The Effect of Basic Fibroblast Growth Factor on the Reversion of Omental Adipocytes from Lean and Obese Patients

Background: this study was designed to characterize some of the biochemical and molecular genetic changes during reversion of human fat cells. Methods: mature adipocytes were isolated from greater omental fat tissue of eight lean and 14 massively obese persons by established methodology. Results: at day 7 of adherence to Leighton tubes, there was appreciable depletion of triacylglycerol, as well as assumption of an elongated contour. Relatedly, there was an increase in the expression of β-actin mRNA and a significant decrease in the specific activity of cytosolic glycerophosphate dehydrogenase. The decrement in the specific activity of glycerophosphate dehydrogenase, after 7 days in culture, was significant at p < 0.001. Basic fibroblast growth factor at 10 ngml^-1 accelerated significantly (p < 0.03) the decrease in the specific activity of glycerophosphate dehydrogenase in adipose cells from lean subjects. In contrast, basic fibroblast growth factor had no significant influence on cells from massively obese persons. Conclusion: such resistance may contribute to the intractability of massive obesity.     

Treatment of Vitamin B12 Deficiency after Gastric Surgery for Severe Obesity

Background: Vitamin B₁₂ deficiency after gastric surgery for obesity is due to a failure of separation of vitamin B₁₂ from protein foodstuffs and to a failure of absorption of crystalline vitamin B₁₂ in the presence of intrinsic factor. The purpose of this study was to determine which of four oral doses of crystalline vitamin B₁₂ was most effective in treating vitamin B₁₂ deficiency in 102 patients. Methods and Results: At time of entry into the study, the patients had a serum vitamin B₁₂ < 100 pmol L ⁻¹, were 29.9 ± 21.7 months post-op, were 37 ± 8 years old and had a body mass index of 30 ± 6 kg m⁻². Eight (8%) had had a vertical banded gastroplasty and 94 (92%) a gastric bypass. For the first 3 months all patients received 350 μg per day of crystalline vitamin B₁₂ and all increased their serum vitamin B₁₂ levels to over 100 pmol L⁻¹. The patients were then assigned to receive for a further 3 month period one of four oral doses of crystalline vitamin B₁₂-100 μg, 250 μg, 350 μg and 600 μg. Serum vitamin B₁₂ levels were greater than 150 pmol L⁻¹ after 6 months in 83.3% of patients who received 100 μg; 92.3% of patients who received 250 μg; 94.7% after 350 μg and 95.2% after 600 μg (p%0.525). Conclusion: At least 350 μg per day is the appropriate oral dose of crystalline vitamin B₁₂ after gastric surgery for obesity to correct low serum vitamin B₁₂ levels in 95% of patients.     

Patient Satisfaction and Results of Vertical Banded Gastroplasty and Gastric Bypass

Background: Morbid obesity contributes to many health risks, including physical, emotional, and social problems. Various surgical treatments for morbid obesity have developed and have so far met with good results. This study compares vertical banded gastroplasty (VBG) with gastric bypass (GBP) and the patients' satisfaction with either procedure. Methods: Between April 1993 and July 1997, 63 bariatric surgical procedures were performed at Eisenhower Army Medical Center. Of those, complete follow-up was obtained for 29 patients. The parameters evaluated included age, preoperative and postoperative weights, body mass index (BMI), type of surgery, complications, and the patient's level of satisfaction. Results: The study group consisted of 27 women and 2 men. The average preoperative weight was 135 kg, and the average preoperative BMI was 48.3 kg/m². There were 17 VBGs and 12 GBPs performed. The average total weight loss was 45.1 kg. The average postoperative BMI was 33.2 kg/m². There were no statistically significant differences in weight loss between VBG and GBP. Four of 17 patients had complications after VBG, and three of 12 patients had complications after GBP. After VBG, 94.1% of patients were satisfied, and after GBP, 100% were satisfied. Twenty-seven of 28 patients stated that they would have the surgery again. Conclusion: There were no statistically significant differences in weight loss or complications after VBG or GBP. Patient satisfaction was high after both procedures. Therefore, bariatric surgery is important in the treatment of appropriately selected, morbidly obese patients.     

Success Habits of Long-Term Gastric Bypass Patients

Background: By identifying common habits of the most successful long-term gastric bypass patients, one is able to establish more specific guidelines for new patients to follow. The first postoperative year is a critical time that must be dedicated to changing old behavior and forming new, lifelong habits. Methods: 100 gastric bypass patients from 1979 to 1995 participated in a comprehensive survey. Surveys were completed in person, by phone, or in writing. Participants were asked to answer questions regarding their eating, drinking, sleeping, exercise, and personal habits. Results: The survey revealed that specific habits are common in gastric bypass patients who have maintained their weight loss for many years. Conclusion: Identifying and defining the common habits of patients who are successful with long-term weight loss enabled specific guidelines to be established for new patients to implement during the initial weight loss phase, which will contribute to life-long success.     

Vertical Banded Gastroplasty Versus Standard or Distal Roux-en-Y Gastric Bypass Based on Specific Selection Criteria in the Morbidly Obese: Preliminary Results

Background: Predicting successful outcomes after bariatric surgical procedures has been difficult, and the establishment of specific selection criteria has been a subject of ongoing research. In an effort to choose the most appropriate surgical procedure for each patient, we have established a specific set of selection criteria for each procedure based on degree of obesity, preoperative dietary habits, eating behavior, and various metabolic features. Methods: From June 1994 to December 1998, 90 bariatric surgical procedures were performed at the authors' institution by a single surgeon (F.K.) based on specific selection criteria. Vertical banded gastroplasty (VBG) was performed in 35 patients, standard Roux-en-Y gastric bypass (RYGB) in 38 patients, and distal RYGB in 17 patients. All patients were monitored postoperatively 1, 3, 6, and 12 months and once per year thereafter, with an additional visit at 18 months in distal RYGB patients. Results: Early postoperative morbidity (<30 days) did not differ significantly between the three groups and averaged 9% of total patients. Long-term postoperative morbidity (>30 days) included 9 incisional hernias (2 in the VBG group, 5 after RYGB, and 2 in the distal RYGB group). There were 6 cases of staple-line disruption, 4 after VBG and 2 after standard RYGB, 1 of which resulted in stomal ulcer. Early postoperative mortality was 0%, and long-term mortality was 1.1%, which was due to pulmonary embolism in 1 standard RYGB patient on the 65th postoperative day. Average percentage of excess weight loss (%EWL) was 62% the first year, 61% the second year, and 50% the third year in VBG patients, and 63.6%, 65%, and 63.3%, respectively, in standard RYGB patients. In distal RYGB patients, where the patient number was significantly smaller, the %EWL at 1 and 2 years, respectively, was 51% and 53%. The most significant metabolic/nutritional complication was the appearance of hypoproteinemia (hypoalbuminemia) in 1 distal RYGB patient 20 months after surgery, which was corrected by total parenteral nutrition and subsequent increase in dietary protein intake. Significant improvement or resolution of pre-existing comorbid conditions was observed in all patient groups. The postoperative quality of eating, as evaluated by variety of food intake and frequency of vomiting, was significantly better in RYGB patients. Conclusions: These results show that selection of the bariatric surgical procedure to be performed in each patient based on specific criteria leads to acceptable weight loss, improvement in preexisting comorbid conditions, and a high degree of patient satisfaction in most patients. On the basis of our own observations as well as those of others, our selection criteria have become more strict over time and our selection of VBG as the operation of choice increasingly infrequent.     

Measurement of Functional Pouch Volume following the Gastric Bypass Procedure

Background: The cottage cheese test was developed in an attempt to find a simple way to measure functional pouch volume and to better understand the fate of the tiny proximal pouch following the gastric bypass procedure. Methods: Our patients were asked to eat cottage cheese in a structured fashion before their return visits from 3 months to 2 years postoperatively. Results: We found there was a step-wise progression of increase in functional pouch volume with statistical significance between each time interval. Also, we compared the patients' excess weight loss at 1, 2, and 3 years postoperatively to their pouch size at 1 year postoperatively. Although there is a wide range (2.5-9.0 oz) of pouch sizes at 1 year, there is no significant difference in excess weight loss between the smaller and larger pouches. Conclusions: The pouches enlarge by the orderly process of hyperplasia. Within the 2.5-9 oz volume variation, the pouch volume alone is not a predictor of weight loss. Rather, how the patient uses the pouch/tool, in addition to the other behavior modifications, determines the degree of weight loss. This data strongly suggests that the surgeon's understanding of and teaching of the optimal use of the pouch/tool may be more important than previously thought.     

Drug Distribution in Obesity and following Bariatric Surgery: A Literature Review

Background: The pharmacokinetic variables of drug clearance and volume of distribution are usually corrected for body weight or surface area. Only recently have the relationships which exist between body size, physiologic function and pharmacokinetic variables been evaluated in the obese population. These effects are not widely known, and data on this and the effects of bariatric surgical procedures are scantily documented in the surgical literature. Methods: Literature review. Results: Drugs with a low or moderate affinity for adipose tissue have a moderate increase in the volume of distribution (Vd), and this correlates with the increase in lean body mass (LBM). Highly lipophilic drugs, with some exceptions, show the expected increase in Vd and prolongation of elimination half-life, indicating a marked distribution into adipose tissue. Drug absorption, in general, is slowed by delayed gastric emptying and is normal when gastric emptying is normal or increased. Most drug absorption occurs in the small intestine where duration of drug/mucosal contact is the most important factor. Conclusions: Drugs whose distribution is restricted to LBM should utilize a loading dose based on ideal body weight (IBW). For those drugs which distribute freely into adipose tissue, the loading dose should be based on total body weight (TBW). Adjustment of the maintenance dose depends on clearance rates. In a few cases dosage adjustment depends on pharmacodynamic data, since drug clearance does not conform to these recommendations, for reasons which remain to be defined. Following bariatric surgery, in the absence of delayed gastric emptying or uncontrolled diarrhea, drug absorption rates are usually comparable to the non-operated patient.     

The Patient Factor

Long-term results of bariatric surgery are reviewed. The weight criteria for patient acceptance for bariatric surgery and their variation are presented graphically and discussed. Factors affecting patient selection in an attempt to improve outcome results in the small group of patients who currently achieve less weight loss than anticipated are defined. An attempt is made to define pre-operative criteria for selection of pure restrictive versus combined restrictive and malabsorptive procedures. Aspects of motivation, co-morbidity, age and pre-operative weight are discussed and the position statement of the ASBS in regard to laparoscopic bariatric surgery is defined.     

Acceptance of Surgery for Obesity by Academic Surgeons in North America

BACKGROUND: Have surgeons in North America accepted operations for the treatment of severe obesity? This question was posed by organizers of the Ninth International Symposium on Obesity Surgery that met in Stockholm in September, 1995. Study design: In order to obtain opinions which might help to answer the question posed, a 1-page questionnaire was sent to 151 chairmen of academic departments of surgery in North America in December 1994 asking about the acceptance and use of surgical operations for the treatment of severe obesity. RESULTS: Answers, received from 112 or 74%, indicated that operative treatment should be used (74%), was effective (77%) and safe (71 %). However, only 65% of departments provided such operations. Operative treatment for obesity was available outside the department in 53%. The operations most frequently used were Roux-en-Y gastric bypass (RGB) and vertical banded gastroplasty (VBG). A single operation was offered by 44 departments and a choice of two or more operations in 30 departments. RGB and VBG were equally in use. Gastric banding was used as an alternative to VBG in six departments. Other operations were in use in six departments either alone (three) or as alternatives to RGB and VBG (three). CONCLUSIONS: It appears that surgical treatment of obesity is accepted and available in the majority of academic departments of surgery.     

The Rationale and Results of Gastroplasty/Distal Gastric Bypass

A recent review of the results of gastroplasties done at the University of Alberta Hospital showed that there was a high incidence of late weight loss failure. Therefore a new operation, gastroplasty/distal gastric bypass, has been performed on 263 patients. This operation results in a profound (mean greatest percentage excess weight loss of 87% at approximately 2 years) and lasting weight loss (mean final percentage excess weight loss of 78%) at 4 years, range 2-7.5 years post-operatively. Only 0.9% of patients failed to maintain at least a 40% excess weight loss. The operation achieves its effect through a moderate restriction that permits patients to eat normal table food from the time of discharge and with a mild malabsorption that is not ordinarily associated with diarrhea or notable deficiencies. Certain patients required debanding of the stoma and others developed staple-line eventration. Neither of these events after long-term follow-up resulted in weight loss failure nor in other serious side-effects. It is concluded that moderate failure of the gastroplasty stoma and staple line does not necessarily result in weight loss failure, because the malabsorptive portion of the operation remains intact. Low hemoglobin occurred in 16% of cases and deficiency of serum iron in 34%; a much smaller number of patients had chronic or intermittent deficiencies of these entities. Correction was easily achieved with oral replacement. Deficiencies in albumin, calcium, phosphorus and folate were rarely seen and minimal elevation of serum AST values occurred in just over 1% of patients. Chronic deficiencies or elevations were not seen in these patients. Stomal ulcer occurred in 6% of patients and bleeding associated with stomal ulcer in 1%. Half the patients with ulcer were managed with H₂ blockers, the other half with vagotomy. Both forms of treatment when individualized effectively prevent re-ulceration.