Early results of ring-reinforced conduit and curved porcine patch in Sano-Norwood procedure

Short and Mid-term Outcomes of Ductal Graft with Bilateral Pulmonary Banding in Hypoplastic Left Heart Syndrome and Variants

This study evaluates a novel surgical technique inspired by the hybrid Norwood procedure, which involves ductal graft placement and bilateral pulmonary artery banding. This technique is designed to avoid the high-risk classical Norwood stage 1 operation and to avoid the need for first stage invasive catheter interventions and interstage catheter interventions when ductal stent placement is not feasible in developing countries with limited resources. Between June 2015 and December 2022, 14 patients with hypoplastic left heart syndrome and variants were treated using this procedure at our center. Polytetrafluoroethylene graft was used for ductal graft procedure and polytetrafluoroethylene bands were used for bilateral pulmonary banding. Atrial septectomy was done selectively. Patients with adequate left heart growth underwent biventricular repair and pulmonary debanding. Patients without left heart growth underwent cavopulmonary anastomosis or necessary intermediate surgical revisions. Seven patients out of 14 reached the second stage. Two received biventricular repair, three underwent bidirectional cavopulmonary anastomosis, and two required repeat palliations other than bidirectional cavopulmonary anastomosis. Modifications of the Norwood procedure is an ongoing process due to the complex nature of hypoplastic left heart syndrome and variants. As experience grows, the mortality associated with ductal graft and bilateral pulmonary banding procedure may decrease, making this technique an alternative for centers where classical Norwood operation or hybrid palliation is not possible, especially in developing countries with limited resources. We might predict promising outcomes, especially for patients with hypoplastic left heart complex where biventricular repair is expected.

Grafts and Patches: Optimized but Not Optimal Materials for Congenital Heart Surgery

A variety of materials are available for the surgery of children with congenital heart defects. In addition to growth-related mismatch, degeneration of the material in particular frequently leads to reoperation. Therefore, the choice of conduits and patches should be made carefully. This article provides an overview of the most commonly implanted materials in pediatric cardiac surgery.Structural changes can be detected in all available materials. Depending on the age at implantation and the site of implantation, the extent and time course of material degeneration vary. Autologous material is still the gold standard in reconstructive surgery. Biological materials have largely replaced artificial materials in clinical use.The search for the ideal material continues. In pediatric cardiac surgery, there are only optimized but no optimal materials.

Industrial Processing Induces Pericardial Patch Degeneration

Background

Autologous pericardium is considered gold standard for various reconstructive surgical procedures in children. However, processed bovine, equine, and porcine pericardial tissue are also widely used. We investigated structural differences and analyzed alterations caused by industrial processing. Additionally human and equine pericardium explants, used during aortic valve reconstruction were analyzed.

Methods

Pericardial tissues (native, processed and explanted) were gathered and stained with HE and EvG to visualize collagen as well as elastic fibers. Fiber structures were visualized by light and polarization microscopy. Antibody staining against CD 3, CD 20, and CD 68 was performed to identify inflammation.

Results

Native pericardium of different species showed small differences in thickness, with bovine pericardium being the thickest [bovine: 390 μm (± 40.6 μm); porcine: 223 μm (± 30.1 μm); equine: 260 μm (± 28.4 μm)]. Juvenile pericardium was 277 μm (± 26.7 μm). Single collagen bundle diameter displayed variations (~3–20 μm). Parallel collagen fibers were densely packed with small inter-fibrillary space. After industrial tissue processing, loosening of collagen network with inter-fibrillary gapping was observed. Pericardium appeared thicker (mean values ranging from 257–670 μm). Processed tissue showed less birefringence under polarized light. All analyzed tissues showed a small number of elastic fibers. Fibrosis, calcification and inflammatory processes of autologous and equine pericardium were observed in patient explants.

Conclusion

None of the analyzed tissues resembled the exact structure of the autologous pericardial explant. Degeneration of pericardium starts during industrial processing, suggesting a potential harm on graft longevity in children. A careful surgical approach prior to the implantation of xenografts is therefore needed.

Aortic arch reconstruction in the Norwood procedure using a curved polytetrafluorethylene patch

OBJECTIVES

The aortic arch enlargement in the Norwood procedure is classically carried out using a curved homograft patch on the inner curvature of the neoaortic arch. The study investigates the outcome of a newly used artificial patch from a vascular prosthesis as an alternative to a homograft patch.

METHODS

Since April 2007, we used curved polytetrafluorethylene (PTFE) patches cut out of a prosthesis as an alternative to homograft patches for the aortic arch reconstruction. The decision for either patch material was made due to anatomic reasons, preferring PTFE patches in larger aortas. In this study, 224 Norwood patients, operated between April 2007 and April 2018, were analysed. A total of 104 patients received a PTFE patch (group PTFE), and 120 patients got a pulmonary homograft patch (group homograft). A single-centre retrospective analysis was carried out concerning postoperative course and long-term follow-up regarding aortic arch interventions and reoperations and comparing the 2 material groups.

RESULTS

There were no material associated operative or postoperative complications. In-hospital mortality was 13% in group PTFE. Six children died late during follow-up (6%). One aortic isthmus dilatation (1%) was carried out 12 months after the Norwood procedure in this group, no arch reoperation was necessary during the complete follow-up.

CONCLUSIONS

The curved PTFE patch showed good qualities in operative technical demands and excellent long-term results. In selected cases of hypoplastic left heart syndrome, it can be well used as alternative to the pulmonary homograft.