The aim of this study is to describe the clinical presentation, indications, and operative treatment as well as assess the morbidity, mortality, and overall performance of revisional GBP after either failed and/or complicated Biliopancreatic Diversion "BPD" for weight loss. With such information, we hope to determine what features might assist us in advancing our knowledge about mechanisms of failure after primary bariatric surgery, mechanism of action of revisional GBP, and performance of revisional GBP through traditional outcome measurements as well as identifying predictors of good or poor outcome after revisional GBP in this specific subpopulation.

In Italy, Professor Nicola Scopinaro, after studies in dogs, performed the first BPD in humans in 1976. Because of the lack of blind-loop syndrome and selective malabsorption for starch and fat, the BPD has an accepted risk-benefit ratio compared to the long ago abandoned Jejunoileal Bypass (a purely malabsorptive procedure). BPD side effects after resumption of full food intake include 2 to 4 bowel movements "BM" per day of foul-smelling, soft stools with flatulence. Modification of food habits and/or administration of neomycin or metronidazole for bacterial overgrowth syndrome tend to decrease BPD side effects after the disappearance of the postcibal syndrome somewhere around the fourth postoperative month.

To optimize its performance but mainly to decrease the protein malnutrition incidence, the BPD has undergone several modifications until 1992 when the ad hoc stomach-ad hoc alimentary limb BPD configuration was implemented. Consequently, the early sporadic and late recurrent forms of protein malnutrition have decreased from as high as 30% and 10% to as low as 2.0% and 1.0%, respectively.

PROTEIN-CALORIE MALNUTRITION

I) After BPD Protein-calorie malnutrition "PCM" is multifactorial and depends on patient-related factors (such as eating habits, capacity to adapt these to requirements set by the surgery, and socio-economic status) and technical factors (including gastric volume, bowel limb lengths, intestinal absorption and adaptation, and amount of endogenous nitrogen loss). Most cases are limited to a single or sporadic episode. In the early postoperative period secondary to the forced reduced food intake, the marasmic form of PCM incidence is higher, which is the aim of the operation. However, when carbohydrate intake is preferred (poor compliance with adequate protein intake), the hypoalbuminemic form will develop. The absorptive capacity of the alimentary limb "AL" and common limb or channel "CC" depends on 1) number of villi per square centimeter, 2) transit time, and 3) total intestinal length of the AL + CC. Thus, any condition that interferes with postoperative intestinal adaptation, mainly villous hypertrophy; increased transit time; and/or decreases the length of the functional AL + CC will lead to late onset of severe PCM. Increased number of bowel movements "BM" or severe diarrhea generally precedes to PCM.

After adequate counseling with life-style changes (mainly consumption of more than 90 g/day of high biological value protein), supplementation with pancreatic enzymes, and management of contributing medical conditions (such as gastroenteritis, lactose intolerance, intestinal bacterial overgrowth syndrome, celiac sprue, and inflammatory bowel disease), recurrent or severe PCM is frequently caused by excessive malabsorption. When mild or moderate protein malnutrition is instated, two to three weeks of parenteral nutrition are generally required to revert it. In contrast, severe PCM refers to the need for prolonged total parenteral nutrition "TPN", recurrent need for TPN, or malnutrition recalcitrant to TPN. Eventually, revisional surgery is required. The recurrent or severe form of PM is rarely secondary to excessive persistence of the food limitation mechanism with or without poor protein intake, requiring restitution of the intestinal continuity or complete reconstruction of the gastrointestinal tract (partial vs. full restoration). The partial restoration of the gastrointestinal tract allows normal protein-energy absorption, still partially preserving the specific effects of BPD on glucose and cholesterol metabolism.

II) After RYGB

1. Over a seven-year period, Avinoah et al. reported the nutritional status of 200 RYGB patients. Meat intolerance was observed in 51%, 60.3%, 59.5% and 55.1% of the patients during the 1st year, 2nd year, 3rd to 6th years, and 7th year after RYGB, respectively. No protein-calorie malnutrition was identified.
2. Moize et al. evaluated food consumption after 93 RYGB patients finding that inadequate protein intake is related to protein intolerance up to one year. Protein intake increased significantly over the first postoperative year from 45 g at 3 months, 46 g at 6 months, and to 58 g at 12 months. Low protein intake along the first year after RYGB is mainly related to intolerance to rich-protein food such as animal protein, mainly red meat.
3. There are no studies that quantify protein malabsorption after short-limb RYGB or any kind of RYGB variant. However, the less acidic environment of the gastric pouch after RYGB delays protein digestion by affecting the release of a cascade of peptides and enzymes, including pepsinogen, gastrin, and cholecystokinin which are involved in the initial breakdown of proteins.
4. In 236 consecutive short-limb, (6.3cm) banded RYGB patients, Faintuch et al. identified 4.7% patients with severe hypoalbuminemic malnutrition from which 63.6% had defined events, such as stenosis at the gastrojejunostomy (36.4%) or associated diseases, and 36.4% had severe emesis without any endoscopic abnormality.
5. In a series of 342 consecutive ringed RYGB, White et al. reported a 2% ring removal rate after placing a 6.5cm ring in 92 patients because of major restriction to solid foods.
6. In 65 patients converted to distal RYGB, Fobi et al. reported a mean BMI decrease of 7 kg/m2; however, 23% of patients developed protein malnutrition requiring revision surgery almost 50% of them.
7. In 27 distal RYGB at the 3rd postoperative year, Sugerman et al. reported a 25% incidence of protein malnutrition for the 150-cm common channel RYGB (n=22). In contrast, all five patients with a 50-cm common channel needed elongation of the common channel and two died of hepatic failure.

After extensive review of the literature, Kushner listed principal variables that contributed to nutritional deterioration after bariatric surgery: 1) sever malabsorption after malabsorptive procedures such as BPD or BPD-DS and distal or very, very long-limb RYGB; 2) surgical mechanical complications, such as stenosis at the gastrojejunostomy, intractable marginal ulcer, and gastro-gastric fistula; and 3) Non-compliance

Same analysis and review of the literature is available but less extensive for Metabolic bone disease, Anemia (Iron, folate, and vitamin B12), liposoluble vitamins and essential fatty acids.

Revisional strategies:

Revisional strategies that have been described for long-term complications after BPD are 1) elongation of common limb or channel, 2) restoration of intestinal continuity (partial restoration), and 3) restoration of gastrointestinal continuity (full restoration).

RYGB vs. BPD: Roux-en-Y configuration

1. Weight maintenance after BPD or BPD-DS appears to be superior to that after restrictive procedures and RYGB. However, this has never been subjected to a randomized controlled trial.

2. Intuitively, one would expect macro and micronutrient deficiency after bariatric surgery to be more frequent and severe when primarily malabsorptive with some restriction or pure malabsorptive procedures have been carried out, and this has been shown to be correct (level of evidence 3 or C).

3. Comparing the incidence rate of the largest series performed by experts, the incidence rate of late metabolic/nutritional complications after standard BPD/BPD-DS is higher than after standard RYGB.

4. There are trials with a level of evidence 3 & 4 (C & D) that favor the overall superiority of RYGB over BPD for clinically severe obesity including among others the following:

   • RYGB has been around longer than BPD
   • Widespread use of RYGB compared to BPD
   • Comparable weight loss however BPD has better weight maintenance than RYGB
   • RYGB has lower morbidity and mortality than BPD including metabolic/nutritional problems, which are more prevalent in BPD than in RYGB.
   • RYGB, in general, is accepted as the best revisional strategy for failed/ complicated restrictive procedures and even malabsortive surgeries such as the jejunoileal bypass

Summarizing, there is no evidence level A or 1 about what is the best overall primary bariatric procedure to address obesity at the long-term. In the USA, most investigators prefer RYGB for primary bariatric procedure, leaving BPD or BPD-DS for select cases including revisionary surgery for poor weight loss. After RYGB and BPD/BPD-DS, patients require to give priority for protein intake over other macronutrients as well as vitamin and mineral supplementation lifelong; there is no objective and standardized recommendation for supplementation. However, when metabolic/nutritional complications after BPD or BPD-DS develops regardless of optimized multispecialty medical management, lengthening of the common channel and partial or full reversals have been described. On the other hand, one-stage revision, either open or laparoscopic, from BPD to standard RYGB has never been reported. With this study, we will advance our knowledge about revisional RYGB, metabolic complications after hybrid bariatric procedures, and along with the existing literature, we will draw preliminary clinical recommendations.

Inclusion Criteria:

• Patients status post biliopancreatic diversion with any combination of the following severe late complications:

  • Metabolic and/or nutritional BPD-related complications.
  • Excessive weight loss
  • Poor weight loss, either Inadequate initial weight loss or Weight recidivism
  • Intolerable intestinal malabsorptive symptoms without severe malnutrition

• Undergoing either open or laparoscopic conversion to Roux-en-Y gastric bypass (RYGB) surgery.

Exclusion Criteria:

• Any other type of revision or conversion surgery.
• Adequate response to medical management of metabolic and nutritional complications after previous BPD
• missing records and/or unreachable patients with scant information for analysis

Patients referred with severe, persistent and/or recurrent metabolic/nutritional complications after open biliopancreatic diversion for clinically severe obesity underwent either laparoscopic or open conversion to Roux-en-Y gastric bypass. Intractability after interdisciplinary optimized medical therapy for metabolic and/or nutritional complications warranted surgical management.