Long-term patency rate of the translocated autologous saphenous vein versus prosthetic material in vascular access surgery for haemodialysis and parenteral nutrition

OBJECTIVE

To evaluate the long-term patency rate of the arteriovenous angioaccess (AVA) with interposition of either autologous or prosthetic material as a last option for vascular access in the upper extremity.

METHODS

This is a retrospective chart review study of all patients who received an AVA with autologous saphenous vein (SV Group, n = 38) or prosthetic material (PTFE Group, n = 25) as a conduit from the year 1996 to 2020 in the Radboud University Medical Center (Radboudumc). Data were retrospectively extracted from two prospectively updated local databases for vascular access, one for haemodialysis (HD) and one for parenteral nutrition (PN). When required, the medical records of each patient were used. Data were eventually collected anonymously and analysed in SPSS 25. Kaplan-Meier life-tables were used for the statistical analysis.

RESULTS

Primary patency at 12 and 48 months was 30% and 20% in the SV group and 45% and 14% in the PTFE group. No significant difference was shown in the median primary patency rate (p = 0.715). Secondary patency at 12 and 48 months was 63% and 39% in the SV group and 55% and 19% in the PTFE group. This was considered a significant difference in median secondary patency in favour of the SV with 41.16 ± 17.67 months against 13.77 ± 10.22 months for PTFE (p = 0.032). The incidence of infection was significantly lower in the SV group (p = 0.0002). A Kaplan-Meier curve could not detect a significant difference in secondary patency between the access for haemodialysis and the access for parenteral nutrition. The secondary patency of the SV in parenteral nutrition access, was significantly higher when compared with PTFE (p = 0.004).

CONCLUSION

The SV can be preferred over PTFE when conduit material is needed for long-term vascular access for HD or PN treatment due to its higher secondary patency and lower infection risk.

Dual pathway inhibition as compared to acetylsalicylic acid monotherapy in relation to endothelial function in peripheral artery disease, a phase IV clinical trial

Objective

Dual pathway inhibition (DPI) by combining acetylsalicylic acid (ASA) with low-dose rivaroxaban has been shown to reduce cardiovascular events in patients with peripheral arterial disease (PAD) when compared to ASA monotherapy. A potential explanation is that inhibition of factor Xa improves endothelial function through crosstalk between coagulation and inflammatory pathways, subsequently attenuating the occurrence of cardiovascular events. We hypothesize that the addition of rivaroxaban to ASA in PAD patients leads to improved endothelial function.

Design

An investigator-initiated, multicentre trial investigating the effect of DPI on endothelial function.

Methods

Patients, diagnosed with PAD, were enrolled in two cohorts: cohort A (Rutherford I-III) and cohort B (Rutherford IV-VI). Participants received ASA monotherapy for a 4-weeks run-in period, followed by 12 weeks of DPI. Macro- and microvascular endothelial dysfunction were studied by measuring carotid artery reactivity upon sympathetic stimulus and by measuring plasma endothelin-1 concentrations, respectively. All measurements were performed during the use of ASA (baseline) and after 12 weeks of DPI.

Results

159 PAD patients (111 cohort A, 48 cohort B) were enrolled. Twenty patients discontinued study drugs early. Carotid artery constriction upon sympathetic stimulation at baseline (ASA) and after 12 weeks of DPI was similar in the total group, 22.0 vs. 22.7% (p = 1.000), and in the subgroups (Cohort A 22.6 vs. 23.7%, p = 1.000; cohort B 20.5 vs. 20.5%, p = 1.000), respectively. The mean concentration of plasma endothelin-1 at baseline and after 12 weeks of DPI did not differ, 1.70 ± 0.5 vs. 1.66 ± 0.64 pmol/L (p = 0.440) in the total group, 1.69 ± 0.59 vs. 1.62 ± 0.55 pmol/L in cohort A (p = 0.202), and 1.73 ± 0.53 vs. 1.77 ± 0.82 pmol/L in cohort B (p = 0.682), respectively.

Conclusion

Macro- and microvascular endothelial dysfunction, as reflected by carotid artery reactivity and plasma endothelin-1 concentrations, are not influenced in PAD patients by addition of low-dose rivaroxaban to ASA monotherapy for 12 weeks.

Trial registration

https://clinicaltrials.gov/ct2/show/NCT04218656.

Effectiveness of surgical banding for high flow in brachial artery-based hemodialysis vascular access

OBJECTIVE

Autogenous arteriovenous hemodialysis (HD) access may develop high flow (>2 L/min) over time. Reducing flow volume of a high-flow access (HFA) using a surgical banding technique has been reported to be successful in the short-term. The aim of this study was to evaluate the efficacy of banding in HFAs in terms of freedom from recurrence of high flow during a 1-year follow-up.

METHODS

All HD patients undergoing surgical banding of an HFA during an 8-year period in three hospitals were retrospectively studied. Access flow data, freedom of recurrent high flow, and complications were analyzed during a 12-month postoperative observation period.

RESULTS

A total of 50 patients (30 males; age, 51 ± 2 years) were available for analysis. Banding was performed 30 ± 6 months after arteriovenous access construction. Most of the HFA patients (56%) required medication for hypertension, but diabetes mellitus and peripheral arterial obstructive disease were seldom observed (6% and 12%, respectively). Most HFAs (96%) were brachial artery-based fistulas (brachiocephalic: 56%, basilic vein transposition: 40%, radiocephalic: 4%). Banding initially reduced access flow by >50% (3070 ± 95 vs 1490 ± 105 mL/min, P < .001). Recurrent high flow (>2 L/min) developed in 52% of the patients during the observation period. Young age (45 ± 3 vs 57 ± 3 years; P = .02) and an access flow >1 L/min immediately after banding (P = .03) were risk factors for recurrent high flow.

CONCLUSIONS

An immediate postbanding access flow >1 L/min and young age are risk factors for recurrent high flow in a banded brachial artery-based HD access during a 1-year follow-up.

Time of onset in haemodialysis access-induced distal ischaemia (HAIDI) is related to the access type

BACKGROUND

A small portion of haemodialysis patients develop hand ischaemia (HAIDI, haemodialysis access-induced distal ischaemia) in the presence of an arteriovenous access (AVA). It is unknown if the time of onset of ischaemia is related to the type of AVA. This review aims to investigate if a relationship is present between the type of AVA and the time of onset and intensity of HAIDI.

METHODS

Standard databases and reference lists of the pertinent literature were systematically searched. HAIDI was classified as 'acute' (<24 h after routine access construction), 'subacute' (within 1 month) or 'chronic' (>1 month). Location, type and follow-up of AVA were tabulated.

RESULTS

Twenty-one studies reporting on surgically or percutaneously corrected HAIDI patients (n = 464) fulfilled the inclusion criteria. Acute HAIDI strongly (88%) correlated with non-autogenous AVA. In contrast, chronic HAIDI was predominantly (91%) observed following autogenous AVA based on the cubital segment of the brachial artery. A simple clinical classification for chronic HAIDI guiding treatment strategies is proposed.

CONCLUSIONS

Hand ischaemia occurring early after routine access surgery is usually related to grafts and not to autogenous access construction. If patients have several risk factors for acute hand ischaemia (diabetes), nephrologists and vascular surgeons may choose an autogenous AVA. A disadvantage of an autogenous access is its association with chronic hand ischaemia, particularly if constructed with a brachial artery.

Access flow, venous saturation, and digital pressures in hemodialysis

BACKGROUND

A hemodialysis arteriovenous fistula (AVF) requires surgical modification in patients with cardiac overload or dialysis access-associated steal syndrome (DASS). Creation of an artificial stenosis (banding) within the AVF may be used, but this technique lacks the guidance of objective parameters. The aim of this pilot study was to identify indicators that reflect AVF flow in dialysis patients with either access-related cardiac overload (CO) or DASS requiring corrective surgery.

METHODS

Patients underwent serial measurements of subclavian venous saturation (Sat(ven)), access flow (Flow(us)), and index digital pressures (P(dig)) during a corrective banding procedure.

RESULTS

Data were obtained in 14 individuals (9 men; mean age, 53 +/- 6 years) during 16 studies (CO, n = 8; DASS, n = 8). Before surgery, correlations between preoperative flow, Sat(ven) and P(dig) were not significant. Stepwise banding of the AVF altered Sat(ven) in both groups from a mean of 91% +/- 1% (open AVF) to 84% +/- 2% (closed AVF, P < .001). The CO patients demonstrated a larger drop (-13%) compared with the DASS patients (-4%). Values of P(dig) increased from 68 +/- 9 to 90 +/- 9 mm Hg (P < .001), and both groups demonstrated a similar +23 mm Hg increase. In concert, the digital brachial index also significantly improved in all patients from 0.60% +/- 0.09% to 0.74% +/- 0.10%. Linearity was present between alterations in Flow(us) and Sat(ven) in all patients, but mostly in the CO patients (r(2) = 0.96).

CONCLUSIONS

Stepwise banding of hemodialysis fistulas leads to dose-dependent decreases in flow and ipsilateral subclavian venous saturation combined with augmented digital pressures in patients with cardiac overload and dialysis associated steal syndrome. Intraoperative measurements of venous saturation and digital pressures may have the potential of guiding surgical correction in these patients.