Traditional thinking is that definitive aortic valve replacement must be performed prior to elective noncardiac surgery in patients with severe aortic valvular stenosis (AS), especially for procedures of moderate to high risk. The 2014 American College of Cardiology guidelines suggest that patients with AS who have indications for aortic valve replacement (such as symptomatic severe AS) have elective noncardiac surgery postponed until after definitive valve repair.¹

With the increasing prevalence of obesity—based on data collected by the National Health and Nutrition Examination Survey for 1988 to 1994, 1999 to 2000, and 2015 to 2016, from 22.9% to 30.5% to 39.6%,^2,3 respectively—as well as the increasing prevalence of AS related to our aging population, the need for cardiothoracic surgery for aortic valve replacement in the morbidly obese population is, as expected, growing.

At the University of Pittsburgh Medical Center Pinnacle campuses in Harrisburg, Pa., we have a busy cardiac surgery program that performs over 1,000 cardiac and thoracic procedures per year. Outcomes research conducted on the morbidly obese patient population of one of our predominant cardiac surgeons indicated statistically significantly poorer cardiac outcomes after aortic valve replacement. With an equally busy bariatric surgery program, the surgeon began referring his higher-BMI patients to the bariatric surgery center for evaluation of bariatric intervention and weight loss optimization prior to cardiac intervention. A review of the literature found only a few studies with similar interests, mostly involving small groups of patients with left ventricular assist devices awaiting cardiac transplantation.⁴

With very limited data to support bariatric surgery prior to cardiac surgery, we began to assess the feasibility of this concept by using a multispecialty approach involving interventional cardiology, cardiothoracic surgery, bariatric surgery and anesthesiology. Patients were screened for overall cardiac pathology, other significant comorbidities, and eligibility for temporizing aortic balloon valvuloplasty prior to bariatric surgery in the most symptomatic individuals. Patients underwent a chart review and in-person physical examinations by a team of cardiologists, surgeons and anesthesiologists.

To date, based on a review of our data, approximately 50 cardiac patients have undergone sleeve gastrectomy, of which 19 presented with severe AS, whether by valve area, peak velocity or mean gradient. Most patients had temporizing aortic valvuloplasty and, regardless of resolution of cardiac symptoms, the patients underwent bariatric surgery within three months of valvuloplasty, often within a month after the procedure following clearance from the interventional cardiologist.

The anesthetic was customized to the individual’s overall pathology; significant obstructive sleep apnea and high pulmonary artery pressures were common findings. All anesthetics involved opioid sparing, with most patients receiving no intraoperative opioids in order to avoid immediate postoperative obtundation and respiratory depression. Although variation in the anesthetic regimen occurred occasionally based on patient factors, the regimen included preoperative oral acetaminophen, celecoxib (Celebrex, Pfizer) and gabapentin, as well as a scopolamine patch. All patients had at least one large-bore IV and radial artery cannula for continuous blood pressure monitoring. Cerebral oximetry was used in the latter group of patients when the technology became regularly available for noncardiac surgery at our institution.

Induction was accomplished with propofol 1 mg/kg IV based on ideal body weight, ketamine 50 mg IV, lidocaine 100 mg IV and rocuronium 0.6 mg/kg IV, based on actual body weight. Next, patients received magnesium 3 g IV over 30 minutes. After induction and tracheal intubation, bilateral ultrasound-guided, single-shot transversus abdominis plane blocks were performed using ropivacaine 0.5%. Patients then received dexamethasone 12 mg IV and ondansetron 8 mg IV as part of the antiemetic regimen.

Intraoperative positioning into a steep reverse Trendelenburg position was done slowly, with pharmacologic cardiovascular support using the alpha agonist phenylephrine via IV bolus to maintain blood pressure within 20% of baseline and stable cerebral oximetry readings (>60% and within 20% of baseline). Surgical time was less than one hour in most cases, and all patients were extubated in the operating room after receiving intravenous sugammadex (Bridion, Merck) based on qualitative train-of-four, and transported with supplemental oxygen by nasal cannula or face mask to maintain arterial oxygen saturation consistently over 92%. No patients required BiPAP (bilevel positive airway pressure) in the PACU. Patients could receive small doses of short-acting opioids in the PACU with close evaluation of level of consciousness and respiratory rate. After discharge from the PACU, oral acetaminophen was continued, with oral opioids only for breakthrough pain. In all cases, arterial lines were discontinued prior to PACU discharge.

Preliminary data showed no significant differences in rate of complications, hospital length of stay and 30-day mortality, with no deaths during that period, when compared with noncardiac bariatric patients undergoing sleeve gastrectomy. Average length of stay was just over one day.

After significant weight loss occurred—with a goal of a body mass index (BMI) of less than 35 kg/m2—patients were scheduled for aortic valve replacement. Approximately 25% of the 19 patients described have undergone successful cardiac intervention, and a small percentage are in a “watch and wait” stage as their cardiac symptoms and echocardiogram findings have improved after the weight loss.

Although moderate- to high-risk noncardiac surgery prior to definitive aortic valve replacement for patients with severe AS goes against traditional practice, our early data show that with a multispecialty approach, sleeve gastrectomy in the morbidly obese AS patient can be performed without increases in complications or mortality, when compared with a noncardiac control population.

Answine reported being a paid speaker for Merck and sugammadex. Mills and Dimarco reported no relevant financial disclosures.

References

1. Nishimura RA, Otto CM, Bonow RO, et al. American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63(22):e57-e185.
2. Hales CM, Fryar CD, Carroll MD, et al. Trends in obesity and severe obesity prevalence in US youth and adults by sex and age, 2007-2008 to 2015-2016. JAMA. 2018;319(16):1723-1725.
3. Ward ZJ, Bleich SN, Cradock AL, et al. Projected U.S. state-level prevalence of adult obesity and severe obesity. N Engl J Med. 2019;381(25):2440-2450.
4. Hawkins RB, Go K, Raymond SL, et al. Laparoscopic sleeve gastrectomy in patients with heart failure and left ventricular assist devices as a bridge to transplant. Surg Obes Relat Dis. 2018;14(9):1269-1273.