GASTROPLASTY

During World War II, the Russian, as part of their war effort,developed a series of surgical instrument which would staple various body tissues togather as a simple and rapid method of dealing with injuries. This concept was adapted and refined by American surgical instrument makers after the war, leading to the surgical stapling instruments in use today. These are capable of laying down as many as four parallel rows of staples, to create a patition, or the instument comes with a knife blade which will cut between the newlyplaced staple rows, dividing and sealing the stapled tissues simultaneously.Other instruments place circular rows of staples which will join two tubes end to end, very useful in connecting intestine togather.

The early use of such stapling devices in obesity surgery involved removal of three staples frothe row and firing the stapler across the top part of the stomach. This staples the two stomach walls togather, except at the point where the three staples were removed, where a small gap remains. The idea being that food which the patient takes in is held up in the segment of stomach above the staple line causing the sensation of fullness. The food then empties slowly through the gap (stoma) into the stomach below the staple line where digestion takes place normally.Unfortunately, the muscular stomach wall has a tendency to stretch and the stoma enlarges. It soon become apparent that while patients lost weight for the first few months while the stoma was small, they soon stopped losing , and, indeed, frequently regained all they had lost. Of course, surgeons tried to counter this by reinforcing the opening between the two components, techniques which were patially successful. The search for a bettergastroplasty was once more led by Dr Edward E. Mason,Professor of Surgery at the University of lowa.(Mason 1982)He realized that the lesser curvature part of the stomachhad the thickest wall and was therefore least like to stretch, so he used a vertical segment of stomach along the lesser curvature for the pouch. Additionally, he was very meticulous in defining the size of the pouch,measuring it at surgery under a standard hydrostatic pressure, and has shown thst best results follow the use of a very small pouch , holding only 14 ccs saline at the time of surgery. The thrid modification which he made was to place a polypropylene band(Marlex Mesh) around the lower end of the vertical pouch, which acts as the stoma, to fix the size of the outlet of the pouch,preventing it from stretching.This is done by use of the circular stampling instruments to staple the front and back walls of the stomach togather, cutting out a circular window to allow the polypropylene band to be placed arround the lower end of the pouch. His extensive studies showed that the correct circumference of the band is 5.0 cms.The whole operation is called Vertical Banded Gastroplasty (VGB). Correctly performed this operation produces good weight loss results.It has the advantages of being a pure restrictive procedure with no malabsorption component and no dumping. Of course sweet eaters will have to avoid sweet on their own if they have this procedure. Similarly there are few complications associated with Vertically Banded Gastroplasty, because all food taken in is degisted normally, and anemia is rare and Vitamin B12 deficiency is almost unknown. The patients does have to be very careful to chew food completely to avoid vomiting, and to avoid high calorie liquids such as regular sodas and ice cream which go down pretty well ! A surgical varient of VBG is the Silastic Ring Vertical Gastroplasty(SRVG) which is functionally identical to VBG but uses a silastic ring to control the stoma size. It should be noted that a few surgeon, Expertin minimal access surgery are performing gastroplasty using laparoscopic techniques.

Techineques of Modified VBG

The abdomen is opened through a vertical upper midline incision or a horizontal incision under the right costal margin, cutting the rectus muscle and usually the falciform ligement. The horizontal incision is preffered but vertical incision is needed in superobese patients. The anaesthetist passes 36FG(11.5mm) or 38FG(12.5mm) Hurst's bougie down the oesophagus which allows easy identification of the cardia and the laser curve on palpation and later calibration of stomal size. The index and middle fingures of the left hand are pushed through the thin window of peritoneum in the lesser omentum and through any adhesions to enter the lesser sac behind the body of stomach. A blunt digital dissection is then made through the gastrosplenic ligiment of at the angle of His, using the index and middle fingeres of both hands until the cardia can be grasped by the left hand in a pincer grip. A TA90 Staple-gun is then introduced into the abdomen with the toe running down the drosum of the left thumb to the angle of His where it is palpated by he tip of the index and middle fingures. The body of the instruments is then rotated in an anticlockwise direction through 90 deg. with the toe of the opened gun following the left index and middle fingeres downwards through the laser sacThe jaws of the staple gun are then closed while ensuring that they lie close to the bougie, thus ensuring a small pouch(20-30 ml.). Teh staple gun is then fired & removed from the abdominal cavity.With a Deever or lateral retractor retracting the liver, the lesser curve is grasped with the left hand and the stomal channel is fashioned, by inserting a No. 1 Ethibond suture right through the staple line at its lower margin, bringing it around the lesser curve. The small bites of serosa or hepato-gastic ligament taken to fix its position on the lesser curve and then it is tied on the anterior surface sufficiently thight enough to indent the serosa but not enough to compress the bougie and narrow the stoma. Two more such sutures are inserted at approximately 1.2 cm intervals proximaly to form a stomal channel. Alternatively Marlex or Gortex mesh may be used in formation of stoma. The bougie is then removed and replaced by a nasogastric tube which is removed about 12 to 24 hours after surgery

figure:

Listing of complications following vertical banded gastroplasty:

1. Leak
   
2. Stenosis with persistent vomiting, if untreated, causing neurological damage
   
3. Ulcer
4. Incisional hernia
   
5. Wound Infection
   
6. Band erosion