Pre- and perioperative considerations
Indications for valve surgery in CaHD patients are outlined in guidelines (11Davar J, Connolly HM, Caplin ME et al. Diagnosing and Managing Carcinoid Heart Disease in Patients With Neuroendocrine Tumors: An Expert Statement. J Am Coll Cardiol. 2017;69(10):1288-1304.) and include progressive right heart failure with echocardiographical findings of moderate to severe insufficiency of the right-sided valves. The TV is always involved in surgical candidates and is usually severely regurgitant, while the PV is often affected, showing a combination of stenosis and regurgitation. The decision for valve replacement should be based on a multidisciplinary evaluation of general operability in relation to oncological status and cardiac function. Timing of surgery with preoperative optimization of nutritional status and somatostatin analog treatment for carcinoid hormonal activity is essential. Studies indicate that earlier intervention rather than late improves outcomes (7). Valve surgery always involves tricuspid valve replacement (TVR) and most often pulmonary valve replacement (PVR). In our experience, the PV pathology is often underestimated on echocardiography, and a larger regurgitation may be unmasked by a higher forward flow after TVR, if leaving the PV untreated. Also, an uncorrected significant pulmonary regurgitation after TVR may lead to progressive right heart dilatation and poorer results (22Connolly HM, Schaff HV, Mullany CJ et al. Carcinoid heart disease: impact of pulmonary valve replacement in right ventricular function and remodeling. Circulation. 2002;106(12 Suppl 1):I51-I56.). Thus, a low threshold is recommended for replacing the PV. The aortic or mitral valves may also be involved in 10-15% of cases with CaHD. A previous report has shown that surgery of the left-sided valves is not a factor for worse results and should be performed concomitantly with right-sided valve surgery if indicated (5).
A particular risk with CaHD patients is the occurrence of a carcinoid crisis during surgery. Anesthesia, surgery or drugs may trigger release of vasoactive hormones, causing potentially life-threatening circulatory instability with severe hypotension and flushing (33Castillo J, Silvay G, Weiner M. Anesthetic Management of Patients With Carcinoid Syndrome and Carcinoid Heart Disease: The Mount Sinai Algorithm. J Cardiothorac Vasc Anesth. 2018;32(2):1023-1031.). Routine therapy to counter this complication is infusion of short-acting octreotide, started prior to surgery (in some cases 24 hours), continued perioperatively and for several days postoperatively. Furthermore, intraoperative protection of right ventricular (RV) function is key. The RV is dilated in most surgical candidates, and surgery should be performed before significant RV dysfunction develops. CaHD patients are at increased risk of bleeding during surgery, due to their oncological status, severe preoperative venous stasis and reduced liver function. Increased attention to bleeding control is important, regarding surgical technique, use of autologous blood recovery systems and optimization of postoperative coagulation using point-of-care techniques.