Hemorrhage after on-ECMO repair of CDH is equivalent for muscle flap and prosthetic patch

Surgical management of the diaphragmatic defect in congenital diaphragmatic hernia: a contemporary review

Worldwide, 150 children are born each day with congenital diaphragmatic hernia (CDH), a diaphragmatic defect with concomitant abnormal lung development. Patients with CDH with large defects are particularly challenging to treat, have the highest mortality, and are at significant risk of long-term complications. Advances in prenatal and neonatal treatments have improved survival in high-risk patients with CDH, but surgical treatment of large defects lacks standardization. Open repair by an abdominal approach has long been considered the traditional procedure, but the type of defect repair (patch or muscle flap) and patch material (non-absorbable, synthetic or absorbable, biological) remain subjects of debate. Increased experience and improved techniques in minimally invasive surgery (MIS) have expanded selection criteria for thoracoscopic defect repair in cardiopulmonary stable patients with small defects. However, the application of MIS to repair large defects remains controversial due to increased recurrence rates and unknown long-term effects of perioperative hypercapnia and acidosis resulting from capnothorax and reduced ventilation. Current recommendations on the surgical management rely on cohort studies of varying patient numbers and data on the long-term outcomes are sparse. Here, we discuss surgical approaches for diaphragmatic defect repair highlighting advancements, and knowledge gaps in surgical techniques (open surgery and MIS), patch materials and muscle flaps for large defects, as well as procedural adjuncts and management of CDH variants.

The role of ECLS in the management of congenital diaphragmatic hernia

In the complex arena of Congenital Diaphragmatic Hernia (CDH) management, Extracorporeal Life Support (ECLS) provides a strategic window for stabilization and surgical correction, during which time marginal gains in patient stability can tip the scales towards survival. In modern neonatal ECLS, the focus is increasingly on minimizing survivor morbidity, which calls for considerable multidisciplinary expertise to enhance patient outcomes. This review will delve into the most up-to-date literature on the management of CDH in the context of ECLS, providing a comprehensive synthesis of current insights.

Surgical approaches to congenital diaphragmatic hernia

Surgical repair of the diaphragm is essential for survival in congenital diaphragmatic hernia (CDH). There are many considerations surrounding the operation - why the operation matters, optimal timing of repair and its relation to extracorporeal life support (ECLS) use, minimally invasive versus open approaches, and strategies for reconstruction. Surgery is both affected by, and affects, the physiology of these infants and is an important factor in determining long-term outcomes. Here we discuss the evidence and provide insight surrounding this complex decision making, technical pearls, and outcomes in repair of CDH.

Muscle Flap Technique Safe for On-ECMO Congenital Diaphragmatic Hernia Repair

INTRODUCTION

Prosthetic patches (patch) and muscle flaps (flap) are techniques used for repair of congenital diaphragmatic hernia (CDH) with a large defect unamenable to primary closure. We hypothesized that the flap technique for CDH repair while on extra-corporeal membrane oxygenation (on-ECMO) would have decreased bleeding complications compared to patch due to the hemostatic advantage of native tissue.

METHODS

A single-center retrospective comparative study of patients who underwent on-ECMO CDH repair between 2008 and 2022 was performed.

RESULTS

Fifty-two patients met inclusion criteria: 18 patch (34.6%) and 34 flap (65.4%). There was no difference in CDH severity between groups. On univariate analysis, reoperation for surgical bleeding was lower following flap repair compared to patch (23.5% vs 55.6%, respectively; p = 0.045), 48-h postoperative blood product transfusion was lower after flap repair (132 mL/kg vs 273.5 mL/kg patch; p = 0.006), and two-year survival was increased in the flap repair group compared to patch (53.1% vs 17.7%, respectively; p = 0.036). On multivariate analysis adjusting for CDH side, day on ECMO repaired, and day of life CDH repaired, flap repair was significantly associated with lower five-day postoperative packed red blood cell transfusion amount, improved survival to hospital discharge, and improved two-year survival.

CONCLUSIONS

Our experience suggests that the muscle flap technique for on-ECMO CDH repair is associated with reduced bleeding complications compared to prosthetic patch repair, which may in part be responsible for the improved survival seen in the flap repair group. These results support the flap repair technique as a favored method for on-ECMO CDH repair.

LEVEL OF EVIDENCE

Level III.

Diagnosis and management of congenital diaphragmatic hernia: a 2023 update from the Canadian Congenital Diaphragmatic Hernia Collaborative

OBJECTIVE

The Canadian Congenital Diaphragmatic Hernia (CDH) Collaborative sought to make its existing clinical practice guideline, published in 2018, into a 'living document'.

DESIGN AND MAIN OUTCOME MEASURES

Critical appraisal of CDH literature adhering to Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Evidence accumulated between 1 January 2017 and 30 August 2022 was analysed to inform changes to existing or the development of new CDH care recommendations. Strength of consensus was also determined using a modified Delphi process among national experts in the field.

RESULTS

Of the 3868 articles retrieved in our search that covered the 15 areas of CDH care, 459 underwent full-text review. Ultimately, 103 articles were used to inform 20 changes to existing recommendations, which included aspects related to prenatal diagnosis, echocardiographic evaluation, pulmonary hypertension management, surgical readiness criteria, the type of surgical repair and long-term health surveillance. Fifteen new CDH care recommendations were also created using this evidence, with most related to the management of pain and the provision of analgesia and neuromuscular blockade for patients with CDH.

CONCLUSIONS

The 2023 Canadian CDH Collaborative's clinical practice guideline update provides a management framework for infants and children with CDH based on the best available evidence and expert consensus.

The Survivorship Bias in Congenital Diaphragmatic Hernia

Current literature for congenital diaphragmatic hernia (CDH) focuses on the comparison of the overall mortality in CDH patients. Only a few studies concentrate on analyzing the unstable patients who could not achieve surgical repair, as well as those who could but did not survive after. Hence, this study aimed to analyze the effects of various parameters on the timing of death. A retrospective analysis was performed by using the data of all CDH patients from 2003 to 2016 at a single tertiary center. Patients who were diagnosed with left-sided CDH and expired were included in the study regardless of the cause. Of the 66 expired patients, 5 were excluded due to right-sided CDH. The study population constituted a total of 61 patients, of which 31 patients expired prior to CDH repair, and 30 patients expired at different times after CDH repair. Multinomial regression analysis identified that the ECMO need (B = 20.257, p = 0.000, OR: 62.756, 95% CI 10.600–371.384) and O/E LHR (B = 20.376, p = 0.000, OR: 70.663, 95% CI 48.716–102.415) values were the independent predictors that influenced mortality in this cohort. Prenatal pulmonary measurements are the major predictors determining the severity of the disease in patients with CDH.

Reversible Fetal Tracheal Occlusion in Mice: A Novel Minimal Invasive Technique

BACKGROUND

There is a certain need for reversible, cheap, and reproducible animal models for understanding the impact of tracheal occlusion (TO) in the congenital diaphragmatic hernia and pathophysiology. We aimed to present an easy, reversible, and minimally invasive murine TO model with optimized time points for introduction and removal of TO.

METHODS

Time-mated C57BL/6 mice underwent laparotomy at embryonic day 16.5 (E16.5) with transuterine TO performed on two fetuses in each uterine horn. In the TO group, the fetuses were harvested at E18.5 without suture removal; the suture was released at E17.5 in the TO-R group, and all fetuses were harvested at E18.5. The lungs of the fetuses were compared by morphometric and histologic analysis.

RESULTS

Successful TO was confirmed in 34 of 37 fetuses. Twenty-nine of them survived to E18.5 (90.6%), six of the fetuses had a spontaneous vaginal delivery. Fetal weights were comparable, but there was significant difference in lung weights and lung-to-body weight ratios (0.020 ± 0.006 [control] versus 0.026 ± 0.002 [TO] versus 0.023 ± 0.005 [TO-R]; P = 0.013). DNA/protein and DNA/lung weight ratios were elevated, whereas protein/lung weight ratio was lower in TO compared with the control group.

CONCLUSIONS

Reversal of fetal transuterine TO at E17.5, which was put at E16.5 in mice, is feasible with comparable outcomes to other current animal models with certain advantages and potential to translate the studies to the human.

Innovative, Stabilizing Self-Expandable Patch for Easier and Safer Thoracoscopic Repair of Congenital Diaphragmatic Hernia

Introduction: Thoracoscopic repair of congenital diaphragmatic hernia (CDH) has become a popular approach and several benefits have been published. Patch closure requires demanding thoracoscopic skills and therefore primary closure with tight sutures is often pursued, which increases the risk of recurrence. The purpose of this study was to create and assess the performance of a new technique for thoracoscopic repair of CDH, which facilitates the surgical procedure. Materials and Methods: An innovative system for thoracoscopic repair of CDH with a novel patch was developed. The patch is self-expandable and offers a traction suture for stabilization, isolating and protecting the viscera. Its performance was assessed and compared with a conventional patch in an inanimate model of the disease through a quantitative and qualitative multivariate analysis. Results: Nine cases of CDH were repaired with each patch. The duration of the procedure was shorter (P < .05) and the level of difficulty was reported to be lower (P < .001) when using the self-expandable patch (SeP). The number of good quality knots was higher and adverse events were less common with this new technique. Conclusions: The stabilizing SeP offers safe and ergonomic performance for thoracoscopic CDH repair, facilitating the surgical technique. The main advantage is that it keeps the viscera isolated into the abdomen while offering a flap on the thoracic side for suturing in a practical manner, minimizing the risk of visceral injury and saving surgical time.

When primary repair is not enough: a comparison of synthetic patch and muscle flap closure in congenital diaphragmatic hernia?

PURPOSE

Primary closure is often inadequate for large congenital diaphragmatic hernia (CDH) and necessitates repair by prosthetic patch or autologous muscle flap. Our aim was to evaluate outcomes of open patch versus flap repair, specifically diaphragmatic reherniation.

METHODS

A retrospective review (IRB #2017-6361) was performed on all CDH patients repaired from 2005 to 2016 at a single academic children's hospital. Patients were excluded from final analysis if they had primary or minimally invasive repair, expired, or were lost to follow-up.

RESULTS

Of 171 patients, 151 (88.3%) survived to discharge, 9 expired after discharge and 11 were lost to follow up, leaving 131 (86.8%) long-term survivors. Median follow-up was 5 years. Open repair was performed in 119 (90.8%) of which 28 (23.5%) underwent primary repair, 34 (28.6%) patch repair, and 57 (47.9%) flap repair. Overall, 6/119 (5%) patients reherniated, 1/28 (3.6%) in the primary group, 3/34 (8.8%) in the patch group, and 2/57 (3.5%) in the flap group. Comparing prosthetic patch to muscle flap repair, there was no significant difference in the number of patients who recurred nor time to reherniation (3 vs. 2, p = 0.295; 5.5 ± 0.00 months vs. 53.75 ± 71.06 months, p = 0.288). One patient in the patch group recurred twice.

CONCLUSIONS

Both muscle flap and patch repair of large CDH are feasible and durable with a relatively low risk of recurrence.