Patch repair of congenital diaphragmatic hernia is not at risk of poor outcomes

Biopolymeric 3D printed scaffolds as a versatile tissue engineering treatment for congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a rare disease in which neonates are born with pulmonary hypoplasia and a diaphragmatic defect. Survival is improving due to advances in fetal intervention for pulmonary hypoplasia leading to increased use of scaffolds for repair. Scaffolds have a significant morbidity rate with recurrence, small bowel obstruction and infrequently postoperative infections. 3D printing (3DP) is a promising technology for the fabrication of personalized medical devices characterised by a more precise and targeted approach to tissue engineering and drug delivery. In this study, blank thermoplastic polyurethane (TPU) and gentamicin sulfate (GNS)-loaded filaments (1 % and 1.5 %wt.) were fabricated with hot melt extrusion (HME) and subsequently processed through 3DP for scaffold manufacturing. Geometrical attributes of the scaffolds, including a specific % infill, were predefined through computer aided design (CAD) and printing parameters were optimised. Physicochemical analysis involving material compatibility and thermal properties of all formulations were examined, determining their thermal and chemical stability during 3DP. Mechanical analysis showed that polymeric matrixes resemble to diaphragm tissue, exhibiting adequate and reproducible elastic performance, while cell studies confirmed TPU's supportive capacity for cellular attachment. Additionally, in vitro dissolution and bacterial studies were carried out for up to a week, denoting GNS's sustained release from the polymeric matrices and efficient bactericidal activity to Gram-positive and Gram-negative bacteria, respectively. Therefore, TPU is a potential biomaterial that can be efficiently used for developing diverse 3D printed diaphragm-like scaffolds possessing antimicrobial activity for CDH.

Thoracotomy patch repair of large diaphragmatic herniae in a porcine model: a tale of two patches

PURPOSE

Congenital diaphragmatic herniae (CDH) may require patch closure in 50% of the cases. We assessed a biologic and composite mesh in a porcine CDH model.

METHODS

Left sided thoracotomy was performed in 20 pigs. Approximately, 30% of the diaphragm was excised and the patch (Surgisis® or Parietex®) inserted to close this defect. The pigs were killed at 6 months and the diaphragm was harvested for biomechanical and histological assessment.

RESULTS

The mean weight of the pigs at surgery and killing were 6.1 kg (4.2-8.4 kg) and 94.1 kg (80-131 kg), respectively. There were two recurrences and three eventrations, all with Surgisis®. There were less dense lung and abdominal adhesions in the Parietex group (P < 0.0001 and 0.025, respectively). The tensile strength of the Surgisis®, the Parietex® groups and controls were similar. There was significantly more muscle in-growth in the Parietex® patch over Surgisis® (p = 0.016).

CONCLUSION

Parietex® and Surgisis® patches at 6 months have a similar tensile strength to normal tissue. All recurrences and eventrations were in the Surgisis® group. Parietex® patches demonstrated more muscle in-growth into the patch compared to Surgisis®. This is the first study utilising Parietex® composite patch in the repair of large diaphragmatic defects in a porcine model.

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.

Comprehensive meta-analysis of surgical procedure for congenital diaphragmatic hernia: thoracoscopic versus open repair

PURPOSE

Previous studies have shown a higher recurrence rate and longer operative times for thoracoscopic repair (TR) of congenital diaphragmatic hernia (CDH) compared to open repair (OR). An updated meta-analysis was conducted to re-evaluate the surgical outcomes of TR.

METHODS

A comprehensive literature search comparing TR and OR in neonates was performed in accordance with the PRISMA statement (PROSPERO: CRD42020166588).

RESULTS

Fourteen studies were selected for quantitative analysis, including a total of 709 patients (TR: 308 cases, OR: 401 cases). The recurrence rate was higher [Odds ratio: 4.03, 95% CI (2.21, 7.36), p < 0.001] and operative times (minutes) were longer [Mean Difference (MD): 43.96, 95% CI (24.70, 63.22), p < 0.001] for TR compared to OR. A significant reduction in the occurrence of postoperative bowel obstruction was observed in TR (5.0%) compared to OR (14.8%) [Odds ratio: 0.42, 95% CI (0.20, 0.89), p = 0.02].

CONCLUSIONS

TR remains associated with higher recurrence rates and longer operative times. However, the reduced risk of postoperative bowel obstruction suggests potential long-term benefits. This study emphasizes the importance of meticulous patient selection for TR to mitigate detrimental effects on patients with severe disease.

Diaphragmatic Defects in Infants: Acute Management and Repair

Congenital diaphragmatic hernia (CDH) is a complex and highly variable disease process that should be treated at institutions with multidisciplinary teams designed for their care. Treatment in the neonatal period focuses on pulmonary hypoplasia, pulmonary hypertension, and cardiac dysfunction. Extracorporeal membrane oxygenation (ECMO) can be considered in patients refractory to medical management. Repair of CDH early during the ECMO course seems to improve mortality compared with other times for surgical intervention. The choice of surgical approach to CDH repair should consider the patient's physiologic status and the surgeon's familiarity with the operative approaches available, recognizing the pros/cons of each technique.

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.

Reduced Long-Term Bowel Obstruction Risk With Minimally Invasive Diaphragmatic Hernia Repair

INTRODUCTION

The introduction of minimally invasive surgery (MIS) for repair of congenital diaphragmatic hernias (CDH) has reduced postoperative length of stay, postoperative opioid consumption, and provided a more esthetic repair. In adult abdominal surgery, minimally invasive techniques have been associated with decreased long-term rates of small bowel obstruction (SBO), although it is unclear if this benefit carries over into the pediatric population. Our objective was to evaluate the rates of SBO following open versus MIS CDH repair.

MATERIAL AND METHODS

Infants who underwent CDH repair between 2010 and 2021 were identified using the PearlDiver Mariner database. Kaplan-Meier curves and Cox proportional hazards models were used to evaluate time to SBO by surgical approach (MIS versus open) while adjusting for mesh use, patient sex, and length of stay.

RESULTS

Of 1033 patients that underwent CDH repair, 258 (25.0%) underwent a minimally invasive approach. The overall rate of SBO was 7.5% (n = 77). Rate of SBO following MIS repair was lower than open repair at 1 y (0.8% versus 5.1%), 3 y, (2.3% versus 9.0%), and 5 y (4.4% versus 10.1%, P = 0.004). Following adjustment, the rate of SBO following MIS repair remained significantly lower than open repair (adjusted hazard ratio: 0.37, 95% confidence interval: 0.18, 0.79).

CONCLUSIONS

Following CDH repair, long-term rates of SBO are lower among patients treated with MIS approaches. Long-term risk of SBO should be considered when selecting surgical approach for CDH patients.

Development of a 3D-printed neonatal congenital diaphragmatic hernia model and standardisation of intra-operative measurement

INTRODUCTION

Three-dimensional (3D) printing is frequently used for surgical simulation and training, however, no widely available model exists for neonatal congenital diaphragmatic hernia (CDH). The aim of this study was to develop a 3D-printed model of CDH and test interobserver variability in the simulated model for obtaining measurements of the diaphragmatic defect and ipsilateral diaphragm.

METHODS

A term fetal MRI (3.5 kg) of thorax, diaphragm and defect (15 mm × 5 mm) were delineated and segmented after parental consent to produce 3D-printed models. Consultant and trainee paediatric surgeons were invited to measure the posterior-lateral diaphragmatic defect and ipsilateral diaphragm. Mean measurement error was calculated (millimetres). Data are presented as median (range) and number/total (%).

RESULTS

An abdominal and thoracoscopic model were produced and tested by 52 participants (20 consultants and 32 trainees). Diaphragmatic defect via laparotomy measured 15 (10-20) mm (AP) × 16 (10-25) mm (ML) and thoracoscopically 14 (11-19) mm (AP) × 15 (11-22) mm (ML). Mean error per measurement was 4 (1-17) mm via laparotomy vs. 3 (0.5-9.5) mm thoracoscopically. Mean error was similar between consultants and trainees via laparotomy (4.3 vs. 3.9 mm, p = 0.70) and thoracoscopically (3 vs. 3 mm, p = 0.79). Error did not correlate with experience as operating surgeon via laparotomy (β = 13.0 [95% CI - 55.9 to 82.0], p = 0.71) or thoracoscopically (β = 1.4[95% CI - 6.4 to 9.2], p = 0.73.

CONCLUSIONS

We have designed and built simulation models for CDH repair via laparotomy and thoracoscopically. Operators can reliably measure the diaphragmatic defect and ipsilateral diaphragm, regardless of surgical experience and operative approach.

Minimal access surgery for congenital diaphragmatic hernia: surgical tricks to facilitate anchoring the patches to the ribs

OBJECTIVE

Minimal Access Surgery (MAS) for Congenital Diaphragmatic Hernia (CDH) repair is well described, yet only a minority of surgeons report this as their preferred operative approach. Some surgeons find it particularly difficult to repair the defect using MAS and convert to laparotomy when a patch is required. We present in this study our institutional experience in using an easy and relatively cheap methodology to anchor the patch around the ribs using Endo Close™. This device has an application in MAS for tissue approximation using percutaneous suturing.

METHODS AND TECHNIQUE

We retrospectively reviewed our database for patients undergoing MAS repair of CDH between 2009 and 2021. Outcome measures included length of surgery and recurrence rates after patch repair. Endo Close™ was used in all patients who required patch repair. We declare no conflict of interest and to not having received any funding from Medtronic (UK). The technique is as follows: (1) The edges of the diaphragm are delineated by dissection. When primary suture repair of the diaphragmatic hernia was unfeasible without tension, a patch was used. (2) The patch is anchored in place by two corner stitches at the medial and lateral borders. (3) The posterior border of the patch is fixed to the diaphragmatic edge by running or interrupted stitches. (4) For securing the anterior border, a non-absorbable suture is passed through the anterior chest wall and the patch border is taken with intracorporeal instruments. (5) Without making another stab incision, the Endo Close™ is tunnelled subcutaneously through the anterior chest wall. (6) The suture end is pulled through the Endo Close™ and the knot is tied around the rib. This procedure can be performed as many times as required to secure the patch.

RESULTS

58 patients underwent MAS surgery for repair of CDH between 2009 and 2021. 48 (82%) presented with a left defect. 34 (58%) had a patch repair. The length of patch repair surgery for CDH ranged from 100-343 min (median 197). There was only one patient (3%) in the patch repair cohort that had a recurrent hernia, diagnosed 12 months after the initial surgery.

CONCLUSIONS

In our experience, MAS repair of CDH is feasible. We adopted a low threshold in using a patch to achieve a tension-free repair. We believe that the Endo Close™ is a cheap and safe method to help securing the patch around the ribs.

Congenital diaphragmatic hernia survival in an English regional ECMO center

Introduction

Congenital diaphragmatic hernia (CDH) remains a cause of neonatal death. Our aims are to describe contemporary rates of survival and the variables associated with this outcome, contrasting these with our study of two decades earlier and recent reports.

Materials and methods

A retrospective review of all infants diagnosed in a regional center between January 2000 and December 2020 was performed. The outcome of interest was survival. Possible explanatory variables included side of defect, use of complex ventilatory or hemodynamic strategies (inhaled nitric oxide (iNO), high-frequency oscillatory ventilation (HFOV), extracorporeal membrane oxygenation (ECMO), and Prostin), presence of antenatal diagnosis, associated anomalies, birth weight, and gestation. Temporal changes were studied by measuring outcomes in each of four consecutive 63-month periods.

Results

A total of 225 cases were diagnosed. Survival was 60% (134 of 225). Postnatal survival was 68% (134 of 198 liveborn), and postrepair survival was 84% (134 of 159 who survived to repair). Diagnosis was made antenatally in 66% of cases. Variables associated with mortality were the need for complex ventilatory strategies (iNO, HFOV, Prostin, and ECMO), antenatal diagnosis, right-sided defects, use of patch repair, associated anomalies, birth weight, and gestation. Survival has improved from our report of a prior decade and did not vary during the study period. Postnatal survival has improved despite fewer terminations. On multivariate analysis, the need for complex ventilation was the strongest predictor of death (OR=50, 95% CI 13 to 224, p<0.0001), and associated anomalies ceased to be predictive.

Conclusions

Survival has improved from our earlier report, despite reduced numbers of terminations. This may be related to increased use of complex ventilatory strategies.

Minimally Invasive Approaches and Use of a Patch Are Not Associated with Increased Recurrence Rates After Congenital Diaphragmatic Hernia Repair

Background: Minimally invasive surgery (MIS) is increasingly used for repair of congenital diaphragmatic hernia (CDH). Reported recurrence after MIS repair varies and is limited by short follow-up and low volume. Our objective was to compare recurrence after MIS versus open repair of CDH. Materials and Methods: Infants who underwent CDH repair between 2010 and 2020 were identified using the PearlDiver Mariner database, a national patient claims data set allowing longitudinal follow-up of patients across systems. Kaplan-Meier analysis and Cox proportional hazards regression models were used to evaluate the association of surgical approach (MIS versus open) and use of a patch with time to recurrence while adjusting for comorbidities (congenital heart disease and pulmonary hypertension) and length of stay (LOS). Results: In a cohort of 629 infants, 25.6% (n = 161) underwent MIS repair with a median follow-up of 4.8 years and recurrence rate of 38.6% (n = 243). Rates of recurrence after MIS repair were lower than open (5 years: 38.6% versus 44.3%; P = .03) and higher with use of patch (5 years: 60.1% versus 40.1%; P = .02). After adjustment for comorbidities and LOS as a proxy for patient complexity, there was no significant difference in recurrence based on approach (adjusted hazard ratio [aHR]: 0.79; confidence interval [95% CI]: 0.57-1.10; P = .16) or use of patch (aHR: 1.22; 95% CI: 0.83-1.79; P = .32). Conclusions: Recurrence rates after repair of CDH were not different based on surgical approach or use of patch after adjustment. Previous data were likely biased by patient complexity, and surgeons should consider these factors in determining approach.

Customized bioreactor enables the production of 3D diaphragmatic constructs influencing matrix remodeling and fibroblast overgrowth

The production of skeletal muscle constructs useful for replacing large defects in vivo, such as in congenital diaphragmatic hernia (CDH), is still considered a challenge. The standard application of prosthetic material presents major limitations, such as hernia recurrences in a remarkable number of CDH patients. With this work, we developed a tissue engineering approach based on decellularized diaphragmatic muscle and human cells for the in vitro generation of diaphragmatic-like tissues as a proof-of-concept of a new option for the surgical treatment of large diaphragm defects. A customized bioreactor for diaphragmatic muscle was designed to control mechanical stimulation and promote radial stretching during the construct engineering. In vitro tests demonstrated that both ECM remodeling and fibroblast overgrowth were positively influenced by the bioreactor culture. Mechanically stimulated constructs also increased tissue maturation, with the formation of new oriented and aligned muscle fibers. Moreover, after in vivo orthotopic implantation in a surgical CDH mouse model, mechanically stimulated muscles maintained the presence of human cells within myofibers and hernia recurrence did not occur, suggesting the value of this approach for treating diaphragm defects.

Recurrence of Congenital Diaphragmatic Hernia: Risk Factors, Management, and Future Perspectives

Recurrence is one of the most common surgical complications in Congenital Diaphragmatic Hernia (CDH). It could remain clinically silent for a long time or present as an acute complication week, months, or even years after the primary surgery. Several risk factors have been identified so far. An extended diaphragmatic defect represents one of the leading independent risk factors, together with indirect signs of large defect such as the liver position related to the diaphragm and the use of the prosthetic patch and with the use of a minimally invasive surgical (MIS) approach. However, the exact contribution of each factor and the overall risk of recurrence during the life span still need to be fully understood. This mini-review aims to give an overview of the current knowledge regarding CDH recurrence, focusing on predisposing factors, clinical presentation, management and follow-up of high-risk patients, and future perspectives.

Surgeon level variation in outcome of repair of congenital diaphragmatic hernia with particular reference to the management of recurrence

INTRODUCTION

The aim of this study is to investigate firstly, the rate of recurrence following primary repair of a congenital diaphragmatic hernia (CDH) and secondly, the rate of recurrence following revisional surgical repair. The primary outcome is rate of recurrence. Secondary outcomes are to establish whether recurrence is related to surgeon, surgeon volume, side of defect, the use of a patch, or a thoracopscopic approach METHODS: All repairs performed in an English regional center over 22 years were recorded. Possible explanatory variables were whether the repair was itself of a recurrence, the surgeon's identity, the surgeon's volume of prior repairs, the side of the defect, the use of a patch.

RESULTS

198 repairs were performed; 170 primary repairs and 28 of recurrences. Failure occurred significantly more commonly among recurrences (32%) than primary repairs (11%), p = 0.005. Failure of the primary repair was significantly more common where a patch was used 8/34 (23%) rather than a sutured repair 10/136 (7%), p = 0.006, or where a thoracoscopic technique was used 4/13 (31%) rather than laparotomy 14/157 (9%) p = 0.01. Failure of the primary repair was unrelated to the identity of the surgeon (Χ² = 5, p = 0.9) or the volume of prior repairs (t = 0.3, p = 0.6). However, failure of repair of a recurrence was significantly related to the surgeon's volume of prior repairs (t = 2.3, p = 0.01) and the identity of the surgeon (Χ² = 17, p = 0.014), but not the use of a patch (Χ² = 1.6, p = 0.2).

CONCLUSIONS

Repair of a recurrence of a CDH has a higher probability of failure than the original repair and is related to both the identity of the surgeon and the prior volume of experience. There is a volume outcome relationship for the repair of recurrence, but not the primary repair of CDH. Our study suggests the repair of recurrence of CDH should be restricted to surgeons with proven outcomes for this procedure.

A systematic review and meta-analysis of surgical morbidity of primary versus patch repaired congenital diaphragmatic hernia patients

Large studies comparing the surgical outcome of primary versus patch repair in congenital diaphragmatic hernia (CDH) patients are rare. This study aims to evaluate the incidence of surgical complications in both types of CDH repair. PubMed, EMBASE, Cochrane and Web of Science were searched for peer-reviewed articles. Studies on CDH between 1991 and August 2020 were systematically screened and meta-analyses were performed. Primary outcomes of this review were: haemorrhage, chylothorax, recurrences and small bowel obstruction (SBO). A total of 6436 abstracts were screened, after which 25 publications were included (2910 patients). Patch repaired patients have a 2.8 times higher risk on developing a recurrence (20 studies) and a 2.5 times higher risk on developing a chylothorax (five studies). Moreover, they have a two times higher risk on developing a SBO. No studies could be included that evaluated the incidence of surgical haemorrhage between these patients. Although the quality of the studies was relatively low, patch repaired patients have a higher risk on developing a recurrence, chylothorax and small bowel obstruction. Large prospective studies are required to adjust for severity of disease, to reveal the true causative factors in order to minimize the risk on these surgical complications in both types of patients.

What should we tell parents? Congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is characterized by a defect in the muscle dividing the thoracic and abdominal cavities. This leads to herniation of the abdominal organs into the thorax and a disturbance of lung development. Two-thirds of cases are identified by prenatal ultrasound in the second trimester, which should prompt referral to a tertiary center for prognosis assessment and counseling by a multidisciplinary team familiar with this condition. In this review, we summarize evidence on prenatal diagnosis and postnatal management of CDH. There is a focus on information that should be provided to expecting parents during prenatal counseling.

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.