Fobi - Scientifict Publications

Obesity Surgery, 8, 283-288

Modern Surgery: Technical Innovations

The Surgical Technique of the Fobi-Pouch Operation for Obesity

(The Transected Silastic Vertical Gastric Bypass)

Mathias A. L. Fobi MD, F.A.C.S.; Hoil Lee MD1

Center for Surgical Treatment of Obesity, Bellwood General Hospital, Bellflower; 'Cedars Sinai Medical
Center, Los Angeles, CA, USA
Correspondence to: Mal Fobi MD, Center for Surgical Treatment of Obesity, 10230 E. Artesia Blvd. Ste 201, Bellflower, CA 90706, USA. Tel: (+1) 562 866 7908; Fax: (+1) 562 925 9761; E-mail: info@cstobesity.com. Q 1998 Lippincott-Raven Publishers

The Fobi-Pouch operation (FPO) for obesity is the product of clinical trials, more than 15 years of personal clinical experience and information gathered from publications, scientific meetings, and personal communications with other bariatric surgeons. The essence of the operation is the small vertical pouch (< 25 ml), an externally supported stoma, the interposed Roux-en-Y limb, the gastrostomy and the bypassed stomach marker to facilitate percutaneous transabdominal access to the bypassed segment. Patients undergoing this operation are usually given bowel prep the day before the operation, admitted the morning of the operation and started on subcutaneous heparin, prophylactic antibiotic and hydration. Antithrombotic sequential compression devices are regularly used. The hospital stay is usually 4 days. Our results and those of other surgeons who have used this modification substantiate the rationale for the modifications entailed in the FPO. Our longer-term experience and results are being compiled for publication. ® 1998 Lippincott-Raven Publishers.

Key words: Foreign body, gastric bypass, morbid obesity, silastic ring, surgical technique, vertical banded gastric pouch.

Introduction
The Fobi-Pouch operation (FPO) for obesity is a surgical operation that has evolved over 15 years of surgical treatment of obesity. Technically it is a transected silastic ring vertical gastric bypass, a modification of the gastric bypass operation that is the gold-standard for surgical operations for obesity. The technique, evolution, and rational of the FPO is the subject of this paper.

The Surgical Technique of the Fobi Pouch Operation

The Roux-en-Y Limb
The Roux-en-Y limbs are formed with an efferent limb about 60 cm long and a Bilio-pancreatic limb about 60 cm from the ligament of Treitz (Figure 1A-D). The entero-enterostomy is side-to-side using the stapling triangulation method. The mesenteric opening between the jejunal limbs is closed with interrupted silk sutures to prevent internal herniation and ensuing closed loop obstruction.

The Proximal Gastric Pouch
The proximal gastric pouch is formed by transecting the stomach vertically from a point 6-7 cm from the gastro-esophageal (GE) junction on the lesser curvature, avoiding the neuro-vascular structures, to a point about 1 cm to the left of the GE junction (Figure 1E-F) using the 7.5 linear cutter made by the Ethicon Endo-Surgical Company. The edges of the proximal pouch and the distal stomach are imbricated with running 3-0 vicryl sutures. The pouch and distal stomach are everted to inspect the posterior walls to detect tears, leaks, bleeding and for visual estimation of the pouch size. A size 8-French silastic tubing, 5.5-6.5 cm long, is placed loosely around the pouch at a point about 2-3 cm from the inferior tip of the pouch. The position of the ring can be adjusted to increase or reduce the pouch size. The pouch size is usually estimated at 10-25 ml. The tubing is held in place by a double strand of 2-0 prolene sutures (Figure 1G-H).

Figure 1. A-D, the Roux-en-Y limbs, E-H, the proximal banded pouch; I-L the gastro-enterostomy; M-P, the gastrostomy and marker.

The Gastro-enterostomy
The efferent limb of the Roux-en-Y is brought up retro-colic and retro-gastric and interposed between the pouch and the bypassed distal stomach (Figure 1I-J). The space between the posterior peritoneal wall and the efferent limb, as it is brought through the meso-colon, is closed with interrupted silk sutures to prevent internal herniation. The proximal part of the limb is used as a serosal patch to the imbricated edge of the proximal pouch from the GE junction down and up to the silastic ring (Figure 1K). A hand-sewn gastro-enterostomy, end-to-side, about 2 cm long, two layer closure with 3-0 vicryl and 3-0 silk is made 0.5-1 cm distal to the silastic tubing band (Figure 1L). A 12mm obturator is used to calibrate the stomal opening. A naso-gastric tube is passed into the pouch, through the stoma, through the gastro-enterostomy anastomosis, into the jejunal limb and removed after extubation and prior to the patient being transferred out of the recovery room.

The Gastrostomy and Bypassed Stomach Marker
A size 18 gastrostomy tube is put in the bypassed stomach and brought out in the left upper quadrant (Figure 1M-N). The gastrostomy site is tagged to the anterior peritoneal wall around the tube. A 6 cm long radio-opaque silastic tubing¹ is put around the gastrostomy site. This serves as a marker to facilitate radiological localization of the bypassed stomach (Figure 10-P). The gastrostomy tube is put to gravity drainage for 36-48 hours, and used for medications and supplemental feedings if required or removed at the first postoperative visit to the office after 7-10 days.

Discussion
The gastric bypass (GBP) operation for obesity (Figure 2A) is considered the gold-standard of obesity operations. This horizontally stapled pouch with a retro-colic, retro-gastric short-limb Roux-en-Y gastroenterostomy is the Griffen/Alden modification of the original Mason GBP.^1-4 We started using this GBP in 1978. Influenced by Mason's initial reports,⁵ we carried out a prospective evaluation of the vertical banded gastroplasty (VBG) (Figure 2B) vs. the GBP in 1982.⁶ Our short-term 1-year outcome with the VBG confirmed Mason's report of comparable outcome with the GBP, and so we switched to using the VBG. Laws⁸ description of the silastic ring vertical gastroplasty (SRVG) in 1981 (Figure 2C) and the mufti-center report on the SRVG by Willbanks, Moore, and Eckhout⁹ prompted our evaluation of this operation in 1984 in a prospective randomized evaluation Vs the VBG¹⁰ We found the SRVG to be as effective but a technically simpler operation than the VBG, and thus we used the SRVG from then onwards for treatment of morbid obesity. By the later part of 1985, the 2-3 year follow-up results with the VBG and SRVG as compared with the GBP revealed a 15% difference in the average percentage excess weight loss (51% in the VBG and SRVG Vs 66% in the GBP).^10-12 Upwards of 40% of our patients were unhappy with the weight loss from VBG and SRVG, forcing us to revert to the GBP operation and to revise some of the unsatisfactory VBG and SRVG patients to GBP.

Two things occurred at this juncture. On the one hand, in a subgroup of patients who underwent revision from VBG and SRVG to GBP, the bands were left in place and the gastro-enterostomy was placed distal to the band for technical reasons (Figure 2D-E). On the other hand, the reports by Scopinaro¹³and Holian¹⁴ on the weight loss after the bilio-pancreatic bypass (BPB), influenced us to modify the GBP when we reverted to using it in 1986. The modification entailed a 60 cm efferent limb and a 150 cm common limb (Figure 2F).15 This modification and variations of it has come to be known as the distal Roux-Y gastric bypass (DRGBP)^15-17 Also, at this time, the GBP operation with a vertical lesser curvature pouch as described by Torres (Figure 2G)¹⁸ was commonly in use.

In the later part of 1988, as we reviewed our experience and compared it with that of others, it became apparent that the best long-term result in terms of weight loss and maintenance and minimal side-effects was found in the patients who had been revised from either VBG or SRVG to GBP with the gastro-enterostomy distal to the band. Salmon ¹⁹ reported the same findings. This observation gave birth to the hybrid operation silastic ring vertical gastric bypass (SRVGBP) (Figure 2H).^20-22 The percentage excess weight loss with this operation approached the 80% excess weight loss obtained with the BPB and DRGBP but without the associated protein malnutrition, the fare watery stools and repugnant body odor. ^l3-15,23

Figure 2. A, the Griffen/Alden modification of the Mason GBP; B, the Mason vertical banded gastroplasty (VBG); C, the laws silastic ring vertical gastroplasty (SRVG); D, the VBG revision to GBP with the band in place; E, the SRVG revision to GBP with the band in place; F, the distal Roux-en-Y gastric bypass (DRYGBP); G, the Torres modification of the GBP with the lesser curvature pouch; H, the silastic ring vertical gastric bypass (SRVGBP); K, transection and reinforcement of cut edges either with hemo-clips or by imbrication; L-O, interposition of Roux-en-Y limb and serosal patch of the pouch edge; P, the Fobi-pouch operation for obesity (FPO).

In 1991, in an effort to address the problem of staple-line failure and the associated marginal ulceration that plague stapled partitions in obesity operations, ^24-30 the pouch of the SRVGBP was transected (Figure 21-J). In the first dozen cases it became very apparent that transection increased the risk of bleeding and leaks. These problems were addressed by initially applying hemostat clips to the cut edges of the pouch and the bypassed stomach (Figure 2K). Later, as the transection was done with a linear cutter instead of between two parallel rows of TA90B set of staples, the cut edges were imbricated with 3-0 running vicryl sutures. By 1993 two cases of gastro-gastric fistula were documented after gastric transection. To prevent or minimize this occurrence the efferent limb of jejunum which is brought up for the gastro-enterostomy is interposed between the pouch and the distal bypassed stomach (Figure 2L), and used as a serosal patch to the imbricated edge of the proximal pouch (Figure 2M-O).

We use a gastrostomy tube routinely to decompress the bypassed segment in order to prevent the syndrome of acute gastric dilatation and also to provide an alternate route for hydration or feeding if the need does arise.^31,32To address the hazard of no readily available access to the bypassed segment, a radio-opaque ring marker, the same radio-opaque silastic ring used for the band,^7,8is routinely put around the gastrostomy site to facilitate future X-ray-guided percutaneous transabdominal access to the bypassed stomach. This composite operation, the transected silastic ring vertical gastric bypass, the interposed jejunal limb used as a serosal patch to the edge of the proximal pouch and the gastrostomy with the radio-opaque marker constitute the FPO (Figure 2P). This operation has been used by us since 1992. Our preliminary 3-year report with the FPO was presented at the Cancun meeting of NAASO Transected Silastic Vertical Gastric Bypass in November 1997,³³ and we are compiling the findings of our 1-7 years experience for future publication. Other surgeons have used this modification of the GBP since its initial presentation in 1989²⁰ and have published their preliminary results. ^34-39

References

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15. Fobi MAL. Exhibit: Distal Roux-Y gastric bypass, a revision operation for failed gastric bypass and gastroplasty operations for obesity. Fourth Annual Symposium on Surgical Treatment of Obesity, Disneyland Hotel, Anaheim, CA, March 5-8 1986. Obesity Surgery, 8, 1998