دانلود رایگان مقاله انگلیسی بیماری قلبی کارسینوئید: یک بررسی - الزویر 2018

INTRODUCTION

Although progress in the medical and surgical management of patients with metastatic neuroendocrine tumors (NETs) has resulted in improved symptoms and survival, carcinoid heart disease (CHD) remains a major cause of morbidity and mortality among patients with carcinoid syndrome. CHD has been previously described in up to 50% of patients with carcinoid syndrome,1,2 although recent studies suggest the prevalence has fallen to approximately 20%,3,4 perhaps secondary to the more widespread use of somatostatin analog therapy. It is reported to occur most frequently in patients with primary small bowel NETs (72%), followed by NETs arising from the lung, large bowel, pancreas, appendix, and ovaries.1 A slight male predominance has been reported (approximately 60%), with a mean age at diagnosis 59 (
11) years.

Choice of Valve Prosthesis

The choice of valve prosthesis remains controversial, as the literature is limited to retrospective, non-randomized studies. Historically, mechanical valve prostheses were preferred for tricuspid valve replacement due to the risk of premature degeneration of bioprostheses secondary to persistent circulating vasoactive peptides.51 However, the literature has progressively supported the use of bioprostheses because of (1) the improved management of carcinoid syndrome, (2) the low rates of carcinoid involvement in recent pathologic series of explanted bioprostheses, (3) the favorable short-term outcomes, (4) the likelihood that the longevity of newer generation bioprosthetic valves will succeed the medium to long-term survival of the patient, (5) the inherent bleeding risk in patients with liver metastases and hepatic dysfunction, and (6) the likelihood of oncological surgery or chemotherapy in the future for which long-term anticoagulation may represent additional risk.46 Furthermore, the recent development of transcutaneous therapies could facilitate “valve-in-valve” replacement in patients with implanted bioprostheses. In the Mayo Clinic series,46 tricuspid valve replacement involved bioprostheses in 159 patients and mechanical valves in 36 patients. Of note, there was no significant difference in survival or reoperation rate in relation to type of prosthesis. Pathologic review of explanted bioprostheses demonstrated carcinoid involvement in only one explanted valve, with thrombus being the most frequent alternative cause of tricuspid bioprosthesis dysfunction. For this reason, vitamin K antagonist anticoagulation is recommended for 3 to 6 months after bioprostheses insertion, followed by serial echocardiography thereafter. Importantly, the reversal of bioprosthesis dysfunction has been reported with reinitiation of vitamin K antagonist anticoagulation.