Hemodynamic depression after carotid surgery: Incidence, risk factors and outcomes

Abstract Introduction: Hemodynamic Depression (HD) characterized by hypotension and bradycardia is a complication of carotid surgery due to direct autonomic stimulation in the carotid sinus. The authors believe the incidence of HD is high and possibly related to major cardiac complications. Methods: Analysis of patient records during admissions for carotid surgery between January 2014 and December 2018 in two hospitals. HD was defined as bradycardia or hypotension in the first 24 postoperative hours. Bradycardia was defined as heart rate < 50bpm; hypotension as systolic blood pressure < 90 mmHg, continuous use of vasopressors, or a drop in SBP > 20% compared to preoperative values. Myocardial infarction, stroke, and cardiovascular death were defined as adverse events. Results: Overall, 237 carotid surgeries (178 endarterectomies, 59 angioplasties) were studied, and the global incidence of HD was 54.4% (hypotension in 50.2%, bradycardia in 11.0%, and hypotension and bradycardia in 6.8%). The independent predictors of HD were asymptomatic carotid stenosis (OR = 1.824; 95% CI 1.014 −3.280; p = 0.045), endovascular surgery (OR = 3.319; 95% CI 1.675−6.576; p = 0.001) and intraoperative hypotension or bradycardia (OR = 2.144; 95% CI 1.222−3.762; p = 0.008). Hypotension requiring continuous vasopressor infusion was the only factor independently associated with adverse cardiovascular events (OR = 5.504; 95% CI 1.729-17.529; p = 0.004). Discussion/conclusion: Incidence of Hemodynamic Depression after carotid surgery is high and independently associated with surgical technique, symptomatic repercussion of the carotid stenosis, and intraoperative hypotension or bradycardia. Hypotension requiring the continuous infusion of vasopressors was independently associated with the occurrence of MACE.

Experimental implantation of an arterial substitute made of silicone reinforced with polyester fabric in rabbits

OBJECTIVES: The aim of this study was to analyze silicone tubes with an internal diameter of 4 mm as a possible material for vascular prostheses. METHODS: Grafts were implanted into the infrarenal aortas of 33 rabbits. Fluoroscopic examinations were performed within 150 days after surgical implantation. Sample grafts were analyzed via electron microscopy to evaluate the eventual endothelialization of the prostheses. RESULTS: The patency rates of the prostheses were 87% (±6.7%) after 30 days, 73% (±9.3%) after 60 days and 48% (±12%) after 120 days. The material presented characteristics that support surgical implantation: good tolerance promoted by polyester tear reinforcement, ease of postoperative removal and a lack of pseudoaneurysms. However, intimal hyperplasia was a limiting factor for the patency rate. CONCLUSIONS: We concluded that polydimethylsiloxane has limited potential as an alternative material for small vascular prostheses.

Developing a new endograft for the treatment of juxtarenal aortic aneurysms: definition and experimentation

OBJECTIVES: To analyze angiotomographic parameters of juxtarenal aneurysms to assess the applicability of an endograft model to patients and to create in vitro and in vivo models to assess the new endograft. METHODS: A total of 49 patients with juxtarenal aneurysms were submitted to angiotomographic evaluation, and parameters such as the aortic diameter, the length of the neck, and the angulations of the celiac trunk, superior mesenteric artery and renal arteries; the distances between them; and anatomic variations were analyzed. Based on these parameters, an endograft model was developed and tested in a newly created in vitro model of juxtarenal aneurysm. An experimental model of juxtarenal aneurysm was then established in six pigs weighing 50-60 kg to assess the new endograft model. RESULTS: The angiotomographic parameters of juxtarenal aneurysm measured in this study were similar to those reported in the literature and allowed the development of an endograft based on the hourglass concept, which was applicable to 85.8% of the patients. The in vitro model of juxtarenal aneurysm evidenced good radiopacity and functionality and permitted adjustments in the new device and technical improvements in the procedures for treating these aneurysms. In addition, the porcine model of juxtarenal aneurysm was successfully created in all six animals using a bovine pericardial patch, and use of the new endograft in three pilot procedures evidenced its feasibility. CONCLUSIONS: The Hourglass endograft was rendered applicable to treatment of the majority of patients with juxtarenal aneurysms simply by changing its diameter. Moreover, the new in vitro and in vivo models were shown to be effective for assessing both the presented endograft and experiments assessing the endovascular treatment of juxtarenal aneurysms. .

Autotransplante de rim em 12 casos de lesao da arteria renal / Kidney auto transplantation in 12 cases of renal artery lesion

O objetivo deste trabalho e analisar os resultados em 12 autotransplantes renais, cuja indicaçao cirurgica foi anomalia da arteria renal. O diagnostico foi arterite primaria da aorta em sete casos, displasia fibromuscular em tres e aterosclerose em dois casos. Os pacientes apresentavam hipertensao arterial incontrolavel. O autotransplante foi indicado por razoes bem definidas: fibrose periaortica, reoperaçoes, arterias renais multiplas, lesoes de ramos ou pacientes pediatricos. Em seis casos foi feito o autotransplante convencional, enquanto nos seis restantes empregou-se reconstruçao microcirurgica sob hipotermia prolongada. Nao houve obitos nem nefrectomia secundaria. Em dez casos a reconstruçao arterial foi bem-sucedida, em um foi incompleta e em 1 houve trombose. O autotransplante renal e tecnica alternativa muito util quando os procedimentos habituais nao podem ser empregados com segurança

Reabilitaçäo em doentes amputados por doença arterial periférica

Cinquenta e um pacientes com amputaçöes de membro inferior decorrentes de doença arterial periférica foram avaliados quanto a condiçöes e tempo de reabilitaçäo e acompanhados no seguimento tardio por um período médio de 24 meses. Trinta e três pacientes (64%) eram diabéticos. Sucesso imediato de reabilitaçäo foi considerado como a recuperaçäo da marcha bi-pedal com prótese. Quarenta e cinco pacientes (88%) atingiram esta condiçäo. O tempo médio de reabilitaçäo para amputados ao nível da perna foi de três meses e para amputados ao nível da coxa de cinco meses. No seguimento tardio a avaliaçäo foi feita quanto `a persistência no uso da prótese e grau de independência de vida. A mortalidade foi estudada pelo método atuarial. Todos os pacientes amputados na perna (100%) usavam a prótese para locomoçäo e tinham vida independente no último seguimento, enquanto 75% dos amputados em coxa estavam em uso da prótese e apenas 25% tinham vida totalmente independente. A mortalidade estudada pelo método atuarial foi analisada para pacientes diabéticos e näo diabéticos. Todas as mortes exceto uma ocorreram nos diabéticos, resultando neste grupo sobrevida cumulativa de 31% em 4 anos