Aortic Stent-Grafting With Transrenal Fixation: Use of Newly Designed Spiral Z-Stent Endograft

Comparative analysis of renal function after treatment of infrarenal abdominal aortic aneurysms with a suprarenal fixation device as opposed to open surgery

We analyzed the repercussions on renal function between suprarenal endograft fixation and open surgery in the treatment of infrarenal abdominal aortic aneurysms (IAAAs) and determined the influential factors. Between 1999 and 2005, 59 IAAAs were treated with elective OS and 56 with SEF. The serum creatinine (Cr) level and its clearance were determined before the procedure, in the intensive care unit (ICU), on discharge, and after 1, 6, 12, and 24 months. A deterioration in renal function was considered to be a >30% increase in Cr or a Cr >2 mg/dL. A univariate statistical analysis and a logistical regression analysis were carried out to determine the predictive factors for repercussions on renal function. There were no statistically significant differences in the rate of renal exacerbation between the groups either on discharge (p = 0.52) or after 1 month (p = 0.483), 6 months (p = 0.451), 12 months (p = 0.457), and 24 months (p = 0.682). The only significant difference was that detected in the ICU (p = 0.033). Diabetes mellitus, time spent in the ICU, postoperative intubation time, intraoperative transfusion, and transfusion in the ICU were factors that influenced the deterioration of renal function in the univariate analysis. The only significant factor in the multivariate analysis was the need for transfusion in the ICU. Exacerbation of renal function occurred in both groups independently of treatment type. In the immediate postoperative period, hemodynamic deterioration is more frequent in the open surgery group. Renal exacerbation tended to disappear in both groups during follow-up.

Transrenal Fixation of Aortic Stent-Grafts: Short- to Midterm Effects on Renal Function—A Systematic Review

PURPOSE

To perform a systematic review of the short- to midterm effects of transrenal fixation of aortic stent-grafts on renal function in patients with abdominal aortic aneurysms.

MATERIALS AND METHODS

A search of the PubMed, MEDLINE, and EMBASE databases for English-language literature was performed. Studies with at least 10 patients were included for data analysis. Only studies on transrenal fixation of aortic stent-grafts that included follow-up results for renal function were included. A log-linear model was used for meta-analysis to compare transrenal fixation with infrarenal fixation.

RESULTS

Twenty-two studies met the inclusion criteria. Because two studies analyzed the same group of patients, one was excluded, for a total of 21 studies. Comparisons between transrenal fixation and infrarenal fixation were found in seven studies. For transrenal versus infrarenal fixation, the combined odds ratio, 95% confidence interval, and P value were found to be statistically significant with respect to postprocedural renal infarction only (combined odds ratio, 5.189; 95% confidence interval: 3.198, 8.420; P < .001). No significant difference was found between transrenal and infrarenal fixation with respect to renal dysfunction, renal artery occlusion, or endoleaks (P > .05).

CONCLUSION

Transrenal fixation of aortic stent-grafts seems to be a relatively safe alternative compared with infrarenal fixation in terms of short- to midterm follow-up. Postprocedural renal infarction, however, was significantly higher for transrenal fixation.

Initial results of endovascular repair of abdominal aortic aneurysms with a self-expanding stent-graft

PURPOSE

This study was performed to evaluate the authors' experience with the endovascular treatment of abdominal aortic aneurysm (AAA) with use of a self-expanding nitinol stent covered with a polyester fabric device and to report the implant's technical features, the immediate results, and the outcome 30 days after device implantation.

MATERIALS AND METHODS

From June 1997 to December 2001, we admitted 169 patients diagnosed with AAA. Of these, 134 were suitable to undergo endovascular repair with use of the Talent stent-graft. In one patient, it was technically impossible to proceed with the implantation procedure. Therefore, a total of 133 patients were treated with use of this technique (78.7%). The average age was 70.7 years (range, 52-88 y). There were 119 men and 14 women. Computed tomographic follow-up was done between the 15th and 30th postoperative days.

RESULTS

The stent-grafts were successfully implanted in all 133 patients. Complications during the procedure included three type-I endoleaks (2.3%) and four iliac artery ruptures (3.0%), which were effectively treated by means of aortic or iliac extension grafts, respectively. The average surgical time was 2.92 hours (from 1.67 h to 7 h). Of the stent-grafts used, 125 were bifurcated (94.0%), two were straight tube grafts (1.5%), and six were conical aortouniiliac grafts (4.5%). Custom-made grafts were used in 62 patients (46.6%) and standard grafts were used in 71 (53.4%). Suprarenal fixation was performed in 117 patients (88%). One female patient developed a serious pulmonary embolism. Eight patients (6.0%) developed serious systemic inflammatory syndrome; two died of disseminated intravascular coagulopathy. There were two additional deaths, one from refractory shock and one suddenly from an unknown cause (total mortality rate, 3.0%). During the postoperative period, 70.3% of the patients developed mild fever (37.6 degrees C-38.9 degrees C). The average length of stay in the intensive care unit was 1.3 days (ranging from 1 d to 12 d) and the total hospitalization time was 4.2 days. Six type-II endoleaks were observed: two were corrected by video laparoscopy-assisted inferior mesenteric artery interruption and the other four were clinically followed up.

CONCLUSIONS

The exclusion of AAA by endovascular techniques with use of the Talent device was possible in the majority of cases with a low incidence of complications. The most common serious postprocedural complication was systemic inflammatory syndrome.

Transrenal versus infrarenal endograft fixation: influence on type I endoleaks

The purpose of this study was to compare the rate of proximal type I endoleaks in patients undergoing endoluminal repair of infrarenal abdominal aortic aneurysms with endografts having either transrenal or infrarenal fixation. From September 1998 to May 2000, 42 patients received endoluminal aortic grafts for the treatment of infrarenal abdominal aortic aneurysms. Patients received either transrenal or infrarenal devices, based on the surgeon's preference. All patients had infrarenal aortic neck lengths measuring at least 1.5 cm and proximal neck angulation of <60 degrees. The endoluminal grafts were oversized by 10-20% relative to the diameter of the infrarenal aorta. The presence of endoleaks was determined at the initial procedure by contrast angiography and during subsequent follow-up at 1 month and 3 months by CT scan or duplex ultrasound. No significant differences in the rate of proximal type I endoleaks can be demonstrated between transrenal and infrarenal device types in this small cohort. Proper patient selection is more important than type of proximal fixation in preventing endoleaks.