The Role of Immunosuppressive Therapy in Aneurysmal Degeneration of Hemodialysis Fistulas in Renal Transplant Patients.

BACKGROUND: Venous aneurysms are long-term complications of arteriovenous fistula (AVF) for hemodialysis with an estimated incidence rate of around 5-6%. The purpose of our study is to investigate the role of immunosuppressive therapy in the development of AVF aneurysms in renal transplant patients, and to determine whether AVF closure following transplantation is necessary. METHODS: Forty-six patients with symptomatic venous AVF aneurysms underwent ligation and resection of their fistulas between January 2013 and January 2020. Immunohistochemical expression of CD3, CD4, and CD8 was assessed on the surgical specimens to characterize lymphocytic infiltrate in the aneurysm wall. Patients were subdivided into "Group A"-kidney transplant patients undergoing immunosuppressive therapy which was comprised of 39 patients and "Group B"-patients who had not undergone kidney transplant which was comprised of 7 patients. The 2 groups did not significantly differ in age, sex nor risk factors for aneurysms. RESULTS: Group A showed a significantly higher aneurysm diameter (P < 0.0001), mean flow (P < 0.0001) and required a longer duration of surgery (P = 0.0007). A CD3+ lymphocytic infiltrate was significantly more common in Group A than in the Group B (90% vs 29%; P < 0.001). No significant differences in localization (adventitia, media or intima) and type (CD4+ vs CD8+) of lymphocytes were found between the 2 groups. CONCLUSION: AVF venous aneurysms were significantly larger and with a more intense T-lymphocytic infiltrate in patients undergoing immunosuppressive therapy. This finding suggests that immunosuppressive therapy plays a role in aneurysm formation, supporting the need for AVF closure in patients with an estimated low risk of rejection.

Simultaneous endovascular treatment of synchronous symptomatic acute type B aortic dissection and large infrarenal aortic aneurysm. Technical tips and case report.

INTRODUCTION: Data from the literature suggest that in patients with acute type B aortic dissection (ATBAD), associated with AAA, rupture risk is higher at the confluence tract than isolated lessions. Herein, we report a case of ATBAD and AAA managed with simultaneous intervention. CASE PRESENTATION: We report a complicated case of a symptomatic patient presenting with a type B aortic dissection and false lumen extension into superior mesenteric artery (SMA) with an infrarenal abdominal aortic aneurysm (AAA). Severe back pain and hypertension were the patient's initial complaints. This patient underwent endovascular repair with a thoracic and infrarenal aortic endograft. DISCUSSION: AAA rupture has been detected at admission in three-fourths of patients with ATBAD that extended to or involved a coexisting unoperated atherosclerotic aneurysms. Prompt surgical intervention is essential to deal with this dreadful aortic emergency. CONCLUSION: In our experience a totally endovascular solution to treat a complicated ATBAD plus AAA was a rapid solution with low invasivity, no complication and complete healing of patients.

Case report of a large cephalic vein aneurysm inducing heart failure in a renal transplant patient with radio-cephalic fistula for haemodialysis.

INTRODUCTION: The autologous arteriovenous fistula (AVF) is considered the best vascular access for haemodialysis in patients with chronic kidney disease but in time can lead to several complications. PRESENTATION OF A CASE: Herein we describe a case of a large cephalic vein aneurysm causing heart failure in a renal transplant patient being treated with radio-cephalic AVF for haemodialysis. The patient was judged to be at very high risk for potential catastrophic rupture of the aneurysm and his cardiac function was deteriorating so a surgical resection was offered. Under general anesthesia, a longitudinal incision was performed on the volar side of the forearm and the anastomotic junction was ligated. The cephalic vein aneurysm was isolated and a total resection of the vein, up to the joint of the elbow, was carried out. A specimen was also submitted for histological and immunohistochemical analysis. DISCUSSION: At present no clear indications pertaining to the need to close an AVF after kidney transplantation exist. Some authors recommend a closing of the fistula in patients with stable renal function to prevent the onset of complications, while others advise never to close the asymptomatic fistula in order to preserve vascular access for haemodialysis in case of graft failure. CONCLUSION: Based on our clinical experience, we suggest not ligating vascular access during the first year following transplantation with the exception of patients needing emergent closure. Otherwise, surgical closure to prevent the onset of complications could be considered a viable option in the following subset of patients: those who are 3 or more years from transplantation with good and stable renal function, those with a significant growth of venous aneurysms or have a high AVF flow rate or are young patients.