatric surgery, Sir Ganga Ram Hospital. The Hospital is a 657 bed, modern, multi-specialist, private, teaching Hospital in Rajinder Nagar New Delhi.(12) It provides comprehensive medical services to patients from all over south east Asia, as well as other continents of the world. The Hospital’s minimal access surgery department was the first such department in south Asia.(12)
4.14 Subjects/Study Population : All consecutive patients who had laparoscopic cholecystectomy for gall bladder disease at the Institute of Minimal Access, Metabolic and Bariatric surgery, Sir Ganga Ram Hospital, were included in the study.
4.15 Exclusion Criteria :
- Patients operated for malignant gall bladder disease.
- Patients with gall bladder perforation.
- Patients with mirizzi syndrome.
- Patients in ASA IV and V
- Patients who were lost to follow up at two weeks.
4.17 Statistical Analysis Plan: The analysis will include profiling of patients on different demographic, clinical and laboratory parameters etc. Quantitative data will be presented in terms of means and standard deviation. Student t test will be used for comparison of individual quantitative parameters. Cross tables will be generated and chi square test will be used for testing of associations. P-value < 0.05 is considered statistically significant. SPSS software will be used for analysis.
4.18 Operative Techniques : All operations were performed under general anaesthesia and orotracheal intubation. Patients are placed in reverse Trendelenberg position (30 degrees) with table tilted right up to displace the intra-abdominal organs away from the gall bladder. A nasogastric tube was placed for decompression.For SILC, after pneumoperitoneum using the standard Veress needle technique, a two centimeter transumbilical incision was made. A 10mm camera port was inserted and diagnostic laparoscopy performed. Two other 5mm ports were placed through the umbilical incision. A striker mini alligator was passed through the right hypochondrium to provide cephalad retraction of the gall bladder fundus. A hunter’s grasper was used to grasp the infundibulum, providing lateral traction. The gall bladder was dissected laterally with a combination of harmonic scapel and blunt suction tip to creat a large lateral window. The hilum was dissected and the cystic duct and cystic artery are identified. The posterior branch of the cystic artery which is present almost all the time is coagulated with harmonic. The cystic artery and cystic duct are clipped and divided. The gall bladder is dissected from the liver bed along the cystic plate. The gall bladder bed was inspected before final separation of the gall bladder from its bed to ensure no bleeding or leaks were left unattended. The specimen was delivered by a retrieval bag through the 10mm port after changing the camera to a 5mm 30 degree camera for retrieval under vision. The umbilical incision was closed with vicryl 2/0 suture.
For the four incision laparoscopic cholecystectomy , after pneumoperitoneum using the standard Veress needle technique. A 10mm 30 degree umbilical port was placed and 360 degrees diagnostic scan of the entire abdomen was performed to exclude injury or bleeding incurred during pneumoperitoneum, first port placement and to identify any unsuspecting gross pathology. Following this, 10mm or 5mm epigastric, 5mm right hypochondriac working ports as well as 5mm assisting port just below right hypochondriac port were subsequently placed. A hunter’s grasper passed through the assisting port was used for cephalad retraction of the gall bladder fundus. Another grasper through the right hypochondriac port is used to provide lateral retraction of the infundibulum of the gall bladder. The gall bladder was dissected laterally with a combination of harmonic scapel and bunt suction tip as describe earlier. The hilum was dissected and the cystic duct and cystic artery were identified. The posterior branch of the cystic artery which is always present was coagulated with harmonic. The cystic duct and artery are clipped and divided. The gall bladder is dissected from the liver bed along the cystic plate. Inspection of the bed was done before the last bit of the gall bladder was completely separated, to ensure adequate haemostasis. The specimen was delivered in a retrieval bag through the 10mm port under vision. The 10mm incision was closed using vicryl 2/0 suture.
Figure 1: port position for silc
Figure 2: port position for 4plc
Figure 3: applying a clip
Figure 4: ligating the cystic duct with a clip
Figure 5: clips in place
Figure 6: delivering the gallblader specimen
Figure 7: inspecting the gallbladder bed
Figure 8: the surgical team
5.1 RESULTS: Of the one hundred and twenty patients who had laparoscopic cholecystectomy at the institute of minimal access, metabolic and bariatric surgery, Sir Gan Garam Hospital, New Delhi, sixty one (50.4%) had conventional four port laparoscopic cholecystectomy (4PLC), while sixty (49.6%) had single incision laparoscopic cholecystectomy (SILC). The average age of the patients was 45.9+or – range 9 years to 85 years fo both groups. The average age for those who had SILC was 46.7+or-15 while that for those who had 4PLC was 45.2+or-14.The number of males who had SILC was 26(43.3%), while 34(56.7%) were females. Those who had conventional four port laparoscopic cholecystectomy had 31(50.8%) males and 34(56.7%) females. Indications for the operation were similar for the two groups (table 3). There was one conversion from SILC to 4PLC. This was a patient who had prior percutaneous drainage of gallbladder empyema in another hospital. Non of the patients in the two groups was however, converted to open cholecystectomy. There was also no intraoperative complication or peri-operative mortality recorded in both groups of patients.
The average length of hospital stay including in-patient and out-patient surgeries was 23.93+or-9.8, range 4 hours to 48 hours for thosewho had SILC and 30.07+or-16, range 8 hours to 72 hours for patients who underwent 4PLC (P=0.014). After undergoing SILC, 90%(54 of 60) of patients went home within 24 hours, while 75% (46 of 61) of thosewho had 4PLC went home within 24 hours ( P=0.05). Patients in both groups had either paracetamol or a non steroidal anti-inflammatory agent (NSAID) as post operative analgesic. Only one (1.7%) patient who had SILC required an NSAID for post operative analgesia, while fifty nine (98.3%) had post operative pain relieve using only paracetamol. Four(6.6%) of patients who had 4PLC required an NSAID for post operative analgesia, while 57(93.4%) had only paracetamol for post operative analgesia (P=0.177), which was not statistically significant.
Follow up was limited to one to two post operative office visits . No complications were noted in this period in the two groups.
Table 1: Shows age distribution and hospital stay
Table 2: Demographics, symptomatology and diagnosis
Table 3: Demographics, symptomatology, SILC and 4PLC Analysis
Table 4: Analgesic requirement , symptomatology, and demographics
Table 5: Demographics and hospital stay
Table 6: Hospital stay SILC VS 4PLC
6.1 DISCUSSION:
Single incision laparoscopic cholecystectomy is not totally a new concept, it wasintroduced into practice as far back as 1992 by Pelosi et al 4 who performed a single puncture laparoscopic appendicectomy. First experiences with SILC were reported by Navarra et al in 1997 and with a different approach by Piskun and Rajpal in 1999 4. There have been many studies establishing the advantages of SILC asa complimentary or subtitude surgical technique to conventional four port laparoscopic choloecystectomy. This topic however, remains contentious and incompletely settled.
This study showed that 90% of patients who had SILC went home within 24 hours. This is similar to a study reported by Brittney et al 16. This showed a statistically significant shorter length of hospital stay for patients who had SILC. Patients who had SILC stayed an average of 7 hours less than those who had 4PLC. This result is similar to the result of other studies 16 who reported the mean post operative hospital stay after SILC to be 12 hours shorter than that of patients who had 4PLC . Prasad also reported a mean post operative hospital stay of 0.34 days after SILC as against 0.98 days after 4PLC 4.
The analgesic requirement of patients who had SILC was not quite different from that of patients who went through 4PLC. Although only one patient in the SILC group required a stronger analgesic(NSAID) as against four patients for the 4PLC group, this was not statistically significant. Other factors which othervstudies have addressed either in favor or against either of the operative procedures include cost, opoerative time, blood loss, ergonomics and return to normal activty. SILC has been reported to have a slightly higher operative cost than 4PLC due to the peculiarity of the roticulating instruments required to ensure ergonomically smooth procdure 4,16 . It has also been reported that SIL take more operative time to complete compaired to 4PLC 16 this has been attributed to the steep learning curve associated with SILC. This has also been associated with a high conversion rate and as well as complications.
There was one conversion from SILC to 4PLC in this study. This was a patient who had prior percutaneous drainage of gallbladder empyema in another hospital.There was no perioperative complications in the two groups.
6.12 LIMITATIONS OF THE STUDY:
This study wasa retrospective non randomized, single centre study with few patients which constituted a limitation to the strength of its findings. The inability of the study to also address factors such as cost, operative time, blood loss and long term outcomes also constitute a weaskness. It is hoped that future studies would address this inherent challenge.
6.13 CONCLUSION:
Single incicion laparoscopic cholecystectomy appears to offer prospects for shorter hospital and early return to work compaired to conventional four port laparoscopic surgery. Patients undergoing either SILC or 4PLC appear to have similar analgesic requirement. Extrapolating this to pain difference between the two surgical technique however, require caution. SILC as a surgical technique is however, feasible and promising for treatment of symptomatic cholelithiasis.
REFERENCES:
- Pan M X, Jian Z S, Cheng Y, Xu X P, Zhang Z , et al: Single incision versus three port laparoscopic cholecystectomy: A prospective randomized study; World J Gastroenterol.2013 Jan 21;19(3);394-8.doi, 10.3748/wjg v 19.13.
- Antoniou S A, Pointner R, Granderath FA,: Single incision laparoscopic cholecystectomy: A systemic review; Surg Endosc.2011 Feb;25(2): 367-77 doi: 10.1007//5004 64-010-1217-5.
- Lianguan G, Chhanghuan S, Jianfen B: Single incision versus conventional laparoscopic cholecystectomy outcomes; A meta-analysis of randomized control trials: Plos ONE 8(10):e 76530.doi:10.1371/journal.pone.0076530.
- Prasad A, Mukherjee KA, Kaul S, Kaur M: Post operative pain after cholecystectomy; Conventional versus single incision laparoscopic cholecystectomy: JMinim Access surg.2011 Jan-Mar;7(1):24-27.
- Petrostos AC, Molinelli BM: Single incision multi-port laparoendoscopic surgery (SIMPLE): Early evaluation of SIMPLE cholecystectomy in a community setting; Surg Endosc. 2009 Nov; 23(11):2631-7.Epub2009 Mar 6.
- SAGES: Conventional four port ( incision) laparoscopic cholecystectomy; Early report of the first prospective randomized sham controlled trial.
- Qiu Z, Sun J, Pu Y, Jiang T, Cao J, Wu W: Learning curve of transumbilical single incision laparoscopic cholecystectomy,; A preliminary study of 80 selected patients with benign gall bladder disease:world j surg.2011 sep;35(9):2092-101. Doi 10.1007/s 00268-011-1144-1
- Marker SR, Karthikesalingam A, et al: Conventional multiport cholecystectomy ; A systemic review and meta-analysis. Surgical endoscopy 2012 26(5); 1205-1213
- Brittney LC, Veronica EC, David TA: Proc( Bayl Univ.med.centr) Oct 2012, 25(4):319-323.
- Robert KE, Solomon D, Duffy AJ, Bell RL: Single incision laparoscopic cholecystectomy; A surgeons initial experience with 56 consecutive cases and a review of the literature; JGastroinyest surg.2010 Mar 14(3), 506-10.doi:10.1007/s11605-009-1116-2.Epub2009 Dec.
- Davidsons BR: Fewer than four ports versus four ports for laparoscopic cholecystectomy Cochrane data-base syst Rev.2014 feb 20;2:CD007109.doi:10.1002/14651858CD007109.
- en.m.wikipedia.org//…/Sir-Ganga Ram……..
- Tandon RK: Prevalence and types of biliary stones in India;World J Gastroentero,2000;6(suppl.3):
- Araoye MO: Research methodology with statistics for health workers and social sciences.NathudexPublishers.2004;115-120,Ilorin,Nigeria
- Cusherie A:How I do it;laparoscopic cholecystectomy. J R Coll.surg.Edin 44 June .1999, 187-92
- Brittney LC, Veronica EC, David TA: Single-incision laparoscopic cholecystectomy versus traditional four-port cholecystectomy Proc (Bayl Univ Med Cent) 2012;25(4):319–323
