Effect of obesity on radiation exposure, quality of life scores, and outcomes of fenestrated-branched endovascular aortic repair of pararenal and thoracoabdominal aortic aneurysms

BACKGROUND

The aim of the present study was to assess the effect of obesity on procedural metrics, radiation exposure, quality of life (QOL), and clinical outcomes of fenestrated-branched endovascular aortic repair (FB-EVAR) of pararenal and thoracoabdominal aortic aneurysms.

METHODS

We reviewed the clinical data from 334 patients (236 men; mean age, 75 ± 8 years) enrolled in a prospective nonrandomized study to evaluate FB-EVAR from 2013 to 2019. The patients were classified using the body mass index (BMI) as obese (BMI ≥30 kg/m²) or nonobese (BMI <30 kg/m²). QOL questionnaires (short-form 36-item questionnaire) and imaging studies were obtained preoperatively and at 2 months and 6 months postoperatively, and annually thereafter. The procedures were performed using two different fixed imaging systems. The end points included procedural metrics (ie, total operative time, fluoroscopic time, contrast volume), radiation exposure, technical success, 30-day mortality, and major adverse events, QOL changes, freedom from target vessel instability, freedom from reintervention, and patient survival.

RESULTS

The aneurysm extent was a pararenal aortic aneurysm in 117 patients (35%) and a thoracoabdominal aortic aneurysm in 217 patients (65%). Both groups had similar demographics, cardiovascular risk factors, and aneurysm extent, except for a greater incidence of hyperlipidemia and diabetes among the obese patients (P < .05). No significant differences were found in the procedural metrics or intraprocedural complications between the groups, except that the obese patients had greater radiation exposure than the nonobese patients (mean, 2.5 vs 1.6 Gy; P < .001), with the highest radiation exposure in those obese patients who had undergone the procedure using system 1 (fusion alone) instead of system 2 (fusion and digital zoom; mean, 4.1 vs 1.5 Gy; P < .001). Three patients had died within 30 days (0.8%), with no difference in mortality or major adverse events between the groups. The mental QOL scores had improved in the obese group at 2 and 12 months compared with the nonobese patients, with persistently higher scores up to 3 years. At 3 years, the obese and nonobese patients had a similar incidence of freedom from target vessel instability (74% ± 6% vs 80% ± 3%; P = .99, log-rank test), freedom from reintervention (66% ± 6% vs 73% ± 4%; P = .77, log-rank test), and patient survival (83% ± 5% vs 75% ± 4%; P = .16, log-rank test).

CONCLUSIONS

FB-EVAR was performed with high technical success and low mortality and morbidity, with no significant differences between the obese and nonobese patients. The procedural metrics and outcomes were similar, with the exception of greater radiation exposure among obese patients, especially for the procedures performed using system 1 with fusion alone compared with system 2 (fusion and digital zoom). Obese patients had higher QOL mental scores at 2 and 12 months, with a similar reintervention rate, target vessel outcomes, and survival compared with nonobese patients.

Digital zoom is a useful, simple, and cost-effective method of reducing radiation exposure in percutaneous coronary intervention

Reducing radiation exposure is a very important issue in interventional cardiology techniques such as percutaneous coronary intervention. Although novel techniques to reduce radiation exposure are valuable, we should also reconsider older techniques. Digital zoom has been available in Japan from 2005. Digital zoom enlarges an 8-inch field of view (FOV) by 1.2 times, allowing visualization of a 6.7-inch FOV without FOV switching. We identified 2101 suitable cases of percutaneous intervention (PCI) and divided them into two groups according to the use of digital zoom; 1195 patients were included in the digital zoom group and 906 patients in the conventional group. We collected data regarding the reference air kerma (RAK) and dose-area product (DAP). We calculated RAK and DAP per minute fluoroscope time (RAK/min, DAP/min, respectively). There were intergroup differences in RAK, DAP, RAK/min, and DAP/min (digital zoom group vs conventional group; RAK, 1590 mGy [990-2410] vs 1850 [1220-2720], p < 0.01, RAK/min; 54.7 mGy/min [38.5-73.2] vs 71.2 [51.5-93.0], p < 0.01; DAP, 16,000 cGy × cm² [10,300-24,400] vs 20,700 [13,400-29,500], p < 0.001; DAP/min, 557 cGy × cm²/min [392-737] vs 782 [571-1010], p < 0.01, respectively). Because of baseline differences between the two groups, we performed propensity score matching. Even after score matching, there were intergroup differences in DAP, DAP/min, RAK, and RAK/min. Furthermore, the least squares method showed that digital zoom is a significant predictor of RAK (β = 0.14, p < 0.01) and DAP (β = 0.20, p < 0.01). Digital zoom is an older cost-effective technique that can significantly reduce radiation exposure in PCI.