One hundred fifty consecutive laparoscopic-assisted colectomies performed by a surgical team were analyzed in an attempt to define a learning curve. These colectomies performed by the Norfolk Surgical Group over a 24-month period, were divided chronologically into six groups of 25 patients each. The groups were then compared to determine if any improvement in length of procedure, complication rate, conversion rate, or length of stay developed as experience increased. Colon cancer and diverticular disease were the most common indications for surgery in all groups. Right hemicolectomy, left colectomy, and low anterior resection accounted for the majority of procedures in all groups. A significant decrease in mean operative time, from 250 min to 156 min over the first 35-50 cases was observed before leveling off at approximately 140 min for the remaining group. Intraoperative complications were low in all groups (range zero to two) and did not show any trend. There was no statistically significant difference in the conversion rate (23.3% overall) among the six groups. Length of stay decreased from 6 days in the first two groups to 5 days in the last four groups, although the difference was not statistically significant. The learning curve for laparoscopic-assisted colectomies is longer than appreciated by many surgeons, requiring as many as 35-50 procedures to decrease operative time to baseline. Complications can be kept at an acceptably low level while on the curve if a cautious approach is taken and the surgeon realizes that a prolonged operative time is not only acceptable, but appropriate during this long learning process. A conversion rate of 20-25% at any phase of the learning process may in fact represent a limitation of current technology. When combined with a low complication rate it may be the sign of a careful surgeon.

Laparoscopic-assisted sigmoid colectomy for diverticulitis can be safely performed. Conversion appears to be associated with complicated diverticulitis (fistula or abscess), which may be better approached by laparotomy. Short-term follow-up indicates that recurrence is rare and suggests that laparoscopic-assisted sigmoid colectomy achieves adequate resection. Laparoscopic-assisted sigmoid colectomy offers benefits of decreased ileus and length of stay and may represent the procedure of choice for elective resection for uncomplicated sigmoid diverticulitis.

ObjectiveThe aim was to evaluate the impact of bariatric surgery on cardiac and sudomotor autonomic C-fiber function in obese subjects with and without Type 2 diabetes mellitus (T2DM), using sudorimetry and heart rate variability (HRV) analysis.MethodPatients were evaluated at baseline, 4, 12 and 24 weeks after vertical sleeve gastrectomy or Roux-en-Y gastric bypass. All subjects were assessed using SudoscanTM to measure electrochemical skin conductance (ESC) of hands and feet, time and frequency domain analysis of HRV, Neurologic Impairment Scores of lower legs (NIS-LL), quantitative sensory tests (QST) and sural nerve conduction studies.ResultsSeventy subjects completed up to 24-weeks of follow-up (24 non-T2DM, 29 pre-DM and 17 T2DM). ESC of feet improved significantly towards normal in T2DM subjects (Baseline = 56.71±3.98 vs 12-weeks = 62.69±3.71 vs 24-weeks = 70.13±2.88, p<0.005). HRV improved significantly in T2DM subjects (Baseline sdNN (sample difference of the beat to beat (NN) variability) = 32.53±4.28 vs 12-weeks = 44.94±4.18 vs 24-weeks = 49.71±5.19, p<0,001 and baseline rmsSD (root mean square of the difference of successive R-R intervals) = 23.88±4.67 vs 12-weeks = 38.06±5.39 vs 24-weeks = 43.0±6.25, p<0.0005). Basal heart rate (HR) improved significantly in all groups, as did weight, body mass index (BMI), percent body fat, waist circumference and high-density lipoprotein (HDL). Glycated hemoglobin (HbA1C), insulin and HOMA2-IR (homeostatic model assessment) levels improved significantly in pre-DM and T2DM subjects. On multiple linear regression analysis, feet ESC improvement was independently associated with A1C, insulin and HOMA2-IR levels at baseline, and improvement in A1C at 24 weeks, after adjusting for age, gender and ethnicity. Sudomotor function improvement was not associated with baseline weight, BMI, % body fat or lipid levels. Improvement in basal HR was also independently associated with A1C, insulin and HOMA2-IR levels at baseline.ConclusionThis study shows that bariatric surgery can restore both cardiac and sudomotor autonomic C-fiber dysfunction in subjects with diabetes, potentially impacting morbidity and mortality.

Adipose tissue inflammation in obesity is a major factor leading to cardiovascular disease and type 2 diabetes.12/15 lipoxygenases (ALOX) play an important role in the generation of inflammatory mediators, insulin resistance and downstream immune activation in animal models of obesity. However, the expression and roles of 12/15ALOX isoforms, and their cellular sources in human subcutaneous (sc) and omental (om) fat in obesity is unknown. The objective of this study was to examine the gene expression and localization of ALOX isoforms and relevant downstream cytokines in subcutaneous (sc) and omental (om) adipose tissue in obese humans. Paired biopsies of sc and om fat were obtained during bariatric surgeries from 24 morbidly obese patients. Gene and protein expression for ALOX15a, ALOX15b and ALOX 12 were measured by real-time PCR and western blotting in adipocytes and stromal vascular fractions (SVF) from om and sc adipose tissue along with the mRNA expression of the downstream cytokines IL-12a, IL-12b, IL-6, IFNγ and the chemokine CXCL10. In a paired analysis, all ALOX isoforms, IL-6, IL-12a and CXCL10 were significantly higher in om vs. sc fat. ALOX15a mRNA and protein expression was found exclusively in om fat. All of the ALOX isoforms were expressed solely in the SVF. Further fractionation of the SVF in CD34+ and CD34-cells indicated that ALOX15a is predominantly expressed in the CD34+ fraction including vascular and progenitor cells, while ALOX15B is mostly expressed in the CD34-cells containing various leucocytes and myeloid cells. This result was confirmed by immunohistochemistry showing exclusive localization of ALOX15a in the om fat and predominantly in the vasculature and non-adipocyte cells. Our finding is identifying selective expression of ALOX15a in human om but not sc fat. This is a study showing a major inflammatory gene exclusively expressed in visceral fat in humans.

ALOX 12 may have a critical role in regulation of inflammation in VAT in obesity and T2D. Selective ALOX 12 inhibitors may constitute a new approach to limit AT inflammation in human obesity.