Page 21 - World Journal of Laparoscopic Surgery

Natural Orifice Translumenal Endoscopic Surgery (NOTES) Towards Brighter Future

transgastric approaches allowed performance of complex pressure carbon dioxide followed by puncture of the
small bowel resections with intracorporeal formation of remaining gastric wall. The endoscope was advanced
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anastomoses. Much of the initial studies focused on the through the tunnel into the peritoneal cavity and a
feasibility of NOTES. It is now believed that although cholecystectomy was performed. The submucosal tunnel
complex and plagued with restrictions, practically any was crafted cephalad to position the endoscope for operating
abdominal operation could be performed using the available in the right upper quadrant. At the end of the operation, the
natural orifice techniques. mucosal entry point was closed with clips or tissue anchors.
Reliable closure of the viscerotomy is the corner stone The Ohio State group has closed gastrotomies in animal
in avoiding intra-abdominal sepsis. As mentioned above, studies with a bio absorbable plug, as in inguinal hernia
repair. 19,20 This eliminated the need for complex tissue
leaving the viscerotomy open and PEG tube occlusion of
manipulation and provided watertight closure with minimal
the gastrotomy were shown to be inadequate in the porcine
chances of infectious complications. This technique might
model. Endoclips for closure have also been used with some
success, 13 however clips only provide mucosal simplify the process of viscerotomy closure.
The pneumoperitoneum in NOTES is commonly created
approximation. Numerous devices have been used to attempt
using endoscopic insufflators and as in laparoscopy, the
full thickness closure. One such instrument is the NDO
intra-abdominal pressure requires continuous monitoring
Plicator which was initially developed for the endoscopic
otherwise unchecked insufflation might lead to abdominal
management of gastroesophageal reflux disease. It is a 15
compartment syndrome. A recent study have shown that
mm instrument whose jaws place a full-thickness permanent
pressure transducers fitted to the end of a gastroscope or
suture with polytetrafluoroethylene bolsters. Closure of full-
passed through a working channel can detect intra-abdominal
thickness gastrotomies has been shown to be reliable with pressure with a high accuracy. 21 Such devices could be
the NDO Plicator. 14,15 Bursting pressures of the porcine easily incorporated into NOTES operating endoscopes.
stomach after closure exceed 90 mm Hg and a water-tight Alternative means to monitor intra-abdominal pressure
closure is achieved, as evidenced by fluoroscopic contrast include passage of a transabdominal Verees needle for the
studies. Survival studies in porcine models have shown same.
minimal rates of intra-abdominal infections after transgastric Adequate retraction is a must to safely perform complex
peritoneoscopy and closure with the NDO Plicator. abdominal operations, such as cholecystectomy but with
Another method of gastrotomy closure is using a endoscopic instruments, appropriate retraction has been
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commercially available over tube and suturing device. The difficult to achieve. Keeping this in mind a group from the
over tube is steerable, torque-stable, fixable, and accommo- University of Texas-Southwestern has developed an
dates a slim endoscope and a suturing device. The suturing ingenious method using intra-abdominal magnets to provide
device consists of a grasper that locks at 45 degrees angle retraction during operations. 22,23 In their technique, an
to the instrument shaft. A needle and suture passes through external magnet is paired to its intra-abdominal counterpart.
the device and can be bolstered with polyester tissue anchors. The organ of interest is attached with a metal device, such
In the porcine stomach, robust, full-thickness sutures and as a clip, and paired to the magnet. Tissue manipulation is
performed by moving the external magnet to achieve the
fine tissue manipulation was achievable using this platform.
desired retraction. To provide a stable surgical field for
The self-approximating translumenal access technique
(STAT) 17,18 has been developed by the Penn State group natural orifice surgery, new endoscopes are under develop-
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ment. Swanstrom and others are using endoscopes that
that might obviate the need for full thickness closure. An
allow the surgeon to operate with both hands, without the
incision is first made in the gastric mucosa, and then a
need of one hand being used for stabilizing the endoscope.
submucosal tunnel is developed of at least 5 cm length using 25
Others are using commercially available multi bending
a dissecting balloon. After tunneling away from the mucosal
endoscopes with dual instrumentation channels to provide
defect, the muscularis and serosa are punctured, and the
better stability and maneuverability at the same time.
abdomen is entered. After the operation, the scope is The NOTES endoscope of the future will have the ability
withdrawn and only the mucosa is closed. In a porcine to maintain a fixed position and its multi working channels
model, this technique has yielded favorable results. would be angled in such a way as to make a diamond baseball
Sumiyama have published transgastric cholecystectomies concept with the operating field.
in laboratory animals using an offset gastrostomy, similar Some groups have overcome these obstacles of diamond
to STAT. A submucosal tunnel was created using high baseball concept and retraction by inserting more than one

World Journal of Laparoscopic Surgery, January-April 2010;3(1):19-25 21