Distal Ischemia Research Articles

376 Laser Interstitial Thermal Therapy for Deep-Seated Perivascular Brain Tumors: Evaluating the Risk of Distal Ischemia

INTRODUCTION: Laser interstitial thermal therapy (LITT) is a novel minimally invasive cytoreductive treatment option for primary and metastatic brain tumors. By relying on stereotactic guidance, the use of LITT carries a risk for direct and thermal vascular injury, especially when targeting deep-seated tumors with surrounding critical vasculature. It is thought that nearby blood vessels act as heat sinks from thermal injury, however, the risk of ablation causing an ischemic stroke is not well reported. METHODS: A retrospective review identified patients who underwent LITT between 2013 – 2021 for brain tumors located within the insula, basal ganglia, and thalamus. Demographic, clinical, and volumetric characteristics were collected. The primary outcome was radiographic evidence of distal ischemia on post-ablation imaging. RESULTS: A total of 50 patients underwent 59 ablations for perivascular brain tumors located in the insula (52%), basal ganglia (24%), and thalamus (24%). Of the tumors treated, 22 (37%) were low-grade gliomas, 32 (54%) were high-grade gliomas, and 5 (8%) were metastatic. No coagulopathies were identified in any patient. A biopsy was performed in 72% of patients. The mean volume of ablation was 12.4 cm3 (S.D. 13.9) with a median extent of ablation of 92% (IQR 30%, 100%). Two patients developed symptomatic intracerebral hemorrhage. One developed a tract hemorrhage attributed to vessel injury from fiber insertion. The other presented with delayed onset hemorrhage one week later due to uncontrolled hypertension. In all patients, there was no radiographic evidence of distal ischemia following LITT on DWI sequencing . The median length of stay was 2 days with 81% of patients being discharged home. CONCLUSIONS: We demonstrate that LITT has minimal risk for new onset distal ischemia for deep-seated perivascular brain tumors.

Distal AVF creation with marginal calcified radial artery: Multicentric experience of intraoperative intravascular lithotripsy.

The first-choice vascular access to starting dialysis in patients with End Stage Renal Disease (ESRD) is autogenous distal arteriovenous-fistula (AVF) to spare vascular district avoiding proximal fistula complications. One of most significant exclusion criteria to create distal AVF is still now the presence of huge calcification of the feeding artery due to large numbers of early failure (EF) and failure in maturation (FTM). In recent years the possibility to use new devices able to deliver intravascular lithotripsy (IVL) to treat high calcified stenosis could be a possibility to recruit these marginal arteries to create distal AVF. ESRD patients with totally calcified radial artery wall were enrolled to participate to this prospective, single arm, multicentric study. The selected patients were treated with intraoperative IVL at surgical time, during anastomosis creation to soften calcified radial artery. Patients were followed 1 month after surgery with eco-doppler, for flow and vessels maturation assessment. At 3 month was investigated how many patients have started dialysis treatment with two needle cannulation and good efficiency. Nineteen distal forearm radio-cephalic fistula were built in 19 patients. One-month doppler assessment showed mean AVF flow of 743 ml/min and efferent vein caliper of 6.46 mm. At 3 months 14 patient have started stable 2 needles dialysis (other three patients were not yet dialysis dependent CKD). Were observed one immediate failure, one failure in maturation, and two late failures at 4 and 16 months respectively. Sixteen months primary and secondary patency was 78.9% and 89.5% respectively. These results showed how intraoperative IVL could help to recruit huge calcified marginal artery to create autogenous distal forearm AVF, avoiding proximal AVF, risking distal ischemia syndrome, and sparing vascular district to eventually rebuilt more proximal AVF in future.

Laser interstitial thermal therapy for deep-seated perivascular brain tumors is not associated with distal ischemia.

Laser interstitial thermal therapy (LITT) is a minimally invasive cytoreductive treatment option for brain tumors with a risk of vascular injury from catheter placement or thermal energy. This may be of concern with deep-seated tumors that have surrounding end-artery perforators and critical microvasculature. The purpose of this study was to assess the risk of distal ischemia following LITT for deep-seated perivascular brain tumors. A retrospective review of a multi-institution database was used to identify patients who underwent LITT between 2013 and 2022 for tumors located within the insula, thalamus, basal ganglia, and anterior perforated substance. Demographic, clinical and volumetric tumor characteristics were collected. The primary outcome was radiographic evidence of distal ischemia on post-ablation magnetic resonance imaging (MRI). 61 LITT ablations for deep-seated perivascular brain tumors were performed. Of the tumors treated, 24 (39%) were low-grade gliomas, 32 (52%) were high-grade gliomas, and 5 (8%) were metastatic. The principal location included 31 (51%) insular, 14 (23%) thalamic, 13 (21%) basal ganglia, and 3 (5%) anterior perforated substance tumors. The average tumor size was 19.6 cm3 with a mean ablation volume of 11.1cm3. The median extent of ablation was 92% (IQR 30%, 100%). Two patients developed symptomatic intracerebral hemorrhage after LITT. No patient had radiographic evidence of distal ischemia on post-operative diffusion weighted imaging. We demonstrate that LITT for deep-seated perivascular brain tumors has minimal ischemic risks and is a feasible cytoreductive treatment option for otherwise difficult to access intracranial tumors.

Critical Limb Threatening Ischemia Due to Severe Polyarteritis Nodosa-A Case Report.

A delayed diagnosis of polyarteritis nodosa may lead to critical limb-threatening ischemia (CLTI). A 74-year-old woman presented with left-foot pain and was treated with oral vasodilators and antiplatelet agents. However, the distal ischemia progressed to CLTI, including gangrene of the fingers and toes, and bilateral foot dropping appeared because of peroneal nerve paralysis. Angiography of the extremities revealed obstruction and stenosis of medium-sized arteries. Based on the progressive distal gangrene, mononeuropathy multiplex, and pathological findings of necrotic vasculitis, polyarteritis nodosa was diagnosed, and the patient's condition improved. A biopsy and neurological examination are essential for the appropriate diagnosis of PAN and immediate treatment.

Symmetrical Peripheral Gangrene resulting from application of henna: a rare clinical occurrence

Symmetrical Peripheral Gangrene (SPG) is a rare clinical syndrome characterized by bilateral symmetric distal limb ischemia leading to gangrene with no evidence of major vascular occlusive disease. The peripheral pulses are usually palpable as a result of the sparing of larger vessels. The mechanism of vascular occlusion is poorly understood. Disseminated intravascular coagulation has been implicated as the final common pathway in its pathogenesis. Initial management is resuscitation followed by amputation when the gangrene becomes demarcated. We report a rare case of symmetrical peripheral gangrene of both hands and feet in a 28-year-old female who presented with pain and darkening of all her fingers and toes for 2 days following the application of henna, with no medical history of the known predisposing conditions. She had amputation of the digits of her hands and tarsometatarsal amputation of her feet bilaterally. She had an uneventful postoperative period and was discharged to see the outpatient department. While reported cases of SPG due to numerous etiologies can be found in the literature, this is to our findings the first time we are seeing it resulting from the cosmetic use of henna. The intriguing case presented here was brought about by the application of henna used as a cosmetic agent and was characterized by a very rapid clinical course with no other apparent predisposing etiology.

Arterial revascularization in patients with hand pain dialyzing with upper arm Arteriovenous (AV) fistulas: A single center experience.

Distal hand ischemia syndrome (DHIS) is a well reported adverse outcome in patients with upper arm AV access. 25%-40% of these patients have been reported to be due to primary arterial disease complicated with significant arterial calcification. The effectiveness of revascularization of the distal arterial circulation on symptom resolution has not been reported yet. Retrospective single center analysis of patients evaluated for hand/forearm pain in patients with upper arm AV access who had arterial revascularization between 01/2016 and 12/2020 were included for the analysis. Fifty-one patients met inclusion criteria. Stenotic lesions greater than 70% in the subclavian, axillary, brachial, radial, or ulnar artery were treated with balloon angioplasty. Institutional approval was obtained to review charts. Successful revascularization, improvement in pain in 48 h, 1 month, and 3 months. Seventy six percent of patients had an upper arm Arteriovenous Fistula (AVF) and 24% patients had an upper arm Arteriovenous Graft (AVG). Mean access flow was 1210 (556) ml/min. 55% of patients had radial or ulnar arterial stenosis, 45% had brachial/axillary or subclavian artery stenosis. 45% patients had lesions in both radial and ulnar arteries, 88% of patients were successfully revascularized. 76% (18) of patients had improvement in symptoms within 48 h and 68% remained symptom free in 3 months. Mean DHIS stage was 3.1 before intervention and improved to 1.1 post intervention (p < 0.001). Patient satisfaction with their AV access improved from 34% to 72% (p < 0.01). Multiple regression analysis did not reveal statistically significant correlations between time on dialysis vintage and other chronic medical conditions on post procedure symptom improvement. DHIS with occlusive arterial disease can be successfully revascularized to improve symptoms. Complete evaluation of the inflow arterial segment and optimal endovascular revascularization could decrease the need for access revision procedures or access abandonment.

Impact on hemodynamics in carotid arteries with carotid webs at different locations: A Numerical Study Integrating Thrombus Growth Model

ObjectiveCarotid webs (CWs), lesions in the carotid arteries, are gaining research interest due to the unclear link to ischemic stroke. Similarity to atherosclerosis in lesion location adds the complexity. The main purpose of study is to investigate the hemodynamic effects of CWs at different locations in carotid arteries. MethodsThree types of models with CWs were reconstructed from the CTA dataset of 8 healthy carotid arteries (Models A: CWs at the common carotid artery; B: at the origin of internal carotid artery; C: at the carotid sinus). Wall shear stress (WSS)-based parameters, including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and endothelial cell activation potential (ECAP) were analyzed. A thrombus growth model was also incorporated to assess long-term thrombus formation across different carotid webs locations. ResultsModels A exhibited helical flow, whereas models B and C showed disturbed flow in the carotid sinus. Recirculation in Models A and B was mainly downstream of CWs, while Models C had both upstream and downstream recirculation. In addition, models A had higher overall TAWSS levels, with the smallest region of TAWSS < 0.4 pa (7.78 ± 8.35%). In contrast, Models C had larger areas with TAWSS < 0.4 pa, RRT > 100, and ECAP > 1.5, accounting for 14.18 ± 5.28%, 1.51 ± 1.17%, and 10.36 ± 4.10%, respectively. Noting that thrombus volume was highest in Models C (7.20 ± 3.95%). ConclusionsNumerical simulations indicate that: 1) CWs have less hemodynamic impact when located in the CCA, but may increase flow resistance leading to distal branch ischemia; 2) CWs contribute to thrombus formation, primarily downstream in the common carotid artery and internal carotid artery origin, and both upstream and downstream in the sinus; 3) CWs at the origin of the ICA are more likely to result in disturbed blood flow patterns and thrombus aggregation than the other two locations, which may increase the risk of ischemic stroke in distal cerebral arteries.

Slowly moving the needle away from Fistula First

ObjectiveIn 2019, the management of end-stage kidney disease (ESKD) shifted away from “Fistula First” (FF) to “ESKD Life-Plan: Patient Life-Plan First then Access Needs.” Indeed, some patients exhibit such excessive comorbidity that even relatively minor vascular surgery may be complicated. The purpose of this study was to retrospectively assess complications and mortality (and delineate operative futility) in patients undergoing arteriovenous fistula (AVF) creation in the FF era. MethodsConsecutive AVFs created in a single institution before 2021 were retrospectively reviewed. Operative futility was defined as never-accessed fistula, no initiation of dialysis, failure of access maturation (despite secondary intervention), hemodialysis access-induced distal ischemia requiring ligation, early loss of secondary patency, and/or patient mortality within the first 6 postoperative months. ResultsA total of 401 AVFs were created including radial-cephalic (44%), brachial-cephalic (41%), and brachial-basilic (15%) constructions. Patients exhibited a mean age of 69 ± 15 years; 63% were male, and most (74%) were already being hemodialyzed at the time of fistula creation. Forty-five patients (11%) suffered a cardiac event, and five patients died (1%) within 90 days of their access surgery. Perioperative cardiac events were significantly more common after age 80 (19% vs 8%; P = .004); age >80 years was an independent predictor of major 90-day complications (odds ratio [OR], 1.88; 95% confidence interval [CI], 1.04-3.39; P = .036) and the sole independent predictor of major morbidity defined as cardiopulmonary complications, stroke, or death within the first year (OR, 2.01; 95% CI, 1.24-3.25; P = .004). Operative futility was encountered in 52% of the cohort (n = 208 patients): 40% (n = 160) of primary AVFs failed to mature despite assistance, 19% (n = 77) had lost secondary patency by 6 months, 13% of patients (n = 53) were never started on dialysis after access creation, 4% (n = 16) were dead by 6 months, 2% of AVFs (n = 10) matured but were never accessed, and 2% (n = 9) required ligation for hemodialysis access-induced distal ischemia. Not surprisingly, the sole independent protector against operative futility was that catheter-based dialysis had been established prior to AVF creation (OR, 0.36; 95% CI, 0.22-0.59; P < .01). ConclusionsApproximately 50% of primary AVF operations performed in the aggressive FF era were deemed futile. Octogenarians were particularly prone to futility and complications during this era. A paradigm shift, from FF to an “ESKD Life-Plan” will, hopefully, more thoughtfully match vascular access strategies to individual patient needs.

Autologous forearm arteriovenous loop vascular access, an option to be considered

Background: Autologous arteriovenous fistula is usually the vascular access of choice for hemodialysis in patients with chronic kidney disease. Autologous forearm loops with cephalic or basilic vein are an alternative in those cases with a suitable forearm vein but with an unsuitable radial artery; however they are rarely used and there is little reported evidence of their usefulness. Our objective is to report our results on the creation of autogenous forearm loops as vascular access for hemodialysis. Methods: We present a prospective cohort study of autogenous forearm loop arteriovenous fistula created between 2010 and 2022, in patients with stage 4–5 chronic kidney disease. Demographic data, surgical details, vein used, follow up to 24 months, maturation, utilization, primary, assisted, and secondary patency estimations with Kaplan-Meier curves, as well as complications during follow-up, were recorded. Results: During the study period, 22 autologous forearm loops were created, 14 of them with cephalic, and 8 with basilic vein. Most (59%) of the patients were men, 19 were already on dialysis and the rest started during follow-up. Sixteen patients had previous vascular accesses. One patient was lost during follow-up. Six-week maturation rate was 61.9% and utilization rate was 57.1%. 6, 12, and 24 months primary and secondary patencies were 75.4%, 59.2%, 41.5% and 85.0%, 69.5%, 56.9% respectively. In five patients an access-induced distal ischemia was diagnosed, four successfully treated and only one patient lost the access. No cases of infection or other major complications were reported. Conclusion: Autologous forearm loops have acceptable maturation (61.9%) and patency rates at follow-up (56.9% 2-years secondary patency). Although rarely used, they are a vascular access alternative that should be considered to preserve the proximal vasculature of the arm for future accesses.

Finding the Right Balance: Partial REBOA in a Swine Model of Uncontrolled Vascular Injury.

We have previously shown that partial REBOA (pREBOA) deployment in the thoracic aorta is safe for 2 to 4 hours, but it is unclear whether the distal blood flow after partial aortic occlusion would lead to ongoing hemorrhage. The objective of this study was to evaluate the hemostatic efficacy of pREBOA in a model of uncontrolled vascular injury. Female Yorkshire swine (n = 10, 40 to 45 kg) were anesthetized and instrumented. A through-and-through injury was created in the common iliac artery. The animals were randomly assigned to: (1) pREBOA-PRO deployment after 3 minutes and (2) control. Both groups were given normal saline resuscitation for hypotension. The pREBOA was adjusted to partial occlusion (distal mean arterial pressure of 30 mmHg), and then left without titration for 2 hours. Then, fresh frozen plasma was transfused and the vessel repaired. The balloon was deflated and the animals were monitored for 2 hours. In the critical care period, 2 L of normal saline was infused, norepinephrine was given for mean arterial pressure ≤55, and electrolytes and acidosis were corrected. Organs were examined for gross and histologic evidence of ischemic injuries. The primary endpoint was post-inflation blood loss. All the pREBOA animals survived until the end, whereas control animals had a mean survival time of 38.2 minutes (p < 0.05). The pREBOA group showed significantly less bleeding after balloon deployment (93.8 vs 1,980.0 mL, p < 0.05), and had appropriate lactate clearance, with minimal histologic distal organ ischemia. Partial aortic occlusion with the newly designed balloon can achieve the desired balance between effective hemorrhage control and adequate distal flow, without a need for ongoing balloon titration.

Vascular Access-Related Distal Ischemia Requiring Intervention: Frequency, Risk Factors, and Consequences.

Distal ischemia is a rare complication in patients undergoing placement of an arteriovenous (AV) fistula or AV graft. There are limited studies on its frequency, risk factors, clinical consequences, or feasibility of subsequent access. A prospective vascular access database from a large academic medical center was queried retrospectively to identify 1498 patients (mean age 56±15 years, 48% female patients, 73% Black patients) undergoing placement of at least one vascular access from 2011 to 2020. For patients who developed access-related distal ischemia requiring surgical intervention, we determined the frequency of distal ischemia, clinical risk factors, and subsequent outcomes. Severe access-related distal ischemia occurred in 28 patients (1.9%; 95% confidence interval, 1.3% to 2.7%). The frequency was 0.2% for forearm AV fistulas, 0.9% for upper arm AV fistulas, 2.4% for forearm AV grafts, 2.2% for upper arm AV grafts, and 2.8% for thigh AV grafts. Risk factors independently associated with distal ischemia included female sex (odds ratio [OR], 3.64 [95% confidence interval, 1.52 to 8.72]), peripheral vascular disease (OR, 6.28 [2.84 to 13.87]), and coronary artery disease (OR, 2.37 [1.08 to 5.23]). Surgical interventions included ligation, excision, plication (banding), and other surgical procedures. Five patients developed tissue necrosis. A subsequent AV graft was placed in 13 patients, of whom only one (8%) developed distal ischemia requiring intervention. Access-related distal ischemia requiring intervention was rare in this study and more common in women and patients with peripheral vascular disease or coronary artery disease. In some cases, a subsequent vascular access could be placed with a low likelihood of recurrent distal ischemia.

Reliability and Safety of Cross-Leg Free Latissmus Dorsi Muscle Flap in Reconstruction of Mutilating Leg Injuries Using End-to-Side Anastomosis.

Background Free tissue transfer is considered the gold standard option for the reconstruction of distal leg defects. Free tissue transfer using recipient vessels in the contralateral leg (cross-leg bridge) is a potential option to supply the flap if there are no suitable recipient vessels in the injured leg. Most studies have described this technique using end-to-end anastomosis which sacrifices the main vessel in the uninjured leg. This study evaluated the use of a cross-leg free latissimus dorsi muscle flap for the reconstruction of defects in single-vessel legs, using end-to-side anastomosis to recipient vessels in the contralateral leg without sacrificing any vessel in the uninjured leg. Methods This is a retrospective study that included 22 consecutive patients with soft tissue defects over the lower leg. All the reconstructed legs had a single artery as documented by CT angiography. All patients underwent cross-leg free latissimus dorsi muscle flap using end-to-side anastomosis to the posterior tibial vessels of the contralateral leg. Results The age at surgery ranged from 12 to 31 years and the mean defect size was 86 cm 2 . Complete flap survival occurred in 20 cases (91%). One patient had total flap ischemia. Another patient had distal flap ischemia. Conclusion Cross-leg free latissimus dorsi muscle flap is a reliable and safe technique for the reconstruction and salvage of mutilating leg injuries, especially in cases of leg injuries with a single artery. As far as preservation of the donor limb circulation is concerned, end-to-side anastomosis is a reasonable option as it maintains the continuity of the donor leg vessels.

The Role of Ultrasound Examination in the Assessment of Suitability of Calcified Arteries for Vascular Access Creation-Mini Review.

Arterial calcifications are present in 20-40% of patients with end-stage kidney disease and are more frequent among the elderly and diabetics. They reduce the possibility of arterio-venous fistula (AVF) formation and maturation and increase the likelihood of complications, especially distal ischemia. This review focuses on methods for detecting arterial calcifications and assessing the suitability of calcified arteries for providing inflow before the construction of an AVF. The importance of a clinical examination is stressed. A grading system is proposed for quantifying the severity of calcifications in the arteries of the arm with B-mode and Doppler ultrasound exams. Functional tests to assess the suitability of the artery to provide adequate inflow to the AVF are discussed, including Doppler indices (peak systolic velocity and resistive index during reactive hyperemia). Possible predictors of the development of distal ischemia are discussed (finger pressure, digital brachial index, acceleration and acceleration time), as well as the outcomes of AVFs placed on calcified arteries. It is concluded that a noninvasive ultrasound examination is probably the best tool for a morphologic and functional assessment of the arteries. An arterial assessment is of utmost importance if we are to create distal radiocephalic AVFs in our elderly patients whenever possible without burdening them with futile surgical attempts.

Ultrasound assessment is useful for evaluating balloon volume of resuscitative endovascular balloon occlusion of the aorta.

Endovascular balloon occlusion of the aorta (EBOA) increases proximal arterial pressure but may also induce life-threatening ischemic complications. Although partial REBOA (P-REBOA) mitigates distal ischemia, it requires invasive monitoring of femoral artery pressure for titration. In this study, we aimed to titrate P-REBOA to prevent high-degree P-REBOA using ultrasound assessment of femoral arterial flow. Proximal (carotid) and distal (femoral) arterial pressures were recorded, and perfusion velocity of distal arterial pressures was measured by pulse wave Doppler. Systolic and diastolic peak velocities were measured among all ten pigs. Total REBOA was defined as a cessation of distal pulse pressure, and maximum balloon volume was documented. The balloon volume (BV) was titrated at 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the perfusion velocity of distal arterial pressures were recorded. Proximal blood pressure increased with increasing BV. Distal pressure decreased with increasing BV, and distal pressure sharply decreased by > 80% of BV. Both systolic and diastolic velocities of the distal arterial pressure decreased with increasing BV. Diastolic velocity could not be recorded when the BV of REBOA was > 80%. The diastolic peak velocity in the femoral artery disappeared when %BV was > 80%. Evaluation of the femoral artery pressure by pulse wave Doppler may predict the degree of P-REBOA without invasive arterial monitoring.

Retrospective Analysis of Finger Entrapments.

Accidental entrapment of fingers poses treatment challenges in the emergency room. The constriction objects cause edema distally and sometimes digital ischemia. Swift and rationally removing or cutting the entrapment objects save the finger from complications. Thirty patients with finger entrapments were retrospectively analyzed between 2016 and 2020. The entrapments were mostly rings and other metals removed using electrical cutting tools. The time delay from injury to removal was recorded and analyzed with digital ischemia. In addition, the immediate and long-term functional outcome, pain scale (visual analogue score), and return to work were examined. The mean follow-up of our study was 16.5months (range 12-19months). All patients had multiple unsuccessful attempts of removal. The rings (60%), workplace metals, door handles, and pipe taps were the commonest entrapments in the series. Distal ischemia (37%), circumferential wounds, and neuropraxia (30%) were common presentations in the series. None of the patients had amputations. There is no significant difference in the functional outcome of patients with a delayed presentation (>6h) to the emergency room (p = 1.0). There is complete recovery of sensation and improved pain scale (p < 0.05) in the follow-up in all patients. Entrapments in fingers are one of the emergencies in hand surgery, where meticulous planning and removal efficiently restore the hand function. Despite delays in presentations to the emergency room and multiple unsuccessful attempts, the electric saw removed the entrapment objects. It achieved immediate pain relief, sensation, vascularity, and an excellent long-term functional outcome. IV, Retrospective case study.

Delayed Presentation of Anterior Tibial Artery Pseudoaneurysm Causing Distal Ischemia – A Case Report with Review of Literature

A pseudoaneurysm is a rare complication involving the vasculature and may be limb threatening if not treated. Pseudoaneurysm typically occurs when there is a breach in the vessel wall such that the blood leaks through the inner wall but is contained by the adventitia or surrounding perivascular soft tissue. These may be caused due to trauma to the vessel (either due to fractures, bony fragments), following endovascular therapy, or infective etiology, or other causes. Tibial and pedal artery aneurysms occur in the setting of penetrating trauma, fractures, or iatrogenic injury during orthopaedic surgery or peripheral interventions. Those causing significant symptoms must be repaired with autologous vein bypass grafts if there is distal ischemia. If other tibial arteries are patent, a simple ligation will also suffice. Coil embolization and conservative management resulting in spontaneous thrombosis of small pseudoaneurysms, have also been reported. We report a case of a 51 year old male with right Anterior Tibial Artery pseudoaneurysm which had developed over several years after a trauma with the patient presenting to us only after he started having symptoms of distal ischemia.

Distal radial artery access is a safe and feasible technique in the anatomical snuffbox for visceral intervention.

Regarding the site of arterial access during the intervention, transracial intervention can reduce the risk of bleeding and vessel-related complications as well as improve patient comfort. Importantly, the distal radial artery (DRA) approach may reduce the incidence of radial artery occlusion and digital ischemia, but the feasibility and safety of DRA in performing subdiaphragmatic vascular interventions remain unclear. From January 2018 to December 2019, 106 patients were admitted to our department for visceral angiography and intervention by left distal radial artery accessing in an anatomical snuffbox. In total, 152 times of vascular interventions were performed during this period. Patients demographics, procedure details, technical success, and access site-related complications were recorded and evaluated. The mean age was 58.9 (range 22-86) years. Males accounted for 80.2%. Thirty-five patients (33%) had 2 or more procedures via the DRA approach. Technical success was achieved for 96.1% of procedures (146 cases) and 3.9% of cases failed to perform the intended procedure via the DRA approach (6 cases). The 4-Fr sheath was used in 86.8% of cases, and the 5 Fr sheath was used in the rest of the 13.2% of procedures. The rate of asymptomatic radial artery occlusion was 5.7% (6 of 106 patients). No patient suffered from distal limb ischemia after a long-time follow-up. Eight patients suffered postoperative local pain, transient numbness, or local bruised in the anatomical snuffbox without major complications. Patients with postoperative complications recovered quickly by using nonsteroidal anti-inflammatory drugs or without further treatment. Left distal radial artery access is safe and feasible as a new technique for visceral angiography and intervention.

#4923 ARTERIOVENOUS FISTULAS AS HEMODIALYSIS ACCESS IN A PEDIATRIC POPULATION – IS YOUNGER AGE A REASON TO MAINTAIN CENTRAL VENOUS CATHETER?

Abstract Background and Aims In the pediatric population, transplantation remains the first-line therapy in patients with end-stage renal disease (ESRD). However, it is not always possible, increasing the need for other kidney replacement therapy (KRT) modalities, and hemodialysis (HD) has been growing as a modality choice in recent years. To provide quality HD treatment, efficient vascular access is mandatory, and the arteriovenous fistula (AVF) is advocated as the best long-term access option. However, its creation is technically challenging, and its development and maintenance are some of the most difficult elements in the pediatric population. In this study, we describe our experience in the utilization of AVFs in children and adolescents on HD. Method We conducted a retrospective study including all the AVFs performed in our center on underage patients between January 2006 and December 2022. We reviewed the medical records, collected data on demographic variables, AVF characteristics, blood test results, and clinical outcomes. Statistical analysis was performed using SPSS software. Results Forty-three AVFs were performed in 32 pediatric patients. The median age at first AVF construction was 13.5 years (min 4.8; max 17.9). The most frequent etiology of ESRD was congenital anomalies of kidney and urinary tract (n = 20, 62.5%) and most patients (n = 24, 75.0%) were already receiving KRT. Median follow-up time was 16.4 months (min 1; max 98.4) and, at the end of the follow-up period, most patients (n = 22, 68.8%) were transplanted. The mortality rate was 6.3% (n = 2). In what concerns to the location of the AVF, radiocephalic was the first choice in 46.9% of the cases (n = 15), accounting for 34.9% of the total AVFs. Brachiocephalic location was used in 34.4% (n = 11) of first fistulas and 6 subsequent accesses, accounting for 39.5% of the total AVFs. The brachiobasilic location was chosen in 18.8% (n = 6) of the first AVFs and 25.6% of the total AVFs. Primary AVF failure occurred in 26.6% (n = 11) cases and, in 4 of these (36.4%), it was possible to successfully use the same location for a second AVF. We observed no statistical association between primary AVF failure dysfunction and gender, age at the construction of the first fistula, AVF location, or dialysis vintage. Platelet-lymphocyte (PLR) and neutrophil-lymphocyte (NLR) ratios also did not differ between groups. Primary and secondary patency rates at one year were, respectively, 62.5% and 93.8%. With respect to total AVF complications, we observed: thrombosis (27.9%), stenosis (18.6%), distal ischemia induced by vascular access (4.7%), and high flow/aneurismatic dilations (18.6%). The presence of complications was statistically related to age (p = 0.046), with more events in older patients at the time of AVF construction. There was no statistical difference between complications’ occurrence and AVF type, sex, gender, PLR, and NLR. Conclusion The utilization of AVF for HD has been growingly recognized as a safe and efficient alternative for the performance of KRT in pediatric patients. Although larger studies are needed, we demonstrate positive results in its usage in a pediatric population, with high primary and secondary patency rates. These outcomes were independent of the AVF location. We also advocate AVF usage in younger patients, as complications were associated with older age. PLR and NLR, which are emerging biomarkers for systemic inflammation, were not associated with AVF dysfunction, aligning with the results of other studies in pediatrics.

The reverse LICAP flap: A laterally based submammary perforator flap for breast reconstruction

The traditional donor sites for autologous breast reconstruction include the abdomen, thigh, buttock, and posterior thorax. Herein, we describe the use of the reverse lateral intercostal perforator (LICAP) flap originating from the submammary region as an option for breast reconstruction. Fifteen patients (30 breasts) were included in this retrospective review. The procedure was performed for immediate reconstruction following a nipple sparing mastectomy utilizing an inframammary incision or an inverted T pattern with preservation of the fifth anterior intercostal perforator (n=8), volume replacement after implant explantation (n=5), and partial lower pole resurfacing with exteriorization of a portion of the LICAP skin paddle (n=2). Flap survival was achieved in all patients. Three flaps (10%) had 1-2cm of intraoperative distal tip ischemia, which was managed by excision prior to inset and closure. At the 12-month postoperative follow-up, stable results with good nipple position, breast shape, and projection were achieved in all patients. The reverse LICAP flap is a safe, effective, and reliable option for breast reconstruction following mastectomy.

Prolonging the zone 1 aortic occlusion time to 4 hours using a partial resuscitative endovascular balloon in a swine model.

The clinical usage of the resuscitative endovascular balloon occlusion of the aorta (REBOA) is limited by distal ischemia resulting from complete aortic occlusion. We hypothesized that animals would physiologically tolerate the prolonged partial occlusion using the novel partially occluding REBOA (pREBOA) with survivable downstream injuries. This study used the pREBOA-PRO catheter in a previously established swine model. Female Yorkshire swine (n = 10) underwent a volume-controlled hemorrhage (40% estimated blood). After 1 hour of shock (mean arterial pressure, 28-32 mm Hg), animals were randomized to partial occlusion for either 2 hours or 4 hours. The pREBOA was inflated in zone 1 to achieve partial occlusion defined as a distal systolic blood pressure (SBP) of 20 ± 2 mm Hg. The balloon was deflated at the end of the occlusion period, and animals were resuscitated for 2 hours. Tissues were examined for gross and histologic injury. The primary endpoint was histologic organ injury, and secondary end points were hemodynamic variables and degree of distal organ ischemia. All animals survived to the endpoint. Both groups had similar proximal and distal SBP at baseline, with a divergence of pressures ranging from 55 mm Hg to 90 mm Hg on inflation. The lactate levels increased throughout the occlusion and decreased approximately 40% during the observation period. More animals required norepinephrine and fluid in the 4-hour group compared with the 2-hour group. There was no gross small bowel ischemia noted in the 2-hour animals. The 4-hour group had surgically resectable patchy short segment ischemia. Neither group showed nonsurvivable organ ischemia on pathology or laboratory values. This is the first study showing that the zone 1 aorta can be occluded for over 4 hours using a new pREBOA device without need for balloon titration. In conclusion, simple changes in balloon design offer reliable partial aortic occlusion, with potentially survivable and surgically manageable downstream injuries.