Gregory Dakin

Laparoscopic sleeve gastrectomy for morbid obesity.

The epidemic of obesity in the United States is a major public health issue and more than a third of adults are now considered obese (body mass index > or = 30 kg/m(2)). Surgery for morbid obesity, bariatric surgery, is the most durable treatment for this disease and about 140,000 cases are performed annually. Laparoscopic sleeve gastrectomy (LSG) has been advocated as the first of a 2-stage procedure for the high-risk, super-obese patient. More recently, LSG has been studied as a single-stage procedure for weight loss in the morbidly obese. LSG has been shown in initial studies to produce excellent excess weight loss comparable with laparoscopic Roux-en-Y gastric bypass in many series with a very low incidence of major complications and death. We describe our technique for LSG.

Vitamin D insufficiency prior to bariatric surgery: risk factors and a pilot treatment study.

Objective  To assess vitamin D status and the influences of race, sun exposure and dietary vitamin D intake on vitamin D levels, and to evaluate two vitamin D repletion regimens in extremely obese patients awaiting bariatric surgery.

Evaluation of nutrient status after laparoscopic sleeve gastrectomy 1, 3, and 5 years after surgery

BACKGROUND Laparoscopic sleeve gastrectomy evolved as a primary bariatric procedure with little information on its nutritional effects. Our objective was to assess the longer term micronutrient and vitamin status after laparoscopic sleeve gastrectomy at a university hospital. METHODS Measurements of ferritin, iron, total iron binding capacity, hemoglobin, hematocrit, parathyroid hormone, albumin, calcium, magnesium, phosphorus, zinc, folate, and vitamins A, B1, B12, and D were obtained at baseline and 1, 3, and 5 years after surgery. Two-sample t tests with multiple adjusted comparisons and Fishers exact test were used to determine deficiency. RESULTS A total of 82 patients (67% women), with a mean age of 46.4 years and a baseline body mass index 55.7 kg/m2 were included in the present study (35 at 1, 27 at 3, and 30 at 5 years postoperatively). The percentage of excess body mass index loss was 58.5% at year 1 in 35 patients, 63.1% at year 3 in 27 patients, and 46.1% at year 5 in 30 patients. The parathyroid hormone level decreased from 75.0 to 49.6 ng/mL in year 1 to 40.7 ng/mL in year 3. The year 5 levels increased to 99.6 ng/mL. The mean vitamin D level increased from 23.6 ng/mL to 35.0, 32.1 and 34.8 at years 1, 3, and 5 (P = .05 for baseline to year 1). The vitamin D level was less than normal in 42% of the patients at year 5. After normalization from baseline, by year 5, parathyroid hormone had increased in 58.3% of patients. At year 5, vitamin B1 was less than normal in 30.8% of patients, and hemoglobin and hematocrit were less than normal in for 28.6% and 25% of patients, respectively. Finally, 28.9% of patients reported taking supplements in year 1, 42.9% in year 3, and 63.3% in year 5. The other variables were not significantly different. CONCLUSIONS Laparoscopic sleeve gastrectomy resulted in health improvements through year 3. At year 5, the nutrient levels had reverted toward the baseline values. These observations provide focus for necessary clinical monitoring.

Laparoscopic sleeve gastrectomy: does bougie size affect mean %EWL? Short-term outcomes

BACKGROUND Laparoscopic sleeve gastrectomy (LSG) has been increasingly offered to high-risk bariatric patients as the first-stage procedure before gastric bypass or biliopancreatic diversion or as the primary weight loss procedure. The bougie size has varied by surgeon during LSG. The aim of this study was to determine whether short-term weight loss correlates with the bougie size used during creation of the sleeve. METHODS We retrospectively reviewed the data from all patients who had undergone LSG at our institution between 2003 and 2006. Revision LSG for failed bariatric procedures was excluded. The data analyzed included preoperative age, body mass index (BMI), bougie size, and percentage of excess weight loss (%EWL). RESULTS A total of 135 patients underwent LSG during the 4-year period. Most of these patients (79%) underwent LSG as part of a 2-stage operation (either gastric bypass or duodenal switch within a mean of 11 months). The mean preoperative age and BMI was 43.5 years and 60.1 kg/m(2), respectively. The mean BMI and %EWL at 6 months was 47.1 kg/m(2) and 37.9%, respectively. The mean BMI and %EWL at 12 months was 44.3 kg/m(2) and 47.3%, respectively. When stratifying the %EWL by bougie size (40F versus 60F), we did not find a significant difference at 6 months (38.8% versus 40.6%, P = NS) or 12 months (51.9% versus 45.4%, P = NS). CONCLUSION LSG results in significant weight loss in the short term. When stratifying outcomes by bougie size, our results suggested that a bougie size of 40F compared with 60F does not result in significantly greater weight loss in the short term. However, longer follow-up of the primary LSG group is required to determine whether a difference becomes evident over time.

Comparison of weight loss and body composition changes with four surgical procedures

BACKGROUND A paucity of information is available on the comparative body composition changes after bariatric procedures. The present study reports on the body mass index (BMI) and body composition changes after 4 procedures by a single group. METHODS At the initial consultation, the weight and body composition of the patients undergoing 4 different bariatric procedures were measured by bioimpedance (Tanita 310). Follow-up examinations were performed at 1 year and at subsequent visits after surgery. Analysis of variance was used to compare the postprocedure BMI and body composition. Analysis of covariance was used to adjust for baseline differences. RESULTS A total of 101 gastric bypass (GB) patients were evaluated at 19.1 + or - 10.6 months, 49 biliopancreatic diversion with the duodenal switch (BPD/DS) patients at 27.5 + or - 16.3 months, 41 adjustable gastric band (AGB) patients at 21.4 + or - 9.2 months, and 30 sleeve gastrectomy (SG) patients at 16.7 + or - 5.6 months (P <.0001). No differences were found in patient age or gender among the 4 groups. The mean preoperative BMI was significantly different among the 4 groups (P <.0001): 61.4 kg/m(2), 53.2, 46.7, and 44.3 kg/m(2) for the SG, BPD/DS, GB, and AGB group, respectively. The postoperative BMI adjusted for baseline differences was 27.8 (difference 23.6 + or - 8.3), 32.5 (difference 15.6 + or - 5.0), 37.2 (difference 18.2 + or - 8.2), and 39.5 kg/m(2) (difference 7.5 + or - 4.3) for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The percentage of excess weight loss was 84%, 70%, 49%, and 38% for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The postoperative percentage of body fat adjusted for baseline differences was 25.7% (23.9% + or - 7.0%) 32.7% (16.1% + or - 10.5%) 37.7% (16.7% + or - 5.6%), and 42% (6.0% + or - 6.8%) for the BPD/DS, GB, SG, and AGB groups, respectively (P <.0001). The lean body mass changes were reciprocal. CONCLUSION Although the BPD/DS procedure reduced the BMI the most effectively and promoted fat loss, all the procedures produced weight loss. The AGB procedure resulted in less body fat loss within 21.5 months than SG within 16.7 months. Longer term observation is indicated.

Surgical approaches to obesity.

Bariatric surgery has evolved considerably since the introduction of jejunoileal bypass in the 1950s. With modifications of early procedures, implementation of new techniques, and establishment of minimally invasive approaches, operative intervention has become the mainstay in the treatment of extreme (class III) obesity. The laparoscopic adjustable gastric band technique is the most common purely restrictive procedure. Advantages of the laparoscopic adjustable gastric band include reduced perioperative morbidity and mortality compared to other bariatric procedures, but this procedure has been associated with substantial intermediate and long-term complications. Although vertical banded gastroplasty was associated with decreased perioperative morbidity and acceptable early weight loss, results from long-term follow-up have been discouraging. Roux-en-Y gastric bypass (RYGB) is the most common bariatric procedure performed in the United States because of its effectiveness in long-term weight loss and low rates of serious complications. Modifications of RYGB to induce malabsorption have led to greater weight loss but increased risks of metabolic and nutritional sequelae. Duodenal switch is a malabsorptive procedure associated with excellent weight loss and resolution of weight-related comorbidities, but concerns regarding potential metabolic and nutritional sequelae have limited its widespread use. Laparoscopic approaches to bariatric procedures have reduced wound-related complications and improved patient recovery. However, the incidence of anastomotic leak and internal hernia is higher after laparoscopic RYGB compared to the open approach. Each of the currently available bariatric procedures has both advantages and disadvantages that must be considered in determining which operation should be selected for an individual patient.

Increased PTH and 1.25(OH)2D Levels Associated With Increased Markers of Bone Turnover Following Bariatric Surgery

The objective of this study was to characterize changes in metabolic bone parameters following bariatric surgery. Seventy‐three obese adult patients who underwent either gastric banding (GB), Roux‐en‐Y gastric bypass (RYGB), or biliopancreatic diversion with duodenal switch (BPD/DS) were followed prospectively for 18 months postoperatively. Changes in the calcium‐vitamin D axis (25‐hydroxyvitamin D (25OHD), 1,25‐dihydroxyvitamin D (1,25(OH)2D), calcium, parathyroid hormone (PTH)), markers of bone formation (osteocalcin, bone‐specific alkaline phosphatase) and resorption (urinary N‐telopeptide (NTx)), as well as bone mineral density (BMD) were assessed at 3‐month intervals during this time period. Bariatric surgery resulted in significant and progressive weight loss over 18 months. With supplementation, 25OHD levels increased 65.3% (P < 0.0001) by 3 months, but leveled off and decreased <30 ng/ml by 18 months. PTH initially decreased 21.4% (P = 0.01) at 3 months, but later approached presurgery levels. 1,25(OH)2D increased significantly starting at month 12 (50.3% increase from baseline, P = 0.008), and was positively associated with PTH (r = 0.82, P = 0.0001). When stratified by surgery type, median PTH and 1,25(OH)2D levels were higher following combined restrictive and malabsorptive operations (RYGB and BPD/DS) compared to GB. Bone formation/resorption markers were increased by 3 months (P < 0.05) and remained elevated through 18 months. Radial BMD decreased 3.5% by month 18, but this change was not significant (P = 0.23). Our findings show that after transient improvement, preoperative vitamin D insufficiency and secondary hyperparathyroidism persisted following surgery despite supplementation. Postoperative secondary hyperparathyroidism was associated with increased 1,25(OH)2D levels and increased bone turnover markers.

Intraluminal migration of bovine pericardial strips used to reinforce the gastric staple-line in laparoscopic bariatric surgery

A 41-year-old morbidly obese woman (BMI 40.8) underwent elective laparoscopic biliopancreatic diversion with duodenal switch. The operation involved: sleeve gastrectomy, division of duodenum, creation of a duodenoenterostomy, and creation of a distal ileoenteric anastomosis. With laparoscopic stapling, bleeding is often a problem along the sleeve gastrectomy staple-line. To reduce this risk, we used bovine pericardial strips to reinforce the staple-line throughout its length. 4 weeks postoperatively, the patient was found to have fragments of pericardium in her vomitus, indicating intraluminal migration of the reinforcing strips. Her subsequent course has been uneventful. This represents the first report of such migration. Indications, benefits, complications and risks of using bovine pericardium to reinforce gastric staple-lines in laparoscopic bariatric surgery are discussed.

Cefazolin Dosing for Surgical Prophylaxis in Morbidly Obese Patients

BACKGROUND Cefazolin is used commonly to prevent surgical site infection (SSI) after operations on patients with morbid obesity (MO), but specific dosing guidelines are lacking. We hypothesized that cefazolin 2 g given by intravenous (IV) push over 5 min (IVP) or infusion over 30 min (INF) would suffice for SSI prophylaxis in MO (body mass index [BMI] 40-50 kg/m(2)), and cefazolin 3 g would be sufficient in patients with super-morbid obesity (SMO) (BMI >50 kg/m(2)). METHODS Twenty-five patients undergoing elective surgical procedures were given a single dose of cefazolin: Ten with MO received 2 g via IVP (MO2-IVP), five with MO received 2 g via 30-min infusion (MO2-INF), five with SMO received 2 g via infusion (SMO2-INF), and five with SMO received 3 g via infusion (SMO3-INF). Serum cefazolin concentrations were measured 5, 30, 120, and 360 min after initiation of the dose. The half-life of the drug was calculated for each patient, as was the time the concentration was above the minimum inhibitory free concentration (fT>MIC) using 8 mcg/mL as the breakpoint. The protective duration of each cefazolin dose was assessed using the pharmacodynamic target for fT>MIC of 70%. RESULTS The mean cefazolin concentrations after 30 min were similar in all groups; the mean concentrations at 120 and 360 min were 67.1-84.8 mcg/mL and 22.9-40.8 mcg/mL, respectively. The half-life ranged from 2.3 to 3.6 h and was unaffected by administration method. The protective duration was 5.1 h for MO2-IVP, 4.8 h for MO2-INF, 5.8 h for SMO2-INF, and 6.8 h for SMO3-INF. CONCLUSIONS A single 2-g dose of cefazolin appears to provide antibiotic exposures sufficient for most common general surgical procedures of <5-h duration, regardless of BMI.

Change in Pain and Physical Function Following Bariatric Surgery for Severe Obesity.

IMPORTANCE The variability and durability of improvements in pain and physical function following Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) are not well described. OBJECTIVES To report changes in pain and physical function in the first 3 years following bariatric surgery, and to identify factors associated with improvement. DESIGN, SETTING, AND PARTICIPANTS The Longitudinal Assessment of Bariatric Surgery-2 is an observational cohort study at 10 US hospitals. Adults with severe obesity undergoing bariatric surgery were recruited between February 2005 and February 2009. Research assessments were conducted prior to surgery and annually thereafter. Three-year follow-up through October 2012 is reported. EXPOSURES Bariatric surgery as clinical care. MAIN OUTCOMES AND MEASURES Primary outcomes were clinically meaningful presurgery to postsurgery improvements in pain and function using scores from the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) (ie, improvement of ≥5 points on the norm-based score [range, 0-100]) and 400-meter walk time (ie, improvement of ≥24 seconds) using established thresholds. The secondary outcome was clinically meaningful improvement using the Western Ontario McMaster Osteoarthritis Index (ie, improvement of ≥9.7 pain points and ≥9.3 function points on the transformed score [range, 0-100]). RESULTS Of 2458 participants, 2221 completed baseline and follow-up assessments (1743 [78.5%] were women; median age was 47 years; median body mass index [BMI] was 45.9; 70.4% underwent RYGB; 25.0% underwent LAGB). At year 1, clinically meaningful improvements were shown in 57.6% (95% CI, 55.3%-59.9%) of participants for bodily pain, 76.5% (95% CI, 74.6%-78.5%) for physical function, and 59.5% (95% CI, 56.4%-62.7%) for walk time. Additionally, among participants with severe knee or disability (633), or hip pain or disability (500) at baseline, approximately three-fourths experienced joint-specific improvements in knee pain (77.1% [95% CI, 73.5%-80.7%]) and in hip function (79.2% [95% CI, 75.3%-83.1%]). Between year 1 and year 3, rates of improvement significantly decreased to 48.6% (95% CI, 46.0%-51.1%) for bodily pain and to 70.2% (95% CI, 67.8%-72.5%) for physical function, but improvement rates for walk time, knee and hip pain, and knee and hip function did not (P for all ≥.05). Younger age, male sex, higher income, lower BMI, and fewer depressive symptoms presurgery; no diabetes and no venous edema with ulcerations postsurgery (either no history or remission); and presurgery-to-postsurgery reductions in weight and depressive symptoms were associated with presurgery-to-postsurgery improvements in multiple outcomes at years 1, 2, and 3. CONCLUSIONS AND RELEVANCE Among a cohort of participants with severe obesity undergoing bariatric surgery, a large percentage experienced improvement, compared with baseline, in pain, physical function, and walk time over 3 years, but the percentage with improvement in pain and physical function decreased between year 1 and year 3. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00465829.