Evolution of fenestrated/branched endovascular aortic aneurysm repair complexity and outcomes at an organized center for the treatment of complex aortic disease

The Current State of Physician-Modified Endovascular Grafts in Complex Abdominal Aortic Aneurysms

Physician-modified endografts (PMEGs) for the treatment of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms are a viable option. Other endovascular options include custom and off-the-shelf devices for fenestrated and branched endovascular aortic repair, parallel grafts, and in situ laser fenestration. The limitations of these devices include time to development, strict anatomic criteria, and durability regarding parallel grafts. PMEGs fill this void with perioperative and long-term outcomes similar to custom-made devices. Postdissection aneurysms also present a unique role for PMEGs given the added complexity with fixing these aneurysms and have been reported with good outcomes. Lastly, we discuss the approach to preoperative planning and the operative component of PMEGs in this brief review.

Expert-Based Narrative Review on Contemporary Use of an Off-The-Shelf Multibranched Endograft for Endovascular Treatment of Thoracoabdominal Aortic Aneurysms: Device Design, Anatomical Suitability, Technical Tips, Perioperative Care, Clinical Applications, and Real-World Experience

Advanced endovascular techniques, such as fenestrated stent grafts, are nowadays available that permit minimally invasive treatment of complex abdominal aortic aneurysms. However, thoracoabdominal aortic aneurysm patients have anatomic limitations to fenestrated stent-grafts given a large lumen, that is, the gap between the endograft and the inner aortic wall. This has led to the development of branched endovascular aneurysm repair as the ideal option for such patients. The Zenith t-Branch multibranched endograft (Cook Medical, Bloomington, IN), which has been commercially available in Europe to treat thoracoabdominal aortic aneurysm since June 2012, represents a feasible off-the-shelf alternative for treatment of such pathologies, especially in the urgent setting, for patients who cannot wait the time required for manufacturing and delivery of custom-made endografts. The device's anatomical suitability should be considered, especially for female patients with smaller iliofemoral vessels. Several tips may help deal with particularly complex scenarios (such as, for instance, in case of narrow inner aortic lumens or when treating patients with failure of prior endovascular aneurysm repair), and a broad array of techniques and devices must be available to ensure technical and clinical success. Despite promising early outcomes, concerns remain particularly regarding the risk for spinal cord ischemia and further assessment of long-term durability is needed, including the rate of target vessel instability and need for secondary interventions. As the published evidence mainly comes from retrospective registries, it is likely that reported outcomes may suffer from an intrinsic bias as most procedures reported to date have been carried out at high-volume aortic centers. Nonetheless, with the never-ceasing adoption of new and refined techniques, outcomes are expected to ameliorate.

Monocentric Evaluation of Physician-Modified Fenestrations or Parallel Endografts for Complex Aortic Diseases

PURPOSE

This study aimed to investigate the demographic and anatomic characteristics, as well as perioperative and follow-up results of fenestration and parallel techniques for the endovascular repair of complex aortic diseases.

MATERIALS AND METHODS

A retrospective study was conducted on 67 consecutive patients underwent endovascular treatment for complex aortic diseases including abdominal aortic aneurysm (AAA), thoracoabdominal aneurysm (TAAA), aortic dissection, or prior endovascular repair with either fenestrated and parallel endovascular aortic repair (f-EVAR or ch-EVAR) at a single institute from 2013 to 2021. Choices of intervention were made by the disease' emergency, patients' general condition, the anatomic characteristics, as well as following the recommendation from the devices' guidelines. Patients' clinical demographics, aortic disease characteristics, perioperative details, and disease courses were discussed. Short- and mid-term follow-up results were obtained and analyzed. Endpoints were aneurysm-related and unrelated mortality, branch instability, and renal function deterioration.

RESULTS

Totally, 34 and 27 patients received f-EVAR and ch-EVAR, while 6 patients received a combination of both. Fenestrated endovascular aortic repair was conducted mainly in AAA affecting visceral branches and TAAA, whereas ch-EVAR was normally utilized for infrarenal AAA. Regarding the average number of reconstructed arteries per patient, there was a significant difference among f-EVAR, ch-EVAR, and the combination group (mean = 2.3 ± 0.9, 1.4 ± 0.6, 3.5 ± 0.5, p<0.001). Primary technical success was achieved in 28 (82.4%), 22 (81.5%), and 3 (50.0%) patients for each group. Besides operational time (5.77 ± 2.58, 4.47 ± 1.44, p=0.033), no significant difference was observed for blood transfusion, intensive care unit (ICU) or hospital stay, blood creatinine level, 30-day complications, or follow-up complications between patients undergoing f-EVAR or ch-EVAR. Patients receiving combination of both techniques had a higher rate of blood transfusion (p=0.044), longer operational time (p=0.008) or hospital stay (p=0.017), as well as more stent occlusion (p=0.001), endoleak (p=0.004) at short-term and a higher rate of endoleak (p=0.023) at mid-term follow-up.

CONCLUSION

In conclusion, this study demonstrated that f-EVAR and ch-EVAR techniques had acceptable perioperative and follow-up results and should be considered viable alternatives when encountering complex aortic diseases.

CLINICAL IMPACT

This study sought to investigate the baseline and pathological characteristics, as well as perioperative and follow-up results of f-EVAR and ch-EVAR at a single Chinese institution. F-EVAR (mostly physician-modified f-EVAR) was applied in patients with a wide range of etiologies and disease types, while ch-EVAR was preferred for AAA in older patients with an average higher ASA grade. Our experience suggested acceptable safety and efficacy both for techniques, and no significant difference was observed between the two groups regarding any short or mid-term adverse events.

Practice patterns of antiplatelet and anticoagulant therapy after fenestrated/branched endovascular aortic repair

OBJECTIVE

Antiplatelet and/or anticoagulant therapy are commonly prescribed after fenestrated/branched endovascular aortic repair (F/BEVAR). However, the optimal regimen remains unknown. We sought to characterize practice patterns and outcomes of antiplatelet and anticoagulant use in patients who underwent F/BEVAR.

METHODS

Consecutive patients enrolled (2012-2023) as part of the United States Aortic Research Consortium (US-ARC) from 10 independent physician-sponsored investigational device exemption studies were evaluated. The cohort was characterized by medication regimen on discharge from index F/BEVAR: (1) Aspirin alone OR P2Y12 alone (single-antiplatelet therapy [SAPT]); (2) Anticoagulant alone; (3) Aspirin + P2Y12 (dual-antiplatelet therapy [DAPT]); (4) Aspirin + anticoagulant OR P2Y12 + anticoagulant (SAPT + anticoagulant); (5) Aspirin + P2Y12 + anticoagulant (triple therapy [TT]); and (6) No therapy. Kaplan-Meier analysis and Cox proportional hazards modeling were used to compare 1-year outcomes including survival, target artery patency, freedom from bleeding complication, freedom from all reinterventions, and freedom from stent-specific reintervention.

RESULTS

Of the 1525 patients with complete exposure and outcome data, 49.6% were discharged on DAPT, 28.8% on SAPT, 13.6% on SAPT + anticoagulant, 3.2% on TT, 2.6% on anticoagulant alone, and 2.2% on no therapy. Discharge medication regimen was not associated with differences in 1-year survival, bleeding complications, composite reintervention rate, or stent-specific reintervention rate. However, there was a significant difference in 1-year target artery patency. On multivariable analysis comparing with SAPT, DAPT conferred a lower hazard of loss of target artery patency (hazard ratio [HR], 0.48; 95% confidence interval [CI], 0.27-0.84; P = .01). On sub-analyses of renal stents alone or visceral stents alone, DAPT no longer had a significantly lower hazard of loss of target artery patency (renal: HR, 0.66; 95% CI, 0.35-1.27; P = .22; visceral: HR, 0.31; 95% CI, 0.05-1.9; P = .21). Lastly, duration of DAPT therapy (1 month, 6 months, or 1 year) did not significantly affect target artery patency.

CONCLUSIONS

Practice patterns for antiplatelet and anticoagulant regimens after F/BEVAR vary widely across the US-ARC. There were no differences in bleeding complications, survival or reintervention rates among different regimens, but higher branch vessel patency was noted in the DAPT cohort. These data suggest there is a benefit in DAPT therapy. However, the generalizability of this finding is limited by the retrospective nature of this data, and the clinical significance of this finding is unclear, as there is no difference in survival, bleeding, or reintervention rates amongst the different regimens. Hence, an "optimal" regimen, including the duration of such regimen, could not be clearly discerned. This suggests equipoise for a randomized trial, nested within this cohort, to identify the most effective antiplatelet/anticoagulant regimen for the growing number of patients being treated globally with F/BEVAR.

Systematic Review and Meta-analysis of Short-term and Mid-term Outcomes After Use of t-Branch Off-the-shelf Multibranched Endograft for Elective and Urgent Treatment of Thoracoabdominal Aortic Aneurysms

OBJECTIVE

To conduct a meta-analysis to assess the safety and efficacy of t-Branch off-the-shelf multibranched endograft for the treatment of thoracoabdominal aortic aneurysm (TAAA).

DATA SOURCES

PubMed, Embase, and Web of Science.

REVIEW METHODS

Online databases were searched from June 2012 to March 2023. The data were pooled together using a random-effects model of proportions. The outcomes overall included technical success, spinal cord ischemia, target vessel occlusion, type I or III endoleak, reintervention, early mortality (30-day), and mid-term outcomes. Subgroup meta-analyses and meta-regression were performed to explore variation among studies.

RESULTS

A total of 15 studies containing 1238 patients were included in the meta-analysis. The overall study quality assessment was found to be moderate to good. The pooled technical success was 97.0% (95% confidence interval [CI]=95.5-98.6, I2=53.01%, 1185/1238 cases, 15 studies). Overall, early mortality was 7.3% (95% CI=4.4-10.1, I2=74.48%, 124/1238 cases, 15 studies). Early spinal cord ischemia was 13.4% (95% CI=9.6-17.2, I2=67.24%, 160/1238 cases, 15 studies), and early type I or III endoleak was 6.0% (95% CI=3.4-8.5, I2=53.71%, 68/1032 cases, 9 studies). Mid-term outcomes showed target vessel occlusion was 4% (95% CI=1.4-6.5, I2=65.18%, 28/528 cases, 10 studies, 5-21.2 months), type I or III endoleak was 4.7% (95% CI=2-7.5, I2=49.74%, 38/512 cases, 10 studies, 5-21.2 months), reintervention was 11.2% (95% CI=8.1-14.3, I2=31.06%, 85/650 cases, 10 studies, 5-21.2 months), and pooled mortality was 13.9% (95% CI=7.2-20.7, I2=76.32%, 84/550 cases, 11 studies, 5-21.2 months). Meta-regression found a significant linear association between higher technical success and earlier publication year (p=0.014) and studies with anatomic inclusion criteria (p=0.037). Urgent patients (p=0.021) and later publication year (p=0.048) were significantly associated with higher early mortality.

CONCLUSION

The use of the off-the-shelf t-Branch multibranched endograft for elective or urgent endovascular TAAA repair is associated with high technical success rates and proved to be safe and effective at early and mid-term follow-up. However, the heterogeneity between the included studies is high, and prospective, randomized studies along with future larger studies with long-term follow-up are needed.

CLINICAL IMPACT

The Zenith t-Branch (Cook Medical, Bloomington, Ind) was approved as a commercially available device in Europe in June 2012. Although a decade has past, the outcomes of t-Branch have rarely been synthesized at the global level. This meta-analysis included 15 studies containing 1238 patients. The meta-analyses included technical success, major adverse events, reintervention, early mortality, and mid-term outcomes. The outcome was very meaningful and representative for the use of t-Branch. It is helpful for endovascular surgeons to make decisions on the treatment of TAAA patients.

Comparative outcomes of physician-modified fenestrated-branched endovascular repair of post-dissection and degenerative complex abdominal or thoracoabdominal aortic aneurysms

OBJECTIVE

Fenestrated-branched endovascular repair has become a favorable treatment strategy for patients with complex abdominal aortic aneurysms (cAAAs) and thoracoabdominal aortic aneurysms (TAAAs) who are high risk for open repair. Compared with degenerative aneurysms, post-dissection aneurysms can pose additional challenges for endovascular repair. Literature on physician-modified fenestrated-branched endovascular aortic repair (PM-FBEVAR) for post-dissection aortic aneurysms is sparse. Therefore, the aim of this study is to compare the clinical outcomes of patients who underwent PM-FBEVAR for degenerative and post-dissection cAAAs or TAAAs.

METHODS

A single-center institutional database was retrospectively reviewed for patients that underwent PM-FBEVAR between 2015 and 2021. Infected aneurysms and pseudoaneurysms were excluded. Patient characteristics, intraoperative details, and clinical outcomes were compared between degenerative and post-dissection cAAAs or TAAAs. The primary outcome was 30-day mortality. The secondary outcomes included technical success, major complications, endoleak, target vessel instability, and reintervention.

RESULTS

Of the 183 patients who underwent PM-FBEVAR in the study, 32 had aortic dissections, and 151 had degenerative aneurysms. There was one 30-day death (3.1%) in the post-dissection group and eight 30-day deaths (5.3%) in the degenerative aneurysm group (P = .99). Technical success, fluoroscopy time, and contrast usage were similar between the post-dissection and degenerative groups. Reintervention during follow-up (28% vs 35%; P = .54) and major complications were not statistically significantly different between the two groups. Endoleak was the most common reason for reintervention, with the post-dissection group having a higher rate of type IC, II, and IIIA endoleaks (31% vs 3%; P < .0001; 59% vs 26%; P = .0002; and 16% vs 4%; P = .03). During the mean follow-up of 14 months, all-cause mortality was similar between the groups (12.5% vs 21.9%; P = .23).

CONCLUSIONS

PM-FBEVAR is a safe treatment for post-dissection cAAAs and TAAAs with high technical success. However, endoleaks requiring reintervention were more frequent in post-dissection patients. The impact of these reinterventions on long-term durability will be assessed with continued follow-up.

Characterization and management of type II and complex endoleaks after fenestrated/branched endovascular aneurysm repair

INTRODUCTION

Endoleaks are more common after fenestrated/branched endovascular aneurysm repair (F/B-EVAR) than infrarenal EVAR secondary to the length of aortic coverage and number of component junctions. Although reports have focused on type I and III endoleaks, less is known regarding type II endoleaks after F/B-EVAR. We hypothesized that type II endoleaks would be common and often complex (associated with additional endoleak types), given the potential for multiple inflow and outflow sources. We sought to describe the incidence and complexity of type II endoleaks after F/B-EVAR.

METHODS

F/B-EVAR data prospectively collected at a single institution in an investigational device exemption clinical trial (G130210) were retrospectively analyzed (2014-2021). Endoleaks were characterized by type, time to detection, and management. Primary endoleaks were defined as those present on completion imaging or at first postoperative imaging, and secondary were those on subsequent imaging. Recurrent endoleaks were those that developed after a successfully resolved endoleak. Reinterventions were considered for type I or III endoleaks or any endoleak associated with sac growth >5 mm. Technical success defined as the absence of flow in the aneurysm sac at procedure conclusion and methods of intervention were captured.

RESULTS

Among 335 consecutive F/B-EVARs (mean ± standard deviation follow-up: 2.5 ± 1.5 years), 125 patients (37%) experienced 166 endoleaks (81 primary, 72 secondary, and 13 recurrent). Of these 125 patients, 50 (40% of patients) underwent 71 interventions for 60 endoleaks. Type II endoleaks were the most frequent (n = 100, 60%), with 20 identified during the index procedure, 12 (60%) of which resolved before 30-day follow-up. Of the 100 type II endoleaks, 20 (20%; 12 primary, 5 secondary, and 3 recurrent) were associated with sac growth; 15 (75%) of those with associated sac growth underwent intervention. At intervention, 6 (40%) were reclassified as complex, with a concomitant type I or type III endoleak. Initial technical success for endoleak treatment was 96% (68 of 71). There were 13 recurrences, all of which were associated with complex endoleaks.

CONCLUSIONS

Nearly half of the patients who underwent F/B-EVAR experienced an endoleak. The majority were classified as type II, with nearly a fifth associated with sac expansion. Interventions for a type II endoleak frequently led to reclassification as complex, with a concomitant type I or III endoleak not appreciated on computed tomography angiography and/or duplex. Further study is needed to determine if the primary treatment goal for complex aneurysm repair is sac stability or sac regression, as this would inform both the importance of properly classifying endoleaks noninvasively and the intervention threshold for managing type II endoleaks.

Analysis of predisposing factors for type III endoleaks from directional branches after branched endovascular repair for thoracoabdominal aortic aneurysms

BACKGROUND

Mid-term durability of branches has already been established, and BF-branched and fenestrated endovascular repair has shown comparable results with open repair in the treatment of thoracoabdominal aortic aneurysms (TAAAs). Nevertheless, target vessel instability remains the most frequent adverse event after complex endovascular aortic repair. Type III endoleaks from directional branches have been reported with a low incidence, but risk factors for this complication have not been investigated yet.

METHODS

This was a dual-center observational retrospective cohort study. Data were collected prospectively for each patient treated with branched endovascular repair between April 2008 and December 2019. The primary outcome was to assess potential risk factors for branch disconnection and fracture. A logistic regression analysis was performed, including preoperative and postoperative measurements as well as intraoperative details. A Cox regression hazard analysis was performed to evaluate the influence of preoperative aneurysm diameter and target vessel angulation on the outcome during follow-up.

RESULTS

Two hundred ninety-five target visceral vessels (TVVs) in 91 patients were considered suitable for cannulation. Technical success was 96.9% (286/295 TVVs). The median follow-up was 32.5 months (interquartile range, 14.2-50.1 months). Twelve type III endoleaks from directional branches were detected (4.2%; 5 bridging stent graft fractures and 7 disconnections). Five type III endoleaks involved the celiac trunk (one fracture and four disconnections), five the superior mesenteric artery (four fractures and one disconnection), and two the renal arteries (both disconnections). The median time to type III endoleak was 22.2 months (interquartile range, 10.9-37.6 months). Preoperative TAAA diameter (P = .028), preoperative TVV angulation (P = .037), the use of a BeGraft stent graft as bridging stent graft (P = .001), and different stent types on the same vessel (P = .048) were associated with type III endoleak at univariable analysis. Using a BeGraft stent graft (P = .010) was the only significant factor predisposing to type III endoleak at multiple logistic regression. The Cox regression analysis showed a two-fold increased risk for type III endoleak for every 10-mm increase in preoperative TAAA diameter (hazard ratio, 2.00; 95% confidence interval, 1.08-3.72; P = .028) and a 1.5 increased risk every 12° increase of preoperative TVV angulation (hazard ratio, 1.47; 95% confidence interval, 1.02-2.10; P = .037).

CONCLUSIONS

Type III endoleaks from directional branches are a non-negligible complication after branched endovascular repair, with a relevant incidence. They tended to be clustered on specific patients, and aneurysm diameter and TVV angulation are strictly associated with the outcome. Different stent types on the same vessel should be avoided whenever possible. An intensified follow-up should be adopted for patients with large aneurysms, implanted with first-generation BeGraft, or who have been already diagnosed with type III endoleaks.

Analysis of Postoperative Remodeling Characteristics after Modular Inner Branched Stent-Graft Treatment of Aortic Arch Pathologies Using Computational Fluid Dynamics

The modular inner branched stent-graft (MIBSG), a novel interventional therapy, has demonstrated good effects in the endovascular treatment of aortic arch pathologies, especially those involving the supra-aortic branches. Nevertheless, the long-term efficacy of the MIBSG and in-depth quantitative evaluation of postoperative outcomes remain to be examined. Moreover, the regularity of postoperative vascular remodeling induced by MIBSG implantation has yet to be explored. To address these questions, we constructed four models (normal, preoperative, 1 week postoperative, and 6 months postoperative) based on a single patient case to perform computational fluid dynamics simulations. The morphological and hemodynamic characteristics, including the velocity profile, flow rate distribution, and hemodynamic parameter distribution (wall shear stress and its derivative parameters), were investigated. After MIBSG implantation, the morphology of the supra-aortic branches changed significantly, and the branch point moved forward to the proximal ascending aorta. Moreover, the curvature radius of the aortic arch axis continued to change. These changes in morphology altered the characteristics of the flow field and wall shear stress distribution. As a result, the local forces exerted on the vessel wall by the blood led to vessel remodeling. This study provides insight into the vascular remodeling process after MIBSG implantation, which occurs as a result of the interplay between vascular morphological characteristics and blood flow characteristics.

Postoperative Outcomes and Reinterventions Following Fenestrated/Branched Endovascular Aortic Repair in Post-Dissection and Complex Degenerative Abdominal and Thoraco-Abdominal Aortic Aneurysms

Background: The outcome of FBEVAR in post-dissection thoracoabdominal aortic aneurysms has not been well established in the literature. The aim of this study was to compare midterm outcomes following FBEVAR in post-dissection aneurysms to degenerative aneurysms. (2) Methods: This was a retrospective review of all patients undergoing FBEVAR in a single center between 2017 and 2020. The baseline characteristics, intraoperative details, and postoperative outcomes of patients with post-dissection aneurysms were compared to those with degenerative outcomes. The primary end point was unplanned reinterventions. Cox regression analysis was performed to identify the determinants of worse outcomes. Results: A total of 137 subjects with a mean age of 70 ± 10 years were included in the study, out of which 30 presented post-dissection aneurysms (22%). Custom-made devices were employed in 119 patients, off-the-shelf devices in 13 and physician-modified endografts in 5, with incorporation in 505 target vessels. The technical success rate was comparable in both groups (97% vs. 98%, p = 0.21). However, the one-year freedom from unplanned reintervention was lower in the post-dissection group (67% vs. 89%, p = 0.011). Conclusion: FBEVAR in post-dissection aneurysms is associated with a favorable technical success rate, but reintervention rates remain high. Long procedural duration and the use of adjunctive techniques are associated with increased risk of reinterventions.

Complex Aortic Interventions Can Be Safely Introduced to the Clinical Practice by Physicians Skilled in Basic Endovascular Techniques

Our purpose was to evaluate the risk associated with the learning curve of starting a complex aortic programme in an Eastern European country. A retrospective study was conducted involving the initial 20 patients (16 males, mean age: 65 ± 11 years) undergoing fenestrated/branched endovascular aortic repair in a single centre. Demographic, anatomical, procedural, and postoperative variables were collected. Our elective patient cohort consisted of 9 pararenal aneurysms (45%) and 11 thoracoabdominal aortic aneurysms (55%), with the latter including 4 chronic dissection cases (20%). A total of 71 branch vessels were incorporated (3.5 ± 0.9 per patient). The per vessel technical success rate was 100%. In-hospital mortality was 5% (1/20). At an average follow-up of 14 ± 22 months, the primary clinical success rate was 45% (9/20) and the secondary clinical success was achieved in 75% of cases (15/20). All-cause mortality at 14 months was 20% (4/20; aortic related: 1/20, 5%). Four bridging stent occlusions were found (5.6%). Mortality and reintervention rates were comparable to the initial results of high-volume centres, while the complexity of our cases and the per vessel technical success rate was comparable to the values reported as late experience. The morbidity of the learning curve could be decreased if operators are skilled in basic endovascular procedures.

Use of a Steerable Sheath for Completely Femoral Access in Branched Endovascular Aortic Repair Compared to Upper Extremity Access

PURPOSE

To compare bridging stent graft (BSG) implantation in downward oriented branches in branched endovascular aortic repair (bEVAR), using a commercially available steerable sheath from an exclusively femoral access (TFA) with traditional upper extremity access (UEA).

METHODS

In a retrospective cohort study, 7 patients with 19 branches in the TFA cohort received BSG insertion using the Medtronic Heli FX steerable sheath from a femoral access, and 10 patients with 32 branches in the UEA cohort from a brachial approach. Technical success, total intervention time, fluoroscopy time, branch cannulation time, and complication rate were recorded.

RESULTS

Technical success was 19/19 branches in the TFA and 31/32 in the UEA cohort. The mean branch cannulation time was considerably shorter in the TFA group (17 vs. 29 min, p = 0.003), and total intervention time tended to be shorter (169 vs. 217 min, p = 0.176).

CONCLUSION

Using a commercially available steerable sheath allowed successful cannulation of all branches in this cohort and was associated with significantly shorter branch cannulation times. Potentially, this technique can lower the stroke and brachial puncture site complication risk as well as reduce total intervention time and radiation dose.

LEVEL OF EVIDENCE

2b, retrospective cohort study.

Microsurgical treatment of middle cerebral artery stenosis or occlusion: a single center experience and literature review

Background

To investigate the effect of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in the treatment of MCA stenosis or occlusion.

Methods

The clinical and imaging data of 31 MCA stenosis or occlusion patients with STA-MCA bypass were analyzed retrospectively. The operation was performed by STA-MCA M4 segment bypass via the frontotemporal approach. Modified Rankin Scale (mRS) was used to evaluate the neurological function of patients.

Results

After operation, head computed tomography (CT) showed that there was no new infarction or hemorrhage in the operation area. CTA and CTP showed that the bypass vessel was unobstructed in 29 cases and the cerebral perfusion was improved in 31 cases. Among the 31 patients, 7 patients had postoperative complications and 13 patients had improvement of clinical symptoms. The other patients had no complications and the clinical symptoms remained unchanged. The mRs score of 31 patients after operation indicated that the neurological function was significantly improved than pre-operation. Of the 31 patients, 23 cases were followed up. The mRs score showed that the neurological function of these 23 patients was further improved than that at discharge. In addition, DSA (or CTA) and CTP showed that the bypass vessel was unobstructed and the cerebral perfusion was further improved.

Conclusion

STA-MCA bypass was an effective method for the treatment of MCA stenosis or occlusion. However, the results should be further verified by large sample, multi-center and long-term follow-up.