Wenhui Huang

Safe Limits of Contrast Vary With Hydration Volume for Prevention of Contrast-Induced Nephropathy After Coronary Angiography Among Patients With a Relatively Low Risk of Contrast-Induced Nephropathy

Background—Few studies have investigated the safe limits of contrast to prevent contrast-induced nephropathy (CIN) based on hydration data. We aimed to investigate the relative safe maximum contrast volume adjusted for hydration volume in a population with a relatively low risk of CIN. Methods and Results—The ratios of contrast volume-to-creatinine clearance (V/CrCl) and hydration volume to body weight (HV/W) were determined in patients undergoing cardiac catheterization. Receiver–operator characteristic curve analysis based on the maximum Youden index was used to identify the optimal cutoff for V/CrCl in all patients and in HV/W subgroups. Eighty-six of 3273 (2.6%) patients with mean CrCl 71.89±27.02 mL/min developed CIN. Receiver–operator characteristic curve analysis indicated that a V/CrCl ratio of 2.44 was a fair discriminator for CIN in all patients (sensitivity, 73.3%; specificity, 70.4%). After adjustment for other confounders, V/CrCl >2.44 continued to be significantly associated with CIN (adjusted odds ratio, 4.12; P<0.001) and the risk of death (adjusted hazard ratio, 2.62; P<0.001). The mean HV/W was 12.18±7.40. We divided the patients into 2 groups (HV/W ⩽12 and >12 mL/kg). The best cutoff value for V/CrCl was 1.87 (sensitivity, 67.9%; specificity, 64.4%; adjusted odds ratio, 3.24; P=0.011) in the insufficient hydration subgroup (HV/W, ⩽12 mL/kg; CIN, 1.32%) and 2.93 (sensitivity, 69.0%; specificity, 65.0%; adjusted odds ratio, 3.04; P=0.004) in the sufficient hydration subgroup (HV/W, >12 mL/kg; CIN, 5.00%). Conclusions—The V/CrCl ratio adjusted for HV/W may be a more reliable predictor of CIN and even long-term outcomes after cardiac catheterization. We also found a higher best cutoff value for V/CrCl to predict CIN in patients with a relatively sufficient hydration status, which may be beneficial during decision-making about contrast dose limits in relatively low-risk patients with different hydration statuses.

Outcomes and Morphologic Changes of Immediate Type Ia Endoleak following Endovascular Repair of Acute Type B Aortic Dissection

BACKGROUND The clinical significance of immediate type Ia endoleaks after thoracic endovascular aortic repair (TEVAR) for aneurysms has been described in detail. However, this phenomenon is still controversial in TEVAR patients treated for acute type B aortic dissection. METHODS A single-institution study was conducted in 81 prospectively evaluated patients treated between January 2012 and June 2012 for acute type B aortic dissection. Preoperative and postoperative computed tomography angiography (CTA) images were analyzed using 3-dimensional reconstruction to measure the areas and indices of the true lumen, false lumen, and total aorta in the proximal, middle, and distal descending thoracic aorta. Data were analyzed and compared between the 2 groups of patients, with and without immediate type Ia endoleaks. RESULTS The average follow-up period was 12 months (range 10-13 months) after the procedure. TEVAR was successfully performed in all patients (mean age 53 years; 86% men). Thirty-six of the 81 patients were diagnosed with complicated type B dissection, including persistent pain (19/36, 52.7%), refractory hypertension (4/36, 11.1%), and end-organ ischemia (13/36, 36.1%). Of all the patients, 37 (45.7%) were diagnosed with immediate type Ia endoleaks. The differences between the 30-day and 1-year all-cause mortality rates between the 2 groups were nonsignificant (13.5% vs. 2.2%, P = 0.08; 16.2% vs. 4.5%, P = 0.13). No stroke or paraplegia occurred during the follow-up. Reintervention was performed in 2 patients for delayed type I endoleaks in the group without immediate type Ia endoleaks. Pre- and postoperative CTA images were available for analysis in 54 patients. Among them, 24 patients had type Ia endoleaks. Patients with immediate type Ia endoleaks had a significantly larger preoperative distal false lumen area (498 ± 274 vs. 284 ± 213 mm(2), P = 0.02) and a larger distal aortic area (759 ± 275 vs. 624 ± 185 mm(2), P = 0.03). The 1-year follow-up CTA demonstrated significantly smaller true lumen indices and larger false lumen areas and false lumen indices in the proximal, middle, and distal sections in patients with immediate type Ia endoleaks. Differences in the postoperative morphological changes of the whole descending thoracic aorta were significant between the 2 groups, with the maximum area and the proximal, middle, and distal regions involved. The occurrence of endoleaks and the rates of postoperative false lumen thrombosis throughout the length of stent grafts were not significant at 1-year follow-up. CONCLUSIONS The majority of immediate type Ia endoleaks following TEVAR in acute type B aortic dissections could seal spontaneously, without additional procedures needed. However, the appearance of such complications could be a risk factor of poorer aortic remodeling. Careful surveillance is recommended more frequently in patients with immediate type Ia endoleaks.

The Prevalence of Sleep Apnea in Type B Aortic Dissection: Implications for False Lumen Thrombosis

Introduction Obstructive sleep apnea (OSA) has been implicated in aortic dissection. Thrombosis of the false lumen is associated with a prognosis of type B aortic dissection (AoD), and partial thrombosis has been reported to be an independent predictor of mortality. This study sought to explore whether the severity of OSA is associated with false lumen thrombosis. Aims and Methods In this observational study, 151 type B AoD patients were recruited consecutively from 2013 to 2015. The status of the false lumen was classified as patent, partially thrombosed, or completely thrombosed based on a computer tomography angiography image. Patients were divided into non-OSA group (apnea-hypopnea index [AHI] < 5), and mild (5 ≤ AHI ≤ 15), moderate (15 < AHI ≤ 30), and severe OSA groups (AHI > 30) using the AHI. Results The prevalence of OSA in type B dissection was 66.2%. Among 151 cases, 51 patients (33.8%) were in the non-OSA group, 56 (37.1%) were in the mild group, 21 (13.9%) were in the moderate group, and 23 (15.2%) were in the severe group. Additionally, a partially thrombosed false lumen was observed in 88 patients (58.3%). Multivariable analysis revealed that OSA severity was positively associated with partial thrombosis (odds ratio, 1.784, 95% confidence interval: 1.182-2.691, P = .006) after adjusting for other confounding factors. Conclusions OSA was present in two-thirds of patients with type B AoD. The severity of OSA was significantly associated with an increased risk of partial false lumen thrombosis. OSA may therefore be implicated in both the etiology and prognosis of AoD.

Outcomes of Chimney Technique for Preservation of the Left Subclavian Artery in Type B Aortic Dissection

OBJECTIVE To report outcomes of the chimney technique for preservation of the left subclavian artery (LSA) in patients with type B aortic dissection (TBAD). METHODS A retrospective analysis was performed of a prospectively maintained database from August 2012 to October 2017. Primary endpoints were 30 day and overall mortality. Secondary endpoints were technical success, type Ia endoleak, chimney stent occlusion, aortic rupture, stroke, spinal cord ischaemia, and re-intervention rate. RESULTS A total of 159 patients (mean age 54 ± 11 years; 141 men) with TBAD were treated using the chimney technique for LSA revascularisation. Acute, subacute, and chronic TBAD accounted for 64%, 28%, and 8% of cases, respectively. One hundred and six cases (67%) were complicated TBAD. One hundred and fifty-six patients (98%) were treated electively, while three (2%) were treated urgently because of intestinal or lower extremity ischaemia. The 30 day mortality and morbidity rates were 2% (3/159) and 4% (7/159), respectively. The technical success rate was 81% (129/159) and immediate type Ia endoleak occurred in 30 (19%) patients. Three major strokes, two spinal cord ischaemia and one aortic rupture, occurred early on. During a mean follow up of 23 ± 16 months (range 1-65 months), three more patients died: from aortic rupture, cerebral haemorrhage, and rectal cancer, respectively. Chimney stent occlusions were observed in four patients and all these chimney stents were self expanding. During follow up, two major strokes, one late type Ia endoleak and one re-intervention, occurred. According to the Kaplan-Meier curve, the estimated one and three year survival rates were 98.1 ± 1.1% and 94.4 ± 2.4%, respectively. CONCLUSION Short and mid-term outcomes in the present study demonstrate that the chimney technique is safe and feasible for preservation of the LSA in patients with TBAD, but the durability of chimney stent needs to be evaluated carefully and immediate type Ia endoleak is a concern.

Risk factors and early outcomes of acute renal injury after thoracic aortic endograft repair for type B aortic dissection

Background Thoracic endovascular aortic repair (TEVAR) has become an emerging treatment modality for acute type B aortic dissection (TBAD) patients in recent years. The risk factors and impacts of acute kidney injury (AKI) after percutaneous TEVAR, however, have not been widely established. Methods We retrospectively studied the clinical records of 305 consecutive patients who admitted to our institution and had TEVAR for TBAD between December 2009 and June 2013. The patients were routinely monitored for their renal functions preoperatively until 7 days after TEVAR. The Kidney Disease Improving Global Guidelines (KDIGO) criteria were used for AKI. Results Of the total 305 consecutive patients, 84 (27.5%) developed AKI after TEVAR, comprising 66 (21.6%) patients in KDIGO stage 1, 6 (2.0%) patients in stage 2 and 12 (3.9%) patients in stage 3. From the logistic regression analysis, systolic blood pressure (SBP) on admission >140 mmHg (odds ratio [OR], 2.288; 95% CI, 1.319–3.969) and supra-aortic branches graft bypass hybrid surgery (OR, 3.228; 95% CI, 1.526–6.831) were independent risk factors for AKI after TEVAR. Local anesthesia tended to be a protective factor (OR, 0.563; 95% CI, 0.316–1.001). The preoperative renal function, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or statin administration, volume of contrast agent, range of TBAD and false lumen involving renal artery were not associated with post-operation AKI. The in-hospital mortality and major adverse events were markedly increased with the occurrence of AKI (7.1% vs 0.9%, P=0.006; 14.3% vs 3.2%, P<0.001, respectively). Conclusions TEVAR for TBAD has a high incidence of AKI, which is associated with worse in-hospital outcomes. SBP on admission and supra-aortic branches graft bypass hybrid surgery were the most significant risk factors. Renopreventive measures should be considered in high-risk patients.