Accuracy of physical examination versus Doppler ultrasonography for determining maturity in postoperative arteriovenous fistula formation

BACKGROUND

Differentiating between arteriovenous fistula (AVF) maturation and failure can help determine which AVF will undergo successful canulation and which ones will require immediate rescue.

METHODS

A prospective observational study was conducted at Vajira Hospital in Bangkok, Thailand, between October 2020-November 2022. A single vascular surgeon performed a physical examination on patients with chronic kidney disease undergoing AVF placement, and a radiologist conducted Doppler ultrasonography during the second and sixth postoperative weeks. Dialysis nurses determined AVF maturity by performing cannulation. The study compared the accuracy of physical examination and Doppler ultrasonography. A model was developed to predict the success of AVF use.

RESULTS

Out Of the 125 recruited patients, 81% demonstrate unassisted maturation of their AVF. The male sex and brachiocephalic type are associated with AVF maturation. The physical examination findings of palpable thrill and the absence of a strong pulse at the 6th week show an area under the receiver operating curve (AUC) value of 0.79. Similarly, arterial end-diastolic velocity on ultrasonography at the 6th week also demonstrates a comparable predictive value with an AUC of 0.82 (p = 0.697). Meanwhile, the model that combined end-diastolic velocity and venous volume flow yields the best results for predicting AVF maturation, with an AUC of 0.92. These models provide more accurate predictions compared to physical examination alone (AUC: 0.92 vs. 0.79; p < 0.01).

CONCLUSION

Although a prudent physician predicts AVF maturation through a thorough physical examination, Doppler ultrasonography is preferred in anticipating the success of postoperative AVF placement.

Long-Term Tunneled Hemodialysis Catheters: Achieving Efficiency Through Tip Position Optimization

BACKGROUND

This retrospective study assesses the influence of tunneled hemodialysis catheter tip location and lateralization on catheter-related complications, including dysfunction and catheter-related bloodstream infection.

METHODS

Using data from 162 patients who underwent catheter placement between January 2017 and December 2020, postoperative chest X-rays and clinical records were reviewed. Outcomes were assessed based on catheter removal duration and complication incidence.

RESULTS

Out of 177 catheter placements, 56 (32%) patients experienced complications during an average 530-day follow-up. Catheters placed in the superior vena cava (SVC) exhibited more severe complications with shorter dwell times compared with those in the pericavoatrial junction (pCAJ) or right atrium (RA). Moreover, complication rates were significantly higher (P < 0.01) in the SVC (1.91 per 1000 catheter days) compared with the pCAJ (0.54) or RA (0.47). Lateralization (right or left internal jugular vein) did not significantly affect the complication rates (0.60 vs. 0.58; P = 0.90). However, in subgroup analysis, a significantly higher complication rate was observed for catheters with tips inserted from the left side into the SVC than for those inserted from the right side (6.6 vs. 1.5; P < 0.01).

CONCLUSIONS

Catheters with tips in the SVC exhibited more severe complications than those in the pCAJ or RA, with left-side insertion of SVC-tipped catheters resulting in significantly higher complication rates compared with right-side insertion. These findings highlight the importance of optimal catheter tip positioning in long-term hemodialysis care to minimize complications and enhance patient outcomes.