Nephrology Partnership for Advancing Technology in Healthcare (N-PATH) program: the teachers' perspective.

The N-PATH (Nephrology Partnership for Advancing Technology in Healthcare) program concluded with the 60th European Renal Association 2023 Congress in Milan, Italy. This collaborative initiative aimed to provide advanced training in interventional nephrology to young European nephrologists. Funded by Erasmus+ Knowledge Alliance, N-PATH addressed the global burden of chronic kidney disease (CKD) and the shortage of nephrologists. CKD affects >850 million people worldwide, yet nephrology struggles to attract medical talent, leading to unfilled positions in residency programs. To address this, N-PATH focused on enhancing nephrology education through four specialized modules: renal expert in renal pathology (ReMAP), renal expert in vascular access (ReVAC), renal expert in medical ultrasound (ReMUS) and renal expert in peritoneal dialysis (RePED). ReMAP emphasized the importance of kidney biopsy in nephrology diagnosis and treatment, providing theoretical knowledge and hands-on training. ReVAC centred on vascular access in haemodialysis, teaching trainees about different access types, placement techniques and managing complications. ReMUS recognized the significance of ultrasound in nephrology, promoting interdisciplinary collaboration and preparing nephrologists for comprehensive patient care. RePED addressed chronic peritoneal dialysis, offering comprehensive training in patient selection, prescription, monitoring, complications and surgical techniques for catheter insertion. Overall, N-PATH's strategy involved collaborative networks, hands-on training, mentorship, an interdisciplinary approach and the integration of emerging technologies. By bridging the gap between theoretical knowledge and practical skills, N-PATH aimed to revitalize interest in nephrology and prepare proficient nephrologists to tackle the challenges of kidney diseases. In conclusion, the N-PATH program aimed to address the shortage of nephrologists and improve the quality of nephrology care in Europe. By providing specialized training, fostering collaboration and promoting patient-centred care, N-PATH aimed to inspire future nephrology professionals to meet the growing healthcare demands related to kidney diseases and elevate the specialty's status within the medical community.

Guideline recommendations on minimal blood vessel diameters and arteriovenous fistula outcomes.

OBJECTIVE: Clinical guidelines provide recommendations on the minimal blood vessel diameters required for arteriovenous fistula creation but the evidence for these recommendations is limited. We compared vascular access outcomes of fistulas created in agreement with the ESVS Clinical Practice Guidelines (i.e. arteries and veins >2 mm for forearm fistulas and >3 mm for upper arm fistulas) with fistulas created outside these recommendations. METHODS: The multicenter Shunt Simulation Study cohort contains 211 hemodialysis patients who received a first radiocephalic, brachiocephalic, or brachiobasilic fistula before publication of the ESVS Clinical Practice Guidelines. All patients had preoperative duplex ultrasound measurements according to a standardized protocol. Outcomes included duplex ultrasound findings at 6 weeks after surgery, vascular access function, and intervention rates until 1 year after surgery. RESULTS: In 55% of patients, fistulas were created in agreement with the ESVS Clinical Practice Guidelines recommendations on minimal blood vessel diameters. Concordance with the guideline recommendations was more frequent for forearm fistulas than for upper arm fistulas (65% vs 46%, p = 0.01). In the entire cohort, agreement with the guideline recommendations was not associated with an increased proportion of functional vascular accesses (70% vs 66% for fistulas created within and outside guideline recommendations, respectively; p = 0.61) or with decreased access-related intervention rates (1.45 vs 1.68 per patient-year, p = 0.20). In forearm fistulas, however, only 52% of arteriovenous fistulas created outside these recommendations developed into a timely functional vascular access. CONCLUSIONS: Whereas upper arm arteriovenous fistulas with preoperative blood vessel diameters <3 mm had similar vascular access function as fistulas created with larger blood vessels, forearm arteriovenous fistulas with preoperative blood vessel diameters <2 mm had poor clinical outcomes. These results support that clinical decision-making should be guided by an individual approach.

Editor's Choice - Interventions to Achieve Functionality in Newly Created Arteriovenous Fistulas in the Shunt Simulation Study Cohort.

OBJECTIVE: Although observational cohort studies report that interventions to achieve functionality are clinically successful in 85% of patients, the proportion of newly created autologous arteriovenous fistulas that result in functional vascular access typically is only 70 - 80%. To address this discrepancy, the selection and outcomes of interventions to achieve functionality in a multicentre prospective cohort study were analysed. METHODS: The Shunt Simulation Study enrolled 222 patients who needed a first arteriovenous fistula in nine dialysis units in The Netherlands from 2015 to 2018 and followed these patients until one year after access creation. In this observational study, the technical and clinical success rates of interventions to achieve functionality based on lesion and intervention characteristics were analysed and the clinical outcomes of arteriovenous fistulas with assisted and unassisted functionality were compared. RESULTS: For patients who were on dialysis treatment at the end of the study, unassisted fistula functionality was 54% and overall fistula functionality was 78%. Thirty-four per cent of arteriovenous fistulas required an intervention to achieve functionality, 68% of which eventually became functional. Seventy-five per cent of these interventions were percutaneous balloon angioplasties of vascular access stenoses. Patients with clinically successful interventions to achieve functionality had larger pre-operative vein diameters (2.8 ± 1.0 mm vs. 2.3 ± 0.6 mm, p = .036) and less often presented with thrombosed fistulas than patients with unsuccessful interventions (7% vs. 43%, p = .006). Arteriovenous fistulas with assisted functionality had similar secondary patency as fistulas with unassisted functionality (100% and 98% at six months, p = .44), although they required more interventions to maintain function (2.6 vs. 1.7 per year; rate ratio 1.52, 95% CI 1.04 - 2.18, p = .032). CONCLUSION: Interventions to achieve functionality were needed in about a third of newly created arteriovenous fistulas. Most thrombosed fistulas were abandoned, and when selected for thrombectomy rarely reached clinical success. On the other hand, interventions to achieve functionality of patent fistulas had high clinical success rates and therefore can be done repeatedly until the fistula has become functional.

Peripheral embolism as first and only clinical symptom of a true aneurysmal degeneration of the radial artery after ligation of a radiocephalic fistula.

True aneurysmal degeneration of the inflow artery after arteriovenous fistula ligation is extremely rare. Pain is the most common symptom and surgical treatment by an autologous venous bypass is considered as the treatment of choice with good long-term results. We present a patient with peripheral embolism as first and only symptom leading to the diagnosis of a true aneurysmal degeneration of the entire left radial artery. It was discovered 5 years after the ligation of his radiocephalic fistula. As illustrated by this case, a conservative treatment by antiplatelet and anticoagulation therapy should be considered a satisfying alternative to the standard bypass surgery in patients with anatomical variations (e.g. an incomplete arterial palmar arch) since the latter include a higher risk of postoperative ischemic complications.

Central venous catheter-related complications in older haemodialysis patients: A multicentre observational cohort study.

BACKGROUND: Central venous catheters (CVC) remain a commonly used vascular access option in haemodialysis, despite guidelines advising to preferably use arteriovenous fistulae. Compared to younger patients, the risk-benefit ratio of CVC in older patients might be more beneficial, but previous studies mainly focussed on catheter-related bacteraemia and/or assessed tunnelled CVC (TCVC) only. This study's aim was to compare all catheter-related infections and malfunctions in older patients with younger patients using all CVC subtypes. MATERIALS AND METHODS: We used data from DUCATHO, a multicentre observational cohort study in The Netherlands. All adult patients in whom a CVC was placed for haemodialysis between 2012 and 2016 were included. The primary endpoint was the occurrence of catheter-related infections, comparing patients aged ⩾70 years with patients aged <70 years (reference). As secondary endpoints, catheter malfunctions and catheter removal due to either infection or malfunction were assessed. Using Cox proportional hazards and recurrent events modelling, hazard ratios (HR) with 95% confidence intervals (CI) were calculated with adjustment of prespecified confounders. Additionally, endpoints were assessed for non-tunnelled CVC (NTCVC) and TCVC separately. RESULTS: A total of 1595 patients with 2731 CVC (66.5% NTCVC, 33.1% TCVC) were included. Of these patients, 1001 (62.8%) were aged <70 years and 594 (37.2%) ⩾70 years. No statistically significant difference was found for the occurrence of catheter-related infections (adjusted HR 0.80-95% CI 0.62-1.02), catheter malfunction (adjusted HR 0.94-95% CI 0.75-1.17) and catheter removal due to infection or malfunction (adjusted HR 0.94-95% CI 0.80-1.11). Results were comparable when assessing NTCVC and TCVC separately. CONCLUSION: Patients aged ⩾70 to <70 years have a comparable risk for the occurrence of catheter-related infections and catheter malfunction. These findings may help when discussing treatment options with older patients starting haemodialysis and may inform the current debate on the best vascular access for these patients.

Optimising Access Surgery in Senior Haemodialysis Patients (OASIS): study protocol for a multicentre randomised controlled trial.

INTRODUCTION: Current evidence on vascular access strategies for haemodialysis patients is based on observational studies that are at high risk of selection bias. For elderly patients, autologous arteriovenous fistulas that are typically created in usual care may not be the best option because a significant proportion of fistulas either fail to mature or remain unused. In addition, long-term complications associated with arteriovenous grafts and central venous catheters may be less relevant when considering the limited life expectancy of these patients. Therefore, we designed the Optimising Access Surgery in Senior Haemodialysis Patients (OASIS) trial to determine the best strategy for vascular access creation in elderly haemodialysis patients. METHODS AND ANALYSIS: OASIS is a multicentre randomised controlled trial with an equal participant allocation in three treatment arms. Patients aged 70 years or older who are expected to initiate haemodialysis treatment in the next 6 months or who have started haemodialysis urgently with a catheter will be enrolled. To detect and exclude patients with an unusually long life expectancy, we will use a previously published mortality prediction model after external validation. Participants allocated to the usual care arm will be treated according to current guidelines on vascular access creation and will undergo fistula creation. Participants allocated to one of the two intervention arms will undergo graft placement or catheter insertion. The primary outcome is the number of access-related interventions required for each patient-year of haemodialysis treatment. We will enrol 195 patients to have sufficient statistical power to detect an absolute decrease of 0.80 interventions per year. ETHICS AND DISSEMINATION: Because of clinical equipoise, we believe it is justified to randomly allocate elderly patients to the different vascular access strategies. The study was approved by an accredited medical ethics review committee. The results will be disseminated through peer-reviewed publications and will be implemented in clinical practice guidelines. TRIAL REGISTRATION NUMBER: NL7933. PROTOCOL VERSION AND DATE: V.5, 25 February 2021.

Surgical intervention for upper extremity nerve compression related to arteriovenous hemodialysis accesses.

OBJECTIVE: Chronic renal failure patients with arteriovenous hemodialysis access may exhibit pain and neurological complaints due to local nerve compression by the access conduit vessels of autogenous arteriovenous fistulas or the prosthesis of arteriovenous grafts. In this study, we have examined the results of surgical intervention for vascular access-related nerve compression in the upper extremity. METHODS: A single center retrospective study was performed of all patients referred for persistent pain and neurological complaints after vascular access surgery for hemodialysis. There were four brachial-cephalic, three brachial-basilic upper arm arteriovenous fistulas, and three prosthetic arteriovenous grafts. All patients had pain and sensory deficits in a distinct nerve territory (median nerve: 6; median + ulnar nerve: 1; medial cutaneous nerve: 1), and two patients had additional motor deficits (median nerve). RESULTS: A total of 10 patients (mean age: 59 years; range: 25-73 years; 2 men; 4 diabetics) were treated by surgical nerve release alone (2 patients) or in combination with access revision (8 patients). Mean follow-up was 23 months (range: 8-46 months). Direct complete relief of symptoms was achieved in six patients. Three patients had minor complaints, and one patient had a reoperation with good success. CONCLUSION: Vascular access-related nerve compression is an uncommon cause for pain, sensory and motor deficits after vascular access surgery. Surgical nerve release and access revision have good clinical outcome with relief of symptoms and maintenance of the access site in the majority of patients.

[Endovascular arteriovenous fistulas: percutaneous creation of vascular access for hemodialysis]. / Endovasculair aangelegde arterioveneuze fistels.

A novel endovascular technique allows percutaneous creation of arteriovenous fistulas for hemodialysis. The proximal radial artery is cannulated through the perforating vein in the cubital fossa using ultrasound guidance. A fused anastomosis between these blood vessels is created using heat and pressure. This results in an arteriovenous fistula that can be regarded as an alternative for a surgically created brachiocephalic fistula. In our early experience, this new technique is safe and successful. Moreover, no complications due to high-flow fistulas have been reported with this technique to date. Nevertheless, the intervention rate and the cost effectiveness of the new endovascular technique need to be compared to traditional open surgery before it can be considered standard clinical care.

The Effect of Geometric Graft Modification on Arteriovenous Graft Patency in Haemodialysis Patients: A Systematic Review and Meta-Analysis.

OBJECTIVE: Arteriovenous grafts (AVGs) are the second best option for haemodialysis access when native arteriovenous fistulae placement is not possible, because they have a lower patency owing to neointimal hyperplasia at the venous anastomosis. This review aimed to evaluate the effect of geometric graft modification to the graft-vein interface on AVG patency. DATA SOURCES: The MEDLINE and Embase (OvidSP) databases were systematically searched for relevant studies analysing the effect of geometrically modified AVGs on graft patency and stenosis formation (last search July 2019). REVIEW METHODS: Data regarding AVG type, patency, and graft outlet stenosis was extracted for further evaluation. Data were pooled in a random effects model to estimate the relative risk of graft occlusion within one year. Follow up, number of patients, and relevant patient characteristics were extracted for the quality assessment of the included studies using Newcastle-Ottawa Scale and Cochrane Risk of Bias Tool. The quality of the evidence was determined according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system. RESULTS: Search strategies produced 2772 hits, of which eight articles met predetermined inclusion criteria. Overall, the included articles had low to moderate risk of bias. In total, 414 expanded polytetrafluoroethylene AVGs (232 geometrically modified and 182 standard) were analysed, comprising two modified AVG types: a prosthetic cuff design (Venaflo®) and grafts with a Tyrell vein patch. Overall, modified grafts did not show a statistically significantly higher one year primary (relative risk [RR] 0.86, 95% confidence interval [CI] 95% 0.64-1.16; GRADE: "low to very low") or secondary patency (RR 0.57, 95% CI 0.32-1.02; GRADE: "low to very low") when compared with standard AVGs. Analysis of prosthetic cuffed grafts (112 patients) separately demonstrated a statistically significantly higher one year primary (RR 0.75, 95% CI 0.61-0.91) and one year secondary patency (RR 0.47, 95% CI 0.30-0.75) compared with standard grafts (92 patients). The results on stenosis formation were inconclusive and inadmissible to quantitative analyses. CONCLUSION: The meta-analysis showed that a prosthetic cuff design significantly improves AVG patency, while a venous cuff does not. Although the heterogeneity and low number of available studies limit the strength of the results, this review shows the potential of grafts with geometric modification to the graft-vein anastomosis and should stimulate further clinical and fundamental research on improving graft geometry to improve graft patency.

Revision using distal inflow for high flow hemodialysis access alters arterial flow characteristics in the dialysis arm.

OBJECTIVE: Revision using distal inflow (RUDI) is currently proposed in patients on hemodialysis having a high flow access (HFA; >2 L/min) or hemodialysis access-induced distal ischemia (HAIDI). However, a recurrence of high flow or hand ischemia is not unusual in the years after RUDI. The aim of the present study was to describe changes in flow characteristics and arterial diameters in the dialysis arm after RUDI for HFA. METHODS: Volume flow, diameter, peak systolic velocity and end diastolic velocity of the brachial artery (BA) were studied 2 and 12 months after RUDI using duplex imaging. In a portion of patients, these characteristics were also assessed at proximal and distal portions of radial and ulnar arteries (proximal forearm radial artery, distal radial artery, ulnar artery, and distal ulnar artery), and in the greater saphenous venous interponate. HFA patients were grouped according to presence of concomitant hand ischemia (HFA-HAIDI) or absence (HFA). RESULTS: Fifteen patients (54 ± 16 year old; 10 males; HFA-HAIDI, n = 6; HFA, n = 9) with a BA HFA (flow volume, 2740 ± 322 mL/min) undergoing RUDI were studied between March 2011 and October 2016 in two Dutch hospitals. After 2 months, flow volume had decreased (1180 ± 189 mL/min), but again increased at 12 months (1520 ± 217 mL/min; P < .001). BA diameters did not change (7.4 ± 0.5 mm), but proximal forearm radial diameters doubled (overall 2.6 ± 0.2 mm to 5.4 ±1.0 mm; P < .001), albeit less prominent in HFA-HAIDI (+80%) than in HFA (+130%; P = .019). During follow-up, the distal ulnar artery peak systolic velocity in HFA-HAIDI (83 ± 10 cm/s) was higher compared with the HFA group (54 ± 5 cm/s; P < .01). Dilatation was not present in the greater saphenous venous interponate. CONCLUSIONS: RUDI for HFA reduction does not reverse BA dilatation, suggesting irreversible structural arterial wall damage possibly contributing to recurrent high flow. Radial artery remodeling is attenuated in HFA patients previously reporting concurrent hand ischemia diminishing the likelihood of high flow recurrence in this subgroup.

Aberrant innominate artery: A possible hazard during total laryngectomy.

BACKGROUND: Surgical management in laryngeal carcinoma remains a challenge with countless unexpected complications. Great vessel anomalies such as anomaly of the innominate artery carry high risk of morbidity and mortality if not managed properly. METHODS: We present our first experience with an aberrant innominate artery during total laryngectomy which complicated the whole surgical procedure and tracheostoma placement. RESULTS: We decided to place a pectoralis major muscle flap to separate and cover up the aberrant vessel from the trachea and end-stoma which ultimately did not lead to major complications postoperatively and postradiation therapy. CONCLUSION: Aberrant innominate artery is an extremely rare entity and failure of recognizance can lead to hazardous complications. Preoperative angiography needs to be done if there are high suspicions of aberrant vessels in the operative field. Careful dissection of the head and neck region, and prompt decision making are mandatory to manage such cases. LEVELS OF EVIDENCE: Case Report.

Flap Fixation Using Tissue Glue or Sutures Appears to Reduce Seroma Aspiration After Mastectomy for Breast Cancer.

BACKGROUND: Up to 90% of patients undergoing breast cancer surgery suffer from seroma formation, which can cause discomfort and various complications after mastectomy. This retrospective observational cohort study aimed to elucidate whether flap fixation with fibrin sealant (ARTISS) tissue glue reduces seroma formation and seroma aspiration after mastectomy when compared with flap fixation using Vicryl sutures and when compared with a conventional wound closure technique. METHODS: All patients undergoing mastectomy due to invasive breast cancer or ductal carcinoma in situ were eligible for inclusion. From May 2012 to March 2013, all patients undergoing mastectomy in 2 large breast cancer centers were treated using flap fixation with Vicryl sutures. From September 2013 to March 2014, all patients undergoing mastectomy were treated with flap fixation using ARTISS tissue glue. The data were retrospectively analyzed and compared with a "drain-only" group that was not treated with flap fixation (May 2011-March 2012). RESULTS: A total of 230 women who underwent mastectomy were retrospectively analyzed in this trial; 88 patients were included in the drain-only group (DO), 92 patients were included in the flap fixation group using Vicryl sutures (FF-1), and 50 patients were included in the flap fixation group using ARTISS tissue glue (FF-2). There was significantly less seroma formation in the group after flap fixation using sutures (P = .006). There were significantly fewer patients who required seroma aspiration in the FF-1 group (P = .001) and the FF-2 group (P = .001) after undergoing mastectomy and sentinel node biopsy or modified radical mastectomy. CONCLUSION: This study suggests that flap fixation after mastectomy using ARTISS tissue glue or sutures reduces postoperative seroma aspiration. As a result, flap fixation might lead to less patient discomfort. A randomized, prospective trial should be performed to verify these results.

Loss of Kidney Function after Endovascular Treatment of Peripheral Arterial Disease.

BACKGROUND: Administration of radiocontrast during endovascular procedures for peripheral arterial disease (PAD) may cause acute kidney injury, which generally recovers with supportive treatment. Long-term effects of endovascular procedures on renal function remain to be investigated. METHOD: This retrospective observational cohort study includes all patients who newly presented to the vascular surgery outpatient clinic with Rutherford class II or III PAD and who were treated with either supervised exercise therapy or endovascular interventions. Changes in estimated glomerular filtration rates (eGFR) after 1 year were compared between the 2 treatment groups. Multivariate regression analysis and propensity score-matched paired analysis were done to correct for potential confounders. RESULTS: One year after treatment, eGFR was reduced by 8.6 mL/min (95% confidence interval [CI], 7.3-9.9, P < 0.001) after endovascular intervention (n = 284) and by 1.7 mL/min (95% CI, 0.9-25, P < 0.001) after supervised exercise therapy (n = 299). After correction for potential confounders, endovascular interventions were associated with 9.2 mL/min (95% CI, 5.9-12.4, P < 0.001) more renal decline compared to exercise therapy. Similar results were found in the propensity score-matched paired analysis. CONCLUSIONS: Endovascular procedures for PAD are associated with clinically relevant and long-term loss of kidney function.

Loss of kidney function in patients with critical limb ischemia treated endovascularly or surgically.

BACKGROUND: Acute kidney injury after the administration of contrast material during endovascular procedures for peripheral arterial disease generally recovers with supportive treatment. However, long-term effects of endovascular procedures for critical limb ischemia on renal function remain to be investigated. METHODS: This retrospective observational cohort study included all patients who newly presented to the vascular surgery outpatient clinic with Rutherford class 4 to class 6 peripheral arterial disease and who were treated with either endovascular or surgical interventions. Changes in estimated glomerular filtration rate (eGFR) after 1 year were compared between the two types of intervention. Multivariate linear regression analysis was done to correct for potential confounders. RESULTS: One year after treatment, eGFR was reduced by 15.0 mL/min (95% confidence interval [CI], 13.1-17.0; P < .001) after endovascular interventions (n = 209) and by 7.6 mL/min (95% CI, 5.1-10.0; P < .001) after surgical therapy (n = 81). Although eGFR rates decreased in both groups, loss of renal function was significantly greater in patients after endovascular interventions (P < .001). Furthermore, 77% of patients receiving endovascular interventions experienced fast renal decline (defined as >4 mL/min loss of eGFR within 1 year) compared with 54% of patients treated surgically (P < .001). After correction for potential confounders, endovascular intervention was associated with 7.4 mL/min (95% CI, 5.4-9.3; P < .001) greater loss of renal function compared with patients treated surgically. CONCLUSIONS: Endovascular procedures for critical limb ischemia are associated with clinically relevant permanent long-term loss of kidney function. This loss of renal function is greater than in comparable patients who were treated with open surgery.

Flap fixation reduces seroma in patients undergoing mastectomy: a significant implication for clinical practice.

BACKGROUND: Seroma formation is a common complication following mastectomy for invasive breast cancer. Mastectomy flap fixation is achieved by reducing dead space volume using interrupted subcutaneous sutures. METHODS: All patients undergoing mastectomy due to invasive breast cancer or ductal carcinoma in situ (DCIS) were eligible for inclusion. From May 2012 to March 2013, all patients undergoing mastectomy in two hospitals were treated using flap fixation. The skin flaps were sutured on to the pectoral muscle using polyfilament absorbable sutures. The data was retrospectively analysed and compared to a historical control group that was not treated using flap fixation (May 2011 to March 2012). RESULTS: One hundred and eighty patients were included: 92 in the flap fixation group (FF) and 88 in the historical control group (HC). A total of 33/92 (35.9%) patients developed seroma in the group that underwent flap fixation; 52/88 (59.1%) patients developed seroma in the HC group (p = 0.002). Seroma aspiration was performed in 14/92 (15.2%) patients in the FF group as opposed to 38/88 (43.2%) patients in the HC group (p < 0.001). CONCLUSIONS: Flap fixation is an effective surgical technique in reducing dead space and therefore seroma formation and seroma aspirations in patients undergoing mastectomy for invasive breast cancer or DCIS.