A Comparison of survival and quality of arteriovenous fistula between local anesthesia and axillary block methods

© 2017 The Authors; Tabriz University of Medical Sciences This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A Comparison of survival and quality of arteriovenous fistula between local anesthesia and axillary block methods

Vascular access for dialysis, the biggest challenge for chronic dialysis patients, can be best achieved through arteriovenous fistula (AVF).The Society for Vascular Surgery (SVS), USA, has reported that the use of the patient's own vein to provide vascular access for dialysis leads to a dramatic reduction in mortality and morbidity of patients. 1The SVS has recommended radiocephalic fistula at the wrist as the first choice, but unfortunately, most patients lack suitable veins in this area.
Therefore, the second best choice is brachiocephalic fistula in the antecubital region. 1 Considering the poor health conditions of patients with end-stage renal disease (ESRD), an alternative method to general anesthesia should be used for AVF.However, since embedding AVF may require replacement and use of an alternative vessel, frequent and high doses of medication may be need for local anesthesia, and thus, regional block could produce better results. 2 In their study, JARCM/ Spring 2017; Vol. 5, No. 2 Lo Monte et al. compared local anesthesia with lidocaine and regional block with bupivacaine, and observed significant venous dilatation and reduction in pulsatility index (PI) in the regional block group compared to the local anesthesia group. 3In many studies, supraclavicular 4 and infraclavicular 5 regional blocks have produced similar results.In the present study, local anesthesia and regional block techniques were compared in terms of AVF flow and patency.
The present study recruited patients with ESRD undergoing hemodialysis via AVF in 2014-2015.A sample size of 30 in each group was sufficient to detect a clinically important difference of 70 points (between the intervention and control groups) on the AVF flow 6 months after the surgery, assuming a standard deviation (SD) of 100 and 94 points for intervention and control groups, respectively, using a two-tailed t-test of the difference between means, a power of 80%, and a significance level of 5%.The calculation was based on the assumption of the normal distribution of the measurements on AVF flow (Equation 1).
(Equation 1) Patients were randomly divided into local anesthesia group (A) [receiving lidocaine 2% (3 cc to 5 cc)], and axillary regional block (B) [receiving lidocaine 1.5% (20 cc to 30 cc)].Both groups then underwent AVF creation in the antecubital region.The study inclusion criteria consisted of lack of vascular diseases in the upper limbs, presence of proximal and distal pulse, no history of vascular thrombosis, and no infection at the injection site.
After local anesthesia, a transverse incision was made about 2 cm below the antecubital fossa where brachial pulse was felt.Brachial artery anastomosis to a suitable adjacent vein was performed end-to-side or side-to-side using proline 7-0 suture.Subsequently, patency of fistula was checked by ensuring presence of thrill and bruit.
Follow-up included examination and Doppler ultrasound of AVF site 24 hours, 10 days, and 6 months after surgery (Figure 1).
Data were analyzed in SPSS software (version 22, IBM Corporation, Armonk, NY).In descriptive analysis, mean and SD was used for quantitative data and frequency percentage for qualitative data.In deductive analysis, t-test and chi-square were used.Significance level was considered less than 0.05.Patients were not charged for this study, and informed written consents were obtained from them.Patients unwilling to take part were excluded.The results obtained were reported anonymously, and patients' personal data remained confidential.
In the present study, 60 patients with ESRD and candidates for AVF creation were randomly and equally divided into local anesthesia (A) and axillary block (B) groups.Patients' mean age was 54.28 (SD = 14.45) years.No significant difference was found in terms of mean age between local anesthesia and axillary block groups (56 years V 52.5 years) (P = 0.353).Of the total number of participants, 29 (48.3%) were women and 31 (51.7%) were men, and no significant difference was found between the two groups in terms of gender distribution (40.0%women in group A and 56.7% women in group B) (P = 0.151).
Mean duration of illness was 52.14 months in group and 57.6 months in group B, with no significant difference between the two groups (P = 0.657).In terms of underlying diseases, 40% of patients in group A and 26.7% in group B had diabetes (P = 0.206), and 20% of patients in group A and 23.3% in group B had ischemic heart disease (IHD) (P = 0.500).Moreover, 76.7% of patients in group A and 73.3% of patients in group B had hypertension (P = 0.500).
AVF failure was observed in 1 case in the local anesthesia group and 4 cases in the axillary block group, with no significant difference between them (P = 0.177).
AVF flow was not affected by gender, but it was significantly lower in patients with diabetes and IHD compared to others.
Type of anesthesia procedure can affect AVF success. 6General anesthesia is a suitable technique for AVF, but leads to reduced blood pressure and cardiac output, which can adversely affect AVF success by reducing AVF flow. 7Local anesthesia and brachial block are suitable alternatives with less effect on cardiovascular and pulmonary systems. 8ue to tissue acidosis and prolonged increased tissue blood flow in chronic renal failure (CRF), local anesthesia is less effective compared to other methods. 9n the present study, the results of AVF creation in local anesthesia and regional block methods were compared.The two groups matched in terms of age and gender, and no significant difference was found between them in underlying diseases such as diabetes, hypertension, and IHD.It seems that the strength of this study was that one surgeon and anesthesiologist performed all operations and its weakness was its relatively low number of patients.
The results obtained showed no significant difference in AVF flow and patency between local anesthesia and axillary block groups.However, AVF flow was significantly lower in patients with diabetes and IHD.Nevertheless, gender had no effect on AVF flow.
In a study by Macfarlane et al. 10 comparing local anesthesia and forearm block in AVF prognosis, forearm block produced better AVF prognosis.Another study showed that two-year AVF survival was 52% in local anesthesia and 93% in brachial block. 11owever, axillary block may cause certain complications due to vascular proximities.In a case study on a patient receiving axillary block, traumatic axillary AVF was created. 12n a study on Bier block (intravenous regional) anesthesia in patients undergoing AVF, Kazemzadeh et al. observed the most vasodilatation in these patients. 13Sahin et al. investigated the effect of ultrasound guided infrabrachial block on AVF flow after surgery, and showed that radial arterial and AVF flows in patients under infraclavicular block were higher compared to patients under local anesthesia. 5n another study, Elsharawy and Al-Metwalli found no significant difference between general and regional (brachial block) anesthesia in short-term AVF prognosis. 14 can be concluded that anesthesia methods cannot change the outcome and patency rate of AVF.