Laparoscopic Sleeve Gastrectomy as Bridge-to-Candidacy for Obese Left-Ventricular Assist Device Patients

Continuous-flow left-ventricular assist devices are increasingly used for the treatment of acute or chronic end-stage heart failure (Mancini 2015). Three main implantation strategies exist: destination therapy (support until end of life), bridge to transplantation (support until transplantation), and bridge to candidacy (support until transplantation criteria are met). Although LVAD support delivers excellent short-term and long-term results, the current gold standard and last resort of treatment for end-stage heart failure remains orthotopic heart transplantation (Lund 2015).

Obesity increases mortality in heart transplantat recipients and therefore is included in the 2006 transplantation criteria. The heart transplant program of the Medical University of Vienna uses a BMI of 30 kg/m2 as the upper limit to be listed for heart transplantation (Mehra 2016).

Ambulatory patients on CF-LVAD support have a tendency to gain weight because of reduced physical fitness, inability to work, and genetic predisposition. In many cases, binge eating is used as a coping mechanism to alleviate depression and anxiety associated with heart failure and LVAD therapy.

Conservative measures to reduce weight and increase physical fitness fail in many patients. As a result, in many cases these patients remain ineligible for heart transplantation for months or years. For the entire period of ineligibility, they are subject to the constant life-threatening risks of LVAD treatment, most importantly ischemic and hemorrhagic stroke, pump thrombosis, infection, right heart failure, and bleeding episodes in the gastrointestinal tract or other organ systems (Kirklin 2015).

Bariatric surgery has been shown to be superior to conservative measures of weight reduction in morbidly obese patients. Laparoscopic sleeve gastrectomy, one of the most commonly employed bariatric procedures, reduces body weight by a non-malabsorptive mechanism (Colquitt 2014). Gastric volume reduction is achieved by resection along the stomach's greater curvature and creation of a gastric tube, leading to reduced capacity for ingested food, decreased appetite and earlier satiety. In contrast to malabsorptive bariatric procedures, resorption and efficacy of immunosuppressive drugs, an inevitable feature of post-transplant therapy, are only minimally influenced following sleeve gastrectomy. Furthermore, there is less requirement for substitution of trace elements and vitamins, for example Vitamin B12. Due to the fact that the majority of obese LVAD patients are within a BMI range of 30 to 40 kg/m2, the moderate weight loss achieved by sleeve gastrectomy is expected to be sufficient for reaching the eligibility criterion for heart transplantation.