Axillary arteriovenous fistula for the palliation of complex cyanotic congenital heart disease: Is it an effective tool?

Indications for and results of axillary arterio-venous fistula in patients with a functionally single ventricle after cavopulmonary anastomosis†

OBJECTIVES

This study aimed to investigate the indications for and the results of axillary arterio-venous fistula in patients with a functionally single ventricle at mid-term follow-up after bidirectional cavopulmonary connection.

METHODS

From 2012 to 2017, 20 patients aged 21.1 ± 8.7 years (median 20.5) underwent axillary arterio-venous fistula after bidirectional cavopulmonary connection in our institution. The interval between bidirectional cavopulmonary connection and axillary arterio-venous fistula was 13.9 ± 7.2 years. The clinical and haemodynamic parameters of the patients were assessed before and after surgery.

RESULTS

There was no in-hospital mortality. Paraesthesia of the arm persisted for 1-7 days. The mean arterial oxygen saturation increased from 72.4 ± 7.1% pre-surgery to 81.6 ± 5.5% (P < 0.001) after surgery, and was 83.8 ± 6.5% at discharge (P = 0.002 Wilcoxon matched pairs test). The haemoglobin, haematocrit, McGoon index and ejection fraction values did not change significantly. The speed and minute volume of the blood flow in the superior vena cava increased from from 21.1 ± 8.3 cm/s to 28.8 ± 14.9 cm/s (P < 0.001) and from 10.6 ± 3.7 ml/s to 12.5 ± 2.9 ml/s (P < 0.001), respectively. At the mid-term follow-up (1-5 years), 2 patients died from concomitant pathology. Stable improvement in the state and tolerance of physical activity was noted: before surgery, 17 patients were classified as New York Heart Association functional capacity (FC) III and 3 patients as FC IV; after surgery, 9 patients were FC II and 3 patients were FC III. One patient underwent a Fontan operation within 3 years.

CONCLUSIONS

Axillary arterio-venous fistula can be used as the stage of surgical treatment and a bridge to Fontan and/or heart transplantation for this category of patients.

Superior Cavopulmonary Connection: Its Physiology, Limitations, and Anesthetic Implications

The superior cavopulmonary connection (SCPC) or "bidirectional Glenn" is an integral, intermediate stage in palliation of single ventricle patients to the Fontan procedure. The procedure, normally performed at 3 to 6 months of life, increases effective pulmonary blood flow and reduces the ventricular volume load in patients with single ventricle (parallel circulation) physiology. While the SCPC, with or without additional sources of pulmonary blood flow, cannot be considered a long-term palliation strategy, there are a subset of patients who require SCPC palliation for a longer interval than the typical patient. In this article, we will review the physiology of SCPC, the consequences of prolonged SCPC palliation, and modes of failure. We will also discuss strategies to augment pulmonary blood flow in the presence of an SCPC. The anesthetic considerations in SCPC patients will also be discussed, as these patients may present for noncardiac surgery from infancy to adulthood.

Arteriovenous fistula creation for hypoxia after single ventricle palliation: A single-institution experience and literature review

BACKGROUND

Hypoxia is a common and sometimes severe morbidity of single ventricle congenital heart disease (CHD). Creation of an arteriovenous fistula (AVF) is occasionally performed for patients after superior or total cavopulmonary connection (SCPC or TCPC) in an attempt to improve oxygen saturations. Despite previous reports, AVF creation is a rare palliation with inadequately defined benefits and risks. We sought to determine changes in peripheral oxygen saturation (SpO₂ ) and risk of adverse event after AVF creation in children with single ventricle CHD at our institution.

METHODS

We conducted a retrospective chart review of patients with a history of single ventricle palliation and history of surgical AVF creation who were seen at our tertiary care center from 1996 to 2017.

RESULTS

A total of seven patients were included in our study. SpO₂ for the overall cohort did not significantly increase after AVF creation (pre-AVF 79.1 ± 6.9%, post-AVF 82.7 ± 6.0% [P = .23]). SpO₂ trended up for large shunts (>5 mm) (pre-AVF 75.0 ± 7.6%, post-AVF 84.0 ± 5.3% [P = .25]). SpO₂ did not improve for small shunts (≤5 mm) (pre-AVF 82.3 ± 6.5%, post-AVF 81.0 ± 8.5% [P = .50]). The 12-month overall and transplant-free survival were 85.7% and 71.4%, respectively. Freedom from AVF-related complication (cephalic edema, thrombotic occlusion) was 51.4% at 12 months.

CONCLUSION

Palliative AVF creation for patients with single ventricle CHD and hypoxia does not universally improve SpO₂ and is prone to early complications. Despite a lack of durable benefit and known risks, AVF creation remains a reasonable palliation for a subset of patients after SCPC who are not candidates for TCPC, or potentially as a bridge to heart transplantation.

Outcome Following Augmentation of Superior Cavopulmonary Blood Flow With an Arteriovenous Fistula

Background:

Axillary or brachial arteriovenous fistulae are occasionally created to improve systemic oxygen saturation in patients with functionally univentricular circulation after superior cavopulmonary anastomosis. Different techniques of fistula construction may account for the conflicting results. We sought to determine the impact of axillary arteriovenous fistula on systemic oxygen saturation and survival before subsequent palliation or heart transplantation.

Methods:

Medical records of patients who underwent a side-to-side anastomosis between an adjacent axillary artery and vein for cyanosis after superior cavopulmonary anastomosis between 1991 and 2010 were reviewed.

Results:

The median age (n = 23) at the time of fistula creation was 54 months (4-278 months). There was no operative mortality. The median duration of fistula patency was 48 months (1-174 months). Oxygen saturation improved from 71% ± 10% preoperatively to 84% ± 4% early ( P < .05) and 81% ± 4% long term after the arteriovenous fistula ( P < .05). Twelve patients underwent additional surgery (total cavopulmonary anastomosis 6, partial biventricular repair 2, and heart transplantation 4) after an interval of 10 to 141 months. Six patients are alive with a patent fistula without subsequent interventions after an interval of 48 to 174 months. Two patients with spontaneous closure or device closure of the fistula are alive after an interval of 76 to 80 months without subsequent interventions. Three deaths occurred with a patent fistula without subsequent interventions after an interval of 1 to 84 months.

Conclusions:

Systemic oxygen saturation improved with creation of an axillary arteriovenous fistula after superior cavopulmonary anastomosis. The fistula extended the duration of this stage of palliation without precluding the option for additional palliation or heart transplantation.