Donor Artery Research Articles

Anatomic Variation of the Superficial Temporal Artery and Posterior Auricular Artery in a Pediatric Moyamoya Disease Population.

In certain cases of pediatric patients with Moyamoya disease undergoing encephaloduroarteriosynangiosis (EDAS) treatment, the posterior auricular artery can be used as an alternative when the parietal branch of the superficial temporal artery is unavailable. In this study, anatomic variations of the superficial temporal and posterior auricular arteries in pediatric patients with Moyamoya disease and postoperative outcomes of posterior auricular artery-EDAS are explored. Medical records of 572 patients with Moyamoya disease who underwent surgical procedures from 2007 to 2017 at the Seoul National University Children's Hospital were reviewed. Anatomic classifications of the superficial temporal and posterior auricular arteries were based on previous classifications. Postoperative hemodynamic changes of posterior auricular artery-EDAS were analyzed using the Matsushima grade. Also, Karnofsky Performance Scale and mRS scores of posterior auricular artery-EDAS cases were reviewed to identify postoperative clinical outcomes. Among 1144 hemispheres, 24 were considered posterior auricular artery-EDAS candidates (2.1%). Of those, 10 hemispheres underwent posterior auricular artery-EDAS (41.7%, in total hemispheres 0.9%). Comparing the Matsushima grades of the superficial temporal artery-EDAS and posterior auricular artery-EDAS groups showed similar postoperative revascularization. Postoperative Karnofsky Performance Scale and mRS scores of patients having undergone posterior auricular artery-EDAS did not show deterioration. In approximately 2% of pediatric patients with Moyamoya disease for whom the superficial temporal artery is unavailable as the EDAS donor, the posterior auricular artery can be considered an alternative. On the basis of the results, the clinical outcome of posterior auricular artery-EDAS was not inferior to that of superficial temporal artery-EDAS. Hence, we suggest an in-depth consideration of the posterior auricular artery as the donor artery if the superficial temporal artery parietal branch is unavailable.

Sleeve Technique is Superior to End-to-End Anastomosis and Cuff Technology in Mouse Model of Graft Vascular Disease

Graft vascular disease (GVD) is the main reason of late transplanted organ failure, which limits the long-term survival of patients. Murine aortic transplant is widely used in the field to understand the mechanisms leading to GVD. Currently, 3 major techniques, end-to-end anastomosis, sleeve suture and cuff technology, have been used to study the mechanism of GVD. However, which method is more suitable in mouse model of GVD? Herein, we compared these 3 surgical techniques in a mouse allograft arteriosclerosis model to determine the technique with the most appreciable outcomes. Male C57Bl/6 (H-2b) and BALB/c (H-2d) mice were used for aorta transplantation with these 3 techniques. These 3 techniques were compared with regard to donor artery acquisition time, artery anastomosis time, overall surgical time, the amount of bleeding of each technique and the success rate of surgery. Hematoxylin and eosin (H&E) and Masson staining were used to examine the pathological changes of grafted vessels. The protein expression of phospho-NF-κb P65 and PCNA were determined to validate laminar flow and proliferative capacity of neointima obtained from different surgical and control groups. Sleeve suture had a shorter vascular anastomosis time and total operation time than end-to-end anastomosis and cuff technique. Sleeve suture and cuff technique had significantly fewer amount of bleeding from the site of vascular anastomosis than end-to-end anastomosis. Moreover, sleeve suture had the highest success rate among these 3 techniques. There was no difference in the degree of graft stenosis and collagen deposition between these 3 techniques. In addition, there was no significant difference in the expression of phospho-NF-κb P65and PCNA between the experimental group. Sleeve suture is superior to end-to-end anastomosis and cuff technique with regard to vascular grafting in the murine model.

Surgical Tips for STA-MCA Bypass from Misato Central General Hospital

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is an essential technique, not just for treating cerebral ischemia but also for assisting aneurysm clipping and compensating for unexpected vascular injuries during surgery.Although it is becoming a more fundamental surgery technique because of the provision of off-the-job training, there are several points that should be considered to achieve successful anastomosis. In this article, we describe important points and tips to consider during STA-MCA bypass.To perform a successful anastomosis, it is important to ensure the following: (1) creation of an operative view without blood and cerebrospinal fluid, (2) selection of a suitable recipient artery, and (3) prevention of anastomosis occlusion.A recipient artery that runs downward from right to left (when the operator is right-handed) is considered suitable because of easier needle handling while suturing. Suturing the backside and inversion of the anastomosis should be avoided to prevent anastomosis occlusion. To avoid suturing the backside, we perform an oval arteriotomy on the recipient artery instead of a linear incision. Furthermore, difficult anastomosis is prioritized, and stay sutures and bilateral sutures are performed by the marked pin method and T-junction bypass when anastomosing in part with a large-diameter branch. To avoid inversion, we require the stitch interval of the donor and recipient arteries to be at a ratio of 6:4. We also tie a knot by pulling the thread from the donor side, which ensures that the inner membranes are attached together.Anastomosis is the most important procedure because the ultimate goal of this operation is to prevent cerebral ischemia by achieving long-term patency. The technique should be unified and simplified so that it is available for even young neurosurgeons.The techniques we have introduced are not difficult or complicated, although they can only be put into practice after acquiring the basic skills. Therefore, young neurosurgeons must continue training and preparing for surgeries.

Combined Bypass and Cerebral Aneurysm Surgery:How to Choose and Practice?

The treatment for cerebral aneurysms has been changing along with the advancements in endovascular treatment. In particular, the induction of a flow-diverter stent can treat even cavernous portion aneurysms, which have been difficult to treat without parent artery occlusion. The definite advantages of the open surgery are low recurrence rates, high angiographic outcome, and bypass. Herein, we describe the bypass method for treating cerebral aneurysms. The purpose of the bypass, difference between high-flow and low-flow bypasses, how to select the donor artery, and variation of bypass technique are described.

The dynamic effect of coronary artery bypass grafting on the instantaneous wave-free ratio in the collateral donor artery of a patient with chronic total occlusion.

Physiological assessment is challenging in patients with multivessel disease (MVD) with a chronic total occlusion (CTO) and may result in inappropriate treatment decisions. We report herein, for the first time to our knowledge, on the dynamic changes of the instantaneous wave-free ratio in the CTO collateral donor artery before and after coronary artery bypass grafting (CABG). Our case highlights the paramount importance of collateral circulation when interpreting invasive indices of coronary stenosis severity to guide decision-making for CABG in MVD patients with a CTO. This may be particularly relevant to reduce the risk of early graft failure in patients with MVD undergoing CABG.

Quantitative analysis of renal arterial variations affecting the eligibility of catheter-based renal denervation using multi-detector computed tomography angiography

Catheter-based renal denervation (RDN) was introduced to treat resistant hypertension. However, the reduction in blood pressure after the RDN was modest. Catheter-based RDN was performed only at main renal arteries, except for accessory and branch arteries due to the diameter being too small for the catheter to approach. Here, we retrospectively analyzed the anatomy of diverse renal arteries via 64-channel multi-detector computed tomography angiograms of 314 consecutive donors who underwent living donor nephrectomy from January 2012 to July 2017. Occurrence rates of one or more accessory renal arteries in donors were 25.3% and 19.4% on the left and right sides, respectively. Early branching rates before 25 mm from the aorta to the right and left renal arteries were 13.7% and 10.5%, respectively. Overall, 63.1% and 78.3% of donors had no accessory artery bilaterally and no branched renal artery, respectively. As a result, 47.1% had only main renal arteries without an accessory artery and early-branching artery. Approximately half of the donors had multiple small renal arteries bilaterally, for which catheter-based denervation may not be suitable. Thus, preoperative computed tomography angiography requires careful attention to patient selection, and there is a need for improved methods for denervation at various renal arteries.

Time-dependent improvement in coronary flow reserve in collateral donor artery following successful recanalization of the Coronary Chronic Total Occlusion

Abstract Background Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment. Purpose Study aim was to assess time-dependent changes in coronary flow reserve (CFR) in collateral donor artery after CTO recanalization and identify factors that influence these changes. Methods Our study enrolled 31 patients with CTO scheduled for percutaneous coronary intervention (PCI). Non-invasive CFR was measured before PCI in collateral donor artery, and 24h and 6 months post-PCI in CTO and collateral donor artery. Gated SPECT MIBI was performed before PCI, while quality of life was assessed by Seattle angina questionnaire (SAQ) pre-PCI, and 6 months after PCI. Results Collateral donor artery showed significant increase in CFR 24h after CTO recanalization compared to pre-PCI values (2.30±0.49 vs. 2.71±0.45, p=0.005), which remained unchanged after 6 months (2.68±0.24). Maximum baseline blood flow velocity of the collateral donor artery showed significant decrease measured 24h post-PCI compared to pre-PCI values (0.28±0.06 vs. 0.24±0.04m/s), and remained similar after 6-months. There was no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24h and 6 months post-PCI. CFR change of the collateral donor artery 24h post-PCI compared to pre-PCI values showed inverse correlation with left ventricle ejection fraction (LVEF) measured on SPECT. CFR changes showed no correlation with the changes in quality of life assessed by SAQ post-PCI compared to pre-PCI. Conclusions Significant increase in CFR of the collateral donor artery was observed within 24h after successful recanalization of CTO artery, which maintained constant after the 6 months follow-up. This increase was largely driven by the significant reduction in the maximum baseline blood flow velocity within 24h after CTO recanalization compared to pre-PCI values. Our results suggest that possible benefit of CTO recanalization could be the improvement in physiology of the collateral donor artery. Funding Acknowledgement Type of funding source: None

STITCH TO STENT: A VASCULAR COMPLICATION OF LUNG TRANSPLANTATION

SESSION TITLE: Medical Student/Resident Transplantation Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Lung transplantation (LTx) is an established treatment for end-stage lung diseases. Pulmonologists will be well-served to be familiar with its complications. We describe a patient with a vascular complication of LTx which is often associated with significant mortality and morbidity. CASE PRESENTATION: A 61-year-old man was admitted with hypoxic respiratory failure 3 months following bilateral LTx for bronchiectasis from Kartagener’s syndrome. Infection, rejection, and heart failure were all ruled out with x-ray, non-contrast CT scan and echocardiography. Bronchoscopy revealed scant clear secretions with negative cultures and no evidence of rejection on transbronchial biopsy. CT pulmonary angiography (CTPA) performed to rule out embolism revealed a severe right pulmonary artery stenosis (PAS) at the anastomotic site. The lesion was dilated with balloon angioplasty resulting in mild improvement on follow up CT scans. Quantitative perfusion scan estimated only 18% perfusion in the right lung due to stenosis of the right pulmonary artery. Angiography was repeated and an Express LD ® 10 mm x 25 mm balloon-expandable stent was placed across the stenosis. Right pulmonary artery blood flow and hypoxia improved, and the patient was soon discharged. At 1 month follow up, right lung perfusion improved to 41%. DISCUSSION: Anastomotic PAS is defined as an anastomotic diameter of 75% or less that of the neighboring vessels. Causes include mismatched lengths of donor and recipient pulmonary artery segments, twisting of the anastomosis, and thrombosis. Clinical presentation is usually within 6 weeks of LTx with unexplained hypoxia and pulmonary hypertension. Delays in diagnosis and correction of PAS can lead to respiratory failure, hemodynamic compromise, and graft failure. Modalities for diagnosis include CTPA, magnetic resonance angiography, echocardiography and quantitative perfusion scanning. CTPA shows detailed anatomy after surgery thus helping to rule out other causes of hypoxia. Invasive pulmonary angiography is the gold standard for confirmation but is usually reserved for cases in which catheter-based intervention (CBI) is required. PAS can be corrected by surgical revision or CBI (angioplasty with or without stenting). The latter is becoming more common due to lower procedural risk, better tolerability and utility in late-presenting cases. Anticoagulants are used if thrombosis is present. CONCLUSIONS: LTx patients with persistent unexplained hypoxia should be evaluated for vascular complications, including anastomotic PAS, given high risk of mortality and morbidity. CTPA is a popular choice for diagnostic imaging. Although historically LTx patients with PAS had extremely poor prognosis, catheter-based stent intervention has the potential to prevent graft failure. Reference #1: Anaya-Ayala JE, Loebe M, Davies MG. Endovascular management of early lung transplant-related anastomotic pulmonary artery stenosis. J Vasc Interv Radiol 2015;26:878–882 Reference #2: Siddique A, Bose AK, Özalp F, Butt TA, Muse H, Morley KE, Dark JH, Parry G, Clark SC. Vascular anastomotic complications in lung transplantation: a single institution's experience. Interact Cardiovasc Thorac Surg. 2013 Oct;17(4):625-31 Reference #3: Batra K, Chamarthy MR, Reddick M, Roda MS, Wait M, Kalva SP. Diagnosis and interventions of vascular complications in lung transplant. Cardiovasc Diagn Ther. 2018 Jun;8(3):378-386. DISCLOSURES: no disclosure on file for Usman Ahmad; No relevant relationships by Christian Cuvillier Padilla, source=Web Response No relevant relationships by ihab Haddadin, source=Web Response No relevant relationships by Lirim Krveshi, source=Web Response No relevant relationships by Carli Lehr, source=Web Response No relevant relationships by Uddalak Majumdar, source=Web Response No relevant relationships by Atul Mehta, source=Web Response No relevant relationships by Wayne Tsuang, source=Web Response No relevant relationships by Maryam Valapour, source=Web Response

Double-Barrel Superficial Temporal Artery-M2 Middle Cerebral Artery Bypass and Creation of a Middle Communicating Artery via M2-M2 End-to-End Reimplantation for Trapping of a Dolichoectatic Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

Large dolichoectatic aneurysms of middle cerebral artery (MCA) trifurcations are rare and often require trapping and revascularization of the region with a bypass.1-9 This video describes the treatment of an MCA trifurcation aneurysm by clip trapping and double-barrel superficial temporal artery (STA) to M2-MCA bypass followed by M2-M2 end-to-end reimplantation to create a middle communicating artery (MCoA). The patient, a 60-yr-old woman, presented with headache, a history of smoking, and a family history of ruptured aneurysms. Angiography demonstrated a 1.7-cm dolichoectatic aneurysm of the MCA trifurcation. While the natural history of these lesions is unclear, the aneurysm size and family history of aneurysmal subarachnoid hemorrhage were factors in proceeding with treatment. Informed written consent was obtained from the patient and her family. The STA branches were harvested microsurgically, a pterional craniotomy was performed, and the aneurysm was exposed through a transsylvian approach. The two STA branches were anastomosed end-to-side to the middle and inferior trunks of the MCA. Due to the significant mismatch between the donor and recipient vessel calibers, we were concerned that the donors might provide insufficient flow in isolation. Therefore, we decided to transect both M2 trunks from the aneurysm, proximal to the inflow of the bypass, and reimplant them end-to-end. This reimplantation created an MCoA, allowing the two donor arteries to supply the new communication between the inferior and middle trunks, redistributing blood flow through the MCoA according to cerebral demand. Bypass patency and aneurysm obliteration were confirmed on postoperative angiography. At the 6-mo follow-up, the patient's modified Rankin Scale (mRS) score was 0. The MCoA is a novel construct that, like natural communicating arteries, redistributes flow in response to shifting demand, without the need for additional ischemia time during the bypass. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Isoform-specific characterization of class I histone deacetylases and their therapeutic modulation in pulmonary hypertension

Pharmacological modulation of class I histone deacetylases (HDAC) has been evaluated as a therapeutic strategy for pulmonary hypertension (PH) in experimental models of PH. However, information of their expression, regulation and transcriptional targets in human PH and the therapeutic potential of isoform-selective enzyme modulation are lacking. Comprehensive analysis of expression and regulation of class I HDACs (HDAC1, HDAC2, HDAC3 and HDAC8) was performed in cardiopulmonary tissues and adventitial fibroblasts isolated from pulmonary arteries (PAAF) of idiopathic pulmonary arterial hypertension (IPAH) patients and healthy donors. Cellular functions and transcriptional targets of HDAC enzymes were investigated. Therapeutic effects of pan-HDAC (Vorinostat), class-selective (VPA) and isoform-selective (CAY10398, Romidepsin, PCI34051) HDAC inhibitors were evaluated ex vivo (IPAH-PAAF, IPAH-PASMC) and in vivo (rat chronic hypoxia-induced PH and zebrafish angiogenesis). Our screening identifies dysregulation of class I HDAC isoforms in IPAH. Particularly, HDAC1 and HDAC8 were consistently increased in IPAH-PAs and IPAH-PAAFs, whereas HDAC2 and HDAC8 showed predominant localization with ACTA2-expressing cells in extensively remodeled IPAH-PAs. Hypoxia not only significantly modulated protein levels of deacetylase (HDAC8), but also significantly caused dynamic changes in the global histone lysine acetylation levels (H3K4ac, H3K9/K14ac and H3K27ac). Importantly, isoform-specific RNA-interference revealed that HDAC isoforms regulate distinct subset of transcriptome in IPAH-PAAFs. Reduced transcript levels of KLF2 in IPAH-PAAFs was augmented by HDAC8 siRNA and HDAC inhibitors, which also attenuated IPAH-associated hyperproliferation and apoptosis-resistance ex vivo, and mitigated chronic hypoxia-induced established PH in vivo, at variable degree. Class I HDAC isoforms are significantly dysregulated in human PAH. Isoform-selective HDAC inhibition is a viable approach to circumvent off-target effects.

Coronary physiology before and after chronic total occlusion treatment: what does it tell us?

Studies performed in the last two decades demonstrate that after successful percutaneous coronary intervention (PCI) of a chronically occluded coronary artery, the physiology of the chronic total occlusion (CTO) vessel and dependent microvasculature does not normalise immediately but improves significantly over time. Generally, there is an increase in fractional flow reserve (FFR) in the CTO artery, a decrease in collateral blood supply and an increase in FFR in the donor artery accompanied by an increase in blood flow and decrease in microvascular resistance in the myocardium supplied by the CTO vessel. Analogous to these physiological changes, positive remodelling of the distal CTO artery also occurs over time, and intravascular imaging can be helpful for analysing distal vessel parameters. Follow-up coronary angiography with physiological measurements after several weeks to months can be helpful and informative in a subset of patients in order to decide upon the necessity for treatment of residual coronary artery stenosis in the vessel distal to the CTO or in the contralateral donor artery, as well as in deciding whether stent optimisation is indicated. We suggest that such physiological guidance of CTO procedures avoids unnecessary overtreatment during the initial procedure, guides interventions at follow-up, and improves our understanding of what PCI in CTO means.

Prompt and consistent improvement of coronary flow velocity reserve following successful recanalization of the coronary chronic total occlusion in patients with viable myocardium

BackgroundCoronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment, but data on coronary hemodynamic changes in relation to myocardial function are limited. We assessed changes in coronary flow velocity reserve (CFVR) by echocardiography in collateral donor and recanalized artery following successful opening of coronary CTO.MethodsOur study enrolled 31 patients (60 ± 9 years; 22 male) with CTO and viable myocardium by SPECT scheduled for percutaneous coronary intervention (PCI). Non-invasive CFVR was measured in collateral donor artery before PCI, 24 h and 6 months post-PCI, and 24 h and 6 months in recanalized artery following successful PCI of CTO.ResultsCollateral donor artery showed significant increase in CFVR 24 h after CTO recanalization compared to pre-PCI values (2.30 ± 0.49 vs. 2.71 ± 0.45, p = 0.005), which remained unchanged after 6-months (2.68 ± 0.24). Baseline blood flow velocity of the collateral donor artery significantly decreased 24 h post-PCI compared to pre-PCI (0.28 ± 0.06 vs. 0.24 ± 0.04 m/s), and remained similar after 6 months, with no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24 h and 6 months post-PCI. CFVR of the recanalized coronary artery 24 h post-PCI was 2.55 ± 0.35, and remained similar 6 months later (2.62 ± 0.26, p = NS).ConclusionsIn patients with viable myocardium, prompt and significant CFVR increase in both recanalized and collateral donor artery, was observed within 24 h after successful recanalization of CTO artery, which maintained constant during the 6 months.Trial registrationClinicalTrials.gov (Number NCT04060615).

Matching Selection of Donor-Recipient Vessels in Revascularization Surgery Effectively Reduce the Incidence of Postoperative Hyperperfusion Syndrome in Adult Moyamoya Disease: A Retrospective Comparison Study

Introduction: Cerebral hyperperfusion syndrome (CHS) is one of the most serious complications after revascularization surgery in patients with moyamoya disease (MMD). However, there are few effective measures to prevent the occurrence of CHS. Objective: The present study aims to examine the effect of the method about matching selection of donor-recipient vessels during revascularization surgery on the incidence of postoperative CHS in adult MMD patients. Methods: 216 Chinese adult patients with MMD received surgery treatment between January 2018 and December 2019 in our hospital were enrolled in this study. 191 out of 216 patients were included in this study. Matching selection method was defined as follows: (1) blood flow: the direction of blood flow and speed of the donor artery and potential receptor arteries were measured by flow 800 indocyanine green video angiography; (2) vascular diameter: the diameters of the donor artery and potential receptor arteries by a miniature ruler. Only the artery with antegrade flow and with smallest difference in flow speed and diameter with the donor artery will be selected as the receptor artery to perform anastomosis. Matching selection was performed from January 2019. Digital subtraction angiography was performed in all patients for initial MMD diagnosis. Perioperative cerebral perfusion and related clinical symptoms were monitored. Clinical characteristics, contralateral progression, and risk factors were reviewed. The incidence of CHS and the correlation of CHS with baseline characteristics or clinical conditions were analyzed. Results: Of these 191 patients, 82 patients received matching selection of donor-recipient vessels during revascularization surgery and 109 patients without. The postoperative CHS incidence in the matching group was 3.66%, which was much lower than that in the nonmatching group (15.60%). Multivariate analysis did not reveal a significant risk factor between the progression group and the nonprogression group. Correlation analysis revealed only the matching selection method was significantly associated with the reduced postoperative CHS incidence in MMD patients. Conclusions: The matching selection of donor-recipient vessels during revascularization surgery effectively reduces the incidence of postoperative CHS in adult patients with MMD.

Free Tissue Transfer Using End-to-side Arterial Anastomosis for Limb Salvage in Patients With Lower Extremity Arterial Disease

Free tissue transfer (FTT) is an invaluable component of functional limb salvage in patients with large lower extremity wounds for whom limb amputation is the only alternative. The traditional FTT technique involves a donor vessel anastomosed in an end-to-end fashion to the recipient vessel. End-to-side anastomosis has rarely been utilized due to perceived technical difficulty with vessel size mismatch. In patients with single vessel runoff, an end-to-end anastomosis is contraindicated. Given our focus on limb salvage in patients with LEAD, we have almost exclusively utilized the end-to-side arterial anastomosis, and herein present our experience. A retrospective review of all patients undergoing FTT at a single institution from 2012 to 2020 was performed. All patients underwent preoperative arteriogram, and LEAD was defined as abnormal tibial runoff of any degree. All patients with evidence of LEAD were included for this analysis. Our operative approach has been previously described and involves a longitudinal arteriotomy in the inflow vessel. The flap donor artery is then sutured from heel to toe in an interrupted fashion under microscopic visualization. There were 141 free flaps performed during this period using an end-to-side anastomosis; 67 patients had evidence of LEAD by arteriography. Average age was 59 years (range, 19-87 years); 54% had diabetes; 18% had one vessel runoff to the foot; 58% had two vessel runoff to the foot; and 19% required preoperative endovascular intervention. Technical success of FTT was achieved in 97% of patients. At 30 days, the limb salvage rate was 96%. No patients died in the perioperative period. At a mean follow-up of 1.1 years, the overall limb salvage rate was 79%. Free flap survival rate was 92%. 83% of patients were ambulatory independently or with an assistive device on most recent follow-up. FTT in patients with LEAD and large wounds is a reasonable approach to limb salvage. End-to-side anastomosis is a feasible technique that allows free flap survival with preservation of distal flow.

AIUM Practice Parameter for the Performance of an Ultrasound Examination of Solid-Organ Transplants.

AIUM Practice Parameter for the Performance of an Ultrasound Examination of Solid-Organ Transplants.

Abstract TP488: Postoperative Remodeling of Donor Arteries on MR Angiography Can Predict Development of Surgical Collaterals in Moyamoya Disease

Object: The calibers of donor arteries can change dynamically after bypass surgery in moyamoya disease (MMD). The present study aimed to evaluate the cut-offs of caliber changes in donor arteries associated with good surgical revascularization and to assess the impact of clinical factors potentially related to bypass development. Methods: We studied 71 hemispheres of 30 adults and 16 children with MMD, who underwent combined revascularization. We quantitatively measured the calibers of the superficial temporal artery (STA), deep temporal artery (DTA), and middle meningeal artery (MMA) with magnetic resonance angiography (MRA) source images and calculated the postoperative caliber change ratios (CCRs), to assess direct and indirect bypass development. They were compared with the findings of digital subtraction angiography, in which revascularization areas were categorized into 3 groups (poor, good, and excellent). Results: In both adult and pediatric hemispheres, median STA and DTA CCRs were higher in better revascularization groups (p < 0.05), while MMA CCRs were not significantly different among the groups. Receiver operation characteristic analysis revealed that the cut-off of >1.1 and >1.3 STA CCRs were associated with good direct revascularization in adult and pediatric hemispheres, respectively. The cut-off of >1.6 and >1.2 DTA CCRs were associated with good indirect revascularization in adult and pediatric hemispheres, respectively. Considering these cut-off values, STA and DTA CCRs showed high median values, irrespective of age, severity of cerebrovascular reserve, disease stage, and disease onset type. Conclusions: Caliber changes in STA and DTA can be easily measured by MRA, which could be indicators of direct and indirect bypass development. The combined bypass procedure could maximize revascularization in both adults and children with MMD.

Unexpected presentation and surgical salvage of transplant renal artery dissection caused by vascular clamping: a case report

BackgroundTransplant renal artery dissection is a rare and serious event that can cause allograft dysfunction and activation of the renin–mediated renovascular hypertension. Most cases are induced by percutaneous transluminal angioplasty, arteriosclerotic disease, or fibromuscular dysplasia. We observed a case of transplant renal artery dissection induced by unusual causes during kidney transplantation.Case presentationA 35-year-old woman, whose mother donated a kidney to her, underwent ABO-incompatible living kidney transplantation. The allograft had one renal artery and vein that were anastomosed to the internal iliac artery and external iliac vein, respectively. Although careful handling was performed in all procedures including vascular clamping, Doppler ultrasonography (US) immediately after reperfusion showed an increase in the systolic blood velocity and urine output was not observed. Arterial anastomotic stenosis was suspected, but upon exploration, a renal artery dissection was detected in the middle portion of the donor artery. The part of the transplant renal artery was resected, and cold reflux was started again. At the resected part of transplant renal artery, dissection was identified. After re-anastomosis, Doppler US revealed that the blood flow of the renal artery was adequate without an increase in the systolic blood velocity, and sufficient blood flow was observed throughout the allograft. Urine output was also observed as soon as blood flow returned, and serum creatinine level decreased to 0.95 mg/dL after surgery. The cause of injury might have been vascular clamping in order to drain the air and check bleeding at the anastomosis.ConclusionsOur case reaffirmed that careful handling is needed in all procedures, including donor nephrectomy, cannulation for transplant perfusion, vascular clamping, and anastomosis, even without any evidence of arteriosclerosis. Kidney transplant recipients commonly have atherosclerosis and hypertension, which are risk factors for arterial dissection. Early diagnosis and intervention can lead to the prevention of allograft dysfunction. Therefore, close monitoring of allograft blood flow by Doppler US during surgery should be considered.

Incidence and Variations of Aberrant Renal Arteries in Kidney Donors Cases

The origin of renal arteries, vessel diameter, and point of entry to the kidney has all been analyzed as potential parameters which are a clinically relevant issue. This anatomical feature may be essential for fully understanding the process of renal perfusion, as it is not only the number of renal arteries that influences the extent of renal blood supply, also their diameter. The aberrant renal arteries that supply the inferior pole are more important because it provides arterial supply to the proximal part of the ureter. The objective of this study is to identify influences and prevalence of aberrant renal arteries of the kidney donors’ cases to perform role of the aberrant renal artery.Prevalence of aberrant renal artery was identified in 26.3% of the cases, incidence was more frequent in left than right side; about 78.7 % of cases presented unilaterally. The remaining cases 21.2 % were RAs presented bilaterally. Diameter of main RA in kidney presenting the RA was 5.73 mm and that of kidney with only single renal artery was 6.19 mm.

Surgical Anatomy of the Donor Arteries for Extracranial-Intracranial Bypass Surgery: An Anatomic and Radiologic Study

To review the microsurgical anatomy of the donor arteries for extracranial-intracranial bypass, namely, the superficial temporal artery (STA), occipital artery (OA), and internal maxillary artery (IMA). Seven cadaveric specimens were dissected to identify the relationships between each artery and its surrounding structures. Nineteen computed tomographic angiographic images of Japanese adult patients (38 sides) were analyzed to examine the course of each artery and to measure the diameters and distances from various anatomic landmarks to each artery. The courses of the STA, OA, and IMA, which must be exposed during revascularization procedures, were shown via cadaver dissection with special reference to the following relationships to surrounding structures: STA, soft tissue layers of the temporoparietal region and facial nerve; OA, suboccipital muscles; and IMA, mandibular nerve. In addition, we measured the diameter of the anastomotic site for each artery and its relationship with surrounding muscles. A precise understanding of the anatomic characteristics of the donor arteries and their relationships with surrounding structures provides safe access to these arteries.

A computed tomography angiography study to correlate main renal artery diameter with presence of accessory renal artery in healthy live kidney donors

Introduction: The chosen technique of surgery during nephrectomy can be influenced by the sudden discovery of an aberrant source of blood supply to the kidney. Thus, a prospective study was undertaken to investigate the relationship between the diameter of the main renal artery and the presence of an accessory renal artery by computed tomography (CT)-angiography. Material and Methods: The study was conducted on 115 healthy kidney donors who presented to the department of nephrology and radiology for voluntary kidney donation. All CT examinations were performed on a 64-slice CT scanner in the arterial phase. The number of the renal arteries supplying each kidney was evaluated and their diameters were measured. Results: Eighty-six of the right side and 88 of the left side of the 115 kidneys donors had a single renal artery whereas 29 had one or more accessory renal artery (aRA) on the right side and 27 had one or more aRA on the left side. The mean diameter of mRA was 5.4 ± 1.0 mm in kidneys without aRA and 4.6 ± 10 mm in kidneys with aRA on the right side and on the left side the mean diameter of mRA was 5.59 ± 1.12 mm in kidneys without aRA and 4.7 ± 1.2 mm in kidneys with aRA. Discussion and Conclusion: The presence of additional renal arteries is very probable when the main renal artery has a diameter of 5.5 mm very probably do not present additional renal arteries. Hence, the renal artery diameter is a factor which should be considered for predicting the presence of additional renal arteries.