ECMO and the management of congenital diaphragmatic hernia with large diaphragmatic defects requiring a prosthetic patch

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level III.

Clinical guidelines for the treatment of congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a birth defect of the diaphragm in which abdominal organs herniate through the defect into the thoracic cavity. The main pathophysiology is respiratory distress and persistent pulmonary hypertension because of pulmonary hypoplasia caused by compression of the elevated organs. Recent progress in prenatal diagnosis and postnatal care has led to an increase in the survival rate of patients with CDH. However, some survivors experience mid- and long-term disabilities and complications requiring treatment and follow-up. In recent years, the establishment of clinical practice guidelines has been promoted in various medical fields to offer optimal medical care, with the goal of improvement of the disease' outcomes, thereby reducing medical costs, etc. Thus, to provide adequate medical care through standardization of treatment and elimination of disparities in clinical management, and to improve the survival rate and mid- and long-term prognosis of patients with CDH, we present here the clinical practice guidelines for postnatal management of CDH. These are based on the principles of evidence-based medicine using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The recommendations are based on evidence and were determined after considering the balance among benefits and harm, patient and society preferences, and medical resources available for postnatal CDH treatment.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Generation of a Functioning and Self-Renewing Diaphragmatic Muscle Construct

Surgical repair of large muscular defects requires the use of autologous graft transfer or prosthetic material. Naturally derived matrices are biocompatible materials obtained by tissue decellularization and are commonly used in clinical practice. Despite promising applications described in the literature, the use of acellular matrices to repair large defects has been only partially successful, highlighting the need for more efficient constructs. Scaffold recellularization by means of tissue engineering may improve not only the structure of the matrix, but also its ability to functionally interact with the host. The development of such a complex construct is challenging, due to the complexity of the native organ architecture and the difficulties in recreating the cellular niche with both proliferative and differentiating potential during growth or after damage. In this study, we tested a mouse decellularized diaphragmatic extracellular matrix (ECM) previously described by our group, for the generation of a cellular skeletal muscle construct with functional features. The decellularized matrix was stored using different conditions to mimic the off‐the‐shelf clinical need. Pediatric human muscle precursors were seeded into the decellularized scaffold, demonstrating proliferation and differentiation capability, giving rise to a functioning three‐dimensional skeletal muscle structure. Furthermore, we exposed the engineered construct to cardiotoxin injury and demonstrated its ability to activate a regenerative response in vitro promoting cell self‐renewal and a positive ECM remodeling. Functional reconstruction of an engineered skeletal muscle with maintenance of a stem cell pool makes this a promising tool toward future clinical applications in diaphragmatic regeneration. stem cells translational medicine2019;8:858&869

Laparoscopic extracorporeal repair without a mesh of parasternal diaphragmatic hernia in an elderly woman: A case report

RATIONALE

The case of parasternal diaphragmatic hernia is relatively rare in adults. The best way for the treatment of diaphragmatic hernia is to receive operation, yet which surgical method is the best remains unclear.

PATIENT CONCERNS

An elderly woman in the hospital was complaining about upper abdominal pain that was complicated by the parasternal diaphragmatic hernia. Such state was found accidentally in a car accident and diagnosed by a computed tomography (CT) scan.

DIAGNOSIS

Parasternal diaphragmatic hernia.

INTERVENTIONS

Laparoscopic surgery was performed. The hernial component was easily drawn back into the abdominal cavity, and hernia sac was resected. Closure hernia sac underwent full-thickness U-shaped transabdominal wall sutures with 3-0 Prolene (ETHICON) after straightening the needle without a mesh.

OUTCOMES

The patient recovered quickly without postoperative complication. The hospital stay was 2 days. There was no recurrence and symptoms at a 6-month follow-up.

LESSONS

Laparoscopic extracorporeal repair without using a mesh is a safe, quick, and effective approach. It seems to be an effective treatment of the parasternal diaphragmatic hernia, in particular for elderly patients.

Long-term morbidity of congenital diaphragmatic hernia: A plea for standardization

Congenital diaphragmatic hernia (CDH) survivors present long-term morbidities in several systems, including the neurodevelopmental, gastrointestinal, pulmonary, and musculoskeletal ones, and CDH long-term sequelae are increasingly being recognized. Due to high co-morbidity, health related quality of life in a significant proportion of CDH patients might be compromised. As a consequence of consciousness on the long-term sequelae of CDH survivors, and their consequences for life, several follow-up programs were brought to life worldwide. In this review, we will summarize the long-term sequelae of CDH survivors, the impact of new treatments, and analyze the consistency of follow-up programs.

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.

Recurrent diaphragmatic hernia: Modifiable and non-modifiable risk factors

RATIONALE

The risk of recurrence of Congenital Diaphragmatic Hernia (CDH) in an era of thoracoscopic surgery is unclear.

OBJECTIVES

(1) estimate the incidence and (2) evaluate the perioperative factors associated with the symptomatic recurrence of CDH.

METHODS

Medical records of CDH infants operated on in the neonatal period at a single-tertiary hospital between January 2000 and January 2013 were retrospectively reviewed.

RESULTS

Of 119 infants with CDH, 34 (28.6%) were excluded: 17 (14.3%) died without recurrence and 17 (14.3%) presented beyond neonatal period or were followed elsewhere. Of 85 survivors, 71 infants had an open repair and 14 had a thoracoscopic repair. Eleven of 85 survivors (13%) developed a recurrence on average 19.8 weeks (range 15-34) after the initial repair. Of 11 recurrences, 6 had an initial thoracoscopic repair and 5 had an open repair (6/14 [43%] vs. 5/71 [7%]; P = 0.002). Two children had multiple recurrences. Statistically significant associations were found between recurrence and the presence of persistent pulmonary hypertension (PPHTN) (P = 0.006), severe PPHTN (P = 0.002), inhaled nitric oxide, or sildenafil use for treatment of PPHTN (P = 0.002), need for perioperative high frequency oscillatory ventilation (HFOV) (P = 0.0006), length of hospital stay (LOS) (P = 0.02), duration of ventilation (P = 0.016), and need for home oxygen (P = 0.003). In multivariate regression analysis both the closure type and home oxygen requirement were statistically significant, independent factors predicting a recurrence (P = 0.04 and 0.02, respectively) but the type of surgery (thoracoscopic vs. open) only approached significance (P = 0.052). The recurrence rate for the seven surgeons who performed at least 5 repairs ranged from 7% to 40%.

CONCLUSIONS

A high survival rate of 85% with a 13% incidence of symptomatic CDH recurrence was demonstrated. Potentially, improved selection of cases for thoracoscopic repair and concentrating the thoracoscopic technique amongst a dedicated team of experienced thoracoscopic surgeons may reduce the rate of recurrence of CDH.

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.

Laparoscopic patch repair of recurrent anterior diaphragmatic hernia in a child with SMA

An anterior congenital diaphragmatic hernia (CDH) is a diaphragmatic defect that allows the passage of abdominal organs into the thorax. It is typically asymptomatic (the diagnosis is incidental) and it requires surgical correction. In this paper we present a 6 year-old girl affected by spinal muscular atrophy (SMA) who was diagnosed with anterior CDH. Four years after laparoscopic closure of the defect by interrupted suture the girl returned for hernia recurrence. Another laparoscopic procedure was performed and the defect was closed using a GORE-TEX patch. We postulate a mechanism of altered respiratory dynamic and increased abdominal pressure related to scoliosis favouring CDH recurrence in patients with neuromuscular pathologies such as SMA. In these patients patch interposition should be considered in the first place in order to reduce tension over margins. Laparoscopy is a safe and feasible procedure for CDH correction also in case of recurrence and when the interposition of a patch is required.

Congenital asymptomatic diaphragmatic hernias in adults: a case series

INTRODUCTION

Congenital diaphragmatic hernia is a major malformation occasionally found in newborns and babies. Congenital diaphragmatic hernia is defined by the presence of an orifice in the diaphragm, more often to the left and posterolateral, that permits the herniation of abdominal contents into the thorax. The aim of this case series is to provide information on the presentation, diagnosis and outcome of three patients with late-presenting congenital diaphragmatic hernias. The diagnosis of congenital diaphragmatic hernia is based on clinical investigation and is confirmed by plain X-ray films and computed tomography scans.

CASE PRESENTATIONS

In the present report three cases of asymptomatic abdominal viscera herniation within the thorax are described. The first case concerns herniation of some loops of the large intestine into the left hemi-thorax in a 75-year-old Caucasian Italian woman. The second case concerns a rare type of herniation in the right side of the thorax of the right kidney with a part of the liver parenchyma in a 57-year-old Caucasian Italian woman. The third case concerns herniation of the stomach and bowel into the left side of the chest with compression of the left lung in a 32-year-old Caucasian Italian man. This type of hernia may appear later in life, because of concomitant respiratory or gastrointestinal disease, or it may be an incidental finding in asymptomatic adults, such as in the three cases featured here.

CONCLUSIONS

Patients who present with late diaphragmatic hernias complain of a wide variety of symptoms, and diagnosis may be difficult. Additional investigation and research appear necessary to better explain the development and progression of this type of disease.

Congenital diaphragmatic hernia

Congenital Diaphragmatic Hernia (CDH) is defined by the presence of an orifice in the diaphragm, more often left and posterolateral that permits the herniation of abdominal contents into the thorax. The lungs are hypoplastic and have abnormal vessels that cause respiratory insufficiency and persistent pulmonary hypertension with high mortality. About one third of cases have cardiovascular malformations and lesser proportions have skeletal, neural, genitourinary, gastrointestinal or other defects. CDH can be a component of Pallister-Killian, Fryns, Ghersoni-Baruch, WAGR, Denys-Drash, Brachman-De Lange, Donnai-Barrow or Wolf-Hirschhorn syndromes. Some chromosomal anomalies involve CDH as well. The incidence is < 5 in 10,000 live-births. The etiology is unknown although clinical, genetic and experimental evidence points to disturbances in the retinoid-signaling pathway during organogenesis. Antenatal diagnosis is often made and this allows prenatal management (open correction of the hernia in the past and reversible fetoscopic tracheal obstruction nowadays) that may be indicated in cases with severe lung hypoplasia and grim prognosis. Treatment after birth requires all the refinements of critical care including extracorporeal membrane oxygenation prior to surgical correction. The best hospital series report 80% survival but it remains around 50% in population-based studies. Chronic respiratory tract disease, neurodevelopmental problems, neurosensorial hearing loss and gastroesophageal reflux are common problems in survivors. Much more research on several aspects of this severe condition is warranted.

Absorbable versus nonabsorbable mesh repair of congenital diaphragmatic hernias in a growing animal model

INTRODUCTION

The repair of large congenital diaphragmatic hernia frequently results in patch disruption and recurrence as patients grow in size. Absorbable meshes allow for ingrowth of endogenous tissue as they are degraded, providing a more natural and durable repair. The aim of this study was to compare the characteristics of the new diaphragmatic tissue between an absorbable biologic mesh and a nonabsorbable mesh for repairing diaphragmatic hernia in a growing animal model.

METHODS

The left hemi-diaphragm of twenty 2-month-old Yucatan pigs was nearly completely resected. Small intestinal submucosa (SIS; Cook Biotech, Lafayette, IN) and expanded polytetrafluoroethylene (ePTFE; W.L. Gore & Associates, Flagstaff, AZ) were randomly assigned to cover the defect in 10 animals each, and were survived for 6 months. During necropsy, newly formed diaphragmatic tissue was evaluated and compared between the two groups.

RESULTS

At necropsy, the animals had tripled their weight. Patch disruption and herniation occurred in 3 animals in the ePTFE group and none in the SIS group. The SIS mesh had better integration to the chest wall (2.8 ± 0.2 versus 1.3 ± 0.3), more muscle growth within the newly formed diaphragmatic tissue (1.9 ± 0.2 versus 0.4 ± 0.2), and less fibrotic tissue (2.1 ± 0.5 versus 3.4 ± 0.4) than ePTFE. There was no difference between SIS and ePTFE in terms of adhesion scores to the lung (2 ± 0.4 versus 2.4 ± 0.4) and liver (1.8 ± 0.3 versus 2.2 ± 0.5).

CONCLUSION

SIS allows for tissue ingrowth from surrounding tissue as it degrades, providing a more durable repair with 30% less incidence of herniation in a porcine model. As the diaphragm grows, SIS resulted in a more natural repair of the defect with more tissue growth, better tissue integration, and a comparable adhesion formation to ePTFE.

Structural and biomechanical characteristics of the diaphragmatic tendon in infancy and childhood: an initial analysis

BACKGROUND

Engineered tendon grafts have been shown, experimentally, to be promising alternatives for partial diaphragmatic replacement. This study was aimed at determining the cellularity, extracellular matrix composition, and biomechanical characteristics of the diaphragmatic tendon in infants and children to be used as a reference for proper diaphragmatic graft engineering.

METHODS

The left diaphragmatic tendon was procured at autopsy from 13 patients divided into 2 groups. Group I (n = 9) consisted of newborns and infants. Group II (n = 4) consisted of children and adolescents. Samples underwent quantitative assays for total DNA, glycosaminoglycans, collagen, and elastin contents. Biomechanical measurements included modular and ultimate tensile strength analyses. Statistical comparisons were by the 2-sample Student's t test.

RESULTS

Group I showed significantly higher levels of total DNA, glycosaminoglycans, collagen, and elastin than group II. Conversely, group II tended to have higher modular and ultimate tensile strengths.

CONCLUSIONS

In neonates and infants, the diaphragmatic tendon has increased cell density and higher levels of major extracellular matrix components than in older children, in whom the diaphragmatic tendon tends to have higher tensile strength. Engineered diaphragmatic constructs should be tailored to the distinct anatomical, functional, and biomechanical characteristics of the diaphragmatic tendon at different age groups.

Outcomes after muscle flap vs prosthetic patch repair for large congenital diaphragmatic hernias

BACKGROUND

Repair of large congenital diaphragmatic hernia (CDH) defects still pose a significant challenge, as the defects cannot be repaired primarily. Two techniques have been widely used: autologous anterior abdominal wall muscle flap and prosthetic patch. The latter has been used more often. Our goal was to compare the short-term and long-term outcomes of these 2 approaches.

METHODS

This is a retrospective review of all neonates undergoing CDH repair at our institution from 1969 to 2006.

RESULTS

Of 188 children undergoing surgery for CDH, primary repair could not be accomplished in 51 infants (27%). Nineteen had muscle flap repair, and 32 had prosthetic patch repair (Gore-Tex [W.L. Gore and Associates, Flagstaff, AZ], n = 15; Marlex [Bard Inc, Cranston, NJ], n = 9; Surgisis [Cook, Bloomington, IN], n = 5; SILASTIC [Dow Corning, Midland, MI], n = 3). There was no significant difference in gestational age or birth weight between groups. Three patients developed an abdominal wall defect at the muscle flap donor site, but none required surgical intervention. Chest wall deformities were found in 9 patients, 3 after a muscle flap and 6 after a prosthetic patch (P = .7). Postoperative bowel obstruction occurred in 3 muscle flap patients and 1 patch patient (P = .2). There were 10 recurrences among survivors: 2 after a muscle flap and 8 after a prosthetic patch (P = .3) There were 2 deaths among the muscle flap patients (10%), and 3 deaths among the prosthetic patch repair patients (9%) (P = .1). Results were confirmed after controlling for age and comorbidities between both groups in a multivariate logistic regression.

CONCLUSION

These results suggest that autologous anterior abdominal wall muscle flap and prosthetic patch repairs provide similar short-term and long-term outcomes.

Multivariate model for predicting recurrence in congenital diaphragmatic hernia

PURPOSE

Risk factors that predispose children with congenital diaphragmatic hernia (CDH) to recurrence remain poorly defined. We report a large series of recurrent CDH and ask whether prenatal patient factors or postnatal treatment variables better predict recurrence.

METHODS

Two hundred thirty-eight neonates with unilateral CDH underwent repair from 1990 to 2006. Data were assessed by chi(2) and Mann-Whitney U tests. Multivariate regression identified independent predictors of recurrence. Statistical significance was set at P < .05.

RESULTS

We identified 24 recurrences (10%). Median time from repair to recurrence diagnosis was 4.9 months. Patients with recurrence were older (P = .02) and more often required abdominal wall patches at initial repair (P = .01) compared to nonrecurrence patients. Postoperative length of stay (LOS) after initial repair (P < .01) and morbidity (P = .01) were greater in recurrence patients. Use of diaphragm patch at initial repair was greater in patients with recurrence but only approached statistical significance (P = .05). Only 2 variables independently predicted recurrence by multivariate regression as follows: abdominal (not diaphragm) wall patch during initial repair (odds ratio [OR] 3.50; P = .04) and postoperative LOS (OR, 1.012; P = .01).

CONCLUSION

Neonates at risk for CDH recurrence are better identified by postnatal treatment variables than by prenatal patient factors. Although age at repair and diaphragm patch use are greater in recurrence patients, the only factors to independently predict recurrence were postoperative LOS and abdominal wall patch use. These data can help optimize follow-up regimens.

Fetal tissue engineering

Attempts at harnessing the prospective benefits of the therapeutic use of fetal cells or tissues date many decades before the modern era of transplantation. The first reported transplantation of human fetal tissue took place in 1922. Fetal cells or tissues also have been used as helpful investigational tools since the 1930s. Still, it was only in the last three decades that fetal tissue transplantation in people has started to lead to favorable outcomes, yet by and large anecdotally. This article offers an outlook on a relatively new dimension in fetal cell-based therapies, namely the engineering of tissues in the laboratory, along with its prospective applications.

Evaluation of diaphragmatic hernia repair using PLGA mesh-collagen sponge hybrid scaffold: an experimental study in a rat model

Patch closure is necessary to achieve tension-free repair in large congenital diaphragmatic hernia. However, the use of prosthetic material may lead to granulation, allergic reaction, infection, recurrence of hernia, and thoracic deformity. Tissue engineering may become an alternative treatment strategy for diaphragmatic hernia repair, since the regenerated autologous tissue is expected to grow potentially without rejection or infection. We evaluated the efficacy of diaphragmatic hernia repair in a rat model using a poly-lactic-co-glycolic acid (PLGA) mesh-collagen sponge hybrid scaffold, designed for in situ tissue engineering. Twenty-four F344 female rats were used. Oval-shaped defects were surgically created in the left diaphragm and repaired with three different grafts, including PLGA mesh in group 1 (n = 7), PLGA mesh-collagen sponge hybrid scaffold in group 2 (n = 7), and PLGA mesh-collagen sponge hybrid scaffold seeded with bone marrow-derived mesenchymal stem cells (MSCs) in group 3 (n = 10). The animals were killed at 1, 2, and 3 months after operation. The specimens were examined macroscopically and microscopically. No recurrence or eventration was observed. In all animals, autologous fibrous tissue with vascularization was generated at the graft site. Although no muscular tissue was detected, scattered desmin-positive cells were observed in groups 2 and 3. The 'neodiaphragm' in groups 2 and 3 was significantly thicker compared with that in group 1. There was no significant difference in the 'neodiaphragm' between groups 2 and 3. The PLGA mesh-collagen sponge hybrid scaffold provided better promotion of autologous in situ tissue regeneration in the diaphragm, suggesting its potential application to diaphragmatic repair in place of other prosthetic patches.

Liver position is a prenatal predictive factor of prosthetic repair in congenital diaphragmatic hernia

OBJECTIVE

To determine whether any common maternal-fetal variable has prenatal predictive value of prosthetic repair in congenital diaphragmatic hernia.

METHODS

This was a 5-year single-center retrospective review of fetal congenital diaphragmatic hernia referrals. Multiple prenatal variables were correlated with the need for a prosthetic repair. Statistical analyses were by Fisher's exact and Mann-Whitney U-tests, as appropriate (p < 0.05).

RESULTS

Fetal liver position was a predictor of prosthetic repair. The presence or absence of liver herniation was correlated with prosthetic repair rates of 83.3 and 23.1%, respectively (p < 0.001). All patients with moderate/severe liver herniation required a prosthetic patch.

CONCLUSION

Liver herniation has prenatal predictive value for the need for prosthetic repair in congenital diaphragmatic hernia. This finding should be valuable during prenatal counseling for clinical trials of engineered diaphragmatic repair.

Effectiveness of diaphragmatic repair using an abdominal muscle flap in patients with recurrent congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Recurrent congenital diaphragmatic hernia (Re-CDH) is a well-known complication of CDH repair. Although surgical treatment is required for Re-CDH, the question regarding which technique is the optimal treatment has not yet been elucidated. We performed a repair using an abdominal muscle flap (AMF) for Re-CDH and herein report our experience.

PATIENTS AND RESULTS

Four patients using AMF had left Re-CDH. The patient's age at operation was around 1 year old in all patients. In the first repair during the neonatal period, a Gore-Tex patch was required for the large defect in 3 patients, whereas a primary closure was selected in 1 patient because the anterior diaphragm remained as a partial remnant. In the 3 patients in whom a Gore-Tex patch was used in the first operation, recurrence occurred twice. All of the patients suffered from both pulmonary hypertension and growth retardation. A repair using AMF (the flap of both the internal oblique and the transversalis abdominal muscle) was performed in all patients. The clinical course was good in all patients, with an improvement of both pulmonary hypertension and growth retardation without any recurrence of CDH.

CONCLUSION

The use of an AMF was thus found to be an effective technique for repairing a large defect in Re-CDH.

ePTFE soft tissue patch reconstruction of hemidiaphragmatic agenesis with late clinical presentation

In this paper we describe a case of a 71-year-old man affected by left hemidiaphragm agenesis who presented an extensive enterothorax after an asymptomatic history for many years. The patient had late development of severe constipation and occasional episodes of bowel obstruction and vomiting. The surgical correction of this congenital anomaly consisted of restoring the continuity of the diaphragmatic barrier with a 2-mm-thick expanded polytetrafluoroethylene soft tissue patch(Gore-Tex) after the herniated viscera have been replaced into the abdominal cavity. At 26 months' follow-up no recurrence has been observed. We would suggest that this is the first known elderly patient surgically treated and the eighth case reported in the literature. The use of a single-layer ePTFE mesh allows a good anatomical and functional repair. An overview of the literature is also reported.

The split abdominal wall muscle flap repair for large congenital diaphragmatic hernias on extracorporeal membrane oxygenation

BACKGROUND

Numerous techniques exist for repairing large congenital diaphragmatic hernias (CDHs) including prosthetic patches, tissue-engineered grafts, and various muscle flaps. A split abdominal wall muscle flap is a simple, durable way to repair a large diaphragmatic hernia. This technique has not gained widespread use, and some have suggested that it would be inappropriate in the setting of extracorporeal membrane oxygenation (ECMO) because of bleeding risk. We present our series of diaphragmatic hernias with a focus on those repaired with the split abdominal wall technique while on ECMO.

METHODS

A retrospective, single-institution chart review was performed on all patients who underwent surgical repair for CDH over 6 years beginning in August 2000.

RESULTS

Seventy-five patients underwent repair. Sixteen were performed with patients on ECMO. Of these, 4 were closed primarily, 7 used a prosthetic patch, and 5 used a split abdominal wall muscle flap. Two patients in the prosthetic group developed a recurrent hernia, and 2 required reoperation for bleeding while on ECMO. No reoperations for bleeding were required in the abdominal muscle flap group.

CONCLUSIONS

The split abdominal wall muscle flap can be safely performed on anticoagulated patients. We believe it is a practical option for repairing large CDHs.

Long-term follow up of infants with congenital diaphragmatic hernia

With improving treatment strategies for congenital diaphragmatic hernia (CDH) infants, an increase in survival of more severely affected patients can be expected. Consequently, more attention is now focused on long-term follow up of these patients. Many reports have emphasized associated morbidity, including pulmonary sequelae, neurodevelopmental deficits, gastrointestinal disorders, and other abnormalities. Therefore, survivors of CDH remain a complex patient population to care for throughout infancy and childhood, thus requiring long-term follow up. Much information has been provided from many centers regarding individual institutional improvements in overall survival. Few of these, however, have reported long-term follow up. The aim of this review is to describe the long-term outcome of survivors with CDH and to suggest a possible follow-up protocol for these patients.

The whole truth: comparative analysis of diaphragmatic hernia repair using 4-ply vs 8-ply small intestinal submucosa in a growing animal model

BACKGROUND

Diaphragmatic reconstruction remains a challenging problem. There is limited information concerning the use of small intestinal submucosa (SIS) in congenital diaphragmatic hernia repair. A canine model was used to evaluate the use of a SIS patch in diaphragmatic reconstruction.

METHODS

Eleven beagle puppies (1.6-4.2 kg, 8 weeks old) underwent left subcostal laparotomy, central left hemidiaphragm excision (2 x 7 cm, 50% loss), and reconstruction with a 4-ply group I (n = 5) or 8-ply group II (n = 6) SIS patch. Chest radiographs were taken at time of operation and 3 and 6 months postoperatively. Animals were killed at 6 months. Adhesion formation (both pleural and abdominal), gross visual evaluation of the patch, and histology were compared.

RESULTS

In group I (4-ply), 1 animal died at 3 months from patch deterioration accompanied by stomach herniation that resulted in respiratory failure. In the 4 remaining animals, chest radiographs showed no evidence of herniation or eventration. On physical examination, there was no evidence of chest wall deformity. During gross surgical examination, the 4-ply patches showed thinning, multiple defects, and liver herniation in 3 animals. In 1 pup, the patch was thickened, intact, well incorporated at the repair site, and adherent to the liver and spleen. In group II (8-ply), 1 animal died of cardiopulmonary failure in the early postoperative period. In the other 5 animals, chest radiographs showed evidence of eventration in 1. On gross examination the patch adhered to the liver in all 5 surviving animals. In 4, the patches were thickened, viable, but had some shrinkage. One patch pulled away from the native diaphragm laterally; however, no visceral herniation was present. In the 1 animal with eventration, there was no evidence of a patch. Adhesion scores (AS) were graded and determined by the sum of extent (0-4), type (0-4), and tenacity (0-3). Average abdominal AS in group I was 5.6 +/- 0.8 vs 10.2 +/- 0.2 (P = .079) for group II. Average lung AS was 0.6 +/- 0.6 in group I vs 3.8 +/- 1.1 (P = .0476) for group II. Histological examination showed group II patches had greater collagen deposition with central calcification and mild inflammation within the residual graft, whereas group I patches were much thinner and were composed of granulation tissue without evidence of residual graft.

CONCLUSIONS

These data indicate that 8-ply SIS repair of diaphragmatic defects was superior (80%; 4/5 to 4-ply, 20%; 1/5, success). Organ adherence appears to be necessary for neovascularization of the SIS composite. Eight-ply grafts appear to be more durable and persist for a longer period, which may improve neovascularization. Long-term follow-up to evaluate remodeling characteristics of the patch material is required.

Prosthetic patches for congenital diaphragmatic hernia repair: Surgisis vs Gore-Tex

PURPOSE

The sequelae of congenital diaphragmatic hernia (CDH) continue well beyond the perinatal period. Up to 50% of these patients have subsequent recurrent herniation or small bowel obstruction (SBO). A recent trend has been toward the use of bioactive prosthetic materials. We reviewed different patch closure techniques used for CDH repair at our institution and their association with these sequelae.

METHODS

A retrospective review was performed of 152 records for patients with CDH. Newborns that underwent patch repair for CDH and survived for at least 30 days were included in the analysis. Primary outcomes evaluated were recurrent herniation and SBO. Two types of prostheses were examined, Gore-Tex, an artificial material, and Surgisis, a bioactive material.

RESULTS

Twelve (44%) of 27 patients who had Surgisis repair had recurrent herniation. Seventeen (38%) of 45 patients who had a Gore-Tex repair had recurrent herniation. Two additional patients in each group presented with SBO. No significant difference in recurrent herniation rates was observed (P > .5). The time to recurrence was similar in both groups (log-rank, P = .75), with most recurrences (92% Surgisis, 76% Gore-Tex) occurring in the first year.

CONCLUSION

The rates of recurrent herniation and SBO after neonatal prosthetic patch repair of CDH were similar regardless of the prosthetic material used (Surgisis or Gore-Tex).

Implantation of a cone-shaped double-fixed patch increases abdominal space and prevents recurrence of large defects in congenital diaphragmatic hernia

BACKGROUND

Large defects in patients with congenital diaphragmatic hernia (CDH) are frequently closed with a polytetrafluoroethylene patch (PTFE). Intraoperative problems include lack of abdominal domain for the reduction of organs and closure of the abdominal wall. Main surgical postoperative complication is the recurrence of the hernia. We suggest a new and easy method of patch implantation, improving these problems, and report first follow-up results.

METHODS

In our clinic, 103 children with CDH were treated, and 87 children underwent reconstruction of the diaphragm in the 5 years between 1998 and 2002. In 52 patients, a patch implantation had to be performed. We have been optimizing our complete pediatric and surgical procedure and present a new standardized technique of preparation and implantation of a PTFE patch. The flat patch is folded to a 90 degrees cone. The cone is fixed in its form with few single stitches. It is implanted with an overlapping border of 1 cm circumferentially. The border is separately fixed with absorbable single stitches to keep from rolling up. The rough side of the patch points toward the rim of the diaphragm to enable ingrowth of the connective tissue. In a 1-year follow-up study, the recurrences in the 3 following groups of PTFE patches were studied: conventional implantation (simple patch without overlapping border), patch with separately fixed overlapping border, and cone-shaped patch with overlapping separately fixed border.

RESULTS

Thirty-three patients were included in the study. After conventional PTFE-patch implantation, 6 (46%) of 13 patients developed reherniation. After PTFE-patch implantation with separately fixed overlapping border, 1 (11%) of 9 patients had a recurrent hernia. In the group with the PTFE-cone implantation, 1 (9%) of 11 patients developed a recurrence. Meanwhile, another 20 CDH patients received implantation of a cone-shaped patch, and no further recurrence occurred up to now. With the additional space (20 mL) provided by the cone-shaped patch, the closure of the abdomen was easier, and the fundus had intraoperatively a physiological position.

CONCLUSION

This optimized patch implantation technique in large diaphragmatic defects offers considerable advantages especially regarding recurrence of the hernia and closure of the abdomen, which are currently the most challenging surgical problems. 1. The cone-shaped 3-dimensional patch increases abdominal capacity. 2. Redundant chest capacity is reduced, and the reconstructed diaphragm shows a physiological shape. 3. The dome of the patch allows a physiological position of the gastric fundus and a normal Hiss angle, thus preventing gastroesophageal reflux. 4. Additional safety of the implantation is achieved by separate fixation of the overlapping border of the cone, preventing recurrence.

Toldt's fascia flap: a new technique for repairing large diaphragmatic hernias

The most popular techniques for repairing large diaphragmatic defects involve the use of synthetic patches. We present an alternative approach using living tissue. We reviewed our cases of congenital diaphragmatic hernia (CDH) diagnosed within the first 24 h of life from 1991 to 2003. Toldt's fascia (TF) flap was used to repair defects that were too large to repair primarily even though the anterior rim of the diaphragm was present. After confirming that a small medial muscle remnant of the diaphragm was present, its mesothelial covering was incised, and the incision was extended to the TF far enough to create a flap sufficiently large to repair the defect. The TF flap, consisting of the small medial muscle remnant, TF, peritoneum, and retroperitoneal connective tissue, was mobilized carefully from the ipsilateral kidney and adrenal gland, and the repair completed with interrupted sutures using nonabsorbable material. We used this TF flap approach in seven of 43 patients with CDH. Two had right-sided CDH. Six survived. The mean size of the diaphragmatic defects in the seven TF flap cases was 5.43+/-0.53 x 3.86+/-1.07 cm, which was significantly larger than the defects in direct primary repair cases (3.40+/-0.77 x 2.03+/-0.59 cm) (p<0.01). The six survivors had good outcomes, and none of them have had recurrence of herniation or required any additional surgical intervention (mean follow-up period: 4.7 years). To the best of our knowledge, this is the first report of TF being used to repair large diaphragmatic hernias. Our technique is simple and has proven to be reliable for durable restoration of the diaphragm, suggesting that it could reduce the dependence on synthetic patch repair, which is associated with certain long-term complications.

Diaphragmatic reconstruction with autologous tendon engineered from mesenchymal amniocytes

PURPOSE

This study examined the effects of amniocyte-based engineered tendons on partial diaphragmatic replacement.

METHODS

Ovine mesenchymal amniocytes were labeled with green fluorescent protein (GFP), expanded, and seeded into a collagen hydrogel. Composite grafts (20 to 25 cm2) based on acellular dermis (group I), or acellular small intestinal submucosa (group II) received either a cell-seeded or an acellular hydrogel within their layers. Newborn lambs (n = 20) underwent partial diaphragmatic replacement with either an acellular or a cellular autologous construct from either group. At 3 to 12 months' postoperatively, implants were subjected to multiple analyses.

RESULTS

Diaphragmatic hernia recurrence was significantly higher in animals with acellular grafts (5 of 5) then in animals with cellular ones (1 of 4) in group I (P <.05) but not in group II (3 of 6 and 4 of 5, respectively). Cellular grafts had higher modular (5.27 +/- 1.98 v. 1.27 +/- 0.38 MPa) and ultimate (1.94 +/- 0.70 v. 0.29 +/- 0.05 MPa) tensile strength than acellular implants in group I (P <.05), but not in group II. Quantitative analyses showed no differences in extracellular matrix components between cellular and acellular implants in either group. All cellular implants showed GFP-positive cells.

CONCLUSIONS

Diaphragmatic repair with an autologous tendon engineered from mesenchymal amniocytes leads to improved mechanical and functional outcomes when compared with an equivalent acellular bioprosthetic repair, depending on scaffold composition. The amniotic fluid may be a preferred cell source for engineered diaphragmatic reconstruction.

The split abdominal wall muscle flap--a simple, mesh-free approach to repair large diaphragmatic hernia

PURPOSE

The authors present a technique to repair large diaphragmatic hernias that is simple, can be done primarily, and offers a durable closure with living tissue.

METHODS

A review of congenital diaphragmatic hernias was performed for the period between January 1991 and August 2000. Repair types included primary repair, synthetic patch, or a split abdominal wall muscle flap. The split abdominal wall muscle flap is performed by downward rotation of the internal oblique and transversalis abdominal wall muscles. This repair requires that the initial subcostal incision be positioned at least 4 to 5 cm below the costal margin, low enough to insure an adequate length of muscle will be available to fill the defect.

RESULTS

Eight of 158 children with congenital diaphragmatic hernia underwent repair by abdominal wall muscle flap. Five of 8 had complete agenesis. Five survived the newborn period. Of the survivors, 4 of 5 required an additional surgical procedure, but none have had a recurrent hernia.

CONCLUSIONS

The split abdominal wall muscle flap is an effective technique to close large diaphragmatic hernias. The repair was carried out successfully in 8 patients with massive defects. In the surviving patients, the repair has proven to be a durable restoration of the diaphragm.

Recurrent diaphragmatic hernia

Recurrent congenital diaphragmatic hernia (CDH) is a well-known complication, but one that has not been examined systematically. Review of the literature shows a varied incidence as well as a myriad of treatment strategies. Evaluation of the available data is made more difficult by lack of standardized repair techniques and comparable patient groups. As an increasing number of diaphragmatic hernia patients survive the newborn period, a study of the true incidence of recurrent diaphragmatic hernia, its etiologic factors, and the methods of repair is essential to prevent and treat this problem.

Reconstruction of congenital agenesis of hemidiaphragm by combined reverse latissimus dorsi and serratus anterior muscle flaps

BACKGROUND/PURPOSE

Diaphragmatic agenesis (DA) is a distinct clinical entity with poorer survival rate compared with patients with posterolateral diaphragmatic hernia. The large defect in DA is repaired frequently with a synthetic patch in the neonatal period. Well-known, long-term complications include recurrent hernia caused by patch dislodgement, chest wall deformation caused by noncompliant patch, and deteriorating pulmonary function. A reverse latissimus dorsi flap (RLD) allows continued growth of the reconstructed diaphragm with an intact pleuro peritoneal separation. When combined with neuroanastomosis of the phrenic and thoracodorsal nerves it has the potential to function as a native diaphragm. Incorporation of Serratus anterior (SA) muscle enables reconstruction of larger defects.

METHODS

Two cases of DA are presented. In each case the primary SILASTIC(R) (Dow Corning, Midland, MI) patch repair failed and was replaced successfully with a RLD flap reconstruction with or without incorporation of SA and neuroanastomosis.

RESULTS

Both patients recovered from surgery with minimal morbidity. The reconstructed diaphragm is intact at long-term follow-up. There is marked improvement of growth of the infants, respiratory difficulties, and chest wall deformity.

CONCLUSIONS

This technique is recommended in DA when the synthetic patch fails.

Prosthetic patch durability in congenital diaphragmatic hernia: a long-term follow-up study

BACKGROUND/PURPOSE

The purpose of this study is to assess the durability of prosthetic patch repair of congenital diaphragmatic hernia (CDH) over time.

METHODS

The authors retrospectively reviewed the records of 109 children who had surgical repair of CDH between January 1989 and December 1996. Prosthetic patches were used for diaphragmatic agenesis or when the diaphragmatic defect was too large for primary closure after mobilizing the posterior leaf. Forty-five (41%) children required a prosthetic patch to repair the diaphragmatic defect, and 29 (64%) of these children survived.

RESULTS

Twelve (41%) of the 29 survivors required 1 or more operations for diaphragmatic reherniation. First-time reherniations occurred between 1 and 36 months postoperatively, median, 12 months. There was a bimodal distribution of first-time reherniations, with 4 children experiencing reherniation between 1 and 3 months, median age, 2 months and 8 children experiencing reherniation between 10 and 36 months, median age, 20 months. Three children returned for surgical repair of second reherniation between 21 and 39 months. Patients who had reherniation presented with bowel obstruction (n = 7), respiratory distress (n = 2), or were asymptomatic (n = 3). Revision of the reherniated patch consisted of placing an additional domed patch to fill the defect.

CONCLUSIONS

About half of all prosthetic patches used to repair CDH show evidence of reherniation and require revision within 3 years. Prosthetic patch repair is not a long-term solution for the child with CDH.

Fetal tissue engineering: diaphragmatic replacement

BACKGROUND/PURPOSE

Prosthetic repair of congenital diaphragmatic hernia has been associated with high complication rates. This study was aimed at applying fetal tissue engineering to diaphragmatic replacement.

METHODS

Fetal lambs underwent harvest of skeletal muscle specimens. Once expanded in vitro, fetal myoblasts were suspended in a collagen hydrogel submitted to controlled radial tension. The construct was then placed in a bioreactor. After birth, all animals underwent creation of 2 diaphragmatic defects. One defect was repaired with the autologous-engineered construct placed in between 2 acellular supporting membranes and the other with an identical construct but without any cells. Each animal was its own control (graft, n = 10). Animals were killed at different time-points postimplantation for histologic examination. Statistical analysis was by analysis of variance (ANOVA).

RESULTS

Fetal myoblasts expanded up to twice as fast as neonatal cells. Hydrogel-based radial tension enhanced construct architecture by eliciting cell organization within the scaffold. No eventration was present in 4 of 5 engineered constructs but in 0 of 5 acellular grafts (P<.05). At harvest, engineered constructs were thick and histologically resembled normal skeletal muscle, whereas acellular grafts were thin, floppy, and showed low cell density with increased fibrosis.

CONCLUSIONS

Unlike acellular grafts, engineered cellular diaphragmatic constructs are anatomically and histologically similar to normal muscle. Fetal tissue engineering may be a viable alternative for diaphragmatic replacement.

Suture or prosthetic reconstruction of experimental diaphragmatic defects

OBJECTIVE

Diaphragmatic reconstruction may cause several respiratory changes. The aims of the present study were to evaluate the respiratory changes induced by two methods of diaphragmatic reconstruction.

METHODS

Two groups of rats with an experimental diaphragmatic defect were studied. In one group (n = 5), diaphragmatic resection was followed by stitching together the borders of the wound (SUT); in another group (n = 5), the defect was repaired by suturing in a polytetrafluoroethylene (PTFE) patch. All animals were sedated, anesthetized, paralyzed, and mechanically ventilated. Spirometry, respiratory mechanics, and thoracoabdominal morphometry were evaluated before and after diaphragmatic reconstruction.

RESULTS

The suture of the diaphragm significantly decreased FVC and FEV(1), and increased respiratory system, lung, and chest wall static and dynamic elastances and viscoelastic/inhomogeneous pressures in relation to their respective control values. On the other hand, diaphragmatic reconstruction with PTFE increased only respiratory system, lung, and chest wall static elastances. In addition, respiratory system, pulmonary, and chest wall viscoelastic/inhomogeneous pressures and dynamic elastances, as well as respiratory system and lung elastances, were significantly greater in SUT than in PTFE. Lateral diameter at the level of the xiphoid and cephalocaudal pulmonary diameter diminished only in the SUT group.

CONCLUSIONS

The reconstruction of the diaphragm with PTFE might be preferred to simple suture for surgical repair of large diaphragmatic defects, at least from a mechanical standpoint.

Antireflux surgery in children under 3 months of age

PURPOSE

The aim of this study was to analyze the indications and results of fundoplication in 110 infants under 3 months of age.

METHODS

A retrospective review was conducted on the charts of all infants operated on for gastroesophageal reflux disease (GERD) at the UCLA Medical Center from January 1980 to December 1997. There were 59 boys and 51 girls. Recurrent emesis was the indication for operation in 62 of 110 infants, and respiratory symptoms in 85 of 110, with 54 of 110 having both. Neurological impairment was present in 32%. Prematurity was present in 21%; 35% had associated anomalies. Overall, 81 of 110 infants (73.6%) had one or more associated major malformations or disorders. Reflux was confirmed by upper gastrointestinal series findings in 63 of 78, esophageal pH monitoring in 60 of 62, and endoscopy in five of seven.

RESULTS

Mean age at operation was 1.8+/-0.1 months and mean weight was 3,686+/-90.2 g. A Nissen fundoplication was performed on 104 children, and six underwent a Thal procedure. Thirty-one had a gastric emptying procedure for delayed gastric emptying. Complications occurred in 7 infants. Emesis was controlled in 57 of 62 patients, aspiration in 38 of 48, and apneic spells in 54 of 57. Follow-up greater than 6 months was available for 73 patients. There were nine late deaths, all related to severe associated malformations. Seven patients required a redo fundoplication for recurrent reflux.

CONCLUSIONS

Nissen fundoplication can be performed safely in symptomatic infants under 3 months of age with low mortality and morbidity rates and with resolution of the presenting symptoms in 79% of infants.

Survival of patients with congenital diaphragmatic hernia during the ECMO era: an 11-year experience

BACKGROUND/PURPOSE

Congenital diaphragmatic hernia (CDH) is associated with significant mortality and morbidity. To evaluate the impact of extracorporeal membrane oxygenation (ECMO) on survival, a review of our experience with CDH patients was initiated.

METHODS

The authors performed a retrospective nonrandomized analysis of 98 consecutive CDH patients who were ECMO candidates, and were symptomatic within the first day of life, and underwent repair between May 1985 and May 1996. The patients were divided into three groups: Group 1 (n = 38) refers to patients who were clinically stable and underwent repair before 48 hours of age and did not need ECMO rescue; Group 2 (n = 29) consists of patients who underwent repair but required ECMO rescue; and Group 3 (n = 31) refers to patients who met ECMO criteria preoperatively and required ECMO for stabilization and later underwent repair on ECMO. The Kaplan-Meier survival graph was used for survival analysis.

RESULTS

During the 11-year span, the overall survival rate of all CDH patients was 72% (71 of 98). The survival rate of patients who did not require ECMO support was 92% (35 of 38), whereas patients who required ECMO after repair had a 72% (21 of 29) survival rate. These were compared with a 48% (15 of 31) survival rate for those undergoing repair on ECMO. The differences in survival among the three groups were statistically significant using the log-rank test (P = .0018).

CONCLUSIONS

Survival was significantly better for infants who underwent successful repair without ECMO than those who required ECMO rescue pre- or postrepair. The overall improved survival of CDH patients to 72% compared with historical controls of 38% to 58% may be attributed to ECMO, but the requirement of ECMO before repair, as well as the presence of congenital anomalies (P < .01), prematurity (P < .01), the need for a Gore-Tex patch at repair (P < .05), prenatal diagnosis at less than 25 weeks' gestation (P < .01), and the occurrence of an intracranial hemorrhage (P < .01), decreases the chances of survival.

An experimental study on the pathogenesis of gastroesophageal reflux after repair of diaphragmatic hernia

BACKGROUND/PURPOSE

Gastroesophageal reflux (GER) is increasingly reported after surgical repair of congenital diaphragmatic hernia (CDH) and eventration. The aim of this study was to test the hypothesis that transdiaphragmatic pressure gradients are increased and that the antireflux barrier is weakened after plication of a previously paralyzed diaphragm.

METHODS

Abdominal and esophageal pressures as well as lower esophageal sphincter pressures (LESP) and diaphragmatic pinchcock pressure (DPP) were measured before and after diaphragmatic plication in 16 rats in which the diaphragm had been previously eventrated by phrenic nerve section.

RESULTS

This maneuver increased the transdiaphragmatic inspiratory pressure gradient from 2.75 +/- 0.54 to 4.51 +/- 0.86 mm Hg (P < .05) by rising both the inspiratory (-2.02 +/- 0.39 v -3.11 +/- 0.92 mm Hg, P < .05) and the expiratory (1.47 +/- 0.87 v 0.51 +/- 0.41 mm Hg, P < .05) intrathoracic pressures. At the same time, the antireflux barrier was weakened because LESP decreased from 17.5 +/- 5.59 to 10.59 +/- 5.74 mm Hg (P < .05) and DPP tended to decrease from 13.57 +/- 8.67 to 6.07 +/- 1.72 mm Hg (ns).

CONCLUSIONS

Plication of the previously paralyzed diaphragm in the rat reinforces the GER driving forces while weakening the antireflux barrier. This may explain why reflux is frequent in children surviving repair of diaphragmatic hernia and eventration.

Can blood gas values predict pulmonary hypoplasia in antenatally diagnosed congenital diaphragmatic hernia?

The prognosis of antenatally diagnosed congenital diaphragmatic hernias (CDH) is clearly related to the degree of pulmonary hypoplasia (PH). After birth, controversies remain regarding the implementation of various therapies, especially the use of extracorporeal membrane oxygenation (ECMO). In the literature, the persistence of a Pao2 below 100 mm Hg and of Paco2 above 40 mm Hg despite optimal conventional therapy indicates poor prognosis. Therefore, since 1992, published and personal experiences led the authors to exclude CDH patients from ECMO when conventional therapy (including high-frequency oscillatory ventilation and nitric oxide) did not obtain Pao2 of above 80 mm Hg and Paco2 of below 60 mm Hg. The aim of this retrospective study is to determine whether blood gas results correlate with postmortem findings. Between July 1990 and July 1994, 32 cases of CDH were monitored antenatally and managed postnatally at the authors' institution. Six patients survived; 26 died, including one immediately at birth. Thirteen were treated by ECMO. Seventeen had a best Pao2 of above 80 mm Hg, including the six survivors. Fourteen did not reach this level, and none of them survived. Twenty-three infants underwent postmortem examination. PH was assessed using two criteria: (1) lung weight to body weight ratio (LW/BW) and (2) radial alveolar count (RAC). Two patients did not have hypoplasia (LW/BW > 0.018). Twenty-one patients had PH; 12 of them had an LW/BW ratio of less than .009; for 9, the LW/BW ratio was between .009 and .018, and the RAC (< 3.1) confirmed PH. All infants with a best Pao2 of less than 80 mm Hg had PH. Patients with a best Pao2 of greater than 80 mm Hg included two infants who died from complications without PH, eight infants with demonstrated PH, and the six survivors. In conclusion. (1) No infant with nonhypoplastic lungs has been deprived of ECMO by the authors' criteria. (2) Adequate values of blood gases may not eliminate PH. Therefore, this probably justifies starting ECMO when conventional therapy fails. (3) Conversely, permanent poor values of Pao2 allowed the prediction of PH in all cases. Such patients probably can be excluded from ECMO treatment.

Congenital diaphragmatic hernia: experience in a single institution from 1978 through 1994

BACKGROUND

Congenital diaphragmatic hernia continues to be a difficult management problem. Essentially all information on the condition has been compiled in a retrospective manner due to the individualized care that each infant must undergo. We contribute a review of our patients to add to the current fund of knowledge and to assess our experience before and since the introduction of extracorporeal membrane oxygenation in our institution.

METHODS

This is a review of records of infants with congenital diaphragmatic hernia treated from 1978 through 1994. Repair has generally been accomplished early with only one repair being accomplished with an infant placed on extracorporeal membrane oxygenation preoperatively.

RESULTS

Overall survival was 63%. Survival was 42% before extracorporeal membrane oxygenation becoming available in our region in 1986, and 75% afterward. Since 1986, 16 of 33 (48%) infants have required extracorporeal membrane oxygenation and 73% have survived.

CONCLUSIONS

Overall survival in our series is comparable with that of other reported series. There appears to be an improvement in survival since the introduction of extracorporeal membrane oxygenation. Our present practice of early repair, and postrepair extracorporeal membrane oxygenation if needed, results in a survival rate comparable with that of currently available series reports regardless of the method of treatment reported.

Diaphragmatic agenesis as a distinct clinical entity

Anatomically, diaphragmatic agenesis (DA) is the most extreme form of congenital diaphragmatic defect, but clinically it has not been defined separately from Bochdalek's hernia (BH). Between 1986 and 1992, the authors treated 55 neonates who had diaphragmatic defects. Forty-eight of these cases presented within 24 hours of birth. Seventeen of these neonates (35.4%) were found to have DA; the other 31 (64.6%) had BH. There were no significant differences in maternal age, gestational age, gender ratio, birth weight, and incidence of coexisting congenital anomalies between the two groups. However, neonates with DA differed significantly from those with BH with respect to incidence of antenatal diagnosis (76.4% v 12.5%, P = .0004), mean Apgar scores at 1 (4.1 +/- 2.0 v 5.7 +/- 2.3; P = .034) and 5 (5.5 +/- 2.7 v 7.6 +/- 2.2; P = .016) minutes, mean duration of preoperative stabilization (2.8 +/- 2.0 v 2.1 +/- 1.9 days; P = .044), and postoperative respiratory support (27.7 +/- 13.6 v 9.3 +/- 8.0 days; P = .002). Complications occurred in all seven DA survivors (100%) and in only four (19.0%) of the 21 BH survivors (P = .0008). The long-term survival rate was significantly lower for neonates with DA (29.4% v 64.5%; P = .04). Diaphragmatic agenesis is a distinct clinical entity; its unique short- and long-term problems require careful management.

Experience with abdominal wall closure for patients with congenital diaphragmatic hernia repaired on ECMO

Congenital diaphragmatic hernia (CDH) and its attendant lack of abdominal domain can create major technical challenges with respect to diaphragmatic and abdominal wall reconstruction, especially in seriously ill infants who require extracorporeal membrane oxygenation (ECMO). The authors reviewed the medical records of all infants with CDH repaired on ECMO at their institution (group 1, 15 patients), and compared them with infants having CDH repair before ECMO (group 2, 20 patients) and with those who had CDH repair but did not require ECMO (group 3, 15 patients). Thirty-seven of 50 patients survived (74%): 10 in group 1, 12 in group 2, and all 15 in group 3. There was a statistically significant difference (P < .001) with respect to the requirement of a polytetrafluoroethylene (PTFE) diaphragmatic patch for patients in group 1 versus those in both groups 2 and 3. There was also a significant difference in the number of patients in whom the abdomen could not be closed (P < .001 for group 1 v groups 2 and 3). Infants who require ECMO before CDH repair are more likely to have large diaphragmatic defects that require prosthetic reconstruction, and abdominal wall closure problems resulting from loss of abdominal domain, which further complicate the management of the physiological derangements from pulmonary hypoplasia and persistent pulmonary hypertension.

Diaphragmatic agenesis as a distinct clinical entity

Anatomically, diaphragmatic agenesis (DA) represents the most extreme form of congenital diaphragmatic defects, but clinically it has not been defined separately from Bochalek's hernia (BH). Between 1986 and 1992, the authors treated 55 neonates who had diaphragmatic defects. Forty-eight of them presented within 24 hours of birth and comprised the study group. Seventeen neonates (35.4%) were found to have DA; the other 31 (64.6%) had BH. There were no differences in the maternal age, gestation course, gender ratio, birth weight, or incidence of co-existing congenital anomalies between the two groups. However, there were significant differences with respect to the incidence of antenatal diagnosis (76.4% for DA patients v 12.5% for BH patients; P = .0004), mean (+/- SD) Apgar scores at 1 (4.1 +/- 2.0 v 5.7 +/- 2.3; P = .034) and 5 minutes (5.5 +/- 2.7 v 7.6 +/- 2.2; P = .016), mean duration of preoperative stabilization (2.8 +/- 2.0 v 2.1 +/- 1.9 days; P = .044) and mean duration of postoperative respiratory support (27.7 +/- 13.6 v 9.3 +/- 8.0 days; P = .002). Complications occurred in all seven survivors of DA and in only four (19.0%) of 21 survivors of BH (P = .0008). The neonates with DA had a significantly poorer long-term survival rates (29.4% v 64.5%; P = .04). Diaphragmatic agenesis is a distinct clinical entity; its unique short-term and long-term problems require careful management.

Gastroesophageal reflux occurring after repair of congenital diaphragmatic hernia

Over the past 2 decades, 110 patients with congenital diaphragmatic hernia (CDH) were treated in the authors' hospital. Eighty-six survived; of these, 10 patients (11.6%) had gastroesophageal reflux (GER) after repair of CDH. Seven occurred in the past 5 years, during which time advanced intensive care including extracorporeal membrane oxygenation (ECMO) was used. Vomiting started within 4 weeks after repair of CDH in eight cases, and hiatal hernia was demonstrated in six cases. Three patients responded to conservative therapy; the other seven required antireflux surgery. Several factors are believed to be possible causes of the development of GER in CDH cases. Among them, slow pulmonary expansion of the affected side was thought to be the most important. Namely, in a case of CDH associated with severe hypoplastic lung, the esophagus may be deviated to the affected side before the lung is expanded. After expansion, the abdominal esophagus shortens, and GER or a hiatal hernia can occur in severe cases. There were seven such patients in our series of 10. With the increase in the survival rate of CDH cases associated with severe hypoplastic lung, the number of such patients also may increase. Therefore, some additional procedure to prevent the lower esophagus from sliding will be necessary in the repair of diaphragmatic hernia.

Gastroesophageal reflux associated with large diaphragmatic hernias

Extracorporeal membrane oxygenation (ECMO) support has improved the outlook for some infants who have large diaphragmatic hernias (CDH). This has resulted in a subset of survivors of CDH with typically larger defects, more severe pulmonary hypoplasia, and more associated pathologies. This report describes the authors' experience with gastroesophageal reflux in patients with large diaphragmatic hernias who require ECMO. Contrary to previous reports, this reflux was severe and intractable. There appears to be a component of associated gastric dysmotility. In treating this reflux, medical therapy and anterior fundoplication were not successful, and Nissen fundoplication combined with pyloroplasty was required to control reflux and to allow gastric feeding. On the basis of the authors' experience, it is recommended that patients who have gastroesophageal reflux after CDH repair, for whom medical management has failed, be managed aggressively by surgery, with early Nissen fundoplication, and pyloroplasty and insertion of a gastric feeding tube.

Complications of neonatal extracorporeal membrane oxygenation

From 1973-1985 to 1988 the average patient complications per case were 1.44 per case and significantly increased during 1990 to 1992 to 2.10 per case (Figure 3). During the same periods patient survival significantly decreased from 84% (1973-1985 to 1988, n = 2463) to 80% (1990 to 1992, n = 4005) (Figure 4). The association between total complication rates and survival rate was examined by regression analysis (Table 5). The correlation of patient complication rate and total complication rate with survival is highly significant; however, causality cannot be established. When comparing different entry criteria (Table 2) for incidence of mechanical and patient complications, no significant differences are apparent. This is not surprising since each of the entry criteria were designed to identify the same patient population. When premature neonates (> 35 weeks) were placed on ECMO, 36% of them had intracranial haemorrhage (ICH) with 62% mortality while only 12% of the neonates < 35 weeks had ICH and a 49% mortality. Similar findings were noted with low birthweight neonates (< 2.2 kg), 28% had ICH with 64% mortality while only 12% of the neonates > 2.2 kg had ICH with a 50% mortality. Selection criteria remain problematic for a variety of reasons. They cannot be viewed as absolute because of variability between centres. What represents likely 80% mortality in one centre may not apply to another. Historical controls are misleading because changing respiratory therapy strategies make historical populations difficult to compare. Also, once an ECMO centre becomes established, a more challenging group of patients will be attracted than previously was the case. Further, a single entry criterion cannot be generalized for all entry diagnoses. Criteria for an 80% predicted mortality is probably not the same for MAS, CHN, PPHN, and sepsis. Subsequent patients registered in the Neonatal ECMO Registry of the Extracorporeal Life Support Organization will address these issues more thoroughly, as specific details of the pre-ECMO condition and therapeutic strategies are collected. This collective review should help to identify trends which require reassessment of technique or patient management.