Impact of Weight Loss Due to Sleeve Gastrectomy on

Authors: Maciej Wiewiora Jerzy Piecuch Marek Glück Ludmila SlowinskaLozynska Krystyn Sosada

Publish Date: 2014/01/14

Volume: 24, Issue: 5, Pages: 806-812

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Abstract

Studies have shown that obesity is associated with venous flow disturbances that lead to changes of the biomechanical forces on the venous wall known as shear stress We hypothesized that weight loss due to bariatric surgery affects the venous hemodynamics and biomechanical forces on the venous wall The aim of this study was to evaluate the effects of laparoscopic sleeve gastrectomy LSG on the wall shear stress WSS and the venous hemodynamics of the femoral veinWe studied ten morbidly obese patients who underwent LSG We investigated venous hemodynamics before 6 and 12 months after LSG The femoral vein diameter crosssectional area peak PeakV and maximum TAmax velocities WSS and shear rate SR were assessedPeakV and TAmax were significantly lower in the obese patients compared with the control group WSS and SR were significantly lower in the obese patients compared with the control subjects Venous hemodynamic parameters increased in the postoperative period at baseline compared with 12 months after surgery PeakV increased from 1753 1425–2001 cm/s to 251 209–301 cm/s P = 004 and the TAmax from 1297 1151–146 cm/s to 1846 1324–2413 cm/s P = 0057 WSS significantly increased from 021 019–023 Pa at baseline to 031 023–052 Pa 12 months after surgery P = 0031 SR also significantly increased from 4792 4393–5855 s−1 at baseline to 7681 5404–1095 s−1 12 months after surgery P = 002The results of recent studies suggest that obesity is associated with an increased risk of venous disease but the main mechanisms leading to the development of chronic venous disease are not clearly defined The previous studies have shown that obesity is associated with an increase in both intraabdominal and iliofemoral venous pressure 1 greater foot venous pressure and deep venous reflux 2 Recent studies also suggest that inflammatory processes play an important role in determining vein wall damage especially in the venous valve in patients with venous disease 3 4These studies confirmed that wall shear stress is a product of the whole blood viscosity and the shear rate effect of endothelium function 5 the migration of leukocytes coagulation and inflammatory reactions 6 These studies also suggest that shear stress may affect factors determining the risk of venous thrombosis and progressive grades of chronic venous insufficiency Other authors have recently reported that obesity is associated with alteration of shear stress and venous hemodynamics in the lower limbs 7 The present study has shown significantly lower shear stress at the femoral vein in the obese individuals compared with the control subjects It is known that low shear stress and turbulent or reversed blood flow lead to inflammatory reactions which has recently been recognized as an important etiologic factor of venous disease 8 To our knowledge the effects of weight loss due to bariatric surgery on wall shear stress of the femoral vein have not yet been established The aim of this study was to evaluate the effects of weight loss due to sleeve gastrectomy on the wall shear stress of the femoral vein in morbid obesityThe study included ten morbidly obese patients without signs and symptoms of chronic venous disease who underwent laparoscopic sleeve gastrectomy Patients with varicosities lower extremity edema pigmentation or lipodermatosclerosis and healed or active venous ulcers were excluded Additional factors used as exclusion criteria included the following smoking diabetes mellitus uncontrolled hypertension heart disease history of leg vein thrombosis history of antithrombotic and/or estrogen and/or contraceptive therapy clinical signs of arterial disease prior limb surgery or sclerotherapy and lack of patient consent to participate The exclusion criteria related to using estrogen contraceptive therapy anticoagulants and antiplatelet agents were applied to a period of 3 months before the study date Ultrasound examinations excluded patients with evidence of a valve dysfunction or thrombosis Anthropometric hemodynamic and biomechanical parameters before the operation were compared to those of the control groupPatients enrolled into the study underwent laparoscopic sleeve gastrectomy LSG In this study LSG was performed according to the commonly used technique 9 10 Greater curvature vessels were divided using the LigaSure device Covidien™ USA A longitudinal resection of the stomach was created using a linear cutting stapler Echelon 60 Flex Endopath® Ethicon Endosurgery USA beginning from the point 5 to 6 cm proximal to the pylorus and continuing to the angle of His tightly abutting the bougie a 36French that was placed transorally into the pyloric channel along the lesser curvature

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