Edward Lin

Transumbilical Gelport Access Technique for Performing Single Incision Laparoscopic Surgery (SILS)

IntroductionSingle incision laparoscopic surgery (SILS) is an area of active research within general surgery.DiscussionA number of procedures, including cholecystectomy, appendectomy, urologic procedures, adrenalectomy, and bariatric procedures, are currently being performed with this methodology. There is, as yet, no standard published technique for single-port access to the peritoneal cavity for SILS. We describe, herein, an access technique utilizing existing instrumentation including a Gelport and wound retractor that is reliable and easy. This technique has been used successfully at our institution for a number of single incision laparoscopic procedures.

Who will fail laparoscopic Nissen fundoplication? Preoperative prediction of long-term outcomes

BackgroundA small but significant percentage of patients are considered failures after laparoscopic Nissen fundoplication (LNF). We sought to identify preoperative predictors of failure in a cohort of patients who underwent LNF more than 10 years ago.MethodsOf 312 consecutive patients undergoing primary LNF between 1992 and 1995, recent follow-up was obtained from 166 patients at a mean of 11.0 ± 1.2 years. Eight additional patients who underwent reoperation were lost to follow-up but are included. Failure is broadly defined as any reoperation, lack of satisfaction, or any severe symptoms at follow-up. Potential predictors evaluated included sex, age, body-mass index (BMI), response to acid reducing medications (ARM), psychiatric history, typical versus atypical symptoms, manometry, esophageal pH, and others. Logistic regression was used to assess significance of predictors in univariate analysis.ResultsOf 174 known outcomes, 131 were classified as successful (75.3%), while 43 were failures (24.7%): 26 reoperations, 13 unsatisfied, and 13 with severe symptoms. Response and lack of response to ARM were associated with 77.1% and 56.0% success rates respectively (P = 0.035). Eighty five percent of patients with typical symptoms had a successful outcome, compared to only 41% with atypical symptoms (P < 0.001). Preoperative morbid obesity (BMI > 35 kg/m2) was associated with failure (P = 0.036), while obesity (BMI 30–34.9 kg/m2) was not. A history of psychiatric illness trended toward significance (P = 0.06).ConclusionsIn a cohort with 11 years follow-up after LNF, factors predictive of a successful outcome include preoperative response to ARM, typical symptoms, and BMI < 35 kg/m2. Patients with atypical symptoms, no response to ARM, or morbid obesity should be informed of their higher risk of failure. Some patients in these groups do have successful outcomes, and further research may clarify which of these patients can benefit from LNF.

Single-incision laparoscopic right hemicolectomy for a colon mass.

PURPOSE: Single-incision laparoscopy is being performed for a wide variety of procedures. We describe our technique of single-incision laparoscopic right hemicolectomy for a colon mass. METHODS: The dissection was performed in a medial-to-lateral fashion with intracorporeal anastomosis. RESULTS: The length of stay was three days, and there were no postoperative complications. CONCLUSIONS: Single-incision laparoscopic colectomy with an intracorporeal anastomosis can provide satisfactory oncologic resection.

Resident Participation in Index Laparoscopic General Surgical Cases: Impact of the Learning Environment on Surgical Outcomes

BACKGROUND The NSQIP database enables measurement of postoperative outcomes across a spectrum of practice settings. This allows for observations about potential effects of resident participation in surgical care during training. STUDY DESIGN We queried the NSQIP database for 6 index laparoscopic surgical procedures performed during 2005-2008. Selected procedures require varying skill level (eg, appendectomy, cholecystectomy, gastric bypass, fundoplication, colectomy, and inguinal hernia), and 79,720 cases were identified. Preoperative, operative, and postoperative outcomes for each procedure were tabulated. Operative and postoperative outcomes assessed included operative time, hospital length of stay, mortality, morbidity, and return to the operating room. Initial analysis compared cases done with a resident present with cases done without residents. Subset analysis was done to determine possible differences in outcomes based on the level of resident participating, divided into Junior (PGY1-2), Senior (PGY3-5), or Fellow (PGY>5). Groups were scrutinized for both clinical and statistical differences. RESULTS Preoperative characteristics were similar between groups. Operative times were 20% to 47% longer with resident participation, with bigger differences seen in more basic procedures. Mortality and return to the operating room were not clinically different between the groups. Morbidity rates were higher in all procedures with resident participation. More senior residents were associated with longer operative times, without adverse impact on outcomes. CONCLUSIONS Resident participation increases operative times for laparoscopic surgery considerably. Morbidity is statistically higher with resident participation but differences are unlikely to be clinically significant. Resident participation is a surrogate for the learning environment. These findings provide impetus for additional development of training techniques that occur outside the operating room.

Contribution of adipose tissue to plasma 25-hydroxyvitamin D concentrations during weight loss following gastric bypass surgery.

Roux‐en‐y gastric bypass (RYGB) surgery is associated with dramatic improvements in obesity‐related comorbidity, but also with nutritional deficiencies. Vitamin D concentrations are depressed in the severely obese, but the impact of weight loss via RYGB is unknown. We determined associations between adiposity and systemic 25‐hydroxyvitamin D (25(OH)D) during weight loss and the immediate and longer‐term effects of RYGB. Plasma 25(OH)D concentrations and fat mass (FAT) were determined by immunoassay and air displacement plethysmography, respectively, at 0 (before RYGB surgery), and at 1, 6, and 24 months in severely obese white and African American (AA) women (n = 20). Decreases in adiposity were observed at 1, 6, and 24 months following RYGB (P < 0.05). Plasma 25(OH)D concentrations increased at 1 month (P = 0.004); a decreasing trend occurred over the remainder months after surgery (P = 0.02). Despite temporary improvement in vitamin D status, a high prevalence of vitamin D insufficiency was observed (76, 71, 67, and 82%, at baseline, 1, 6, and 24 months, respectively), and plasma 25(OH)D concentrations were lower in AA compared to white patients (P < 0.05). Strong positive baseline and 1 month cross‐sectional correlations between FAT and plasma 25(OH)D were observed, which remained after adjustment for age and race subgroup (β = 0.76 and 0.61, respectively, P = 0.02). In conclusion, 25(OH)D concentrations increased temporarily and then decreased during the 24 months following RYGB. The acute increase and the positive associations observed between adipose tissue mass and systemic 25(OH)D concentrations suggest storage in adipose tissue and release during weight loss.

Loss of Total and Visceral Adipose Tissue Mass Predicts Decreases in Oxidative Stress After Weight Loss Surgery

It is not known whether there are mechanisms linking adipose tissue mass and increased oxidative stress in obesity. This study investigated associations between decreasing general and abdominal fat depots and oxidative stress during weight loss. Subjects were severely obese women who were measured serially at baseline and at 1, 6 (n = 30), and 24 months (n = 18) after bariatric surgery. Total fat mass (FAT) and volumes of visceral (VAT) and subcutaneous abdominal adipose tissue (SAT) were related to plasma concentrations of derivatives of reactive oxidative metabolites (dROMS), a measure of lipid peroxides and oxidative stress. After intervention, BMI significantly decreased, from 47.7 ± 0.8 kg/m2 to 43.3 ± 0.8 kg/m2 (1 month), 35.2 ± 0.8 kg/m2 (6 months), and 30.2 ± 1.2 kg/m2 (24 months). Plasma dROMS also significantly deceased over time. At baseline, VAT (r = 0.46), FAT (r = 0.42), and BMI (r = 0.37) correlated with 6‐month decreases in dROMS. Similarly, at 1 month, VAT (r = 0.43) and FAT (r = 0.41) correlated with 6‐month decreases in dROMS. Multiple regression analysis showed that relationships between VAT and dROMS were significant after adjusting for FAT mass. Increased plasma dROMS at baseline were correlated with decreased concentrations of high‐density lipoprotein (HDL) at 1 and 6 months after surgery (r = −0.38 and −0.42). This study found longitudinal associations between general, and more specifically intra‐abdominal adiposity, and systemic lipid peroxides, suggesting that adipose tissue mass contributes to oxidative stress.

Incidence and prevalence of copper deficiency following roux-en-y gastric bypass surgery

Introduction and Objectives:The frequency of copper deficiency and clinical manifestations following roux-en-y gastric bypass (RYGB) surgery is not yet clear. Objectives were to determine the prevalence and incidence of copper deficiency in patients who have undergone RYGB.Design and Methods:We sought to determine the number of RYGB patients undergoing medical and nutritional follow-up visits at the Emory Bariatric Center who experienced copper deficiency and associated hematological and neurological complaints (n=136). Separately, in patients followed longitudinally before and during 6 and 24 months following RYGB surgery, we obtained measures of copper status (n=16). Systemic blood cell counts and measures of copper, zinc and ceruloplasmin were determined using standardized assays in reference laboratories including atomic absorption spectrometry and immunoassays.Results:Thirteen patients were identified to have copper deficiency suggesting a prevalence of copper deficiency of 9.6%, and the majority of these had concomitant complications including anemia, leukopenia and various neuro-muscular abnormalities. In the longitudinal study, plasma copper concentrations and ceruloplasmin activity decreased over 6 and 24 months following surgery, respectively (P<0.05), but plasma zinc concentrations did not change. A simultaneous decrease in white blood cells was observed (P<0.05). The incidence of copper deficiency in these subjects was determined to be 18.8%.Conclusions:The prevalence and incidence of copper deficiency following RYGB surgery was determined to be 9.6% and 18.8%, respectively, with many patients experiencing mild-to-moderate symptoms. Given that copper deficiency can lead to serious and irreversible complications if untreated, frequent monitoring of the copper status of RYGB patients is warranted.

Increases in Adiponectin Predict Improved Liver, but Not Peripheral, Insulin Sensitivity in Severely Obese Women During Weight Loss

Obesity-related glucose intolerance is a function of hepatic (homeostatic model assessment-insulin resistance [HOMA-IR]) and peripheral insulin resistance (Si) and β-cell dysfunction. We determined relationships between changes in these measures, visceral (VAT) and subcutaneous (SAT) adipose tissue, and systemic adipocytokine biomarkers 1 and 6 months after surgical weight loss. HOMA-IR decreased significantly (−50%) from baseline by 1 month and decreased further (−67%) by 6 months, and Si was improved by 6 months (2.3-fold) weight loss. Plasma concentrations of leptin decreased and adiponectin increased significantly by 1 month, and decreases in interleukin-6, C-reactive protein (CRP), and tumor necrosis factor-α were observed at 6 months of weight loss. Longitudinal decreases in CRP (r = −0.53, P < 0.05) were associated with increases in Si, and decreases in HOMA-IR were related to increases in adiponectin (r = −0.37, P < 0.05). Decreases in VAT were more strongly related to increases in adiponectin and decreases in CRP than were changes in general adiposity or SAT. Thus, in severely obese women, specific loss of VAT leads to acute improvements in hepatic insulin sensitivity mediated by increases in adiponectin and in peripheral insulin sensitivity mediated by decreases in CRP.

The impact of renal function on outcomes of bariatric surgery

The effect of CKD on the risks of bariatric surgery is not well understood. Using the American College of Surgeons National Surgical Quality Improvement Program Participant Use File, we analyzed 27,736 patients who underwent bariatric surgery from 2006 through 2008. Before surgery, 34 (0.12%) patients were undergoing long-term dialysis. Among those not undergoing dialysis, 20,806 patients (75.0%) had a normal estimated GFR or stage 1 CKD, 5011 (18.07%) had stage 2 CKD, 1734 (6.25%) had stage 3 CKD, 94 (0.34%) had stage 4 CKD, and 91 (0.33%) had stage 5 CKD. In an unadjusted analysis, CKD stage was directly associated with complication rate, ranging from 4.6% for those with stage 1 CKD or normal estimated GFR to 9.9% for those with stage 5 CKD (test for trend, P<0.001). Multivariable logistic regression demonstrated that CKD stage predicts higher complication rates (odds ratio for each higher CKD stage, 1.30) after adjustment for diabetes and hypertension. Although patients with higher CKD stage had higher complication rates, the absolute incidence of complications remained <10%. In conclusion, these data demonstrate higher risks of bariatric surgery among patients with worse renal function, but whether the potential benefits outweigh the risks in this population requires further study.

Improvement in β-cell function in patients with normal and hyperglycemia following Roux-en-Y gastric bypass surgery

Glycemic disorders resolve following Roux-en-Y gastric bypass (RYGB) surgery, but early and longer-term mechanisms regarding effects on β-cell dysfunction as well as relationships with decreasing adiposity are not well understood. We evaluated longitudinal changes in peripheral insulin sensitivity (Si), the acute insulin response to glucose (AIRg), and the composite estimate of β-cell function, the disposition index (DI), over 24 mo via frequently sampled intravenous glucose tolerance testing in severely obese women who had fasting normoglycemia (n = 16) and hyperglycemia (n = 11) before RYGB surgery; homeostatic model assessment (HOMA-IR) estimated insulin resistance; air displacement plethysmography determined adipose tissue mass. At baseline, subjects with normoglycemia had adequate DI associated with elevated AIRg, but DI was markedly reduced in subjects with hyperglycemia. Within 1-6 mo post-RYGB, glycemic control was normalized in subjects with hyperglycemia related to reduced HOMA-IR (-54% at 1 mo, P < 0.005) and increased DI (23-fold at 6 mo vs. baseline, P < 0.05). Over 24 mo, DI improved in subjects with hyperglycemia (15-fold vs. baseline, P < 0.005) and also modestly in subjects with normoglycemia (58%, P < 0.05), due largely to increased Si. Decreasing adiposity correlated with longer-term HOMA-IR and Si values at 6 and 24 mo, respectively. In patients exhibiting fasting hyperglycemia before surgery, β-cell function improved early following RYGB, due largely to increases in insulin secretion. For both normoglycemic and hyperglycemic subjects, further improvement or stabilization of β-cell function over the 2 yr is due largely to improved Si associated with reduced adiposity.