What is the best prosthetic material for patch repair of congenital diaphragmatic hernia? Comparison and meta-analysis of porcine small intestinal submucosa and polytetrafluoroethylene

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.

Patches in Congenital Diaphragmatic Hernia: Systematic Review

OBJECTIVE

This systematic review aims to evaluate current choices in practice and outcomes of biomaterials used in patch repair of congenital diaphragmatic hernia (CDH).

BACKGROUND

Multiple biomaterials, both novel and combinations of pre-existing materials are employed in patch repair of large size CDHs.

METHODS

A literature search was performed across Embase, Medline, Scopus, and Web of Science. Publications that explicitly reported patch repair, material used, and recurrences following CDH repair were selected.

RESULTS

Sixty-three papers were included, presenting data on 4595 patients, of which 1803 (39.2%) were managed using 19 types of patches. Goretex® (GTX) (n=1106) was the most frequently employed patch followed by Dualmesh® (n=267), Surgisis® (n=156), Marlex®/GTX® (n=56), Tutoplast dura® (n=40), Dacron® (n=34), Dacron®/GTX® (n=32), Permacol® (n=24), Teflon® (n=24), Surgisis®/GTX® (n=15), Sauvage® Filamentous Fabric (n=13), Marlex® (n=9), Alloderm® (n=8), Silastic® (n=4), Collagen coated Vicryl® mesh (CCVM) (n=1), Mersilene® (n=1), and MatriStem® (n=1) Biomaterials were further subgrouped as: synthetic nonresorbable (SNOR) (n=1458), natural resorbable (NR) (n=241), combined natural and synthetic nonresorbable (NSNOR) (n=103), and combined natural and synthetic resorbable (NSR) (n=1). The overall recurrence rate for patch repair was 16.6% (n=299). For patch types with n>20, recurrence rate was lowest in GTX/Marlex (3.6%), followed by Teflon (4.2%), Dacron (5.6%), Dualmesh (12.4%), GTX (14.8%), Permacol (16.0%), Tutoplast Dura (17.5%), SIS/GTX (26.7%), SIS (34.6%), and Dacron/GTX (37.5%).When analyzed by biomaterial groups, recurrence was highest in NSR (100%), followed by NR (31.5%), NSNOR (17.5%), and SNOR the least (14.0%).

CONCLUSION

In this cohort, over one-third of CDH were closed using patches. To date, 19 patch types/variations have been employed for CDH closure. GTX is the most popular, employed in over 60% of patients; however, excluding smaller cohorts (n<20), GTX/Marlex is associated with the lowest recurrence rate (3.6%). SNOR was the material type least associated with recurrence, while NSR experienced recurrence in every instance.

Abdominal wall muscle weakness outcomes after split abdominal flap repair of large congenital diaphragmatic hernias in newborn

PURPOSE

Split abdominal wall muscle flap (SAWMF) is a technique to repair large defects in congenital diaphragmatic hernia (CDH). A possible objection to this intervention could be any associated abdominal muscle weakness. Our aim is to analyze the evolution of this abdominal muscle wall weakness.

METHODS

Retrospective review of CDH repair by SAWMF (internal oblique muscle and transverse) from 2004 to 2023 focusing on the evolution of muscle wall weakness.

RESULTS

Eighteen neonates of 148 CDH patients (12,1%) were repaired using SAWMF. Mean gestational age and birth weight were 35.7 ± 3.5 weeks and 2587 ± 816 g. Mean lung-to-head ratio was 1.49 ± 0.28 and 78% liver-up. Seven patients (38%) were prenatally treated by tracheal occlusion. Ninety-four percent of the flaps were used for primary repair and one to repair a recurrence. One patient (5.6%) experienced recurrence. Abdominal muscle wall weakness was present in the form of a bulge. Resolution of weakness at 1, 2 and 3 years was 67%, 89% and 94%, respectively. No patient required treatment for weakness or died.

CONCLUSIONS

Abdominal muscular weakness after a split abdominal wall muscle flap repair is not a limitation for its realization since it is asymptomatic and presents a prompt spontaneous resolution.

LEVEL OF EVIDENCE

IV.

Evolution of biomimetic ECM scaffolds from decellularized tissue matrix for tissue engineering: A comprehensive review

Tissue engineering is essentially a technique for imitating nature. Natural tissues are made up of three parts: extracellular matrix (ECM), signaling systems, and cells. Therefore, biomimetic ECM scaffold is one of the best candidates for tissue engineering scaffolds. Among the many scaffold materials of biomimetic ECM structure, decellularized ECM scaffolds (dECMs) obtained from natural ECM after acellular treatment stand out because of their inherent natural components and microenvironment. First, an overview of the family of dECMs is provided. The principle, mechanism, advances, and shortfalls of various decellularization technologies, including physical, chemical, and biochemical methods are then critically discussed. Subsequently, a comprehensive review is provided on recent advances in the versatile applications of dECMs including but not limited to decellularized small intestinal submucosa, dermal matrix, amniotic matrix, tendon, vessel, bladder, heart valves. And detailed examples are also drawn from scientific research and practical work. Furthermore, we outline the underlying development directions of dECMs from the perspective that tissue engineering scaffolds play an important role as an important foothold and fulcrum at the intersection of materials and medicine. As scaffolds that have already found diverse applications, dECMs will continue to present both challenges and exciting opportunities for regenerative medicine and tissue engineering.

Evaluation of a biodegradable polyurethane patch for repair of diaphragmatic hernia in a rat model: A pilot study

INTRODUCTION

Congenital diaphragmatic hernia (CDH) repair is an area of active research. Large defects requiring patches have a hernia recurrence rate of up to 50%. We designed a biodegradable polyurethane (PU)-based elastic patch that matches the mechanical properties of native diaphragm muscle. We compared the PU patch to a non-biodegradable Gore-Tex™ (polytetrafluoroethylene) patch.

METHODS

The biodegradable polyurethane was synthesized from polycaprolactone, hexadiisocyanate and putrescine, and then processed into fibrous PU patches by electrospinning. Rats underwent 4 mm diaphragmatic hernia (DH) creation via laparotomy followed by immediate repair with Gore-Tex™ (n = 6) or PU (n = 6) patches. Six rats underwent sham laparotomy without DH creation/repair. Diaphragm function was evaluated by fluoroscopy at 1 and 4 weeks. At 4 weeks, animals underwent gross inspection for recurrence and histologic evaluation for inflammatory reaction to the patch materials.

RESULTS

There were no hernia recurrences in either cohort. Gore-Tex™ had limited diaphragm rise compared to sham at 4 weeks (1.3 mm vs 2.9 mm, p = 0.003), but no difference was found between PU and sham (1.7 mm vs 2.9 mm, p = 0.09). There were no differences between PU and Gore-Tex™ at any time point. Both patches formed an inflammatory capsule, with similar thicknesses between cohorts on the abdominal (Gore-Tex™ 0.07 mm vs. PU 0.13 mm, p = 0.39) and thoracic (Gore-Tex™ 0.3 mm vs. PU 0.6 mm, p = 0.09) sides.

CONCLUSION

The biodegradable PU patch allowed for similar diaphragmatic excursion compared to control animals. There were similar inflammatory responses to both patches. Further work is needed to evaluate long-term functional outcomes and further optimize the properties of the novel PU patch in vitro and in vivo.

LEVEL OF EVIDENCE

Level II, Prospective Comparative Study.

Synthetic versus Biological Patches for CDH: A Comparison of Recurrence Rates and Adverse Events, Systematic Review, and Meta-Analysis

OBJECTIVE

 Our systematic review aims to compare recurrence rates and complications of biological versus synthetic patches for the repair of congenital diaphragmatic herniae.

METHODS

 Studies from January 1, 1980 to April 25, 2020, with patients under the age of 16 years and with a minimum 6-month follow-up, were included from MEDLINE, Embase, and Cochrane databases. Funnel plots for recurrence rates were constructed for biological and synthetic patches. Subgroup analysis was performed for recurrence rate at the 1-year time-point and data were gathered on individual adverse events from relevant studies.

RESULTS

 A total of 47 studies with 986 patients (226 biological, 760 synthetic) were included. Funnel plot analysis determined overall recurrence rates of 16.7% for synthetic and 30.3% for biological patches. Subgroup analysis of 493 and 146 patients with synthetic and biological patches, respectively, showed recurrence rates of 9.9 and 26%, respectively.The most commonly used patch types-PTFE (polytetrafluoroethylene) and SIS (small intestinal submucosa)-had 11.5 and 33.3% recurrence, respectively. Adhesive bowel obstruction rates ranged from 4 to 29% in studies that systematically reported it for synthetic, and 7 to 35% for biological patches. Gastroesophageal reflux rates ranged from 25 to 48% in studies that systematically reported it for synthetic, and 21 to 42% for biological patches. Pectus deformity rates were reported as high as 80% for synthetic patches.

CONCLUSION

 Biological patches appear to have higher recurrence rates than synthetic patches, while skeletal deformities are associated more commonly with synthetic patches. Results of biological patches are mainly using SIS and this may overestimate complications of current superior biological patches.

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.

A Systematic Review Examining the Experimental Methodology Behind In Vivo Testing of Hiatus Hernia and Diaphragmatic Hernia Mesh

INTRODUCTION

Mesh implants are regularly used to help repair both hiatus hernias (HH) and diaphragmatic hernias (DH). In vivo studies are used to test not only mesh safety, but increasingly comparative efficacy. Our work examines the field of in vivo mesh testing for HH and DH models to establish current practices and standards.

METHOD

This systematic review was registered with PROSPERO. Medline and Embase databases were searched for relevant in vivo studies. Forty-four articles were identified and underwent abstract review, where 22 were excluded. Four further studies were excluded after full-text review-leaving 18 to undergo data extraction.

RESULTS

Of 18 studies identified, 9 used an in vivo HH model and 9 a DH model. Five studies undertook mechanical testing on tissue samples-all uniaxial in nature. Testing strip widths ranged from 1-20 mm (median 3 mm). Testing speeds varied from 1.5-60 mm/minute. Upon histology, the most commonly assessed structural and cellular factors were neovascularisation and macrophages respectively (n = 9 each). Structural analysis was mostly qualitative, where cellular analysis was equally likely to be quantitative. Eleven studies assessed adhesion formation, of which 8 used one of four scoring systems. Eight studies measured mesh shrinkage.

DISCUSSION

In vivo studies assessing mesh for HH and DH repair are uncommon. Within this relatively young field, we encourage surgical and materials testing institutions to discuss its standardisation.

The incidence of different forms of ileus following surgery for abdominal birth defects in infants: a systematic review with a meta-analysis method

Objectives

Ileus following surgery can arise in different forms namely as paralytic ileus, adhesive small bowel obstruction or as anastomotic stenosis. The incidences of these different forms of ileus are not well known after abdominal birth defect surgery in infants. Therefore, this review aims to estimate the incidence in general between abdominal birth defects.

Content

Studies reporting on paralytic ileus, adhesive small bowel obstruction or anastomotic stenosis were considered eligible. PubMed and Embase were searched and risk of bias was assessed. Primary outcome was the incidence of complications. A meta-analysis was performed to pool the reported incidences in total and per birth defect separately.

Summary

This study represents a total of 11,617 patients described in 152 studies of which 86 (56%) had a follow-up of at least half a year. Pooled proportions were calculated as follows; paralytic ileus: 0.07 (95%-CI, 0.05-0.11; I 2=71%, p≤0.01) ranging from 0.14 (95% CI: 0.08-0.23) in gastroschisis to 0.05 (95%-CI: 0.02-0.13) in omphalocele. Adhesive small bowel obstruction: 0.06 (95%-CI: 0.05-0.07; I 2=74%, p≤0.01) ranging from 0.11 (95% CI: 0.06-0.19) in malrotation to 0.03 (95% CI: 0.02-0.06) in anorectal malformations. Anastomotic stenosis after a month 0.04 (95%-CI: 0.03-0.06; I 2=59%, p=0.30) ranging from 0.08 (95% CI: 0.04-0.14) in gastroschisis to 0.02 (95% CI: 0.01-0.04) in duodenal obstruction. Anastomotic stenosis within a month 0.03 (95%-CI 0.01-0.10; I 2=81%, p=0.02) was reviewed without separate analysis per birth defect.

Outlook

This review is the first to aggregate the known literature in order approximate the incidence of different forms of ileus for different abdominal birth defects. We showed these complications are common and the distribution varies between birth defects. Knowing which birth defects are most at risk can aid clinicians in taking prompt action, such as nasogastric tube placement, when an ileus is suspected. Future research should focus on the identification of risk factors and preventative measures. The incidences provided by this review can be used in those studies as a starting point for sample size calculations.

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.

Biological versus synthetic patch for the repair of congenital diaphragmatic hernia: 8-year experience at a tertiary center

PURPOSE

The aim of this study is to compare outcome between small intestinal submucosal (SIS) and polytetrafluoroethylene (PTFE) patches in patients with congenital diaphragmatic hernia (CDH) with large muscular defects.

MATERIAL AND METHODS

We performed a retrospective review of prospectively collected data of patients who underwent CDH repair from January 2011 to June 2019, with a minimum follow-up of 1 year. Data were collected regarding length of stay (LOS), mortality and recurrence. Kaplan-Meier analyses was used.

RESULTS

In the study period, 195 patients with CDH were admitted, 176 underwent surgical repair and 19 died before surgery. Sixty-two (35%) required a patch. Over the last 5 years, our institution transitioned from the use of all SIS to all PTFE. SIS was used in 18 cases and PTFE in 25. Overall survival rate was 89% (174/195). There was no significant difference regarding LOS and mortality. Nine patients (50%) of SIS and 1 (4%) of PTFE repairs recurred (P < 0.01; log-rank test P <  0.01), with a time course of recurrence of 18 (SD = 13) and 8 months, respectively. Median follow-up was 60 months (SD: 23) for the SIS group and 26 (SD: 10) for the PTFE group.

CONCLUSION

A significant lower recurrence was found using PTFE patches instead of SIS for the repair of large CDH.

LEVEL OF EVIDENCE

Level 3. Retrospective comparative study.

Porcine small intestine graft for reconstruction of oral defects

OBJECTIVE

To evaluate the feasibility and outcomes of porcine submucosal allograft (Biodesign Sinonasal Repair Graft [Cook Medical, Bloomington, IN]) in oral cavity and oropharynx reconstruction after ablative surgery.

METHODS

We conducted a prospective and retrospective review of patients who underwent Biodesign Sinonasal Repair Graft reconstruction for oral and oropharyngeal surgical defects at a single institution between 2018 and 2020. A total of 11 patients were included in the study. Data points included their perioperative medical and demographic data, immediate postoperative course, and follow-up visits at 10 days and at 2 months. The clinicopathologic characteristics of their disease, postoperative esthetic, and functional outcomes were recorded and analyzed.

RESULTS

Eleven procedures have been performed, and all patients received Biodesign reconstruction either immediately after ablation or after they failed a previous reconstruction. None of the patients had bone exposure. The subsites included oral tongue (n = 6), floor of the mouth (n = 3), buccal mucosa (n = 1), and soft palate (n = 1). In all cases, the operations and the postoperative course were uneventful. The mean defect size was 22 cm2. The median start of oral intake was at 2 days postoperatively. The Biodesign graft healed well in all patients with no total graft loss. There was one complication that required revision surgery due to obstruction of Wharton's duct by the Biodesign material.

CONCLUSIONS

Biodesign can be a viable option for small and medium-sized oral and oropharyngeal defects in patients who are medically unfit or do not want to undergo a free flap surgery.

LEVEL OF EVIDENCE

4.

Decellularization of Small Intestinal Submucosa

Small intestinal submucosa (SIS) is the most studied extracellular matrix (ECM) for repair and regeneration of different organs and tissues. Promising results of SIS-ECM as a vascular graft, led scientists to examine its applicability for repairing other tissues. Overall results indicated that SIS grafts induce tissue regeneration and remodeling to almost native condition. Investigating immunomodulatory effects of SIS is another interesting field of research. SIS can be utilized in different forms for multiple clinical and experimental studies. The aim of this chapter is to investigate the decellularization process of SIS and its common clinical application.

Porcine Decellularized Diaphragm Hydrogel: A New Option for Skeletal Muscle Malformations

Hydrogels are biomaterials that, thanks to their unique hydrophilic and biomimetic characteristics, are used to support cell growth and attachment and promote tissue regeneration. The use of decellularized extracellular matrix (dECM) from different tissues or organs significantly demonstrated to be far superior to other types of hydrogel since it recapitulates the native tissue’s ECM composition and bioactivity. Different muscle injuries and malformations require the application of patches or fillers to replenish the defect and boost tissue regeneration. Herein, we develop, produce, and characterize a porcine diaphragmatic dECM-derived hydrogel for diaphragmatic applications. We obtain a tissue-specific biomaterial able to mimic the complex structure of skeletal muscle ECM; we characterize hydrogel properties in terms of biomechanical properties, biocompatibility, and adaptability for in vivo applications. Lastly, we demonstrate that dECM-derived hydrogel obtained from porcine diaphragms can represent a useful biological product for diaphragmatic muscle defect repair when used as relevant acellular stand-alone patch.

Porcine dermal patches as a risk factor for recurrence after congenital diaphragmatic hernia repair

PURPOSE

Recurrence of congenital diaphragmatic hernia (CDH) is a treatment-related morbidity which can be preventable. There is no consensus about the ideal material for diaphragmatic substitution. The aim of our study is to identify if the use of porcine dermis patches increases the risk of CDH recurrence.

METHODS

Retrospective review of medical records of CDH patients treated between 2013 and 2017 in our center was carried out. Demographic, clinical and surgical variables were collected. Regression analysis was performed to identify which factors increase the risk of recurrence.

RESULTS

50 patients entered the study. 94% of the patients had a left CDH, mean observed/expected lung-to-head ratio was 46%. 17 patients underwent a primary closure, the rest a patch closure: 25 Gore-Tex^® and 8 porcine dermis patches were used. Seven patients presented recurrence (14%). Median follow-up time was 3.5 years (1.2-6.2). Univariate analysis revealed that the use of a porcine dermis patch (75%) increased the risk of recurrence compared with Gore-Tex^® patch (4%) and primary closure (0%) p < 0.001 (HR 58.7; IC 95%: 6.9-501.2; p < 0.001).

CONCLUSION

The main risk factor for CDH recurrence is the use of a porcine dermis patch. We do not recommend the use of these patches for CDH repair.

Longitudinal Follow-Up With Radiologic Screening for Recurrence and Secondary Hiatal Hernia in Neonates With Open Repair of Congenital Diaphragmatic Hernia-A Large Prospective, Observational Cohort Study at One Referral Center

Objective: After neonatal repair of congenital diaphragmatic hernia (CDH) recurrence is the most severe surgical complication and reported in up to 50% after patch implantation. Previous studies are difficult to compare due to differences in surgical techniques and retrospective study design and lack of standardized follow-up or radiologic imaging. The aim was to reliably detect complication rates by radiologic screening during longitudinal follow-up after neonatal open repair of CDH and to determine possible risk factors. Methods: At our referral center with standardized treatment algorithm and follow-up program, consecutive neonates were screened for recurrence by radiologic imaging at defined intervals during a 12-year period. Results: 326 neonates with open CDH repair completed follow-up of a minimum of 2 years. 68 patients (21%) received a primary repair, 251 (77%) a broad cone-shaped patch, and 7 a flat patch (2%). Recurrence occurred in 3 patients (0.7%) until discharge and diaphragmatic complications in 28 (8.6%) thereafter. Overall, 38 recurrences and/or secondary hiatal hernias were diagnosed (9% after primary repair, 12.7% after cone-shaped patch; p = 0.53). Diaphragmatic complications were significantly associated with initial defect size (r = 0.26). In multivariate analysis left-sided CDH, an abdominal wall patch and age below 4 years were identified as independent risk factors. Accordingly, relative risks (RRs) were significantly increased [left-sided CDH: 8.5 (p = 0.03); abdominal wall patch: 3.2 (p < 0.001); age ≤4 years: 6.5 (p < 0.002)]. 97% of patients with diaphragmatic complications showed no or nonspecific symptoms and 45% occurred beyond 1 year of age. Conclusions: The long-term complication rate after CDH repair highly depends on surgical technique: a comparatively low recurrence rate seems to be achievable in large defects by implantation of a broad cone-shaped, non-absorbable patch. Longitudinal follow-up with regular radiologic imaging until adolescence is essential to reliably detecting recurrence to prevent acute incarceration and chronic gastrointestinal morbidity with their impact on prognosis. Based on our findings and literature review, a risk-stratified approach to diaphragmatic complications is proposed.

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.

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

PURPOSE

Recurrence of congenital diaphragmatic hernia (CDH) was retrospectively evaluated after correction with or without a patch in an institution where tension-free repair is advocated.

METHODS

Demographics and outcomes of patients with a postero-lateral CDH repaired (2000-2016) were analyzed (univariate tests and binary logistic regression adjusting for time since start of study, gender, defect side, liver herniation, patch, surgical approach, absence of postero-lateral rim and length of follow-up).

RESULTS

Of 203 patients, 107 received a patch (P), and 96 were not patched (NP). Groups were not different for gestational age birthweight, gender, defect side and minimally invasive approach rate. Preoperative ECMO incidence (P:29.9% vs. NP:2.1%, p < 0.01), liver herniation (P:57.0% vs. NP:22.9%, p < 0.01) and absence of a postero-lateral rim (P:61.7% vs. NP:8.3%, p < 0.01) were higher in the P group. The mortality rate was 10.8% (P:15.0% vs. NP:6.2%, p = 0.07). Recurrence was not different (P:9.3% vs. NP:4.2%, p = 0.15). Multivariate analysis showed that recurrence was higher after thoracoscopy compared to open (OR = 12.2 [2.2-68], p < 0.01); neither the use of patch (OR = 2.3, [0.5-10.4], p = 0.28) nor any other factors were associated with recurrence.

CONCLUSION

In this single centre series where tension-free repair was advocated, patch repair of CDH was not associated with higher recurrence, though access route was.

TYPE OF STUDY

Cohort Study.

LEVEL OF EVIDENCE

Level III.

One-year outcomes of infants born with congenital diaphragmatic hernia: a national population cohort study

OBJECTIVE

To report outcomes to 1 year, in infants born with congenital diaphragmatic hernia (CDH), explore factors associated with infant mortality and examine the relationship between surgical techniques and postoperative morbidity.

DESIGN

Prospective national population cohort study.

SETTING

Paediatric surgical centres in the UK and Ireland.

METHOD

Data were collected to 1 year for infants with CDH live-born between 1 April 2009 to 30 September 2010. Factors associated with infant mortality are explored using logistic regression. Postoperative morbidity following patch versus primary closure, minimally invasive versus open surgery and biological versus synthetic patch material is described. Data are presented as n (%) and median (IQR).

RESULTS

Overall known survival to 1 year was 75%, 95% CI 68% to 81% (138/184) and postoperative survival 93%, 95% CI 88% to 97% (138/148). Female sex, antenatal diagnosis, use of vasodilators or inotropes, being small for gestational age, patch repair and use of surfactant were all associated with infant death. Infants undergoing patch repair had a high incidence of postoperative chylothorax (11/54 vs 2/96 in infants undergoing primary closure) and a long length of hospital stay (41 days, IQR 24-68 vs 16 days, IQR 10-25 in primary closure group). Infants managed with synthetic patch material had a high incidence of chylothorax (11/34 vs 0/19 with biological patch).

CONCLUSION

The majority of infant deaths in babies born with CDH occur before surgical correction. Female sex, being born small for gestational age, surfactant use, patch repair and receipt of cardiovascular support were associated with a higher risk of death. The optimum surgical approach, timing of operation and choice of patch material to achieve lowest morbidity warrants further evaluation.

Polydopamine Functionalization: A Smart and Efficient Way to Improve Host Responses to e-PTFE Implants

Among the different materials used as protheses for the treatment of Congenital Diaphragmatic Hernia, expanded polytetrafluoroethylene (e-PTFE) plays a leading role owing to its mechanical properties as explained in the first part of this review. However, this material is poorly cell adhesive, which is expected for its contact on the abdominal face, but should display specific tissue adhesion on its thoracic exposed faced. A side specific functionalization method is hence required. The deposition of a nanosized polydopamine film on PTFE is known to be possible but immersion of the e-PTFE membrane in an aerated dopamine solution leads to a functionalization not only on both faces of the membrane but also in its porous volume. The fact that polydopamine also forms at the water/air interface has allowed to transfer a polydopamine film on only one face of the e-PTFE membrane. The deposition method and applications of such Janus like membranes are reviewed in the second part of the review.

Allogenic tissue-specific decellularized scaffolds promote long-term muscle innervation and functional recovery in a surgical diaphragmatic hernia model

Congenital diaphragmatic hernia (CDH) is a neonatal defect in which the diaphragm muscle does not develop properly, thereby raising abdominal organs into the thoracic cavity and impeding lung development and function. Large diaphragmatic defects require correction with prosthetic patches to close the malformation. This treatment leads to a consequent generation of unwelcomed mechanical stress in the repaired diaphragm and hernia recurrences, thereby resulting in high morbidity and significant mortality rates. We proposed a specific diaphragm-derived extracellular matrix (ECM) as a scaffold for the treatment of CDH. To address this strategy, we developed a new surgical CDH mouse model to test the ability of our tissue-specific patch to regenerate damaged diaphragms. Implantation of decellularized diaphragmatic ECM-derived patches demonstrated absence of rejection or hernia recurrence, in contrast to the performance of a commercially available synthetic material. Diaphragm-derived ECM was able to promote the generation of new blood vessels, boost long-term muscle regeneration, and recover host diaphragmatic function. In addition, using a GFP + Schwann cell mouse model, we identified re-innervation of implanted patches. These results demonstrated for the first time that implantation of a tissue-specific biologic scaffold is able to promote a regenerating diaphragm muscle and overcome issues commonly related to the standard use of prosthetic materials. STATEMENT OF SIGNIFICANCE: Large diaphragmatic hernia in paediatric patients require application of artificial patches to close the congenital defect. The use of a muscle-specific decellularized scaffold in substitution of currently used synthetic materials allows new blood vessel growth and nerve regeneration inside the patch, supporting new muscle tissue formation. Furthermore, the presence of a tissue-specific scaffold guaranteed long-term muscle regeneration, improving diaphragm performance to almost complete functional recovery. We believe that diaphragm-derived scaffold will be key player in future pre-clinical studies on large animal models.

Providing direction improves function: Comparison of a radial pore-orientated acellular collagen scaffold to clinical alternatives in a surgically induced rabbit diaphragmatic tissue defect model

Gore-Tex® is a widely used durable patch for repair of congenital diaphragmatic defects yet may result in complications. We compared Gore-Tex with a composite of a radial pore-orientated collagen scaffold (RP-Composite) and clinically used porcine small intestinal submucosa (SIS; Surgisis®) in a rabbit model for diaphragmatic hernia. The growing rabbit mimics the rapid rib cage growth and reherniation rates seen in children. We created and immediately repaired left hemidiaphragmatic defects in 6-week-old rabbits with Gore-Tex, SIS, and an RP-Composite scaffold. An additional group of rabbits had a sham operation. At 90 days, survivors more than doubled in weight. We observed few reherniations or eventrations in Gore-Tex (17%) and RP-Composite (22%) implanted animals. However, SIS failed in all rabbits. Maximum transdiaphragmatic pressure was lower in Gore-Tex (71%) than RP-Composite implanted animals (112%) or sham (134%). Gore-Tex repairs were less compliant than RP-Composite, which behaved as sham diaphragm (p < 0.01). RP-Composite induced less foreign body giant cell reaction than Gore-Tex (p < 0.05) with more collagen deposition (p < 0.001), although there was a tendency for the scaffold to calcify. Unlike Gore-Tex, the compliance of diaphragms reconstructed with RP-Composite scaffolds were comparable with native diaphragm, whereas reherniation rates and transdiaphragmatic pressure measurements were similar.

Decellularized Diaphragmatic Muscle Drives a Constructive Angiogenic Response In Vivo

Skeletal muscle tissue engineering (TE) aims to efficiently repair large congenital and acquired defects. Biological acellular scaffolds are considered a good tool for TE, as decellularization allows structural preservation of tissue extracellular matrix (ECM) and conservation of its unique cytokine reservoir and the ability to support angiogenesis, cell viability, and proliferation. This represents a major advantage compared to synthetic scaffolds, which can acquire these features only after modification and show limited biocompatibility. In this work, we describe the ability of a skeletal muscle acellular scaffold to promote vascularization both ex vivo and in vivo. Specifically, chicken chorioallantoic membrane assay and protein array confirmed the presence of pro-angiogenic molecules in the decellularized tissue such as HGF, VEGF, and SDF-1α. The acellular muscle was implanted in BL6/J mice both subcutaneously and ortotopically. In the first condition, the ECM-derived scaffold appeared vascularized 7 days post-implantation. When the decellularized diaphragm was ortotopically applied, newly formed blood vessels containing CD31⁺, αSMA⁺, and vWF⁺ cells were visible inside the scaffold. Systemic injection of Evans Blue proved function and perfusion of the new vessels, underlying a tissue-regenerative activation. On the contrary, the implantation of a synthetic matrix made of polytetrafluoroethylene used as control was only surrounded by vWF⁺ cells, with no cell migration inside the scaffold and clear foreign body reaction (giant cells were visible). The molecular profile and the analysis of macrophages confirmed the tendency of the synthetic scaffold to enhance inflammation instead of regeneration. In conclusion, we identified the angiogenic potential of a skeletal muscle-derived acellular scaffold and the pro-regenerative environment activated in vivo, showing clear evidence that the decellularized diaphragm is a suitable candidate for skeletal muscle tissue engineering and regeneration.

Engineering and repair of diaphragm using biosheet (a collagenous connective tissue membrane) in rabbits

BACKGROUND

Prosthetic patches can be used to repair large congenital diaphragmatic hernia defects but may be associated with infection, recurrence, and thoracic deformity. Biosheets (collagenous connective tissue membranes) have been used in regenerative medicine. We evaluated the efficacy of Biosheets in a rabbit model.

METHODS

Biosheets were prepared by embedding silicone plates in dorsal subcutaneous pouches of rabbits for 4weeks. In group 1 (n=11), Gore-Tex® sheets (1.8×1.8cm) were implanted into a diaphragmatic defect. In group 2 (n=11), Seamdura®, a bioabsorbable artificial dural substitute, was implanted in the same manner. In group 3 (n=14), biosheets were autologously transplanted into the diaphragmatic defects. All rabbits were euthanized 3months after transplantation to evaluate their graft status.

RESULTS

Herniation of liver was observed in 5 rabbits (45%) in group 1, 8 (73%) in group 2, and 3 (21%) in group 3. A significant difference was noted between groups 2 and 3 (P=0.017). Biosheets had equivalent burst strength and modulus of elasticity as native diaphragm. Muscular tissue regeneration in transplanted biosheets in group 3 was confirmed histologically.

CONCLUSION

Biosheets may be applied to diaphragmatic repair and replacement of diaphragmatic muscular tissue.

LEVEL OF EVIDENCE

Level III.

Isolation of myogenic progenitor cell population from human placenta: A pilot study

PURPOSE

The purpose of this study was to demonstrate a method of isolating myogenic progenitor cells from human placenta chorionic villi and to confirm the myogenic characteristics of the isolated cells.

METHODS

Cells were isolated from chorionic villi of a second trimester male placenta via a combined enzymatic digestion and explant culture. A morphologically distinct subpopulation of elongated and multinucleated cells was identified. This subpopulation was manually passaged from the explant culture, expanded, and analyzed by fluorescence in situ hybridization (FISH) assay, immunocytochemistry, and flow cytometry. Myogenic characteristics including alignment and fusion were tested by growing these cells on aligned polylactic acid microfibrous scaffold in a fusion media composed of 2% horse serum in Dulbecco's modified Eagle medium/high glucose.

RESULTS

The expanded subpopulation was uniformly positive for integrin α-7. Presence of Y-chromosome by FISH analysis confirmed chorionic villus origin rather than maternal cell contamination. Isolated cells grew, aligned, and fused on the microfibrous scaffold, and they expressed myogenin, desmin, and MHC confirming their myogenic identity.

CONCLUSION

Myogenic progenitor cells can be isolated from human chorionic villi. This opens the possibility for translational and clinical applications using autologous myogenic cells for possible engraftment in treatment of chest and abdominal wall defects.

Minimal modulation of the host immune response to SIS matrix implants by mesenchymal stem cells from the amniotic fluid

PURPOSE

Surgical restoration of soft tissue defects often requires implantable devices. The clinical outcome of the surgery is determined by the properties inherent to the used matrix. Mesenchymal stem cells (MSC) modulate the immune processes after in vivo transplantation and their addition to matrices is associated with constructive remodeling. Herein we evaluate the potential of MSC derived from the amniotic fluid (AF-MSC), an interesting MSC source for cell therapeutic applications in the perinatal period, for immune modulation when added to a biomaterial.

METHODS

We implant cell free small intestinal submucosa (SIS) or SIS seeded with AF-MSC at a density of 1 × 10⁵/cm² subcutaneously at the abdominal wall in immune competent rats. The host immune response is evaluated at 3, 7 and 14 days postoperatively.

RESULTS

The matrix-specific or cellular characteristics are not altered after 24 h of in vitro co-culture of SIS with AF-MSC. The host immune response was not different between animals implanted with cell free or AF-MSC-seeded SIS in terms of cellular infiltration, vascularity, macrophage polarization or scaffold replacement. Profiling the mRNA expression level of inflammatory cytokines at the matrix interface shows a significant reduction in the expression of the pro-inflammatory marker Tnf-α and a trend towards lower iNos expression upon AF-MSC-seeding of the SIS matrix. Anti-inflammatory marker expression does not alter upon cell seeding of matrix implants.

CONCLUSION

We conclude that SIS is a suitable substrate for in vitro culture of AF-MSC and fibroblasts. AF-MSC addition to SIS does not significantly modulate the host immune response after subcutaneous implantation in rats.

A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery

OBJECTIVE

Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality.

BACKGROUND

Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated.

METHODS

Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality.

RESULTS

112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses). Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA, review includes comparison of interventions and review registration. The latter three variables were significant in multivariate regression.

CONCLUSIONS

There are gaps in the conduct and reporting of systematic reviews in paediatric surgery. More endorsement by journals of the PRISMA guideline may improve review quality, and the dissemination of reliable evidence to paediatric clinicians.

Complications in neonatal surgery

Neonatal surgery is recognized as an independent discipline in general surgery, requiring the expertise of pediatric surgeons to optimize outcomes in infants with surgical conditions. Survival following neonatal surgery has improved dramatically in the past 60 years. Improvements in pediatric surgical outcomes are in part attributable to improved understanding of neonatal physiology, specialized pediatric anesthesia, neonatal critical care including sophisticated cardiopulmonary support, utilization of parenteral nutrition and adjustments in fluid management, refinement of surgical technique, and advances in surgical technology including minimally invasive options. Nevertheless, short and long-term complications following neonatal surgery continue to have profound and sometimes lasting effects on individual patients, families, and society.

Partial replacement of left hemidiaphragm in dogs by either cryopreserved or decellularized heterograft patch

OBJECTIVES

Large diaphragmatic defects are still a challenging issue for reconstruction using either synthetic prosthesis or bioprosthesis. To evaluate the possibility of using diaphragm allograft as a natural bioprosthesis in humans, we conducted a two-group study and compared cryopreserved and decellularized diaphragmatic heterograft patched in a canine model.

METHODS

At the end of organ harvesting from a human donor, the left hemidiaphragm was taken to the laboratory in phosphate-buffered saline solution. The next step was freezing the grafts at -80°C, and preserving them for up to 2 months in Group 1. It was subjected to a detergent-enzymatic method (containing sodium deoxycholate/DNase lavations) of decellularization for 25 cycles in Group 2. Through left thoracotomy in the eighth intercostal space, cryopreserved patches in six dogs and decellularized patches in five dogs replaced the diaphragm. During the follow-up, sonography was done in all animals, but three and two dogs in Group 1 and 2 underwent computed tomography (CT) scan, respectively. The animals were euthanized after 6 months.

RESULTS

There was no mortality. Sonography showed only motion impairment of the patches in all cases. In Group 1, CT scan showed mild atelectasis and scattered infiltration in the left lower lobe, fibrotic bands and minimal fluid collection under the diaphragm. In Group 2, CT scan showed scattered fibrotic bands and mild to moderate elevation of the left hemidiaphragm. There was no evidence of gross disruption and complete healing of the suture line. Necropsy in both groups showed patches were completely replaced with a dense fibrous tissue. In Group 1, focal calcification was noticeable in every case and foreign body-type granulomas were clearly seen all over the grafted tissue. Histology in Group 2 animals showed less inflammatory cell infiltration and scattered foreign body granulomas in comparison with the cryopreserved patch graft.

CONCLUSIONS

The gross healing process in the decellularized heterograft is similar to the cryopreserved diaphragm but with fewer inflammatory cells and foreign body granulomas on histology. Both of them can be used instead of bioprostheses with regard to the fact that the decellularized patch technique is more complex and expensive. It is recommended to compare them with commercial bioprostheses.

Repair of Postoperative Abdominal Hernia in a Child with Congenital Omphalocele Using Porcine Dermal Matrix

Introduction. Incisional hernias are a common complication appearing after abdominal wall defects reconstruction, with omphalocele and gastroschisis being the most common etiologies in children. Abdominal closure of these defects represents a real challenge for pediatric surgeons with many surgical techniques and various prosthetic materials being used for this purpose. Case Report. We present a case of repair of a postoperative ventral hernia occurring after congenital omphalocele reconstruction in a three-and-a-half-year-old child using an acellular, sterile, porcine dermal mesh. Conclusion. Non-cross-linked acellular porcine dermal matrix is an appropriate mesh used for the reconstruction of abdominal wall defects and their postoperative complications like large ventral hernias with success and preventing their recurrence.

Management of congenital diaphragmatic hernia: A systematic review from the APSA outcomes and evidence based practice committee

OBJECTIVE

Variable management practices complicate the identification of optimal strategies for infants with congenital diaphragmatic hernia (CDH). This review critically appraises the available evidence to provide recommendations.

METHODS

Six questions regarding CDH management were generated. English language articles published between 1980 and 2014 were compiled after searching Medline, Cochrane, Embase and Web of Science. Given the paucity of literature on the subject, all studies irrespective of their rank in the levels of evidence hierarchy were included.

RESULTS

Gentle ventilation with permissive hypercapnia provides the best outcomes. Initial high frequency ventilation may be considered but its overall efficacy is unproven. Routine inhaled nitric oxide (iNO) or other medical adjuncts for acute, severe pulmonary hypertension demonstrate no benefit. Evidence does not support routine administration of pre- or postnatal glucocorticoids. Mode of extracorporeal membrane oxygenation (ECMO) has little bearing on outcomes. While the overall timing of repair does not impact outcomes, early repair on ECMO has benefits. Open repair leads to significantly fewer recurrences. Polytetrafluoroethylene (PTFE) is the most durable patch repair material.

CONCLUSIONS

Limited high-level evidence prevents the development of robust management guidelines for CDH. Prospective, multi-institutional studies are needed to identify best practices and optimize outcomes.

Congenital diaphragmatic hernia, management in the newborn

Congenital diaphragmatic hernia (CDH) in the newborn poses challenges to the multi-disciplinary teams involved in its management. Mortality remains significantly high, despite growing understanding and treatment options. Early intubation of antenatally diagnosed cases is crucial in preventing deterioration and persistent pulmonary hypertension. Early recognition of cases not diagnosed on antenatal scan, with appreciation of differential diagnosis, requires an index of suspicion and imaging. Increasing options and modalities are available, with only modest, if any, survival advantage. Permissive hypercapnea and minimal ventilation have made the most significant impact on survival in modern era. High-frequency oscillatory ventilation (HFOV), inhaled nitric oxide (iNO), treatment of pulmonary hypertension, and ECMO are used in a somewhat stepwise manner for stabilisation. Delayed surgery has become established later in management plan. The impact of individual therapies (e.g. HFOV, iNO, ECMO) on outcome is difficult to ascertain. Little level 1 or 2 evidence exists. Randomised studies and reviews on the role of ECMO have not yet proven any long-term survival benefit. One pilot randomised study of thoracoscopic repair suggests increased acidosis; intraoperative blood gases and CO2 levels should be closely monitored. Monitoring tissue oxygenation should be considered. There is no evidence to suggest the best patch material.

Diaphragm Repair with a Novel Cross-Linked Collagen Biomaterial in a Growing Rabbit Model

Background

Neonates with congenital diaphragmatic hernia and large defects often require patch closure. Acellular collagen matrices (ACM) have been suggested as an alternative to synthetic durable patches as they are remodeled by the host or could also be used for tissue engineering purposes.

Materials and Methods

2.0x1.0 cm diaphragmatic defects were created in 6-weeks old New-Zealand white rabbits. We compared reconstruction with a purpose-designed cross-linked ACM (Matricel) to 4-layer non-cross-linked small intestinal submucosa (SIS) and a 1-layer synthetic Dual Mesh (Gore-Tex). Unoperated animals or animals undergoing primary closure (4/0 polyglecaprone) served as age-matched controls. 60 (n = 25) resp. 90 (n = 17) days later, animals underwent chest x-ray and obduction for gross examination of explants, scoring of adhesion and inflammatory response. Also, uniaxial tensiometry was done, comparing explants to contralateral native diaphragmatic tissue.

Results

Overall weight nearly doubled from 1,554±242 g at surgery to 2,837±265 g at obduction (+84%). X-rays did show rare elevation of the left diaphragm (SIS = 1, Gore-Tex = 1, unoperated control = 1), but no herniation of abdominal organs. 56% of SIS and 10% of Matricel patches degraded with visceral bulging in four (SIS = 3, Matricel = 1). Adhesion scores were limited: 0.5 (Matricel) to 1 (SIS, Gore-Tex) to the left lung (p = 0.008) and 2.5 (Gore-Tex), 3 (SIS) and 4 (Matricel) to the liver (p<0.0001). Tensiometry revealed a reduced bursting strength but normal compliance for SIS. Compliance was reduced in Matricel and Gore-Tex (p<0.01). Inflammatory response was characterized by a more polymorphonuclear cell (SIS) resp. macrophage (Matricel) type of infiltrate (p<0.05). Fibrosis was similar for all groups, except there was less mature collagen deposited to Gore-Tex implants (p<0.05).

Conclusions

Matricel induced a macrophage-dominated inflammatory response, more adhesions, had appropriate strength but a lesser compliance compared to native tissue. The herein investigated ACM is not a viable option for CDH repair.

Current Concepts in the Management of Congenital Diaphragmatic Hernia in Infants

The therapeutic approach to congenital diaphragmatic hernia (CDH) has shifted from one of immediate repair to management of pulmonary hypertension, physiologic stabilization, and delayed surgical repair. Lung hypoplasia, remodeled pulmonary vasculature, and ventricular dysfunction all contribute to the high morbidity and mortality associated with CDH. In addition, genetic syndromes associated with CDH can increase the incidence of serious anomalies and hence impact survival. Prenatal and postnatal management of infants with CDH is challenging in the best of circumstances and need multidisciplinary teams for optimal outcomes. However, advances using ultrasound and fetal MRI can predict prognosis and survival and plan for postnatal management. Survival rates for patients with CDH have increased for the past decade with better management at resuscitation; implementation of gentle ventilation strategies; and medical management of pulmonary hypertension, physiologic stabilization, and extracorporeal membrane oxygenation. However, follow-up of these infants for long-term morbidities is essential for optimal outcomes after discharge.

Congenital diaphragmatic hernia

There is a paucity of level 1 and level 2 evidence for best practice in surgical management of CDH. Antenatal imaging and prognostication is developing. Observed to expected lung-to-head ratio on ultrasound allows better predictive value over simple lung-to-head ratio. Based on 2 randomised studies, the verdict is still out in terms the best group and indication for antenatal intervention and their outcome. Tracheal occlusion is best suited for prospective randomised studies of benefit and outcome. Only one pilot randomised controlled study of thoracoscopic repair exists, suggesting increased acidosis; blood gases and CO2 levels should be closely monitored. Only poorly controlled retrospective studies suggest higher recurrence rates. Randomised studies on the outcome of thoracoscopic repair are needed. Careful selection, anaesthetic vigilance, monitoring and follow-up of these cases are required. There is no evidence to suggest the best patch material to decrease recurrences. Evidence suggests no benefit from routine fundoplication based on the one randomised study. Multi-disciplinary follow-up is required. This can be visits to different specialities, but may be best served by a multi-disciplinary one-stop clinic.

Advances in the surgical approach to congenital diaphragmatic hernia

Congenital diaphragmatic hernia is a birth defect that affects about one in 2500 live births. Although the overall survival has improved over the last several decades thanks to advancements in postnatal resuscitation and intensive care treatment, morbidity and mortality remain high. The surgical management of these infants is far from being standardized, and many aspects are still disputed among experts. The timing of surgical repair remains controversial and the indications for the ideal time for surgery have not been validated. The main novelty in the surgical treatment is related to the use of minimally invasive techniques, although these have been associated with intraoperative blood gas disturbances and higher recurrence rates. Herein, we report and comment on the main controversies of postnatal CDH repair in this rapidly evolving field.

Prenatal MR imaging of congenital diaphragmatic hernias: association of MR fetal lung volume with the need for postnatal prosthetic patch repair

OBJECTIVE

To assess whether the need for postnatal prosthetic patch repair of the diaphragmatic defect in neonates with a congenital diaphragmatic hernia (CDH) is associated with the antenatal measured observed-to-expected magnetic resonance fetal lung volume (o/e MR-FLV).

METHODS

The o/e MR-FLV was calculated in 247 fetuses with isolated CDH. Logistic regression analysis was used to assess the prognostic value of the individual o/e MR-FLV for association with the need for postnatal patch repair.

RESULTS

Seventy-seven percent (77%) of patients with a CDH (190/247) required prosthetic patch repair and the defect was closed primarily in 23% (57/247). Patients requiring a patch had a significantly lower o/e MR-FLV (27.7 ± 10.2%) than patients with primary repair (40.8 ± 13.8%, p < 0.001, AUC = 0.786). With an o/e MR-FLV of 20%, 92% of the patients required patch repair, compared to only 24% with an o/e MR-FLV of 60%. The need for a prosthetic patch was further influenced by the fetal liver position (herniation/no herniation) as determined by magnetic resonance imaging (MRI; p < 0.001). Fetal liver position, in addition to the o/e MR-FLV, improves prognostic accuracy (AUC = 0.827).

CONCLUSION

Logistic regression analysis based on the o/e MR-FLV is useful for prenatal estimation of the prosthetic patch requirement in patients with a CDH. In addition to the o/e MR-FLV, the position of the liver as determined by fetal MRI helps improve prognostic accuracy.

KEY POINTS

• The o/e MR-FLV is associated with the need for postnatal patch repair in CDH. • The need for a patch is associated with a significantly lower o/e MR-FLV (p < 0.001). • The patch requirement is also influenced by fetal liver position. • Fetal liver position, in addition to the o/e MR-FLV, improves prognostic accuracy. • CDH-fetuses with a high probability for patch requirement can be identified prenatally.

Porcine small intestine submucosal grafts for post-tumor resection orbital reconstruction

OBJECTIVES/HYPOTHESIS

Removal of the medial orbital wall for sinonasal tumor involvement is required to obtain complete oncologic resection. However, orbital fat herniation can produce significant morbidity, including enophthalmos and diplopia. The purpose of the current study was to evaluate outcomes following use of porcine small intestine submucosa (SIS) grafts for orbital reconstruction following extirpation of sinonasal malignancies.

STUDY DESIGN

Case series in a tertiary hospital setting.

METHODS

Review of prospectively collected data regarding orbital reconstruction using SIS was performed. Demographics, tumor histology, size of orbital defect, adjuvant treatment, clinical status, and complications were recorded.

RESULTS

Seventeen patients (average age, 58 years; range, 27-82 years) had SIS grafting of the medial orbital wall over a 5-year period at our tertiary academic institution. The average orbital wall defect size was 4.6 cm(2) (range, 1 cm(2)-24 cm(2)). Tumor histopathology included esthesioneuroblastoma (n = 5), squamous cell carcinoma (n = 4), adenocarcinoma (n = 2), sinonasal undifferentiated carcinoma (n = 2), melanoma (n = 3), and neuroendocrine carcinoma (n = 1). Surgical goals were curative intent in all patients. Ten patients had postoperative radiation therapy, whereas five individuals had surgical extirpation following neoadjuvant chemotherapy and radiation. All patients had complete locoregional control at last clinical follow-up (average, 16 months; range, 2-54 months), although three patients developed distant metastases. The only orbital complications noted were enophthalmos (n = 1), periorbital cellulitis (n = 1), and orbital wall crusting (n = 1).

CONCLUSIONS

SIS reconstruction of orbital wall defects was effective in the current series of patients, with only one patient developing noticeable enophthalmos and a low incidence of surgical complications.

LEVEL OF EVIDENCE

4.

Outcomes following prosthetic patch repair in newborns with congenital diaphragmatic hernia

Background

The anatomical defect in congenital diaphragmatic hernia (CDH) can usually be closed primarily but prosthetic patch repair may be required in newborns with a deficient diaphragm. High rates of patch failure and hernia recurrence (up to 50 per cent) have been reported. This study evaluated contemporary outcomes following patch repair of CDH at a UK paediatric surgical centre.

Methods

Medical records of newborns undergoing surgery for CDH between 1 February 1990 and 1 November 2010, and attending a multidisciplinary follow-up clinic, were examined. Operative details and patch utilization are reported.

Results

Of 118 newborns with CDH, 37 required a patch to the diaphragmatic defect. Gore-Tex® patches were used in 35 and biological Surgisis® patches in two. Eight babies additionally required an abdominal wall patch. Seven infants had an abdominal patch alone with primary diaphragm repair. A total of 102 infants (86·4 per cent) survived after surgery. Two early recurrences were both related to the use of biological patches, leading to revisional surgery with Gore-Tex® patch reconstruction. Diaphragmatic patch use was associated with a greater requirement for intensive cardiovascular and respiratory support, although there was no significant difference in mortality between patch versus primary diaphragm repair. The mortality rate was significantly higher among infants requiring abdominal wall patching (with or without a diaphragmatic patch): 40 per cent (6 of 15) versus 9·7 per cent (10 of 103) (P = 0·006). Postoperative survival rates for infants with a diaphragmatic patch alone, abdominal wall patch alone, and both abdominal and diaphragmatic patches were 86 per cent (25 of 29), 57 per cent (4 of 7) and 63 per cent (5 of 8) respectively.

Conclusion

Prosthetic diaphragmatic hernia repair at this centre has a good outcome and low rate of recurrence (5 per cent). The recognition of an inadequate abdominal domain prenatally may additionally prove to be a useful marker for predicting increased mortality in newborns with CDH.

Heparinized collagen scaffolds with and without growth factors for the repair of diaphragmatic hernia: construction and in vivo evaluation

A regenerative medicine approach to restore the morphology and function of the diaphragm in congenital diaphragmatic hernia is especially challenging because of the position and flat nature of this organ, allowing cell ingrowth primarily from the perimeter. Use of porous collagen scaffolds for the closure of surgically created diaphragmatic defects in rats has been shown feasible, but better ingrowth of cells, specifically blood vessels and muscle cells, is warranted. To stimulate this process, heparin, a glycosaminoglycan involved in growth factor binding, was covalently bound to porous collagenous scaffolds (14%), with or without vascular endothelial growth factor (VEGF; 0.4 µg/mg scaffold), hepatocyte growth factor (HGF; 0.5 µg/mg scaffold) or a combination of VEGF + HGF (0.2 + 0.5 µg/mg scaffold). All components were located primarily at the outside of scaffolds. Scaffolds were implanted in the diaphragm of rats and evaluated after 2 and 12 weeks. No herniations or eventrations were observed, and in several cases, growth factor-substituted scaffolds showed macroscopically visible blood vessels at the lung site. The addition of heparin led to an accelerated ingrowth of blood vessels at 2 weeks. In all scaffold types, giant cells and immune cells were present primarily at the liver side of the scaffold, and immune cells and individual macrophages at the lung side; these cell types decreased in number from week 2 to week 12. The addition of growth factors did not influence cellular response to the scaffolds, indicating that further optimization with respect to dosage and release profile is needed.