Endovascular Conversion of a Failed Nellix AAA-Repair by a Custom-Made Branched Device.

PURPOSE: This technical note presents a case of a patient with a failed Nellix device (Endologix, Irvine, Calif) who was not deemed fit for open conversion. Our planned approach for repair involved an endovascular procedure utilizing a custom-made branched device. TECHNIQUE: An endovascular repair was performed via a custom-made four outer branched device in conjunction with a custom-made bifurcated graft featuring inverted limbs (Cook Inc., Bloomington, Ind). All branches were connected to the target vessel with Gore Viabahn VBX balloon-expandable covered stents (Gore & Associates Inc.). CONCLUSION: Endovascular conversion with branched endovascular repair in a patient not deemed fit for open surgery was successfully performed, thereby reducing the risk of a high morbid and mortal procedure. CLINICAL IMPACT: Novel useful treatment solution of failed EVAR with Nellix device.

Early multicentric outcomes of the on-label and CE-marked combination of the Endurant with the Radiant chimney graft for the chimney endovascular aortic repair (EnChEVAR): The LaMuR Registry.

BACKGROUND: The aim of this study was to evaluate the early results of the CE-marked standardized device combination consisting of Endurant and the Radiant chimney graft (En-ChEVAR) for the treatment of juxtarenal aortic aneurysms. METHODS: We analyzed multicentric non-industry sponsored case series evaluating the EnChEVAR technique for patients treated between December 2022 and February 2024. Clinical, perioperative procedure-related and radiological data were collected. The primary outcome measure was the freedom of a type Ia gutter-related endoleak at postoperative computed tomography angiography (CTA). Secondary outcome measures included early type Ia endoleak-related reinterventions, target vessel complications including dissection or loss of target vessel, major adverse events, and mortality. Continuous variables were presented as median (interquartile range [IQR]) and categorical variables as count and percentage. RESULTS: Ten patients were included in the present study. Eight (80%) were males, in nine cases a single chimney was implanted, and the other one was a double chimney graft placement. The treated aneurysms had an infrarenal neck length of 3.4 (1.2) mm. The rate of main body oversizing was 30%. The new neck length after chimney graft placement was 18 (3) mm. The median procedural time was 130 (17) mm, contrast medium use was 109 (26) mL, radiation time was 45 (12) min. The technical success was 100%. No type Ia endoleak was detected at the postoperative CTA. There were no target vessel issues. No major adverse events or death were observed. CONCLUSIONS: First reported cohort of patients treated with EnChEVAR demonstrated reproducible clinical and procedural outcomes within the 3 vascular centers with total exclusion of the aneurysms, patent renal arteries, and no evidence of gutter-related type IA endoleak. Further evidence with larger sample size of treated patients and longer follow-up are needed.

One-year results of a balloon expandable endoprosthesis as a bridging stent for branched endovascular aortic repair.

OBJECTIVE: This post-market multicenter registry aimed to evaluate the safety and performance of the GORE VIABAHN VBX balloon expandable endoprosthesis (VBX stent) implanted in peripheral vessels. In this subgroup analysis, we assessed the outcomes of the VBX stent as a bridging stent graft for visceral vessels during branched endovascular aortic repair at 1 year. METHODS: A single cohort from a prospective, multicenter, observational, 16-site European registry. Patients were enrolled from November 2018 to March 2022. Endpoints included 1-year primary patency (PP), primary assisted patency (PAP), and secondary patency (SP), stent graft-related death and serious adverse events through 30 days. RESULTS: Seventy-three patients were enrolled in this registry sub-cohort, 57 (78.1%) were male, and the mean age was 73 ± 8.1 years. Thoracoabdominal aneurysms predominated the cohort with 68 patients (93.2%), followed by five patients (6.8%) with pararenal and infrarenal aneurysms. Overall, 233 target vessels were treated with the index bridging graft. The overall per stent graft analysis demonstrated a PP of 95.8% at 1 year; PAP was 95.8%, and SP reached 97.9%. The per-target vessel analysis demonstrated a PP, PAP, and SP in the celiac trunk of 100%, 100%, and 100%; in the superior mesenteric artery of 96.0%, 96.0%, and 100%, and in the renal arteries of 94.2%, 94.2%, and 95.1%, respectively. Four patients (5%) died at 1 year; none of the deaths were device-related. The composite endpoint of target vessel technical success and freedom from VBX stent-related serious adverse events through 30 days was achieved in 98.6% of patients. CONCLUSIONS: In this prospective post-market multicenter registry, the VBX stent demonstrated excellent results at 1 year, with almost 96% primary patency and 98% secondary patency. Patency in the renal arteries seems to be lower. Nevertheless, the VBX stent appears to be a reliable bridging stent for branched endovascular aortic repair.

In Vitro Radiological Evaluation of Different Types of Chimney Stents Using a Silicon Flow Model with Adjustable Physiological Simulating Conditions.

OBJECTIVE: To evaluate in vitro the performance of in vivo published covered or bare metal chimney stents (ChSs) in combination with the Endurant II abdominal endograft (Medtronic) as the only CE approved main graft (MG) in the treatment of juxtarenal abdominal aortic aneurysms with the chimney endovascular aneurysm repair (chEVAR) technique. METHODS: Bench top experimental study. A silicon flow model with adjustable physiological simulating conditions and patient based anatomy was used to test nine different MG-ChS combinations: Advanta V12 (Getinge); BeGraft+ (Bentley); VBX (Gore & Associates Inc.); LifeStream (Bard Medical); Dynamic (Biotronik); Absolute Pro (Abbott); double Absolute Pro; Viabahn (Gore) lined with Dynamic; and Viabahn lined with EverFlex (Medtronic). Angiotomography was performed after each implantation. DICOM data were analysed blindly twice per observer by three independent experienced observers. Each blinded evaluation was performed at one month intervals. The main analysed parameters were the area of gutters, MG and ChS maximum compression, and the presence of infolding. RESULTS: Bland-Altman analysis confirmed adequate results correlation (p < .05). Each employed ChS showed significantly different performance favouring the balloon expandable covered stent (BECS). The smallest gutter area was seen in the combination with Advanta V12 (0.26 cm2). MG infolding was observed in all tests. The lowest ChS compression was observed in the combination with BeGraft+ (compression 4.91%, D ratio 0.95). In our model, BECSs showed higher angulations than bare metal stents (BMSs) (p < .001). CONCLUSION: This in vitro study shows the variability of performance with each theoretically possible ChS and explains the divergent ChS outcomes in the published literature. BECS in combination with the Endurant abdominal device confirms their superiority vs. BMS. The presence of MG infolding in each test underlines the need for prolonged kissing ballooning. Angulation evaluation and comparison with other in vitro and in vivo publications demands the need for further investigation in transversely or upwardly oriented target vessels.

Systematic review of atherectomy of inguinal arteries for atherosclerotic lesions.

INTRODUCTION: Surgical endarterectomy represents the gold standard for the treatment of atherosclerotic lesions of the groin vessels. Endovascular treatment such as atherectomy with or without drug coated angioplasty (DCA) of the so called no stenting zones, i.e. inguinal and popliteal vessels, is gaining growing acceptance as alternative option to open surgery. This systematic review aims to scrutiny the current clinical evidence regarding atherectomy and DCA for the common artery (CFA). EVIDENCE ACQUISITION: We conducted an exhaustive research in multiple platforms (Medline, PubMed, Cochrane, Google Scholar, Embase) on studies over atherectomy and angioplasty for inguinal atherosclerotic lesions published between 2000 and 2021. As search strategy we used a wide list of MeSH items, words, synonyms. Bibliographies of review articles were checked for further relating studies regarding atherectomy of CFA. A qualitative and quantitative data analysis was carried out. EVIDENCE SYNTHESIS: Fifteen studies were included in the qualitative review. Not all studies were focused only on atherectomy of inguinal vessels, despite including such treatment. Hence, data regarding this treatment were not exhaustive. A fairly homogeneous data analysis was possible in 7 of 15 studies. The remaining 8 studies were qualitatively analyzed but not included in the statistical analysis. In all 7 included studies directional atherectomy and DCA under filter protection were carried out. In this subgroup, overall, 497 patients were treated with atherectomy. Sixty-eight percent of the patients were males. Rutherford class from 1-3 dominated against 4-6 (63% vs. 37%). Mean technical success rate was 96%, with a primary and secondary patency rate of 92% and 98% respectively at one year. Procedure related vascular complications ranged from 1% to 6%. CONCLUSIONS: Current literature about atherectomy for inguinal arteries is scant, data are inhomogeneous and so are treatment modalities. Nevertheless, the results of this systematic review suggest that this endovascular strategy is feasible with good short and midterm results. Prospective trials with larger patient cohorts are necessary to confirm these preliminary results.

Early experience with the Bolton Relay Pro/Plus for physician-modified fenestrated TEVAR.

BACKGROUND: Thoracic endovascular aortic repair (TEVAR) can be challenging in cases involving the aortic arch and the visceral segment. We report our initial experience with fenestrated TEVAR (f-TEVAR) for thoracic aortic disease involving aortic branches using physician-modified stent grafts (PMSGs). METHODS: Between February 2019 and November 2020 nine patients were treated with a PMSG. Indication to treatment were a symptomatic acute type B aortic dissection (TBAD) in three cases, a penetrating aortic ulcer in three cases (two in zone 3 and one in zone 6), one case of an endoleak type IA after TEVAR, a chronic TBAD after TEVAR in one case and one case of a contained rupture of a thoracoabdominal aneurysm in zone 3. Pre-, intra- and postoperative clinical data were recorded. RESULTS: The median patient age was 65 (IQR 60.5-71) years, and eight (89%) patients were men. Nine stent grafts (six Bolton Relay Plus and three Bolton Relay Pro, Terumo Aortic, Vascutek Ltd., Inchinnan, UK) were deployed. Small fenestrations (8 mm) were created on table, median duration for on table stent graft modifications was 20 minutes (range 13-22). The technical success rate was 100%. Median operative time was 188 (range 116-252) minutes. No major adverse events of any sort occurred during the first 30-day postoperatively. There were no type I or type III endoleaks at the end of the procedure, and no cases of spinal cord ischemia. Two access related complications occurred (22%). After a median of 12 (range 5-12) months all patients survived and all target vessels remained patent with one case of fenestration-related type I endoleak, which required open conversion. CONCLUSIONS: The results of our initial experience with f-TEVAR using PMSGs with the Bolton Relay stentgraft for the treatment of aortic diseases are acceptable. These results should be confirmed on larger patient cohorts.

Influence of TEVAR on blood pressure in subacute type B aortic dissection (TBAD) patients with refractory and non-refractory arterial hypertension.

BACKGROUND: Aim of this study was to compare the modifications of systemic blood pressure in patients with subacute type b aortic dissection (TBAD) and refractory (rHTN) and non-refractory arterial hypertension (N-rHTN) treated by thoracic endovascular aortic repair (TEVAR). METHODS: Patients were divided into two groups, rHTN defined as blood pressure >140/90 mmHg with ≥5 antihypertensive drugs and patients with N-rHTN. Primary endpoint was the variation of mean systolic, diastolic and overall pressure (MSP, MDP and MAP) before and after antihypertensive treatment or TEVAR. Secondary endpoints were the 30-days mortality. Fifty-seven patients were included in this study. RESULTS: Of the 44 Patients of the TEVAR group 21 were included in the N-rHTN group. The MSP before and after surgery for the N-rHTN group was 130 (±10 SD) and 111 (±22 SD) mmHg, P=0.01. In the rHTN group 164 (±17 SD) and 118 (±17 SD) mmHg (P=0.01). The reduction of MSP was greater in the rHTN group (P=0.01). The MAP before and after the TEVAR for the N-rHTN group was 90 (±10 SD) and 74 (±12 SD) mmHg (P=0.01), in the rHTN group 111 (±14 SD) and 70 (±9 SD) mmHg (P=0.01). The overall mortality rate group was 2.2% (1/44). CONCLUSIONS: TEVAR for TBAD appears to positively affect blood pressure in patients with rHTN and N-rHTN.

Monitoring Endothelin-A Receptor Expression during the Progression of Atherosclerosis.

Cardiovascular disease remains the most frequent cause of death worldwide. Atherosclerosis, an underlying cause of cardiovascular disease, is an inflammatory disorder associated with endothelial dysfunction. The endothelin system plays a crucial role in the pathogenesis of endothelial dysfunction and is involved in the development of atherosclerosis. We aimed to reveal the expression levels of the endothelin-A receptor (ETAR) in the course of atherogenesis to reveal possible time frames for targeted imaging and interventions. We used the ApoE-/- mice model and human specimens and evaluated ETAR expression by quantitative rtPCR (qPCR), histology and fluorescence molecular imaging. We found a significant upregulation of ETAR after 22 weeks of high-fat diet in the aortae of ApoE-/- mice. With regard to translation to human disease, we applied the fluorescent probe to fresh explants of human carotid and femoral artery specimens. The findings were correlated with qPCR and histology. While ETAR is upregulated during the progression of early atherosclerosis in the ApoE-/- mouse model, we found that ETAR expression is substantially reduced in advanced human atherosclerotic plaques. Moreover, those expression changes were clearly depicted by fluorescence imaging using our in-house designed ETAR-Cy 5.5 probe confirming its specificity and potential use in future studies.

Surgical versus endovascular revascularization of subclavian artery arteriosclerotic disease.

BACKGROUND: Endovascular treatment offers an alternative, less invasive approach to open repair for subclavian artery atherosclerotic disease (SAAD). However, only few studies compared the outcomes of both strategies in the long run. This study reports on the performance of endovascular and surgical revascularization for SAAD. METHODS: A retrospective review was conducted on patients treated for SAAD at two institutions between January 1998 and December 2015. Primary outcome of this study was the composite endpoint of reintervention-free survival (RFS) defined as time to reintervention and/or death from any cause. Secondary endpoints included primary patency (PPR) and secondary patency (SPR) rates as well as overall survival and time to reintervention. RESULTS: Surgical treatment was the preferred treatment option in 27 (25%) patients, while 83 (75%) patients underwent primary stent therapy. The median follow-up was 87 months (interquartile range [IQR]: 38 to 151) in the surgical group and 27 (IQR: 12 to 59) in the endovascular (P=0.0001). Severe arterial wall calcification was more commonly observed in the surgical arm (P<0.0001), while mild and moderate calcification in the endovascular (P=0.0004 and P=0.014). Vessel occlusion was more frequent among patients treated surgically (100% vs. 34%, P<0.0001). At 98 months RFS was significantly higher after surgical treatment (95% vs. 54%, HR: 8.4, 95% CI: 3.9 to 18.1, P=0.0002). Although overall survival did not differ significantly between the two groups (HR: 4.28, 95% CI: 0.86 to 21.22, P=0.093), open repair was associated with reduced reintervention rate (HR: 12.04, 95% CI: 4.98 to 29.12, P=0.001). The PPR at 98 months following surgical and endovascular therapy amounted to 96% and 65% (HR: 12.87, 95% CI: 5.44 to 30.44, P=0.0008) respectively. No significant difference was observed regarding the SPR between the two groups (100% vs. 95%, P=0.090). CONCLUSIONS: Surgical treatment was associated in this cohort with increased patency and a significant reduction of reinterventions compared to the endovascular approach.

Intra-arterial catheter-directed CT angiography for assessment of endovascular aortic aneurysm repair.

OBJECTIVE: To compare the efficacy and safety as well as associated image quality of catheter-directed CT angiography (CCTA) with a low dose of iodine contrast agent compared to intravenous CTA in patients undergoing endovascular aortic aneurysm repair (EVAR). METHODS: Retrospective data analysis of 92 patients undergoing EVAR between January 2009 and December 2017 was performed. Patients were divided in two groups; those receiving CTA (n = 59) after intravenous contrast agent application and those receiving CCTA (n = 33) via an intraarterial catheter placed in the descending aorta. Demographic and cardiovascular risk factors as well as renal function parameters before, immediately after and 6-60 months after EVAR were evaluated. As primary endpoint, changes in serum creatinine levels in the two groups were evaluated. Secondary endpoints encompassed complications associated with intraarterial catheter placement. Objective (signal-to-noise ratios) and subjective image quality (5-point Likert scale) were compared. RESULTS: Amount of contrast medium was significantly lower in CCTA compared to i.v. CTA (23 ± 7 ml vs. 119 ± 15 ml, p<0.0001). Patients undergoing catheter-directed CTA had higher baseline creatinine values compared to the group with intravenous iodine application (1.9 ± 0.6 mg/dl vs. 1.3 ± 0.5 mg/dl; p<0.0001). Follow-up serum creatinine levels however did not show significant alterations between the two groups (1.9 ± 0.4 mg/dl vs. 1.3 ± 0.5 mg/dl). No major complications were detected in the CCTA group. Signal-to-noise ratio (SNR) was comparable between i.v. CTA and CCTA (8.5 ± 4.6 vs. 7.7 ± 4.0; p = 0.37) and subjective image similarly revealed no differences with a good interobserver agreement (ICC = 0.647). CONCLUSIONS: Catheter-directed CTA is safe and provides comparable image quality with a substantial retrenchment of the needed amount of iodine-based contrast medium. However, no benefit of the reduced contrast medium protocol with respect to renal function was observed.

Impact of aortic stent-graft oversizing on outcomes of the chimney endovascular technique based on a new analysis of the PERICLES Registry.

OBJECTIVE: Chimney endovascular aortic aneurysm repair is gaining ever greater acceptance. However, persistent gutters leading to type IA endoleaks represent an unsolved issue. The aim of the current study was to analyze the impact of abdominal endograft oversizing to the occurrence of this phenomenon. METHODS: The PERformance of the snorkel/chImney endovascular teChnique in the treatment of compLex aortic PathologiesES registry includes the largest experience with chimney endovascular aortic aneurysm repair from 13 vascular centers in Europe and the U.S. Prospectively collected data from centers with standard use of the Endurant stent-graft and balloon-expandable covered stents as chimney grafts only were included in the present analysis. The parameter which varied was the degree of oversizing of the aortic stent-graft classifying the cohort in two groups, group A (20% and less oversizing) and group B (>20% of oversizing). The primary endpoint was the incidence of persistent type IA endoleak needed reintervention. Secondary endpoints were all-cause mortality and freedom from reintervention. RESULTS: Group A included 21 patients while group B 144. The mean preoperative pathology's neck length and diameter was 5.8 mm (±4.4) versus 4.9 mm (±3.8) and 27.6 mm (±4.7) versus 24.9 mm (±3.7) for group A and group B, respectively. The mean length of the new sealing zone after chimney graft placement was similar for both groups (group A versus group B; 17.9 mm versus 18.3 mm, respectively, P = .21). The percentage of oversizing of the aortic stent-graft ranged between 13.8 and 20% versus 22.2 and 30%, for group A and group B, respectively. Patients of group A had more type 1A endoleaks, (14.3%) versus patients of group B (2.1%) based on the first follow-up imaging, P = .02. The incidence of persistent type IA endoleaks needing a reintervention was 14.3 and 1.4% for the group A and group B, respectively, P = .01. The mean volume of contrast medium used was greater in group A versus group B with 239 ml versus150 ml, P = .05. Additionally, 14.3% of patients of group A experienced acute renal failure compared to those in group B which was 1.0%, P = .01. CONCLUSIONS: Oversizing of ideally 30% of the Endurant stent-graft is associated with significant lower incidence of type IA endoleaks requiring reintervention for patients treated by chimney endovascular aortic aneurysm repair.

Outcomes of Surgical Explantation of Infected Aortic Grafts After Endovascular and Open Abdominal Aneurysm Repair.

OBJECTIVES: Infection of the vascular graft represents one of the most threatening complications after aortic repair. It is rare and associated with high morbidity and mortality rates. The aim of this study was to present short-term outcomes after surgical treatment of infected aortic grafts after endovascular and open repair of abdominal aortic aneurysms (AAAs). METHODS: Data of all patients affected by aortic graft infection after aneurysm repair who underwent an explantation of a conventional or endovascular aortic graft between January 2008 and December 2016 were retrospectively reviewed. All patients underwent in situ reconstruction using a rifampicin soaked synthetic graft. The primary endpoint of this study was 30 day mortality; secondary endpoints were major post-operative complications. RESULTS: Twenty-six patients were included in the cohort, 16 with an infected endograft (iEVAR) and 10 patients with an infected conventional graft (iOAR). Thirty-day mortality was 23.1% overall, 37.5% for iEVAR and 0% (p = .027) for iOAR. Post-operative major complications occurred in eight (50%) patients from the iEVAR group and in four (40%) patients from the iOAR group (p = .619). The supravisceral clamping rate was higher in patients with infected iEVAR (93.8 vs. 20%, p = .001), furthermore a greater incidence of post-operative acute kidney injury was observed (50 vs. 0%, p = .009). CONCLUSIONS: Explantation of the graft and in situ reconstruction for aortic graft infection is accepted as the therapy of choice. However, re-operation for iEVAR is related to significantly higher mortality and morbidity rates. The need for suprarenal aortic clamping seems to be a possible explanation for worse outcomes in iEVAR.

Efficacy and Safety of Transbrachial Access for Iliac Endovascular Interventions.

PURPOSE: To evaluate the use of a brachial artery access for endovascular treatment of iliac artery disease. METHODS: A retrospective review was conducted of 201 patients (mean age 73 years; 147 men) treated via a brachial artery access for iliac artery stenosis. The majority (n=141, 70%) presented with lifestyle-limiting claudication (Rutherford category 3), whereas the incidence of critical limb ischemia (Rutherford categories 4-6) was 30% (n=70). Diagnostic angiography revealed a TransAtlantic Inter-Society Consensus II (TASC) C/D lesion in 114 (57%) patients. The primary outcome was technical success achieved exclusively with a brachial artery access. Secondary outcomes were secondary technical success (adjunctive transfemoral access), access site complications, and stroke/transient ischemic attack (TIA). RESULTS: In 17 (8%) patients, lesion crossing was unsuccessful, while an adjunctive transfemoral approach was necessary to restore iliac vessel patency in 23 (11%) cases. Thus, the primary and secondary technical success rates were 81% and 92%, respectively. Local hematomas (9, 4%) dominated the access site complications, followed by pseudoaneurysms (8, 4%), late brachial artery bleeding (4, 2%), brachial artery occlusion (2, 1%), and puncture site infection (2, 1%). No transient or permanent median nerve dysfunction was observed. The stroke/TIA rate was 2% (n=4). A single patient died due to acute coronary syndrome (0.5% mortality). TASC II class (p=0.58), sex (p=0.66), and target vessel (p>0.3 for all locations) had no effect on technical success. Female gender unfavorably influenced the incidence of access site complications (hazard ratio 6.7, 95% confidence interval 2.7 to 15, p<0.001), but sheath size did not (p=0.22). CONCLUSION: Brachial artery access enables endovascular treatment of iliac artery disease in the majority of patients, although an adjunctive transfemoral access may be required. However, the high incidences of access site complications and cerebral events remain a significant limitation of the transbrachial approach.

Current evidence regarding chimney graft occlusions in the endovascular treatment of pararenal aortic pathologies: a systematic review with pooled data analysis.

PURPOSE: To review the literature on pararenal endovascular aneurysm repair (EVAR) to determine the frequency and clinical relevance of chimney graft occlusions. METHODS: A comprehensive search of the English-language literature abstracted in the Medline and the Cochrane Library databases was performed to identify case series involving pararenal aortic pathologies (degenerative aneurysms, penetrating atherosclerotic ulcers, type Ia endoleaks, and para-anastomotic aneurysms) treated with EVAR and chimney grafts; thoracoabdominal, iliac, or aortic arch chimney graft placements were excluded, as were case reports in which the total number of chimney grafts implanted at the reporting center could not be determined. The literature search identified 83 studies regarding chimneys/snorkels for pararenal pathologies published between January 2007 and March 2014. Of these, 7 studies met the inclusion criteria and were included in the analysis. RESULTS: There were 15 (4.5%) occlusions in the overall 334 renovisceral vessels in which chimney grafts were deployed. The mean time to chimney graft occlusion was 3.5 months (range 1-270 days) over a mean follow-up of 1.4 months (range 9-24). The target arteries were the renal artery (n=12) and the superior mesenteric artery (SMA; n=3). Seven patients were asymptomatic, and no description was given in 5 cases. In the other 3 patients, the symptoms were acute renal failure, intestinal ischemia, and malignant hypertension. The treatment strategy included open conversion and iliorenal bypass (n=1), exploratory laparotomy to revascularize the SMA (n=1), hemodialysis (n=1), placement of bare metal stents (n=4), conservative treatment (n=2), and unknown (n=6). One (6.7%) patient died (an occluded SMA). Two patients with renal chimney occlusion suffered from temporary renal function deterioration. CONCLUSION: The present analysis identified a low rate of chimney graft occlusions, which appear to occur generally a few months after placement. Involvement of the renal artery had no severe clinical consequences, while occlusion of the SMA can be associated with life-threatening complications. More detailed information regarding occluded chimney grafts will be needed in future publications to help identify the causes.