Effect of Operating Surgeon on Outcome of Arteriovenous Fistula Formation

Standardization of Pre-operative Evaluation to Improve the Outcome of Arteriovenous Fistula for Vascular Access of Hemodialysis: A Review of 700 Cases

Background With the advent of COVID-19, mortality rates of end-stage kidney disease (ESKD) rose by 37% which makes its treatment an important part of healthcare. Arteriovenous fistula (AVF) is linked to higher patient survival rates. Cimino-Brescia fistula is the most effective vascular access technique, but it has a high rate of primary failure (PF) and a several-week maturation period before it can be used. The current study aims to verify the preoperative evaluation in improving survival among AVF patients. Methodology The current study is a retrospective analysis of the hospital database from Jan 2022 to July 2023, with patients of a mean age of 60.2 years. The sample size was around 700, including the patients indicated for long-term hemodialysis (HD) with an estimated GFR of less than 20 mm/min/1.73m². Following AVF surgery, post-operative outcomes, PF, and maturation time were considered. Results Among the 757 AVF procedures, 588 (82%) were new cases, and 112 (16%) had prior AVF history on the same side. PF was observed in 126 (18%) AVFs, while 574 (84%) achieved maturation. Age at surgery did not correlate with PF. Male sex and brachiocephalic AVF (BCAVF) had lower PF rates, while female gender, non-BCAVF, and vascular chronic kidney disease (CKD) were independent predictors. Proximal fistulas had a higher failure risk (32%). During surgery, the PF occurred six times more frequently in patients with veins and arteries under 2 mm and without a bruit. Conclusion AVF maturation aims to achieve a functional AVF for easy dialysis, requiring meticulous vein selection, doppler vascular mapping, and a standardized process to reduce PF rates. Factors determining PF include thrill and bruit, flow rates, and comorbidities. These findings can help clinicians make informed decisions and improve outcomes for patients undergoing fistula surgery.

Efficacy of blood flow measurement using intraoperative color flow Doppler ultrasound as a predictor of autologous arteriovenous fistula maturation

INTRODUCTION

Hemodialysis vascular access parameters of intraoperative Color flow Doppler ultrasound remain controversial. This study aimed to evaluate the optimal cut-off value and efficacy of intraoperative arteriovenous fistula parameters identified by Color flow Doppler ultrasound for arteriovenous fistula maturation success.

METHODS

This retrospective study consisted of a review of the medical records of 137 consecutive patients who underwent their first autologous arteriovenous fistula formation under local anesthesia for end-stage renal disease from April 9, 2020 to March 19, 2021.

RESULTS

The receiver operating characteristic curve analysis revealed that the optimal cut-off for intraoperative cephalic vein flow volume for brachiocephalic arteriovenous fistula maturation at the 4-week follow-up was 349.53 ml/min (area under the curve, 0.792; p, 0.036; Youden index, 0.514).

CONCLUSION

Intraoperative color Doppler ultrasound outflow cephalic vein flow volume is a useful factor in predicting arteriovenous fistula maturation. Intraoperative Color flow Doppler ultrasound should be performed.

Determinants of successful arteriovenous fistulae creation including intraoperative transit time flow measurement

BACKGROUND

The prevalence of hemodialysis patients is increasing, and it is important to create the arteriovenous fistula as early as possible to avoid hemodialysis by central venous catheter. International guidelines recommend arteriovenous fistula as the vascular access of first choice. Arteriovenous fistulae are associated with a failure rate of 23%. The success of an arteriovenous fistula can be evaluated intraoperatively by physical examination and by measuring the blood flow.

OBJECTIVES

The aim of the study is to describe the predictive value of various factors for fistula maturation in the context to the current literature.

METHODS

We report on a prospective cohort study of 41 patients, undergoing a primary arteriovenous fistula at the upper extremity. The primary endpoint of the study was the successful fistula maturation after 6 weeks.

RESULTS

The intraoperative measurement of the blood flow in the outflow vein has been identified as the unique significant parameter for the fistula maturation.

CONCLUSION

The predictive value of intraoperative flow measurement is superior to intraoperative physical examination and could help reduce the fistula dysmaturation rate. Intraoperative transit time flow measurement is an easy method and can be used to predict successful fistula maturation in a high percentage rate.

Surgeon Characteristics and Dialysis Vascular Access Outcomes in the United States: A Retrospective Cohort Study

RATIONALE & OBJECTIVE

An arteriovenous fistula (AVF) is the preferred access for most patients receiving maintenance hemodialysis, but maturation failure remains a challenge. Surgeon characteristics have been proposed as contributors to AVF success. We examined variation in AVF placement and AVF outcomes by surgeon and surgeon characteristics.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

National Medicare claims and web-based data submitted by dialysis facilities on maintenance hemodialysis patients from 2009 through 2015.

EXPOSURES

Patient characteristics, including demographics and comorbid conditions; surgeon characteristics, including specialty, prior volume of AVF placements, and years since medical school graduation.

OUTCOMES

Percent of access placements that were an AVF from 2009 to 2015 (designated AVF placement), and percent of AVFs with successful use within 6 months of placement (maturation) from 2013 to 2014.

ANALYTICAL APPROACH

Multilevel logistic regression models examining the association of surgeon characteristics with the outcomes, adjusted for patient characteristics and dialysis facilities as random effects.

RESULTS

Among 4,959 surgeons placing 467,827 accesses, median AVF placement was 71% (IQR, 59%-84%). More recent year of medical school graduation and general surgery specialty (vs vascular, cardiothoracic, or transplantation surgery) were associated with higher odds of AVF placement. Among 2,770 surgeons placing 49,826 AVFs, the median AVF maturation rate was 59% (IQR, 44%-71%). More recent year of medical school graduation, but not surgical specialty, was associated with higher odds of AVF maturation. Greater prior volume of AVF placement was associated with higher odds of AVF maturation: OR of 1.46 (95% CI, 1.37-1.57) for highest (>84 AVF placements in 2years) versus lowest (<14) volume quintile.

LIMITATIONS

The study relied on administrative data, limiting capture of some factors affecting access outcomes.

CONCLUSIONS

There is substantial surgeon-level variation in AVF placements and AVF maturation. Surgeons' prior volume of AVF placements is strongly associated with AVF maturation.

Relevance of a skilled vascular surgeon and optimized facility practices in the long-term patency of arteriovenous fistulas: a prospective study

Introduction:

Arteriovenous fistulas (AVF) are the best hemodialysis vascular accesses, but their failure rate remains high. Few studies have addressed the role of the vascular surgeon's skills and the facility's practices. We aimed to study these factors, with the hypothesis that the surgeon's skills and facility practices would have an important role in primary failure and patency rates at 12 months, respectively.

Methods:

This was a single-center, prospective cohort study carried out from March 2005 to March 2017. Only incident patients were included. A single surgeon made all AVFs, either in the forearm (lower) or the elbow (upper). Vascular access definitions were in accordance with the North American Vascular Access Consortium.

Results:

We studied 113 AVFs (65% lower) from 106 patients (39% diabetics, 58% started with catheter). Time to first connection was 21.5 days (IR: 14 - 31). Only 14 AVFs (12.4%) underwent primary failure and 18 failed during the first year. Functional primary patency rate was 80.9% (SE 4.1) whereas primary unassisted patency rate, which included PF, was 70.6% (4.4). Logistic regression showed that diabetes (OR = 3.3, 95%CI 1.38 - 7.88, p = .007) and forearm location (OR = 3.03, 95CI% 1.05 - 8.76, p = 0.04) were predictors of AVF failure. Patency of lower and upper AVFs was similar in non-diabetics, while patency in diabetics with lower AVFs was under 50%. (p = 0.003).

Conclusions:

Results suggest that a long-lasting, suitable AVF is feasible in almost all patients. The surgeon's skills and facility practices can have an important role in the long term outcome of AVF.

Rate of Open Reduction for Supracondylar Humerus Fractures Varies Across Pediatric Orthopaedic Surgeons: A Single-Institution Analysis

OBJECTIVES

To (1) define a single institution's rate of open reduction for operative pediatric supracondylar humerus (SCH) fractures; (2) describe variability by surgeon in rates of irreducible fracture (IRF) and open reduction; and (3) determine whether variation in opening rate correlated with surgeon experience.

DESIGN

Retrospective analytic study.

SETTING

Urban tertiary care Level 1 trauma center.

PATIENTS/PARTICIPANTS

Twelve fellowship-trained pediatric orthopaedists.

MAIN OUTCOME MEASUREMENTS

Rate of open reduction for operatively treated SCH fractures (OTA/AO 13-M/3).

RESULTS

One thousand two hundred twenty-nine type II SCH fractures (none of which required open reduction) were excluded from the analysis. A total of 1365 other SCH fractures were included: 1302 type III fractures, 27 type IV fractures, and 36 fractures with unspecified type. 2.9% of type III and 22.2% of type IV fractures required open reduction. None of the injuries with unspecified type required open reduction. The rate of open reduction among 11 surgeons ranged from 0% to 15.0% in type III-IV fractures (P = 0.001). 86% (38/44) of open reductions were performed for IRF. In regression analysis, patient age was associated with open reduction for IRF (odds ratio 1.22, P = 0.001), but surgeon years-in-practice (0.321) and number of previous cases (0.327) were not associated with open reduction. Other indications for opening included suspected vascular or neurologic injury.

CONCLUSIONS

Open reduction was rarely performed in this sample, but IRF was the dominant indication for opening. We found true variation in surgeons' rates of performing open reductions. More experience was not correlated with decreased likelihood of open reduction.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Programmatic change leads to enhanced resource utilization and efficiency in port placement

BACKGROUND

Central venous port (CVP) placement is performed by a variety of surgeons in different subspecialties, and our previous work suggests that individual surgeons-regardless of training-are the strongest predictor of outcomes. We sought to prospectively evaluate a programmatic shift toward a resource-conscious, patient-focused algorithm for this common and simple surgical procedure.

MATERIALS AND METHODS

After implementation of a systems-level program for efficient CVP placement, 78 CVPs were placed by a single surgeon. Primary outcomes were procedure time, total operating room (OR) time, total facility time, and procedure-related complications. These prospective data were compared with retrospective cohorts of surgically placed and interventional radiology-placed CVP. Demographic data were analyzed by chi-square analysis, whereas time data were analyzed by the Wilcoxon rank-sum test.

RESULTS

The programmatic delivery (prospective) set showed significantly shorter procedural (median 16 min versus 26-40, P <0.05), OR times (median 36 min versus 46-70, P <0.05), and facility times (median 235 min versus 299-319, P <0.05) except for the interventional radiology facility time (median 187 versus 235, P <0.05). The range of OR time savings with the prospective versus comparison groups was 10-34 min, representing 22%-49% reductions in OR time (P <0.05). Complication rates were not significantly different (P = 0.13).

CONCLUSIONS

Through a programmatic change emphasizing efficiency and patient-centered outcomes, procedural/OR/facility time can be reduced greatly without changing complication rates. These data provide compelling evidence that common and ostensibly simple operative procedures can be substantially improved upon with thoughtful, data-driven systems-level enhancements.

Surgeon experience affects outcome of forearm arteriovenous fistulae more than outcomes of upper-arm fistulae

INTRODUCTION

There is still an ongoing discussion about the influence of vascular surgeon experience on the immediate and long-term outcome of newly created arteriovenous fistula (AVF) for patients on hemodialysis (HD). The aim of this study was to compare failure and patency rates of AVF between experienced consultants and resident trainees with special focus on location of the anastomosis on the forearm or upper arm.

METHODS

Between November 2012 and September 2016, 159 patients (83 on HD and 76 preemptive) received an AVF (90 radiocephalic [RCAVF] on the forearm; 69 brachiocephalic [BCAVF] in the elbow) by two experienced vascular surgeons (group A; n = 74) or five residents in training with one-to-four years of experience (group B; n = 85). We compared the two groups for demographic and treatment data, immediate failures (IF), bleeding complications and patency rates.

RESULTS

There were no significant differences in demographic data between the two groups. Vessel diameters were significantly lower for forearm compared to upper arm arteries (p = 0.026) and veins (p = 0.05). There was a significantly increased risk for IF in group B for RCAVF (p = 0.003), but not for BCAVF (p = 1.000). Furthermore, the cumulative primary patency was reduced in group B for RCAVF (p<0.001), but not for BCAVF (p = 0.899).

CONCLUSION

Surgeon experience seems to have more influence on the immediate and long-term outcome of newly created forearm AVF compared to those located on the upper arm.

Impact of surgeon factor on radiocephalic fistula patency rates

Introduction

Hemodialysis with arteriovenous fistula (AVF) has been widely accepted treatment modality for patients with chronic renal failure (CRF). Radiocephalic fistulas are considered to be the most desirable for the initial vascular access. The aim of this study is to investigate the surgeon factor on radiocephalic fistula patency rates.

Methods

A total of 186 patients with diagnosis of CRF underwent Radiocephalic fistula for hemodialysis access were included. Patients were divided into 2 groups according to operating surgeon. Patients were evaluated according to demographic characteristics, secondary patency rates, second AVF creation and complications.

Results

Mean age was 57.7 ± 14.8 years. The most common etiology of CRF was idiopathic (66.6%). 40 (75.5%) patients in group 1 and 122 (91.7%) patients in group 2 were pre-dialysis patients (p < 0.05). Overall secondary patency rate was 77.4%. Patients in group 1 and group 2 have secondary patency rates of 83% and 75.2%, respectively (p = 0.458). Second AVF creation was done in 2 (3.8%) patients in group 1 and 23 (17.3%) patients in group 2 (p < 0.05). Postoperative complication rate was 9.6%.

Conclusion

Operating surgeon is not a major factor of secondary patency in radiocephalic arteriovenous fistulas.

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Overall secondary patency rate was found in 144 (77.4%) patients.

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No statistical difference was observed according to secondary patency rates.

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Postoperative complication rate was 9.6%.

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Operating surgeon is not a major factor on radiocephalic fistula patency rates.

Should patients be on antithrombotic medication for their first arteriovenous fistulae?

PURPOSE

Evidence on the effect of antithrombotic medication on reducing early and late fistula failure is inconclusive. Antithrombotic use carries risks in patients with end-stage renal failure and could increase the risk of needling complications as a result of bleeding. The objectives of this study are to determine the effect of antithrombotic agents on early and late fistula failure and on the risk of interrupted start of cannulation of the fistula.

METHODS

Retrospective analysis of two prospectively maintained databases of access operations and dialysis sessions of 671 patients who had their first fistula between 2004 and 2011. Early failure was defined as failure to reach six consecutive dialysis sessions at any time with two needles on the index form of access. Fistula survival was defined as the time from when the fistula was first used to fistula abandonment.

RESULTS

Primary failure was similar between patients on antiplatelet (18.8%), anticoagulants (18.4%) or no antithrombotic medication (18.8%; p = 0.998). Antithrombotic medication did not have an effect on AVF survival (p = 0.86). Antithrombotic medication did not increase complicated cannulation rates, defined as the percentage of patients failing to achieve six uninterrupted dialysis sessions from the start (p = 0.929).

CONCLUSIONS

Antithrombotic medication had no significant effect on primary failure rate, long-term fistula survival or initial complicated cannulation rates in our study. This suggests that patients already on antithrombotic medication can continue taking them without increasing the risk of interrupted dialysis.

What is the best training for vascular access surgery?

Questions have been raised whether there is a lack of appropriate training in access creation and maintenance, and if training juniors in arteriovenous (AV) fistulas may affect the outcome. A survey was undertaken to study "experts" opinion in access training using a closed questionnaire. The majority of "experts" consented that there is a lack of appropriate training in access creation and maintenance in a great extent, although they located the main deficit regarding access training in the preoperative planning and decision making. Regarding the second question, a literature search revealed only four studies, comparing the outcomes of AV fistulas created either by consultant surgeons or trainees. A meta-analysis performed revealed that 1-year patency rate was not statistically significant different among access procedures created either by consultants or trainees. Access surgery shares the same basic principles with vascular surgery and provides a valuable workload for the trainees and is a necessity to become a building component in all "core" vascular curricula; the required skills can be acquired with the trainees operating independently simple cases, as the latter is not leading to suboptimal outcomes.

Preserving arteriovenous fistula outcomes during surgical training

PURPOSE

Arteriovenous fistulae (AVFs) are the preferred option for vascular access, as they are associated with lower mortality in hemodialysis patients than in those patients with arteriovenous grafts (AVGs) or central venous catheters (CVCs). We sought to assess whether vascular access outcomes for surgical trainees are comparable to fully trained surgeons.

METHODS

A prospectively collected database of patients was created and information recorded regarding patient demographics, past medical history, preoperative investigations, grade of operating surgeon, type of AVF formed, primary AVF function, cumulative AVF survival and functional patency.

RESULTS

One hundred and sixty-two patients were identified as having had vascular access procedures during the 6 month study period and 143 were included in the final analysis. Secondary AVF patency was established in 123 (86%) of these AVFs and 89 (62.2%) were used for dialysis. There was no significant difference in survival of AVFs according to training status of surgeon (log rank x2 0.506 p=0.477) or type of AVF (log rank x2 0.341 p=0.559). Patency rates of successful AVFs at 1 and 2 years were 60.9% and 47.9%, respectively.

CONCLUSION

We have demonstrated in this prospective study that there are no significant differences in outcomes of primary AVFs formed by fully trained surgeons versus surgical trainees. Creation of a primary AVF represents an excellent training platform for intermediate stage surgeons across general and vascular surgical specialties.

Arteriovenous Fistula Formations: Key to Vascular Surgical Training

Purpose

To highlight missed training opportunities in daycase surgery for trainees to acquire competency in vascular anastomosis by performing arteriovenous fistula (AVF) formations.

Methods

Operative Room Management Information System records were reviewed for AVF procedures in daycase and general theatres at a UK Foundation Trust between 2007 and 2012. Data collected included procedure, procedure time (PT), patient length of stay (LOS), readmissions within 30 days of procedure and lead and assistant surgeons involved.

Results

Of 199 daycase AVF procedures reviewed, 59.3% (n=118) were brachiocephalic formations and 34.2% (n=68) radiocephalic formations. Trainees attended 41.2% of daycase AVF procedures and were lead surgeon in 7.3% of these. Mean PT was 64 minutes for consultants compared with 56 minutes for trainees, with no significant difference (p=0.297). Median patient LOS was less than 24 hours for both groups. Six daycase AVF procedures resulted in patient readmission within 30 days; five of these were operated on by consultants and one by a staff grade. During the same period, 258 AVF procedures were performed in general theatres. Trainees attended 64.3% of AVF formations performed in general theatres and were lead surgeon in 5.8% of these.

Conclusions

Trainees attended and led few daycase AVF formations despite no significant difference in PT, patient LOS or readmission rate between consultant-led and trainee-led cases. Trainees attended more AVF formations performed in general theatres than daycase. However, trainees led a greater proportion of daycase AVF formations, possibly due to a less complex case mix that is more suitable for training.

A systematic review of the effects of residency training on patient outcomes

BACKGROUND

Residents are vital to the clinical workforce of today and tomorrow. Although in training to become specialists, they also provide much of the daily patient care. Residency training aims to prepare residents to provide a high quality of care. It is essential to assess the patient outcome aspects of residency training, to evaluate the effect or impact of global investments made in training programs. Therefore, we conducted a systematic review to evaluate the effects of relevant aspects of residency training on patient outcomes.

METHODS

The literature was searched from December 2004 to February 2011 using MEDLINE, Cochrane, Embase and the Education Resources Information Center databases with terms related to residency training and (post) graduate medical education and patient outcomes, including mortality, morbidity, complications, length of stay and patient satisfaction. Included studies evaluated the impact of residency training on patient outcomes.

RESULTS

Ninety-seven articles were included from 182 full-text articles of the initial 2,001 hits. All studies were of average or good quality and the majority had an observational study design. Ninety-six studies provided insight into the effect of 'the level of experience of residents' on patient outcomes during residency training. Within these studies, the start of the academic year was not without risk (five out of 19 studies), but individual progression of residents (seven studies) as well as progression through residency training (nine out of 10 studies) had a positive effect on patient outcomes. Compared with faculty, residents' care resulted mostly in similar patient outcomes when dedicated supervision and additional operation time were arranged for (34 out of 43 studies). After new, modified or improved training programs, patient outcomes remained unchanged or improved (16 out of 17 studies). Only one study focused on physicians' prior training site when assessing the quality of patient care. In this study, training programs were ranked by complication rates of their graduates, thus linking patient outcomes back to where physicians were trained.

CONCLUSIONS

The majority of studies included in this systematic review drew attention to the fact that patient care appears safe and of equal quality when delivered by residents. A minority of results pointed to some negative patient outcomes from the involvement of residents. Adequate supervision, room for extra operation time, and evaluation of and attention to the individual competence of residents throughout residency training could positively serve patient outcomes. Limited evidence is available on the effect of residency training on later practice. Both qualitative and quantitative research designs are needed to clarify which aspects of residency training best prepare doctors to deliver high quality care.

Outcome comparison of two surgical methods used for the treatment of acute thrombosis of arteriovenous fistulas: thrombectomy versus de novo creation of arteriovenous fistula

The aim of this study was to evaluate efficacy of two surgical methods used for the treatment of acute arteriovenous fistula (AVF) thrombosis. Twenty two out of twenty five patients that were admitted at the Clinic for vascular surgery in Sarajevo received successful surgical treatment for the salvage of acutely thromboses AVF from 2007-2009. They were included in retrospective, descriptive clinical study. Based on the type of surgical procedures performed, 22 patients were divided into two groups. The first group included 10 patients and they had successful thrombectomy of thromboses AVF while 12 patients in second group underwent de novo creation of AVF using blood vessels already exploited for construction of thromboses AVF. Patency rate of salvaged AVF in analyzed groups was compared one month and 6 months after intervention. In the postoperative follow up there was no statistically significant difference in patency rate of salvaged AVF between analyzed groups after one month, (80% vs 100%, Fisher exact test value =2,520, p= 0.195). Patency rate of salvaged AVF after six months of the follow up was significantly better in group that received de novo construction of AVF when compared to thrombectomy group (25% vs. 91%, Fisher exact test value = 1,062, p=0.002). De novo construction of AVF in case of acutely thrombosed AVF offered better patency rate of salvaged AVF when compared to surgical thrombectomy in the follow up period of six months.