Effect of brachial plexus block-driven vascular access planning on primary distal arteriovenous fistula recruitment and outcomes

Perineural low dexamethasone dose as adjuvant in supraclavicular brachial plexus block for arteriovenous fistula creation in end stage renal disease: a randomized controlled trial

BACKGROUND AND AIMS

Dexamethasone as adjunct to local anesthetic solution improves the quality of brachial plexus block (BPB). However, evidence for its efficacy at low doses (< 4 mg) is lacking. This study was designed to evaluate the duration of analgesia attained with low dose dexamethasone as adjuvant to local anesthetic for creation of arteriovenous fistula (AVF) under BPB.

METHODS

Sixty-six patients scheduled for AVF creation were randomly allocated to receive either saline (control) or 2 mg dexamethasone, together with 0.5% ropivacaine and 0.2% lignocaine. The primary outcome was duration of analgesia, defined as time from performing the block to the first analgesic request. The secondary outcomes were time from injection to complete sensory block, time from injection to complete motor block, duration of motor block, postoperative analgesic consumption, and fistula patency at three months.

RESULTS

All the blocks were effective. In the group that received dexamethasone, the time to first analgesic request was significantly delayed (432 ± 43.8 minutes vs. 386.4 ± 40.2 minutes; p < 0.01). The onset of sensory and motor blockade occurred faster in dexamethasone group and overall analgesic consumption was also reduced. However, dexamethasone addition did not prolong the duration of motor block. There was no statistically significant difference in the patency of fistulas between the two groups at three months. (p = 0.34).

CONCLUSION

Addition of low-dose perineural dexamethasone to local anesthetic solution significantly prolonged the duration of analgesia. Further trials are warranted to compare the adverse effects between dexamethasone doses of 4 mg and lower.

The feasibility of small-caliber veins for autogenous arteriovenous fistula creation: A single-center retrospective study

Objective

Autogenous arteriovenous fistula (AVF) is recommended as the first choice for hemodialysis vascular access. A small-caliber vein is one of the independent risk factors for AVF maturation and patency. However, the specific threshold is still unclear, making it difficult to accurately determine whether these vessels are suitable for AVF creation.

Design

This is a single-center retrospective study.

Method

Patients who underwent AVF creation in our medical center between January 2020 and September 2022 and satisfied the eligibility criteria were included in this retrospective study. Logistic regression analysis was performed to identify risk factors for functional maturation and additional intervention. The optimal cutoff value was determined based on the receiver operating curve (ROC) and the Youden index. Kaplan-Meier analysis was utilized in further patency rate comparisons.

Result

A total of 125 forearm AVFs were created in 121 patients with end-stage renal disease (ESRD). The mean age was 53.88 ± 15.10  years. Preoperative vascular Doppler ultrasound (DUS) was conducted and recorded in 106 cases (84.80%). The mean targeted artery and vein diameters were 2.17 ± 0.54 and 1.71 ± 0.75  mm, respectively. Small-caliber vein is the risk factor for functional maturation failure (OR = 0.256, 95%CI [0.06-0.75], p = 0.033) and additional intervention (OR = 0.306, 95% CI [0.09-0.78], p = 0.031). The optimal cutoff value is 1.35  mm (augmented) when specificity and sensitivity reach 80 and 63.7%, respectively. The AVFs with a vein diameter of more than 1.35 mm (augmented) showed higher patency rates (p < 0.01).

Conclusion

After comprehensive DUS evaluation, intraoperative hydrodilation, postoperative active exercise and intensive DUS detection, and application of balloon-assisted maturation, if necessary, using a vein more than 1.35 mm (augmented), could achieve satisfactory functional maturation and postoperative patency in AVF formation.

The Effects of Vasodilation Induced by Brachial Plexus Block on the Development of Postoperative Thrombosis of the Arteriovenous Access in Patients with End-Stage Renal Disease: A Retrospective Study

Although brachial plexus block (BPB)-induced vasodilation reduces the incidence of arteriovenous access (AC) thrombosis, BPB cannot completely prevent its development. Therefore, we retrospectively investigated the factors affecting BPB-induced vasodilation and their effects on AC thrombosis development. Ninety-five patients undergoing AC surgery under BPB were analyzed. Vessel diameters were measured before and 20 min after BPB. The surgery abandoned before the BPB placement was performed when the BPB-induced increases in vessel diameters met its indications. Complete occlusive access thrombosis (COAT) was defined as loss of pulse, thrill, or bruit. Fourteen patients (14.7%) developed COAT. The outflow vein was more dilated by BPB than the inflow artery (0.6 versus 0.1 mm in median, p < 0.001). The original surgery plan was changed for seven patients (7.4%). Diabetes mellitus (DM) and ischemic heart disease (IHD) decreased the extent of increases in the inflow artery by -0.183 mm (95% confidence interval [CI] [-0.301, -0.065], p = 0.003) and outflow vein diameters by -0.402 mm (95% CI [-0.781, -0.024], p = 0.038), respectively. However, DM, IHD, and changes in the vessel diameters had insignificant effects on the development of COAT. In conclusion, although DM and IHD attenuate the vasodilating effects of BPB, they do not contribute to the development of COAT.

Assessment of Duplex ultrasound carried out by the vascular surgeon after locoregional anesthesia for preferred arteriovenous fistula access

OBJECTIVES

Preoperative vascular mapping by duplex ultrasound is required in construction of an arteriovenous fistula for hemodialysis (AVF). Due to venous vasospasm in cool temperatures and variability of the dialysis patient's blood volume, the conditions for performing this examination may be less than ideal. However, local regional anesthesia (LRA) resulting in vasodilation of the limb, can allow the use of veins considered to be of insufficient caliber during preoperative ultrasound mapping. The aim of this study was to assess the functionality of AVF when duplex ultrasound is performed by the surgeon following LRA. These results were compared with those from the preceding year, during which preoperative duplex ultrasound had been performed without LRA by vascular specialists, (Clinical Trial registration number: NCT04978155).

MATERIALS AND METHODS

This is a prospective study of all the patients having received AVF after systematic immediate preoperative ultrasound (US) under LRA (US-LRA group) in 2020. The initial surgical programming based on the Silva criteria was reported by a vascular medicine specialist. The change of AVF strategy following US-LRA was reported together with AVF usability and patency and compared to the results of the control group, in which AVF had been performed in 2019 without US-LRA.

RESULTS

Ninety patients were included in the US-LRA group and 93 in the control group. Modified surgical planning was observed in 38% of cases (35/90) in the US-LRA group including more distal AVF in 28% of patients (26/90) and alternative target vein in 6.6% (6/90). AVF usability at 6 weeks was 80% (72/90) in the US-LRA group and 51.6% (48/93) in the control group (p<.001). Median follow-up was 12 months [IQR:9-15] in the US-LRA group and 13 months [IQR:9-18] in the control group. Primary patency at 6, 12, 18 months was significantly better in the US-LRA group (73.6% vs. 57.4%, 54.4% vs. 40.2%, 31.3% vs. 28.2%, respectively, p<.001). Assisted patency and secondary patency were comparable in the two groups.

CONCLUSION

This study showed the benefit of having the surgeon perform US-LRA before starting the procedure, thereby allowing for more distal AVF, better usability and patency.

Expandability of Cephalic Veins after Brachial Plexus Block in Arteriovenous Fistula Formation for Hemodialysis

Background

Arteriovenous fistula (AVF) for hemodialysis is essential for patients with end-stage renal disease. However, it is difficult to maintain AVF reliably. It is vitally important to select proper blood vessels for AVF formation. In a previous study, a minimum diameter of 3 mm for the autologous vein was proposed. However, patients who did not meet the minimum vascular diameter before anesthesia, but fulfilled other criteria, showed satisfactory venous dilatation after brachial plexus block (BPB). This study investigated the extent of vein expansion by BPB and the surgical outcomes of dilated veins after BPB.

Methods

Sixty-one patients who underwent AVF formation using an autologous vein between August 2018 and December 2019 were included in the study. The clinical characteristics of the patient groups, hemodynamic parameters including the diameter of blood vessels before and after BPB, and complications were investigated. Based on the venous diameter measured by sonography before anesthesia, patients were divided into group A (26 patients) and group B (35 patients), with venous diameters <3 mm and ≥3 mm, respectively.

Results

The venous diameter expanded after anesthesia by 41% overall, by 62% in group A, and by 25% in group B. This difference between groups A and B was statistically significant (p=0.001). No other variables showed statistically significant differences.

Conclusion

Sufficient venous dilatation was observed after BPB. Therefore, if the vein is sufficiently dilated after BPB, even in patients with a pre-anesthesia venous diameter <3 mm, surgery may still be performed with an expected desirable outcome.

Reliability of preoperative venous mapping ultrasonography in predicting for autogenous arteriovenous fistula maturation

BACKGROUND

Autogenous arteriovenous fistula creation is the preferred route for vascular access for hemodialysis. Although preoperative venous mapping ultrasonography has been advocated as an operative planning adjunct and recently incorporated into the Society for Vascular Surgery clinical guidelines, controversy remains regarding its usefulness for predicting access success. The purpose of the present retrospective clinical study was to test the hypothesis that vein size measured on routine preoperative venous mapping is a poor predictor of primary fistula maturation.

METHODS

Consecutive upper extremity autogenous arteriovenous fistulas created by three dedicated vascular surgeons were retrospectively reviewed. The demographic characteristics, preoperative venous mapping, functional maturation, and patency were analyzed. The clinically relevant variables were tested for predictive significance using a logistic regression model.

RESULTS

A total of 199 upper extremity autogenous arteriovenous fistulas had been created during a 5-year period. Patients were aged 70 ± 16 years (range, 20-96 years), and 62% were men. Most had already been undergoing dialysis before fistula creation (83%), usually via a tunneled central venous catheter (62%). Radial-cephalic, brachial-cephalic, and brachial-basilic arteriovenous fistulas had been created in 82 patients (41%), 76 patients (38%), and 10 patients (5%), respectively. Fistula maturation, defined as a palpable thrill and/or successful cannulation of the fistula with the ability to deliver a flow rate of 400 mL/min, was achieved in 67% of the patients. A higher body mass index was associated with nonmaturation on both univariate and multivariate analyses (success, 28.6 ± 7.7 kg/m²; vs failed, 31.6 ± 9.4 kg/m²; P = .029; odds ratio [OR], 1.06; 95% confidence interval [CI], 1.02-1.10; P < .01). On univariate analysis, the maximum target vein diameter assessed by preoperative venous mapping was slightly larger in the group achieving successful maturation (2.9 ± 1.1 mm vs 2.6 ± 0.9 mm; P = .014). However, neither the maximum target vein diameter nor a target vein size >3 mm was significantly predictive of maturation on multivariate analysis (maximum vein diameter: OR, 0.65; 95% CI, 0.35-1.22; P = .176; vein size >3 mm: OR, 0.91; 95% CI, 0.32-2.60; P = .857). After a median follow-up of 15 months (interquartile range, 26 months), the primary functional patency, primary-assisted patency, and secondary patency rates were 39.1% ± 0.6%, 94.5% ± 0.6%, and 97.9% ± 0.5%. No association of vein diameter with long-term patency was found.

CONCLUSIONS

Despite the national fistula-first initiatives, most patients still undergo access via catheter at the initiation of hemodialysis. The use of routine preoperative venous mapping does not predict successful primary maturation. Also, no clinically useful predictor of fistula maturation was identified in the present study.

Addition of serratus-intercostal plane block/BRILMA for arteriovenous access surgery

ARTERIOVENOUS: access creation is mandatory in patients with end stage renal disease for hemodialysis treatment. It frequently involves upper arm or axillary dissection and general anesthesia is predominantly used as axillary compartment innervation is complex. Avoiding general anesthesia may be beneficial in these risk patients. We present two cases where serratus-intercostal plane block (SIPB/BRILMA) was used, along with ultrasound guided supraclavicular block and multimodal analgesia for proximal arm and axillary AV access surgery. Regional anesthesia combination of supraclavicular and serratus-intercostal/BRILMA block in arteriovenous fistula surgery was successful and should be considered by anesthesiologist in order to avoid general anesthesia.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Regional anesthesia for vascular surgery: does the anesthetic choice influence outcome?

PURPOSE OF REVIEW

Outcomes following surgery are of major importance to clinicians, institutions and most importantly patients. This review examines whether regional anesthesia and analgesia influence outcome after vascular surgery.

RECENT FINDINGS

Large database analyses of contemporary practice suggest that utilizing regional anesthesia for both open and endovascular aortic aneurysm repair, lower limb revascularization and carotid endarterectomy reduces morbidity, length of stay and possibly even mortality. Results from such analyses are limited by an inherent risk of bias but are nevertheless important given the number of patients required in randomized trials to detect differences in rare outcomes. There is minimal evidence that regional anesthesia influences longer term outcomes except for arteriovenous fistula surgery where brachial plexus blocks appear to improve 3-month fistula patency.

SUMMARY

Patients undergoing vascular surgery often have multiple comorbidities and it is important to be able to outline both benefits and risks of regional anesthesia techniques. Regional anesthesia in vascular surgery allows avoidance of general anesthesia and does provide short-term benefits beyond superior analgesia. Evidence of long-term benefits is lacking in most procedures. Further work is required on newer patient centered outcomes.

The forearm arteriovenous graft between the brachial artery and the brachial vein as a reliable dialysis vascular access for patients with inadequate superficial veins

OBJECTIVE

The arteriovenous fistula (AVF) is recommended as the preferred hemodialysis access. However, placing an AVF in all patients may result in poor access outcomes and increased central venous catheter (CVC) use because of increased comorbid conditions, age, and suboptimal vessels. In patients with inadequate superficial veins for AVFs, the use of the brachial veins for creation of forearm arteriovenous grafts (AVGs) has received limited attention. This retrospective study aimed to evaluate outcomes of forearm brachial-brachial AVGs (BB-AVGs) placed in patients with poor superficial veins.

METHODS

We identified 111 BB-AVGs created in 111 consecutive patients, using standard-walled polytetrafluoroethylene grafts, between January 2010 and December 2015. After excluding 6 patients (non-dialysis initiation, missing information, and death within 1 month), we included 105 patients from 21 dialysis centers. We analyzed primary failures, time to cannulation, patency, complications, and revisions. Patency rates were calculated by the Kaplan-Meier method. The incidence of complications and revisions was expressed as number of events per person-year.

RESULTS

A total of 105 patients (median age, 69 years) were followed up for a median time of 21.2 months (interquartile range, 9.2-36.5 months). Of the patients, 72.4% were on chronic hemodialysis and had previously undergone one or more access procedures. At the time of BB-AVG placement, prior accesses were 39 AVFs, 20 tunneled CVCs, and 17 AVGs. BB-AVG rates of primary failure and revision before cannulation were 7.6% and 5.7%, respectively. BB-AVGs were cannulated after a median time of 3.4 weeks (interquartile range, 2.8-4.1 weeks). Primary patency rates at 12, 24, and 36 months were 49.5%, 29.5%, and 19.5%. Secondary patency rates at 12, 24, and 36 months were 76.3%, 62.7%, and 54.6%. After cannulation, the incidence of complications and revisions was 1.054 and 0.649 per person-year, respectively. Most complications and interventions were due to thrombosis (0.527 per person-year) or stenosis (0.381 per person-year) and related interventions (0.490 per person-year). A minority of patients experienced AVG infections (0.052 per person-year), with only two requiring access removal.

CONCLUSIONS

In patients with poor superficial veins, the forearm BB-AVG is a reliable access because of low access-related morbidity and considerable long-term access survival. BB-AVG placement has the advantage of preserving proximal vessels. In these patients, such an approach can delay both rapid exhaustion of vascular sites and early recourse to CVC permanent use.

Repeated mappings of arm veins by physical examination: role of nephrologists in the selection of suitable veins for AV fistula surgery

Multidisciplinary team work is important for a successful hemodialysis vascular access program. The authors present a clinical case to illustrate the potential dynamic factors that can affect vein sizes, independent from the operators' skills and experiences. Therefore, if the first examination fails to detect suitable veins, repeated examinations of arm veins by nephrologists during routine office visits may greatly assist the surgeons in the selection of suitable arm veins for arteriovenous fistula surgery.