A simulator for training in endovascular aneurysm repair: The use of three dimensional printers.

OBJECTIVES: To develop an endovascular aneurysm repair (EVAR) simulation system using three dimensional (3D) printed aneurysms, and to evaluate the impact of patient specific training prior to EVAR on the surgical performance of vascular surgery residents in a university hospital in Brazil. METHODS: This was a prospective, controlled, single centre study. During 2015, the aneurysms of patients undergoing elective EVAR at São Paulo University Medical School were 3D printed and used in training sessions with vascular surgery residents. The 3D printers Stratasys-Connex 350, Formlabs-Form1+, and Makerbot were tested. Ten residents were enrolled in the control group (five residents and 30 patients in 2014) or the training group (five residents and 25 patients in 2015). The control group performed the surgery under the supervision of a senior vascular surgeon (routine procedure, without simulator training). The training group practised the surgery in a patient specific simulator prior to the routine procedure. Objective parameters were analysed, and a subjective questionnaire addressing training utility and realism was answered. RESULTS: Patient specific training reduced fluoroscopy time by 30% (mean 48 min, 95% confidence interval [CI] 40-58 vs. 33 min, 95% CI 26-42 [p < .01]), total procedure time by 29% (mean 292 min [95% CI 235-336] vs. 207 [95% CI 173-247]; p < .01), and volume of contrast used by 25% (mean 87 mL [95% CI 73-103] vs. 65 mL [95% CI 52-81]; p = .02). The residents considered the training useful and realistic, and reported that it increased their self confidence. The 3D printers Form1+ (using flexible resin) and Makerbot (using silicone) provided the best performance based on simulator quality and cost. CONCLUSION: An EVAR simulation system using 3D printed aneurysms was feasible. The best results were obtained with the 3D printers Form1+ (using flexible resin) and Makerbot (using silicone). Patient specific training prior to EVAR at a university hospital in Brazil improved residents' surgical performance (based on fluoroscopy time, surgery time, and volume of contrast used) and increased their self confidence.

Limb salvage using bypass to the perigeniculate arteries.

OBJECTIVE: To describe bypass to perigeniculate vessels for limb salvage. DESIGN: Retrospective cohort study. MATERIAL AND METHODS: Between 1995 and 2009, 47 bypass procedures to perigeniculate collateral arteries were performed in 46 patients (15 women, 31 men; median age, 68 years). All patients presented with critical ischaemia (tissue loss in 87.5%, rest pain in 12.5%). Mean ankle brachial index was 0.27 ± 0.17. The site of distal anastomosis was the descending genicular artery (DGA) in 23 bypasses (1 bilateral) and the medial sural artery (MSA) in 24. Proximal anastomosis was to the external iliac artery in 2 cases, common femoral artery in 23 cases, superficial femoral artery in 8 cases, deep femoral artery in 8 cases, above-knee poplitaeal artery in 2 cases, and previous graft in 4 cases. RESULTS: There were four deaths during the immediate postoperative period. Mean follow-up duration was 27 months. Ten patients required major amputation. Mean ankle brachial index post-operatively was 0.60 ± 0.21. At 3 years, primary patency was 74.7 ± 7%, secondary patency was 83.4 ± 8%, and the limb salvage and survival rates were 73.5 ± 7% and 77.4 ± 7%, respectively. CONCLUSION: Bypass to perigeniculate arteries is a viable treatment option for critical limb ischaemia in selected patients.

Aortorenal arterial autografts: long-term assessment.

Ninety-four iliac arterial autografts were placed in 86 hypertensive patients (age range, 7 to 57 years) during a 16-year period for renal artery reconstruction of nonatherosclerotic lesions. Ten patients were children, and nine patients had a solitary kidney. Ex vivo repair was used in 21 patients. There were no early postoperative deaths; one patient died three months postoperatively of unrelated disease. Two grafts occluded in the early postoperative period. Follow-up of one to 16 years (mean, 5.6 years) was available in 77 patients (93%). Forty-one patients underwent late arteriography at an average of 5.7 years postoperatively. Fifty-one patients (66%) were regarded as cured of their hypertension, the conditions of 25 patients (32%) improved, and the condition of one patient (1.2%) was unchanged. There were no late autograft occlusions. Atherosclerotic anastomotic stenosis developed in one autograft 13 years postoperatively and was relieved by reoperation. Dilation of one autograft was observed seven years postoperatively but did not increase on subsequent arteriograms. In five children, follow-up angiograms showed that the size of the autograft paralleled that of the contralateral renal artery. These results support the preferential use of an autograft during reconstruction of nonatherosclerotic lesions that cause renovascular hypertension.

Reducing cross-clamping duration in aortoiliac reconstruction after renal transplantation. A case report.

A fifty-two-year-old male renal transplant patient underwent aortoiliac reconstruction with a bifurcated prosthesis for treatment of hypertension and deteriorating allograft function. A modified technique was used that reduced aortic cross-clamping time to twelve minutes. This simple technique is applicable to most patients, reduces warm ischemia to a minimum, and saves time for a careful aortoiliac reconstruction.

Origin of intestinal lymph cholesterol in rats: contribution from luminal absorption, mucosal synthesis and filtration from plasma.

Measurement of cholesterol transport from plasma to intestinal lymph based on i.v. labeling with radioactive beta-sitosterol was validated by the simultaneous i.v. administration of 4-14C-beta-sitosterol and of 1,2-3H-cholesterol to two rats with bile duct, intestinal lymph, duodenum and jugular vein cannulations. In 11 other rats undergoing intestinal lymph duct cannulation, each potential source of lymph cholesterol was determined 2-3 weeks after i.v. pulse administration of 1,2-3H-beta-sitosterol and 4-14C-cholesterol. For this purpose, lymph fat, after an intragastric infusion of cottonseed oil (1900mg), was used as a marker for total cholesterol mass transported into intestinal lymph. In these two experimental groups of rats, namely, in the absence and in the presence of supplemental dietary cholesterol, filtration of cholesterol from plasma to lymph and absorption of cholesterol derived from bile did not change in the presence of exogenous cholesterol. In other words, absorption of cholesterol based on the amount of cholesterol in intestinal lymph by direct measurement was comparable to the level obtained by the isotopic procedure based upon lowering of the lymph/plasma ratio of 4-14C-cholesterol specific activity (d.p.m./mg of cholesterol). Plasma cholesterol appearing in intestinal lymph was transported mainly in lymph lipoproteins at a density below 1.006 (i.e., chylomicrons). Esterification was not necessary for luminal cholesterol absorption under these experimental conditions.

Fitting of electronic elbow on an elbow disarticulated patient by means of a new surgical technique.

Rehabilitation of trans-humeral amputees represents a challenge. One of the difficulties to overcome is prosthetic suspension. In the case of elbow disarticulation the presence of humeral condyles permits better suspension, but there is no room for elbow joints, particularly electronic ones, and the only available mechanisms are provided by external hinges. The purpose of this report is to present a case of a primarily elbow disarticulated patient, with indication for surgical revision due to bad skin coverage, neuroma and the wish to improve prosthetic fitting. The surgical plan outlined was to produce a shortening of the humerus, by means of an osteotomy just above the humeral condyles, preserving them for prosthetic suspension. This bone reduction was carried out with complementary shaping of bone segments with an indentation to enhance fixation. The operation was completed with neuroma resection, myodesis and removal of the skin grafted area. Preservation of the humeral condyles actually produced effective suspension. For final fitting a Utah Arm II was used, with wrist rotator, and interchangeable hand and Greifer for terminal devices. Good initial results and at nine months follow-up suggest this procedure should be considered in other elective situations.

Rehabilitation after amputation for vascular disease: a follow-up study.

Rehabilitation of one hundred and twenty eight patients with lower limb amputation performed for vascular disease from 1979 to 1987 was assessed. Arteriosclerotic occlusive disease was the most frequent cause of amputation (85.9%). Sixty seven patients (52.3%) were diabetic. Early and late results were analysed. For long-term follow-up evaluation, Univariate method of Kaplan-Meyer product limit was employed. Multifactorial analysis was used to assess factors influencing mortality. On immediate evaluation of rehabilitation with a prosthesis 85.2% of patients were successfully fitted. On long term evaluation 47.8% of below-knee and 22.1% of above-knee amputees were alive and using the prosthesis full time at five years of follow-up (p = 0.0026). Opposite limb preservation at five years was 69.5% for diabetics and 90.2% for non-diabetics, respectively (p = 0.0013). Survival rate at five years was 42.4% for diabetics, and 85.0% for non-diabetics (p = 0.0002). On multifactorial analysis diabetic patients showed a risk of late mortality six times greater than non-diabetics. In conclusion rehabilitation after vascular amputation is feasible in a large number of patients, despite a limited life span. Diabetes represents a major risk factor both for life and for the opposite limb. Knee preservation is an important factor for better rehabilitation.

Assessment of quality of life of patients with severe ischemia as a result of infrainguinal arterial occlusive disease.

The purpose of this cohort study was to assess the quality of life of patients with severe ischemia as a result of infrainguinal arterial occlusive disease. Spitzer's QL-INDEX was selected to measure quality of life at baseline and at 3, 6, and 12 months. On the basis of initial treatment, 61 patients were grouped as follows: IC (conservative, n = 31), IR (arterial reconstruction, n = 14), and IA (major amputation, n = 16). After 12 months of follow-up, 48 patients were similarly regrouped according to ultimate treatment as follows: UC (n = 19), UR (n = 9), and UA (n = 20). At 12 months the mean score was significantly higher than the baseline in IC (6.43 vs 3.84, p less than 0.0001) as well as IR (5.64 vs 3.57, p less than 0.01), but not in IA (4.43 vs 3.62). The QL-INDEX mean score was lower in UA than in UC (4.15 vs 6.58, p less than 0.01) or UR (4.15 vs 7.11, p less than 0.0001). The correlation between QL-INDEX and an arbitrary scale was also high (r = 0.726, p less than 0.001). In conclusion, quality of life of patients with limb ischemia can be confidently assessed, improves during the first year of follow-up if major amputation is avoided, and improves and is sustained by a functioning graft.

Walking ability and quality of life as outcome measures in a comparison of arterial reconstruction and leg amputation for the treatment of vascular disease.

OBJECTIVES: To compare the walking ability and the quality of life of patients with severe limb ischaemia treated with an arterial reconstruction (AR) or a primary below-knee amputation (BKA). DESIGN: A cohort study of patients with the first episode of ischaemia. SETTING: University tertiary referral centre. PATIENTS: Thirty-eight (AR 22, BKA 16) patients were studied over a 12-month period with a complete follow-up. CHIEF OUTCOME MEASURES: Walking ability was assessed with a subjective scale and quality of life was measured with the Spitzer QL-INDEX. The results were assessed for patients still alive (Step 1) as well as for all patients (Step 2). RESULTS: Walking ability was better in the AR group at 3 (OR = 10.37; CI 2.12; 50.74; p = 0.004), 6 (OR = 6.47; CI 1.83, 22.79; p = 0.004), and 12 (OR = 3.82; CI 1.20, 12.15; p = (0.03) months. Quality of life was significantly better for AR patients at 3 (OR = 4.32; CI 1.55, 12.02; p = 0.005) and 6 (OR = 4.40; CI 1.68, 11.53; p = (0.003) months, but not at 12 months (OR = 2.44; CI 0.95, 6.26; p = 0.06). the 12 month foot salvage rate was 68%. CONCLUSION: Walking ability and quality of life are better for AR patients than for BKA patients, even with a moderate food salvage rate.

Outcome and quality of life of patients with severe chronic limb ischaemia: a cohort study on the influence of diabetes.

OBJECTIVE: To determine the influence of diabetes on the use of arterial reconstruction, the rate of amputation and death, and the quality of life of patients with severe limb ischaemia. DESIGN: A prospective study of patients with the first episode of ischaemia. SETTING: University tertiary referral centre. METHODS: Thirty-seven patients with diabetes and 50 without diabetes, were studied over a 12 month period with complete follow-up. MAIN OUTCOME MEASURES: The proportion of patients undergoing an arterial reconstruction, amputation rate, death rate, and quality-of-life scores. RESULTS: Patients with diabetes underwent an arterial reconstruction less often than patients without diabetes (7/37 vs. 18/50). The odds of patients with diabetes having a higher incidence of adverse outcome was 1666:1 for minor amputation, 26:1 for major amputation, and 4.7:1 for death. There was a tendency towards a lower quality of life for patients with diabetes at 3 (OR 1.94, p = 0.036), 6 (OR 1.58, p = 0.117), and 12 (OR 1.47, p = 0.185) months. CONCLUSIONS: In patients with diabetes, (1) the opportunity of undergoing an arterial reconstruction is lower, (2) morbidity and mortality are higher, and (3) the quality of life tends to be worse.

Resultados tardios e complicaçöes específicas das derivaçöes aortofemorais / Long-term results and graft related complications after aortofemoral bypass grafting

O objetivo deste estudo foi avaliar os resultado tardios da derivaçào aortofemoral feita em casos de doença obstrutiva com seguimento de até 15 anos. De 1970 a 1991 foram feitas 274 derivaçöes aortoilíaco-femorais com prótese. O quadro clínico era de claudicaçäo intermitente em 51 por cento e de isquemia grave m 48 por cento. Os resultados foram avaliados com o uso de numerosas variáveis: funçäo primária (V1) e secundária (V2); isquemia terminal (V3); sobrevida (V4); ausência de morte vascular (V5)de aneurisma anastomótico (V6) ou de infecçào da prótese (V7). combinaçöes apropriadas de V1 a V5 resultaram em outras variáveis como V432 e V532, definidas pela ocorrência de V1 a V5 conforme o caso. Os resultados foram descritos pelo método de Kaplan-Meier. O benefício para o paciente foi estimado a cinco, dez, e 15 anos como sendo de 38 por cento, 27 por cento e 5 por cento, de acordo com V432 e ao nível de 51 por cento, 42 por cento e 11 por cento de acordo com V532. Nos mesmos intervalos de tempo, 6assumiou os valores de 95 por cento, 87 por cento e 59 por cento e V7 foi estimado em 94 por cento, 83 por cento e 83 por cento. Conclui-se que: 1) O benefício para os pacientes foi limitado. 2) As complicaçöes específicas das próteses näo foram raras. 3) A derivaçäo aortofemoral com prótese deve ser indicada de modo mais seletivo.