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JEJUNO-ILEAL BYPASS: (JIB):
Two variants of jejunoileal anastomosis were developed, the end-to-side (Payne and DeWind 1969) and end-to end (Scott, Dean et al. 1973) anastomoses of the proximal jejunum to distal ileum. In both instances an extensive length of small intestine was bypassed, not excised, excluding it from the alimentary stream. In both these variants a total of only about 35 cms (18") of normally absorptive small intestine was retained in the absorptive stream, compared with the normal length of approximately 7 meters (twenty feet). In consequence, malabsorption of carbohydrate, protein, lipids, minerals and vitamins inevitably occur.Patients with intestinal bypass develop diarrhea 4-6 times daily.
The frequency of stooling varying directly with fat intake. There is a general tendency for stooling to diminish with time, as the short segment of small intestine remaining in the alimentary stream increases in size and thickness, developing its capacity to absorb calories and nutrients, thus producing improvement in the patients nutrition and counterbalancing the ongoing weight loss. This happy result does not occur in every patient, but approximately one third of those undergoing "Intestinal Bypass" have a relatively benign course. Unfortunately, even this group is at risk of significant late complications, many patients developing irreversible hepatic cirrhosis several years after the procedure.JIB is the classic example of a malabsoptive weight loss procedure.
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BILIOPANCREATIC DIVERSION: (BPD):
A modern improvement of the Jejuno-ileal Bypass (JIB) is Biliopancreatic Diversion,(BPD), a procedure which differs from JIB in that no small intestine is defunctionalized and, consequently, liver problems are much less frequent. This procedure was developed by Professor Nicola Scopinaro, of the University of Genoa, Italy.(Scopinaro, Gianetta et al. 1996). This procedure has two components. A limited gastrectomy results in reduction of oral intake, inducing weight loss, especially during the first postoperative year. The second component of the operation, construction of a long limb Roux-en-Y anastomosis with a short common "alimentary" channel of 50 cms length. This creates a significant malabsorptive component which acts to maintain weight loss long term. Dr Scopinaro recently published long term results of this operation, reporting 72% excess body weight loss maintained for 18 years. These are the best results, in terms of weight loss and duration of weight loss, reported in the bariatric surgical literature to this date. From the patient's perspective, the great advantages of this operation are the ability to eat large quantities of food and still achieve excellent, long term weight loss results. Disadvantages of the procedure are the association with loose stools, stomal ulcers, and foul smelling stools and flatus.
The most serious potential complication is protein malnutrition, which is associated with hypoalbuminemia, anemia, edema, asthenia, alopecia, generally requires hospitalization and 2 - 3 weeks hyperalimentation. BPD patients need to take supplemental calcium and vitamins, particularly Vitamin D, lifelong. Because of this potential for significant complications, BPD patients require lifelong follow-up. In BPD patients who have received 200 - 300 cm alimentary limbs because of protein malnutrition concerns, the incidence of protein malnutrition fell dramatically to range from 0.8% to 2.3%.
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BILIOPANCREATIC DIVERSION WITH DUODENAL SWITCH (BPD/DS)
In 1988, Hess, ussing a combination of Scopinaro's BPD and the duodenal switch described by DeMeester in 1987, developed a hybrid operation with the advantages of the BPD but without some of the associated problems. The duodenal switch, originally designed for patients with bile reflux gastritis, consists of a suprapapillary Roux-en-Y duodeno-jejunostomy. This allows the first portion of the duodenum to remain in the alimentary stream thus reducing the incidence of stomal ulcer. When combined with a 70%-80% greater curvature gastrectomy (sleeve resection of the stomach) continuity of the gastric lesser curve is maintained while simultaneously reducing stomach volume. A long limb Roux-en-Y is then created.
The efferent limb acts to decrease overall caloric absorption and the long biliopancreatic limb diverting bile from the alimentary contents, specifically to induce fat malabsorption. This technique, was first presented by Hess in 1992 and first published in a paper by Marceau, Biron et al in 1993 is known as Biliopancreatic Diversion with Duodenal Switch (BPDDS). This procedure is claimed to essentially eliminate stomal ulcer and dumping syndrome.BPD and its variants are the most major procedures performed for obesity and it follows that prospective patients who wish to consider BPD should seek out experienced surgeons with life-long follow up programs.
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GASTRIC BYPASS:
Gastric Bypass (RGB) was developed by Dr Edward E. Mason, of the University of Iowa, based on the observation that females who had undergone partial gastrectomy for peptic ulcer disease, tended to remain underweight following the surgery, and that it was very difficult to achieve weight gain in this patient group. He therefore applied the principles of partial gastrectomy to obese females, finding that they did indeed lose weight. (Mason and Ito 1967) With the availability of surgical staples, he was able to create a partition across the upper stomach using staples, and did not require removal of any of the stomach. Subsequent modifications of the technique include a pouch of 50 ml or less, a gastro-enterostomy stoma of 0.9 mm, use of the Roux-en-Y technique to avoid loop gastroenterostomy and the bile reflux which may ensue. Lengthening of the Roux limb to 100-150 cms to include a greater element of malabsorption and improve weight loss and the use of the retrocolic and retrogastric routing of the gastrojejunostomy to ease the technical difficulties of the procedure and improve long term weight loss results.
Staple line failures have been found to occur many years after the procedure, in consequence surgeons have responded by use of techniques designed to prevent this. These include transection of the stomach, in which the staple line is divided and the cut ends oversewn. An alternative technique using superimposed staple rows is claimed to exert its effect by crushing the stomach tissue causing firm scarring along the staple line. Additionally, there have been attempts to stabilize the gastroenterostomy by the use of a prosthetic band, fashioned into a ring positioned just above the junction of gastric pouch and small intestine. Gastric Bypass has also stood the test of time, with one series of greater than 500 cases, followed for 14 years, maintaining 50% excess weight loss.
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Silastic Ring Gastric Bypass: Vertical banded gastric bypass (Fobi);
The use of rings to control the stoma size, proven with Vertical Banded Gastroplasty, has led to their adoption by some surgeons as an addition to gastric bypass procedures, again to control the stoma size and prevent late stretching of the opening and, hopefully, improve the long term weight maintenance results. Both silastic rings and Marlex bands have been used. Usually the recommendation is for the ring circumference to be considerably larger than that used in primary obesity procedures, so that the limiting effect only comes into play after some degree of stretching of the pouch has occurred.Listing of complications following silastic ring gastric bypass. As for gastric bypass plus band erosion
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- GASTRIC BANDING:
Another way to limit food intake is to place a constricting ring completely around the top end (fundus) of the stomach, creating an hour-glass effect, just like your Microsoft cursor! Except that the ring has to be placed near the upper end of the stomach, just below the junction of stomach and esophagus. This idea of gastric banding has been around for quite a number of years, and was pursued in Europe and Scandinavia particularly. Initially, readily available materials such as arterial graft was used for the band.
The results, however, were not as good as RGB or VBG and the concept has only become popular with the development of modern bands designed for the task and techniques to measure the size of the "stoma" created under the band and associated pressures. An ingenious variant, the inflatable band was developed by Dr Kuzmak (Kuzmak, Yap et al. 1990) who devised a band with an inflatable balloon as its lining. This balloon was connected to a small reservoir which is placed under the skin of the abdomen, through which, the balloon can be inflated, thus reducing the size of the stoma, or deflated thus enlarging the stoma.
Even more ingenious, has been the development of models which can be inserted laparoscopically, thus saving the patient the discomfort of a large incision. Since the hour glass configuration only constricts the upper stomach, with no malabsorptive effect, it acts as a pure restrictive operation. Like VBG, the favorable consequences are absence of anemia, dumping and malabsorption, while the disadvantages include the need for strict patient compliance. Long term results of this device are not yet available, but logic would suggest they are likely to be comparable to VBG results with an unknown additional effect due to manipulation of the inflatable balloon. At the present time there are two devices on the world market.
