Bypass Patency Research Articles

8mm Conduit Outperforms 6mm Conduit in Extra-anatomic Bypass

Extra-anatomic bypass is an important tool in relieving supra-inguinal occlusive disease. These bypasses are frequently conducted with prosthetic material, commonly available in 6-mm and 8-mm sizes. Previous studies have demonstrated infra-inguinal bypass has improved patency when graft size is 6 mm or greater. This study aimed to examine outcomes of 6-mm vs 8-mm prosthetic graft use in extra-anatomic bypasses. A retrospective analysis of the Vascular Quality Initiative supra-inguinal database (2010-2022) was conducted. Patients undergoing either axillary-femoral or femoral-femoral prosthetic bypass with available conduit size data were included. Primary endpoints included graft patency and major adverse limb events (MALE). A logistic regression analysis was performed of demographic and operative variables to determine if any factors contributed to the selection of graft size. Then, multivariable Cox regression analysis was conducted in groups based on prosthetic diameter (6 mm vs 8 mm), controlling for these factors. Seven mm was excluded from formal regression analysis due to small sample size but included in survival curves to demonstrate the stepwise impact of graft size. A total of 6463 patients were included for analysis; 2355 axillary-femoral bypasses and 4128 femoral-femoral bypasses. Of these, 1071 patients underwent bypass with 6-mm graft, and 5392 patients underwent bypass with 8-mm graft. Significant predictors (P < .05) of 8-mm graft use in both types of extra-anatomic bypass included male gender, body mass index (BMI) of 25-35 kg/m2, and common femoral as distal target when compared to profunda, superficial femoral artery, and other distal vessels. The most significant predictor (P < .001) of improved primary patency in both types of extra-anatomic bypass examined was larger conduit diameter (8 mm vs 6 mm axillary-femoral hazard ratio [HR], 0.5; femoral-femoral HR, 0.66). Cox regression curves by graft size were generated for both axillary-femoral and femoral-femoral bypasses (Figs 1 and 2), which demonstrated significantly higher primary patency in patients with 8-mm bypasses over time. Improved performance in 8-mm graft compared with 6-mm graft was additionally demonstrated in primary-assisted patency, secondary patency, and MALE regression curves with P < .001 for both axillary-femoral and femoral-femoral bypasses. In this retrospective analysis of extra-anatomic bypasses, 8-mm grafts had significantly improved patency rates and fewer MALE when compared with 6-mm grafts over time. Male sex and body mass index were associated with larger diameter bypass use; after controlling for these preoperative factors, 8-mm grafts still outperformed 6-mm grafts. Vascular surgeons should be cognizant of the potential implications in limb salvage when selecting prosthetic graft for extra-anatomic bypass.Fig 2Primary patency of axillary-femoral bypass over time by graft size.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Risk factors of postoperative cerebral hyperperfusion syndrome and its relationship with clinical prognosis in adult patients with moyamoya disease

BackgroundTo investigate the incidence, risk factors, and clinical prognosis of cerebral hyperperfusion syndrome (CHS) after superficial temporal artery-middle cerebral artery anastomosis combined with encephalo-duro-arterio-synangiosis (STA-MCA/EDAS) in adult patients with moyamoya disease (MMD).MethodsThe clinical data of 160 adult patients with MMD treated by STA-MCA/EDAS from January 2016 to January 2017 were retrospectively analyzed. According to CHS diagnosis, MMD patients were divided into CHS and non-CHS group. Univariate and multivariate analysis of risk factors and Kaplan-Meier curve of stroke-free survival for CHS were performed.ResultsA total of 12 patients (7.5%) developed postoperative CHS, of which 4 patients (2.5%) presented with cerebral hemorrhage. Univariate and multivariate analysis showed moyamoya vessel on the surgical hemisphere (OR = 3.04, 95% CI = 1.02–9.03, P = 0.046) and left operated hemisphere (OR = 5.16, 95% CI = 1.09–21.34, P = 0.041) were independent risk factors for CHS. The other variables, such as age, gender, presentation, hypertension, diabetes, smoking, mean mRS score on admission, modified Suzuki stage and pre-infarction stage on surgical hemisphere, and bypass patency, had no association with postoperative CHS (P > 0.05). At final follow-up with average 38 months, there were 18 out of 133 patients (13.5%, 4.91% per person year) presented with newly developed complications. There was no significant difference between newly developed complications, mean mRS scores, and Kaplan-Meier curve of stroke-free survival in patients with and without CHS (P > 0.05).ConclusionThe concentration of moyamoya vessels and left operated hemisphere was independent risk factors for CHS, which could not affect the clinical prognosis if treated timely and properly. The current study offers a new perspective of moyamoya vessels and supporting data for choosing MMD candidates on cerebral revascularization.

393 Sonolucent Cranioplasty for Real-Time Ultrasound Monitoring of Extra-to-Intracranial Bypass: Early Multicenter Experience of 44 Cases

INTRODUCTION: The new sonolucent cranioplasty implant (clear polymethyl methacrylate, PMMA) adds functionality besides reconstruction during and after surgery. One possible application uses transcranioplasty ultrasound (TCUS) technique after PMMA cranioplasty to assess graft patency of extracranial-intracranial (EC-IC) bypass procedures. METHODS: Multicenter analysis of consecutive EC-IC bypass patients from 5 US centers between 2019-2022 with closure post bypass using the translucent PMMA cranioplasty implant. RESULTS: Forty-four patients (median-age 53, 68.2% females) were included. The most common indication for bypass was Moyamoya disease/syndrome (77.3%) and superficial temporal artery to middle cerebral artery (STA-MCA) bypass was the most common procedure (79.5%). Pre-treatment modified Rankin Scale of 0 and 1-2 was noted in 11.4% and 59.1% of the patients, respectively, with hypertension being the most common comorbidity (72.7%). Intraoperative imaging for bypass patency involved utilizing combination of modalities in all patients, with intraoperative doppler being the most commonly utilized monitoring modality (90.9%) followed by indocyanine green (ICG) and catheter angiography (86.4% and 61.4%, respectively). Qualitative TCUS assessment of the graft patency was feasible in all cases without technical difficulties. Post-operative inpatient TCUS confirmation of the bypass patency was recorded in 56.8% of the cases, and outpatient TCUS surveillance for monitoring bypass patency through the implant was recorded in 22.7% of the patients. There were no cases of bypass failure noted in this cohort necessitating retreatment. Similarly, no implant-related complications were encountered in the cohort. Major complications requiring additional surgery occurred in 2 patients (4.6%) including epidural hematoma requiring surgical evacuation (2.3%) and post-operative surgical site infection (2.3%) that was unrelated to the implant. CONCLUSIONS: This multicenter study supports the safety and feasibility of using the sonolucent PMMA implant in the setting of EC-IC bypass surgery with the goal to monitor bypass patency using TCUS.

PD12-06 MICRO-SURGICAL PENILE REVASCULARIZATION AFTER PELVIC FRACTURE URETHRAL INJURIES

You have accessJournal of UrologyCME1 Apr 2023PD12-06 MICRO-SURGICAL PENILE REVASCULARIZATION AFTER PELVIC FRACTURE URETHRAL INJURIES Reynaldo Gomez, Jessica Pfeifer, Laura Velarde, and Rodrigo Campos Reynaldo GomezReynaldo Gomez More articles by this author , Jessica PfeiferJessica Pfeifer More articles by this author , Laura VelardeLaura Velarde More articles by this author , and Rodrigo CamposRodrigo Campos More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003259.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Micro-surgical revascularization of the penis after a pelvic fracture urethral injury (PFUI) has been proposed to recover erections and / or to improve the irrigation of the spongiosum prior to urethroplasty, aiming to prevent ischemic failure of the reconstruction. METHODS: Patients who lost their erection after a PFUI were studied with color Doppler ultrasound of the cavernous arteries after intracavernous injection of prostaglandin. Those diagnosed with arteriogenic erectile dysfunction were confirmed with a selective pudendal pharmaco-arteriography (with intracavernous prostaglandin) and were offered a micro-surgical penile revascularization by means of a bypass of the inferior epigastric artery to the dorsal artery of the penis. RESULTS: Between April 1990 and July 2022, 16 patients were revascularized before urethroplasty. All were acutely managed by suprapubic cystostomy without realigment. The median age was 32 years (range 20-57), the median time between the accident and revascularization was 9 months (range 2-30) and the median time between revascularization and urethroplasty was 2 months (range 1-7). The mean surgical time was 280 min (220-290), with no intraoperative complications. There were 2 Clavien I postoperative complications and one Clavien II.With a median follow-up of 102 months (range 3-367), no patient presented urethroplasty stricture failure and no patient recovered erections despite bypass patency (verified by postoperative Doppler ultrasound in 11). CONCLUSIONS: Micro-surgical revascularization of the penis is feasible and safe, requires expertise in micro surgery and does not seem to have a role in recovering erections after PFUI. On the other hand, long-segment ischemic stricture failure is an infrequent but catastrophic complication of urethral reconstruction linked to post traumatic penile arterial insufficiency. In this setting, penile revascularization may contribute to increase urethral blood flow and may be valuable to prevent ischemic failure of the urethral reconstruction. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e402 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Reynaldo Gomez More articles by this author Jessica Pfeifer More articles by this author Laura Velarde More articles by this author Rodrigo Campos More articles by this author Expand All Advertisement PDF downloadLoading ...

167 STA-MCA Bypass for Symptomatic Moyamoya Disease—Lessons Learnt From 89 Revascularisations

INTRODUCTION: Efficacy of surgical revascularisation procedures over conservative management in moyamoya disease (MMD) has been established in the past. However there is dearth of literature on comprehensive evaluation of impact of age and Suzuki staging on clinical and angiographic outcome in symptomatic MMD patients undergoing direct revascularisation (DR) via superficial temporal artery – middle cerebral artery (STA-MCA) bypass. METHODS: We analysed consecutive MMD patients who underwent direct-revascularisation (DR) via STA-MCA bypass. Primary outcome measures were mRS scale and stroke risk reduction. Secondary outcome measure was angiographic outcome score (AOS). RESULTS: 70 patients (89 DR procedures), including 37.9% adults (&gt;18 yr), were operated over a duration of 8 years and followed up for 2 years (mean). Long-term bypass-patency rates were deemed 83.3% and 88.8% in children and adults respectively. In pediatric age group, median mRS scores improved from 3 to 2 (p = 0.001), 97.3% were free of recurrent strokes and AOS scores improved significantly (p = 0.002). Amongst adult MMD patients, median mRS score marginally improved from 3 to 2 (p = 0.25), 100% were free of recurrent strokes and AOS improved significantly (p=0.02). On comparing pediatric and adult patients, improvement in mRS scores (p = 0.14) and AOS scores (p = 0.65) were similar across the two age groups. Overall late stage MMD patients (Suzuki stages IV-VI) showed better improvement in mRS scores when compared with early stage MMD patients (Suzuki stages I-III; p = 0.04). Recurrent stroke rates were similar in both groups (p = 0.26). AOS scores improved significantly in both early and late stage MMD (p &lt; 0.001 in both), though the improvement amongst the two groups was similar (p = 0.88). CONCLUSIONS: Using meticulous surgical technique, excellent long-term bypass patency rates can be achieved to facilitate optimal clinical and angiographic outcome in symptomatic MMD patients, irrespective of the age group and stage of disease.

Sonolucent Cranioplasty in Extracranial to Intracranial Bypass Surgery: Early Multicenter Experience of 44 Cases.

The new sonolucent cranioplasty implant (clear polymethyl methacrylate, PMMA) adds functionality besides surgical reconstruction. One possible application uses the transcranioplasty ultrasound (TCUS) technique after PMMA cranioplasty to assess graft patency of extracranial-intracranial (EC-IC) bypass procedures. To report our early multicenter experience. This is a multicenter analysis of consecutive EC-IC bypass patients from 5 US centers (2019-2022) with closure postbypass using PMMA implant. Forty-four patients (median age 53 years, 68.2% females) were included. The most common indication for bypass was Moyamoya disease/syndrome (77.3%), and superficial temporal artery to middle cerebral artery bypass was the most common procedure (79.5%). Pretreatment modified Rankin Scales of 0 and 1 to 2 were noted in 11.4% and 59.1% of patients, respectively. Intraoperative imaging for bypass patency involved a combination of modalities; Doppler was the most used modality (90.9%) followed by indocyanine green and catheter angiography (86.4% and 61.4%, respectively). Qualitative TCUS assessment of graft patency was feasible in all cases. Postoperative inpatient TCUS confirmation of bypass patency was recorded in 56.8% of the cases, and outpatient TCUS surveillance was recorded in 47.7%. There were no cases of bypass failure necessitating retreatment. Similarly, no implant-related complications were encountered in the cohort. Major complications requiring additional surgery occurred in 2 patients (4.6%) including epidural hematoma requiring evacuation (2.3%) and postoperative surgical site infection (2.3%) that was believed to be unrelated to the implant. This multicenter study supports safety and feasibility of using sonolucent PMMA implant in EC-IC bypass surgery with the goal of monitoring bypass patency using TCUS.

Early Experience of Surgical Planning for STA-MCA Bypass Using Virtual Reality

The superficial temporal artery (STA)-to-middle cerebral artery (MCA) bypass requires precise preoperative planning, and 3-dimensional virtual reality (VR) models have recently been used to optimize planning of STA-MCA bypass. In the present report, we have described our experience with VR-based preoperative planning of STA-MCA bypass. Patients from August 2020 to February 2022 were analyzed. For the VR group, using 3-dimensional models from the patients' preoperative computed tomography angiograms, VR was used to locate the donor vessels, potential recipient, and anastomosis sites and plan the craniotomy, which were referenced throughout surgery. Computed tomography angiograms or digital subtraction angiograms were used to plan the craniotomy for the control group. The procedure time, bypass patency, craniotomy size, and postoperative complication rates were assessed. The VR group included 17 patients (13 women; age, 49 ± 14 years) with Moyamoya disease (76.5%) and/or ischemic stroke (29.4%). The control group included 13 patients (8 women; age, 49 ± 12 years) with Moyamoya disease (92.3%) and/or ischemic stroke (7.3%). For all 30 patients, the preoperatively planned donor and recipient branches were effectively translated intraoperatively. No significant difference were found in the procedure time or craniotomy size between the 2 groups. Bypass patency was 94.1% for the VR group (16 of 17) and 84.6% for the control group (11 of 13). No permanent neurological deficits occurred in either group. Our early experience has shown that VR can serve as a useful, interactive preoperative planning tool by enhancing visualization of the spatial relationship between the STA and MCA without compromising the surgical results.

Routine Completion Angiography for Infrainguinal Bypasses Using Prosthetic Conduit: No Effect on Postoperative Patency

Recent studies have demonstrated increased postoperative patency with the use of routine completion angiography for bypass using venous conduit. Compared to vein conduits, however, prosthetic conduits are less plagued by technical issues such as unlysed valves or arteriovenous fistulae. The effect of routine completion angiography on bypass patency in prosthetic bypasses has yet to be compared to the more traditional selective use of completion imaging. A retrospective review of all infrainguinal bypass procedures using prosthetic conduit completed at a single hospital system from 2001 to 2018 was performed. Demographics, comorbidities, intraoperative reintervention rates, and 30-day rates of graft thrombosis were analyzed. Statistical analysis included t-tests, chi-square tests, and cox regression. Four hundred and ninety-eight bypasses that were performed in 426 patients met inclusion criteria. Fifty-six (11.2%) bypasses were classified into the routine completion angiogram group compared to 442 (88.8%) into the no completion angiogram group. Patients who underwent routine completion angiograms had a rate of intraoperative reintervention of 21.4%. When comparing bypasses that underwent routine completion angiography versus no completion angiography, there were no significant differences in rates of reintervention (3.5% vs. 4.5%, P=0.74) or graft occlusion (3.5% vs. 4.7%, P=0.69) at 30-days postoperatively. Almost one-quarter of lower extremity bypasses using prosthetic conduit that undergo routine completion angiography undergo postangiogram bypass revision; however, this is not associated with an increased graft patency at 30 days postoperatively.

Hypothenar hammer syndrome: outcomes after ulnar artery reconstruction with autologous vein graft

The most common surgical procedure for the treatment of hypothenar hammer syndrome (HHS) is resection of the pathological segment followed by arterial reconstruction using a venous bypass. Bypass thrombosis occurs in 30% of cases, with various clinical consequences, ranging from no symptoms to reappearance of the preoperative clinical symptoms. We reviewed 19 patients with HHS who underwent bypass graft, to assess clinical outcomes and graft patency, with a minimum follow-up of 12 months. Objective and subjective clinical evaluation and ultrasound exploration of the bypass were carried out. Clinical results were compared according to bypass patency. At a mean follow-up of 7 years, 47% of patients had complete resolution of symptoms; symptoms were improved in 42% of cases, and unchanged in 11%. Mean QuickDASH and CISS scores were 20.45/100 and 28/100, respectively. Bypass patency rate was 63%. Patients with patent bypass had shorter follow-up (5.7 vs 10.4 years; p = 0.037) and a better CISS score (20.3 vs 40.6; p = 0.038). There were no significant differences between groups for age (48.6 and 46.7 years; p = 0.899), bypass length (6.1 and 9.9 cm; p = 0.081) or QuickDASH score (12.1 and 34.7; p = 0.084).Arterial reconstruction gave good clinical results, with the best results in case of patent bypass.Level of evidence: IV.

Assessment of bypass patency using transcranial Doppler sonography: correlations with computerized tomography angiography findings in patients with moyamoya disease

To explore the utility of transcranial Doppler (TCD) findings when assessing bypass patency in patients with Moyamoya disease (MMD). Computed tomography angiography (CTA) and TCD sonography (TCDS) were performed before and after surgery to evaluate bypass patency. The peak systolic flow velocity (PSV) of the superficial temporal artery (STA) and the pulsatility index (PI) were compared between the groups that achieved patency and not, and receiver operating characteristic (ROC) curve analyses were used to define the TCDS criteria revealing patency. This study included 35 hemispheres (15 women; mean age 47 years) with Moyamoya disease who underwent STA-middle carotid artery bypass in our institution between January 2022 and October 2022. The PSV first increased on postoperative days 4-5 and then decreased on postoperative days 6-7 and 7-8. Patients with transient neurological diseases (TNDs), compared to those without, evidenced a significantly lower PSV value (P < 0.05). Compared with the non-patency group, the PSV was higher (P < 0.001) in the patency group. The cutoff values reflecting patency with good sensitivity and specificity were PSV > 49.00; PSV ratio (postoperative/preoperative) > 1.218; PSV ratio (operation side/contralateral side) > 1.082; and PSV ratio (adjusted) > 1.202. In the patency group, the PSV and PI significantly increased (P < 0.001) and decreased (P < 0.001) respectively. Bypass patency can be noninvasively and accurately evaluated via TCDS, affording an objective basis for assessment of the effect of revascularization surgery on patients with MMD.

Three-Year Patency Results following Endovascular Transvenous Femoropopliteal Bypass

Background and Objectives: Peripheral artery disease is one of the most common vascular pathologies. There is an ongoing debate among specialists on whether open or endovascular revascularization is preferred in cases of complex superficial femoral artery (SFA) lesions. The purpose of this study was to assess patency results of a relatively new transvenous endovascular bypass device. This could add to existing evidence and aid in comparison between open and endovascular bypass. Materials and Methods: Patients with complex TASC-C and D SFA lesions who had indications for revascularization were identified. Prospective analysis of stent graft patency from 54 transvenous femoropopliteal bypass procedures was performed. Patency was assessed by Duplex ultrasound every six months. Kaplan-Meier analysis was performed to assess primary, primary-assisted, and secondary patency of transvenous bypass. Results: Following endovascular transvenous femoropopliteal bypass, 3-year graft primary, primary-assisted, and secondary patency was 43.8%, 66.3%, and 73.9%, respectively. Conclusions: Transvenous endovascular femoropopliteal bypass is a viable option for selected patients who lack adequate saphenous vein or have comorbidities that increase the risk of open femoropopliteal bypass. Strict post-operative follow-up is necessary to improve patency rates.

The Hibiscus Model: A Feasible Cadaveric Model Using Continuous Arterial Circulation for Intracranial Bypass Training and Its Validation

The frequency of intracranial bypass procedures has declined. Thus it is difficult for neurosurgeons to develop the necessary skills for this complex procedure. We present a perfusion-based cadaveric model to provide a realistic training experience with high anatomic and physiological fidelity, as well as instantaneous assessment of bypass patency. Validation was assessed by evaluating the educational impact and skill improvement of the participants. Fourteen participants attended a hands-on revascularization course with 7 cadaveric models connected to a continuous arterial circulation system pumping a red-colored solution through the entire cranial vasculature, mimicking blood circulation. The ability to perform a vascular anastomosis was evaluated initially. Further, a questionnaire on prior experience was provided. At the end of the 36-hour course, the ability to perform an intracranial bypass was reexamined and the participants completed a self-assessment questionnaire. Initially, only 3 attendees were able to perform an end-to-end anastomosis within the time limit, and only 2 of these anastomoses showed adequate patency. After having accomplished the course, all participants were able to complete a patent end-to-end anastomosis within the time limit, thus demonstrating a significant improvement. Further, both overall educational gain and surgical skills were regarded as remarkable (n= 11 and n= 9). Simulation-based education is considered an important aspect of medical and surgical development. The presented model is a feasible and accessible alternative to the prior models used for cerebral bypass training. This training may serve as a helpful and widely available tool to improve neurosurgeons' development irrespective of financial resources.

Influence of Patient and Technical Variables on Combined Direct and Indirect Cerebral Revascularization: Case Series.

Cerebral bypass for flow augmentation is an important technique for selected neurosurgical patients, with multiple techniques used (direct, indirect, or combined). To assess the impact of patient and technical variables on direct and indirect bypass flow after combined revascularization. This was a retrospective, single-institution review of patients undergoing direct superficial temporal artery-to-middle cerebral artery bypass with indirect encephaloduro-myosynangiosis for moyamoya disease and steno-occlusive cerebrovascular disease over a 2-year period. We evaluated the effect of baseline patient characteristics, preoperative imaging characteristics, and operative variables on direct and indirect patency grades. Twenty-six hemispheres (8 moyamoya disease and 18 steno-occlusive cerebrovascular disease) in 23 patients were treated with combined revascularization. The mean patient age was 53.4 ± 19.1 years. Direct bypass patency was 96%. Over a mean follow-up of 8.3 ± 5.4 months, there were 3 strokes in the treated hemispheres (11.5%). The mean modified Rankin Scale score improved from 1.3 ± 1.1 preoperatively to 0.7 ± 0.8 postoperatively. Preservation of the nondonor superficial temporal artery branch was associated with a lower direct bypass grade ( P < .01), whereas greater mean time to maximum perfusion (Tmax)> 4 and >6 seconds and mismatch volumes were associated with higher direct bypass grades ( P < .05). Tmax >4-second volume inversely predicted indirect bypass patency. Patient and technical variables may influence the relative contributions of the direct and indirect components of combined revascularizations.

Ultrasonographic Appearance of the Lower Extremity Arteries After Femoropopliteal Bypass Surgery

Objective: The aim of this study was to assess the ultrasonographic appearance of the lower extremity arteries, after a femoropopliteal bypass surgery. Materials and Methods: Ninety patients, with atherosclerotic peripheral artery disease, underwent either autologous vein (30 subjects) or synthetic femoropopliteal bypass grafting, using an end-to-side (30 subjects) or end-to-end anastomotic technique. The outcomes were compared to 30 volunteers, who were recruited to serve as healthy controls. A lower extremity duplex ultrasonogram (DUS) was performed 1 year after treatment. The healthy volunteers underwent DUS at the point of being included in the study. Results: In healthy volunteers, the angle between the profunda femoris artery (deep femoral artery, PFA) and common femoral artery (CFA) did not exceed 30° of angulation. The diameter of the CFA, in the bifurcation area, was 9.8 ± 1.5 mm. The bypass patency rates, CFA diameter, PFA angle, and neointimal hyperplasia rates differed between the groups as presented. Conclusion: The results that were obtained may indicate the importance of bypass graft surveillance, using DUS, with precise analysis of the topography and geometry of the lower extremity arteries and vascular conduits, during the perioperative period. In addition, in this cohort, femoropopliteal bypass procedures were associated with an increase in the angle of the PFA from 30° to 80° of angulation. An increase in the diameter of the CFA in the area of the proximal anastomosis from 9.8 to 15.1 mm was also noted. In these patients, the saphenous vein bypasses were associated with minimal changes of the vascular geometry and better patency rates.

Influence of crural vessel run-off on short- and mid-term outcomes following femoro-popliteal bypass grafting.

To determine the influence that the number of patent crural run-off vessels has on short- and mid-term outcomes following femoro-popliteal bypass. All patients undergoing index femoro-popliteal bypass grafting between 2013 and 19 at our unit were included. Preoperative imaging was used to stratify patients into cohorts with either one or ≥2 patent run-off vessels. Primary outcomes measures included bypass patency and limb salvage rates at one and 3years post-operatively. Survival analysis was performed using Kaplan-Meier curves and Logrank test. 147 bypasses performed on 143 patients were included. 24 patients had one-vessel run-off and 123 had ≥2 vessels patent. Patients with one-vessel run-off had a higher proportion of emergency admissions (54% vs 41%) and diabetes (42% vs 31%). 31% of patients underwent diagnostic angiogram imaging in addition to having duplex ultrasound and/or computed tomography angiography. There were no significant differences in primary, primary-assisted or secondary patency rates between the cohorts at 12 or 36 months. Limb salvage rates were significantly higher amongst those with ≥2 vessel run-off at 12 (86% vs 71%, p = 0.03) and 36 (85% vs 71%, p = 0.04) months. For those with occluded grafts, a higher proportion of patients with ≥2 vessel run-off subsequently had an attempt at redo bypass grafting. Femoro-popliteal bypass is a reasonable treatment option for patients with one-vessel run-off. However, whilst patency rates are comparable, clinicians should be aware of the lower successful limb salvage rates for patients with one patent vessel (especially those presenting with tissue loss).

A chart review on surgical myocardial debridging in symptomatic patients: a safe procedure with good long-term clinical outcome and coronary computed tomographic angiography results

Myocardial bridging is mostly diagnosed as an incidental imaging finding but can result in severe vessel compression and significant clinical adverse complications. Since there is still an ongoing debate when to propose surgical unroofing, we studied a group of patients where this was performed as an isolated procedure. In 16 patients (38.9 ± 15.7 years, 75% men) who had surgical unroofing for symptomatic isolated myocardial bridges of the left anterior descending artery, we retrospectively analysed symptomatology, medication, imaging modalities used, operative techniques, complications and long-term outcome. Computed tomographic fractional flow reserve was calculated to understand its potential value for decision-making. Most procedures were performed on-pump (75%, mean cardiopulmonary bypass 56.5 ± 27.9 min, mean aortic cross-clamping 36.4 ± 19.7 min). Three patients needed a left internal mammary artery bypass since the artery dived inside the ventricle. There were no major complications or deaths. The mean follow-up was 5.5 years. Although there was a dramatic improvement in symptoms, still 31% experienced atypical chest pain at various moments during follow-up. Postoperative radiological control was performed in 88%, showing no residual compression or recurrent myocardial bridge and patent bypass if performed. All postoperative computed tomographic flow calculations (7) showed a normalization of coronary flow. Surgical unroofing for symptomatic isolated myocardial bridging is a safe procedure. Patient selection remains difficult but introducing standard coronary computed tomographic angiography with flow calculations could be helpful in preoperative decision-making and during follow-up.

Infrainguinal bypass using varicose veins with external scaffolding

Background: Chronic limb-threatening ischemia (CLTI) is associated with high rates of mortality, amputation, and impaired quality of life. The great saphenous vein (GSV) is the first-choice material for surgical revascularization of the infrapopliteal arteries. It may occur that the autologous material is not of good quality, presenting varicosities and ectasias which can affect bypass patency. The long-term patency rate of these operations is still not clear and few evidences are still present in literature. The aim of our study is to report the technical feasibility and efficacy of infrainguinal bypasses performed with autologous ectatic or varicose vein and with the use of external vascular supports. Materials and Methods: From September 2005 to January 2023, infrainguinal venous bypasses with autologous varicose or ectatic vein using an external vascular support were collected in the present study. The indication for surgery was the presence of CLTI with rest pain and/or gangrene. In case of localized dilatations of a segment of the GSV a partial bypass scaffolding (i.e. 10 to 15 cm) was used. Patients with a long segment of varicose vein underwent a completely covered ex situ vein bypass after a bench devalvulation. Follow-up was performed at 1, 3, 6 and 12 months and every 6 months thereafter, by clinical examination and color Doppler ultrasound. The outcome measures were technical success, 30-day and long-term primary and primary assisted bypass patency, as well as the limb salvage rate. External support infection rates upon reoperation for surgical wound infection as well as graft aneurysmal dilatation over time were also analyzed. Results: 63 patients underwent infrainguinal bypass with autologous varicose or ectatic venous material. In 51 patients (80.9%) the GSV was used, in 3 cases (4.8%) the short saphenous vein (SSV) and in 9 cases (14.3%) a composition of both saphenous veins or with one arm vein. Technical success was achieved in all cases and the mean surgical time was 320±80 minutes. No intraoperative mortality was recorded. At 30 days the primary patency and limb salvage rate were 97.8%, due to two early bypass occlusions. No infections of the external vascular support were recorded. During a mean follow-up of 54.6±27.2 months 8 (13.1%) hemodynamic stenoses requiring reoperation and 3 (4.9%) thromboses of the bypass were found. The primary patency rate was 62.8%, assisted primary 76.3%, with a limb salvage rate of 78%. Conclusion: In our experience, the great saphenous vein, even if ectatic or varicose, has proved to be a valuable conduit for the preparation of a infrainguinal bypasses in CLTI patients, with a satisfactory patency and limb salvage rates. In addition, composite vein graft also using arm vein, could be used in infrainguinal bypass with acceptable results. Also in the light of these results, a “saphenous sparing" surgical approach during corrective surgery for venous insufficiency of the lower limbs should be recommended, so as not to preclude future surgical treatments for limb salvage.

Femorodistal bypasses using venous “cuffs”

Background/Aim. Although distal venous patch and cuff techniques are recommended to improve the patency of by-pass in the lower extremities, the advantage of these techniques remains unproven. Autovenous bypass graft remains the method of choice, but when there is no possibility of using the great saphenous vein, the venous cuff method may have an advantage. The aim of this study was to evaluate the results of femorodistal bypass procedures with a venous cuff in critical lower extremity ischemia. Methods. The study described the results of femorodistal bypass procedures after a follow-up period of 6 to 24 months. We followed 28 patients with distal composite anastomosis of femorodistal arterial reconstruction. Indications for surgical treatment were set on the basis of the clinical exam and morphological criteria based on multidetector computed tomographic angiography. Three types of distal graft-arterial anastomoses were applied: Miller?s cuff, Taylor?s patch, and St. Mary?s vein boot anastomosis. Results. After 6 months of surgery, all bypasses were passable; after one year, 2 (7%) patients had graft occlusion and above-knee amputation, and 8 (28%) patients died; after 24 months, 18 (64%) patients had primary bypass patency. Conclusion. Femorodistal bypass procedures using a synthetic graft and venous cuff have good long-term results. The optimal anastomosis type is St. Mary?s boot. A longer follow-up period and comparison with the autovenous bypass are necessary for a more detailed assessment of the final conclusion.

Importance of Flow Waveform and Flow Volume as Prognostic Indicators for the Patency of Infra-Inguinal Autologous Vein Bypass

To investigate the association of the intraoperative flow waveform and the flow volume with the graft prognosis of infrainguinal vein bypass. Retrospective study. Intraoperative flowmetry was performed for infrainguinal autologous vein bypass between 2011 and 2020. Flow waveforms were classified into type 0-IV according to the Kyushu University (KU) classification. The patients (n=340) were divided into three groups based on the flow waveform predicting the graft patency: type 0/I (long patency), type II (no early occlusion but late occlusion possible) and type III/IV (early occlusion). The graft occlusion rates of popliteal artery bypass (PAB) and infrapopliteal artery bypass (IPAB) within 30 days after surgery were compared between type 0/I+II and type III/IV groups, while the mid-term graft patency rates were compared between type 0/I and type II groups. Additionally, a multivariate analysis was performed to identify independent risk factors for early and late graft occlusion. The early graft occlusion rates of type 0/I+II and type III/IV groups were 3.9 % and 0%, respectively, (p=1.00) for PAB and 5.3 % and 46.2% respectively, (p<.001) for IPAB. The 2 years' primary patency rates of type 0/I and type II groups were 91% and 75%, respectively, (p= .030) for PAB and 58% and 63%, respectively, (p= .72) for IPAB. An independent risk factor for early occlusion was none in PAB and flow waveform (type IV) in IPAB. An independent risk factor in PAB was flow waveform (type II), end-stage renal disease, and dual antiplatelet use and those in IPAB were older age, female sex, lower flow volume, and iterative bypass for primary patency loss. Intraoperative flowmetry is useful for predicting the graft prognosis in infrainguinal vein bypass and its significance depends on the distal target artery.

How I do it: internal maxillary artery to middle cerebral artery bypass to manage giant thrombosed internal carotid artery aneurysm.

Internal maxillary artery (IMA) bypass has become popularized due to its medium-to-high blood flow, short graft length, and well-matched arterial caliber between donor and recipient vessels. We described an open surgery of a NEW "workhorse," the IMA bypass, to treat a giant, thrombosed cerebral aneurysm. The extracranial middle infratemporal fossa (EMITF) approach was used to unveil the pterygoid segment of the IMA for cerebral revascularization. Although this technique is technically challenging, the variations in IMA can be effectively identified and sufficiently exposed in this technique to achieve favorable clinical outcomes with a high bypass patency rate.