[show abstract][hide abstract] ABSTRACT: In morbidly obese patients, oscillometric blood pressure measurements with an upper-arm cuff are often difficult to perform. The alternative method, invasive blood pressure monitoring, can be difficult to place and is associated with risks. A wrist-mounted blood pressure-monitoring device, the Vasotrac, provides accurate blood pressure measurements in lean patients. Even in the obese, wrist morphology remains relatively unchanged. We thus assessed the degree to which blood pressure measurements with the Vasotrac on the wrist and cuff measurements agree with invasive arterial blood pressure monitoring.
We evaluated 22 morbidly obese patients undergoing bariatric surgery lasting 3.8+/-1.1 h. Intraoperative blood pressure was simultaneously measured using the Vasotrac mounted on one wrist; an arterial catheter was inserted in the opposite radial artery, and an oscillometric cuff was positioned on the upper arm. Preoperative patient comfort was evaluated on a scale from 1 to 10, with 10 being most uncomfortable, just after the first oscillometric cuff inflation. Values from the Vasotrac and arterial catheter were recorded at 5-s intervals. Bias, precision, and clinically acceptable agreement were calculated between the two continuous monitoring devices and between the arterial catheter and the cuff measurements, with the arterial catheter providing the reference value.
The patients' age was 44.3+/-9.5 years (mean+/-SD), body mass index was 66.7+/-13.8 kg/m2, and arm circumference was 48.6+/-7.5 cm. Patients found the Vasotrac more comfortable than the oscillometric device [1.7+/-1.8 vs 5.3+/-0.5 (P=0.009)]. A total of 40,411 pairs of values from the Vasotrac and arterial catheter were recorded. Lin's concordance correlation coefficient (95% CI) for mean arterial blood pressure measured between the arterial line and the Vasotrac was 0.74 (0.67, 0.82). The bias (mean error) was -0.25 mmHg; however, the Bland-Altman limits where 95% of individual pressure differences are expected to fall was (-20, 20) mmHg. The precisions for diastolic and systolic pressures were even worse.
The Vasotrac was more comfortable than an oscillometric device. Although the average accuracy was good, individual mean Vasotrac and noninvasive blood pressure pressures often differed considerably from arterial values. These results suggest that the Vasotrac monitor should not be substituted for an arterial catheter in super-obese patients.
Obesity Surgery 08/2008; 19(6):717-24. · 3.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: Roux-en-Y gastric bypass is the most frequently performed bariatric surgery for morbid obesity. Gastrojejunal anastomotic strictures are a relatively frequent postoperative complication.
To evaluate the clinical outcomes and therapeutic response to through-the-scope balloon dilation performed to treat anastomotic strictures after Roux-en-Y gastric bypass surgery.
Single-center, retrospective study.
Academic medical center.
Between 1997 and 2005, 801 patients with morbid obesity underwent Roux-en-Y gastric bypass surgery at our institution.
The development of an anastomotic stricture after Roux-en-Y gastric bypass surgery. The response to through-the-scope balloon dilation after diagnosis.
Forty-three of 801 patients (5.4%) developed an anastomotic stricture (26 of 294 open surgeries [8.8%]; 17 of 507 laparoscopic surgeries [3.4%]; P < .001). Strictures were dilated to 15.5 +/- 0.4 mm. There were no perforations or clinically significant bleeding after dilation; 93% of the strictures were successfully managed with 1 or 2 endoscopic sessions. Dilation to at least 15 mm did not affect weight loss at 1 year when compared with the group without a stricture (percentage excess weight loss: stricture group, 76%; no stricture group, 74%).
Single-center, retrospective study.
Endoscopic balloon dilation is a safe and effective method for the management of gastrojejunostomy strictures after Roux-en-Y gastric bypass. Dilation to at least 15 mm is safe and decreases the need for further endoscopic dilation.
[show abstract][hide abstract] ABSTRACT: Pancreatic leak remains a significant cause of morbidity after distal pancreatectomy. We report the use of an absorbable mesh to reinforce a stapled pancreatic transection line for distal pancreatectomy. Forty consecutive distal pancreatectomies (33 open and 7 laparoscopic) were performed since the introduction of mesh reinforcement. We utilized an inclusive definition of pancreatic leak to critically evaluate the staple line reinforcement material. In addition, we compared the pancreatic leak rate for this case series with the antecedent 40 cases where mesh reinforcement was not available. In the prospective series there was 1 leak in 29 cases (3.5%) in which mesh reinforcement was utilized, and 4 leaks in 11 cases (36%) when mesh was not utilized (p < 0.005). The 12.5% leak rate for the 40 cases during the prospective period, compared favorably to the 27.5% leak rate for the 40 cases preceding the study period (p = 0.09). Twenty-nine cases receiving mesh compared favorably to the 23 stapled cases in the control series, reducing leak rate from 22 to 3.5% (p = 0.04). Mesh reinforcement of the stapled pancreatic transection line reduced the pancreatic leak rate after distal pancreatectomy. Mesh reinforcement was possible with open or laparoscopic resections. No complications were attributable to the use of absorbable mesh.
Journal of Gastrointestinal Surgery 01/2007; 11(1):59-65. · 2.36 Impact Factor
[show abstract][hide abstract] ABSTRACT: Risk of wound infection is increased in morbidly obese surgical patients, in part because a major determinant of wound infection risk, tissue oxygenation, is marginal. Unlike in lean patients, supplemental inspired oxygen (Fio2) only slightly improves tissue oxygenation in obese patients. Mild hypercapnia improves tissue oxygenation in lean patients but has not been evaluated in obese patients. We thus tested the hypothesis that mild hypercapnia markedly improves tissue oxygenation in morbidly obese patients given Fio2 80% during major abdominal surgery. Thirty obese patients (body mass index 61.5 +/- 17 kg/m2) scheduled for open gastric bypass were randomly assigned to normocapnia (n = 15, end-tidal Pco2 35 mm Hg) or hypercapnia (n = 15, end-tidal Pco2 50 mm Hg); Fio2 was 80%. Anesthetic management and other confounding factors were controlled. Tissue oxygen tension was measured subcutaneously at the upper arm using a polarographic probe in a silastic tonometer. Demographic characteristics, cardiovascular measurements, and Pao2 (222 +/- 48 versus 230 +/- 68 mm Hg in normocapnic versus hypercapnic; mean +/- sd; P = 0.705) were comparable in the groups. Tissue oxygen tension, however, was greater in hypercapnic than in normocapnic patients (78 +/- 31 versus 56 +/- 13 mm Hg; P = 0.029). Mild hypercapnia increased tissue oxygenation by an amount believed to be clinically important and could potentially reduce the risk of surgical wound infection in morbidly obese patients.
Anesthesia and analgesia 10/2006; 103(3):677-81. · 3.08 Impact Factor