Agenesis of the left diaphragm: surgical repair and physiologic consequences

Defect size determines survival in infants with congenital diaphragmatic hernia

OBJECTIVES

Congenital diaphragmatic hernia is a significant cause of neonatal mortality. The objective of this study was to evaluate the clinical factors associated with death in infants with congenital diaphragmatic hernia by using a large multicenter data set.

METHODS

This was a prospective cohort study of all liveborn infants with congenital diaphragmatic hernia who were cared for at tertiary referral centers belonging to the Congenital Diaphragmatic Hernia Study Group between 1995 and 2004. Factors thought to influence death included birth weight, Apgar scores, size of defect, and associated anomalies. Survival to hospital discharge, duration of mechanical ventilation, and length of hospital stay were evaluated as end points.

RESULTS

A total of 51 centers in 8 countries contributed data on 3062 liveborn infants. The overall survival rate was 69%. Five hundred thirty-eight (18%) patients did not undergo an operation and died. The defect size was the most significant factor that affected outcome; infants with a near absence of the diaphragm had a survival rate of 57% compared with infants having a primary repair with a survival rate of 95%. Infants without agenesis but who required a patch for repair had a survival rate of 79% compared with primary repair.

CONCLUSIONS

The size of the diaphragmatic defect seems to be the major factor influencing outcome in infants with congenital diaphragmatic hernia. It is likely that the defect size is a surrogate marker for the degree of pulmonary hypoplasia. Future research efforts should be directed to accurately quantitate the degree of pulmonary hypoplasia or defect size antenatally. Experimental therapies can then be targeted to prospectively identify high-risk patients who are more likely to benefit.

Infants with Bochdalek diaphragmatic hernia: sibling precurrence and monozygotic twin discordance in a hospital-based malformation surveillance program

Congenital diaphragmatic hernia (CDH) is a common and often devastating birth defect. In order to learn more about possible genetic causes, we reviewed and classified 203 cases of the Bochdalek hernia type identified through the Brigham and Women's Hospital (BWH) Active Malformation Surveillance Program over a 28-year period. Phenotypically, 55% of the cases had isolated CDH, and 45% had complex CDH defined as CDH in association with additional major malformations or as part of a syndrome. When classified according to likely etiology, 17% had a Recognized Genetic etiology for their CDH, while the remaining 83% had No Apparent Genetic etiology. Detailed analysis using this largest cohort of consecutively collected cases of CDH showed low precurrence among siblings. Additionally, there was no concordance for CDH among five monozygotic twin pairs. These findings, in conjunction with previous reports of de novo dominant mutations in patients with CDH, suggest that new mutations may be an important mechanism responsible for CDH. The twin data also raise the possibility that epigenetic abnormalities contribute to the development of CDH.

Surgical embryology and anatomy of the diaphragm with surgical applications

This article reviews the development, surgical anatomy, and teratology of the diaphragm, and discusses the diagnostic procedures, surgical therapy, and prognosis of congenital disturbances. Special attention is paid to the traumatic rupture of the diaphragm, concerning incidence, cause, diagnosis, prognosis, and surgical repair.

Neurological outcome is diminished in survivors of congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation

In a series of 61 infants who had congenital diaphragmatic hernia (CDH) treated at our center from 1978 through 1996, 37 of 59 (61%) survived the perioperative period with two infants lost to follow-up. Nine (47%) of 19 infants survived before the introduction of extracorporeal membrane oxygenation (ECMO) into our region in 1986. Since 1986, 28 (70%) of 40 infants survived. Eighteen infants required ECMO, and 12 (75%) survived. A chart review was performed to determine whether infants surviving CDH are suffering from delays in neurological development, and, if so, whether this is attributable to ECMO. Of 12 ECMO survivors, 8 (67%) exhibited functional or anatomic evidence for neurological delay. Of 21 non-ECMO survivors, where adequate follow-up was available to make an assessment of neurological development, five (24%) exhibited evidence for delay. This difference was significant (P < .05, Fisher's Exact test). Of these five infants, three were premature, and one had DiGeorge syndrome. More ECMO survivors required diaphragmatic (67%) and abdominal (67%) patches at the time of diaphragmatic repair than non-ECMO survivors (4% and 12%, respectively; P < .05, Fisher's Exact test). In addition, more ECMO survivors required gastrostomy tube placement for feeding (50%) than non-ECMO survivors (16%; P < .05, Fisher's Exact test). A greater need for Nissen fundoplication in ECMO survivors (42%) than in non-ECMO survivors (12%) approached significance (P = .05, Fisher's Exact test). There were trends toward higher 1 and 5 minute APGAR scores and initial and best preoperative P(O2) in the non-ECMO survivors. A comparison between ECMO survivors who exhibited evidence of neurological delay with those who did not showed no differences in duration of ECMO, incidence of intracranial complications during ECMO, need for gastrostomy tube feeding or Nissen fundoplication, or incidence of carotid artery repair between the two groups. Infants surviving CDH who require ECMO have a greater incidence of neurological delay than those who do not. This is likely because of severity of the presenting illness as reflected by a greater need for diaphragmatic and abdominal patches during diaphragmatic repair, the need for Nissen fundoplication and gastrostomy tube feeding, and a trend toward poor APGAR scores and best preoperative P(O2) levels in these patients. However, there may be characteristics of ECMO, as yet unidentified, that may contribute to this outcome.

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.

An association of pulmonary hypoplasia with unilateral agenesis of the diaphragm

During a period of 5 years, 33 newborns with congenital diaphragmatic hernia were treated. Three groups presenting with respiratory distress in the delivery room were identified. These included 8 newborns with agenesis (group 1) and 4 newborns with nonagenesis (group 2), all of whom died. There were 19 nonagenesis survivors (group 3), giving an overall survival rate of 61%. Two newborns who presented beyond 6 hours of life were excluded. No one specific arterial blood gas value or ventilation parameter obtained preoperatively could predict survival. Postmortem right and left lung weights, lung/body weight ratio, and radial alveolar counts demonstrate that agenesis is a unique subgroup with profound pulmonary hypoplasia and a dismal prognosis.

Prosthetic diaphragm reconstruction in the growing animal

Widespread use of extracorporeal membrane oxygenation (ECMO) has allowed an increasing number of infants with total agenesis of the diaphragm to survive. Polytetrafluoroethylene (PTFE) is the most widely used material for reconstruction. However, recurrent hernia is a growing problem; PTFE also does not grow with the patient. This study evaluated different materials for diaphragmatic reconstruction in growing animals. Sprague-Dawley rats with a mean weight of 93 g were anesthetized and underwent laparotomy. The control group had an incision into the diaphragm with primary repair. The other three groups underwent complete removal of the left hemidiaphragm and were randomly assigned to one of three reconstruction methods: oxidized cellulose, polyglactin mesh, or a 1-mm PTFE patch. All patch materials were sewn around the ribs circumferentially and into the membranous portion of the central diaphragm medially with 4-0 silk. Thirty-seven animals survived operation, were followed with weekly chest radiographs, and were killed when they reached 400 g. The radiographs were reviewed in a blinded fashion by two observers as were the necropsies, and rib deformity was graded on a scale of 0 to 3. Histological examination of several animals from each group was performed. There was significantly greater rib deformity (2.0 v 0.2, P < .01) in the PTFE group versus controls with 5 of 10 animals also having a smaller thorax. The PTFE pulled away from the chest wall in the animals leaving a fibrous remnant anteriorly. The polyglactin group had significantly more animals with eventration (P < .03, 7/10) compared with all others.(ABSTRACT TRUNCATED AT 250 WORDS)

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

From 1977 to 1991, 136 neonates have had corrective surgery for diaphragmatic hernia at Children's Hospital of Los Angeles. A retrospective study was performed to determine how many of the 136 neonates had defects large enough to require the use of a prosthetic patch to repair the defect. Twelve were found. All 12 were symptomatic at birth for respiratory distress. Mean arterial blood gas values at birth were pH 6.95, PCO2 94.8, and PO2 47.2. The mean oxygen index (n = 10) was 61.8. Six of these patients were repaired without extracorporeal membrane oxygenation (ECMO) support while the other six received ECMO bypass perioperatively. All six of the patients who did not receive ECMO support died despite successful diaphragmatic repair. Five of six patients who received ECMO perioperatively survived (83%). These surviving infants are now between 1 month and 4 years of age. In the survivors, four of five required subsequent repair and patch enlargement for a recurrent diaphragmatic hernia. Gastroesophageal reflux, requiring a Nissen fundoplication in two infants, complicated the course of three survivors. Four survivors were discharged with supplemental oxygen therapy lasting less than 13 months. Patch disruption is predicted to occur at approximately 18 months of age in all patients, especially if little or no muscle was available at primary repair for prosthetic attachment. These children should be followed closely for feeding or respiratory symptoms. Diagnosis of patch disruption can be made by chest x-rays and confirmed by contrast studies. Patch expansion by laparotomy and careful search for additional musculature for patch attachment is recommended when reherniation occurs.

Unilateral absence of the diaphragm in an asymptomatic adult

An asymptomatic 22-year-old man was evaluated for a persistent left lower lobe infiltrate. Barium enema and upper gastrointestinal series revealed colon and small bowel freely mobile in the left thorax. CT confirmed absence of the left hemidiaphragm. This is the first reported case of total absence of a hemidiaphragm in an adult, and extends the clinical spectrum of diaphragmatic defects where strangulation of hernia contents may occur , the asymptomatic presentation of complete absence of the hemidiaphragm with the unimpeded movement of abdominal contents suggests that no treatment is necessary.

Unilateral agenesis of the diaphragm

During a period of 4 1/2 years, 37 infants with congenital diaphragmatic hernia were treated. The overall survival rate was 68%. Survival depended more on cardiopulmonary function than the size of the diaphragmatic defect. There was little evidence that infants with agenesis of the diaphragm formed a special group with a poor prognosis, and four of the ten patients with unilateral agenesis survived. A Dacron prosthesis is recommended as a substitute for the missing diaphragm.

Congenital diaphragmatic hernia in monozygotic twins

This is the third reported instance of identical twins, each with left-sided posterolateral congenital diaphragmatic hernia (CDH) (Bochdalek type), who have been operated upon successfully. The associated anomalies were mirror image undescended testicles. Comparative review of familial and sporadic cases of CDH revealed that males were more commonly affected in the former, while females were more commonly affected in the latter. There was no known etiology in either type. Both familial and sporadic cases shared a high incidence of associated anomalies (40% to 50%). Three anomalies were equally found in both types, mainly pulmonary hypoplasia, intestinal malrotation, and patent ductus arteriosus. Central nervous system anomalies were highly prevalent in the sporadic cases (55% to 75%), while cardiovascular and genitourinary anomalies (30% each) were the more common anomalies encountered in the familial cases.

Familial diaphragmatic defects: early prenatal diagnosis and evidence for major gene inheritance

Congenital diaphragmatic defect (CDD) is a relatively common malformation and results in neonatal death in over 50% of affected infants [Harrison and de Lorimier, 1981]. Although most cases are sporadic, familial aggregation occurs, and controversy exists as to whether this is a "multifactorial" or autosomal recessive trait. Statistical genetic analysis of affected families has not been reported. We report on two new families with multiple occurrence of CDD. In one of the families, the lesion was detected in the fetus by ultrasound at 14 weeks, the earliest reported prenatal diagnosis of CDD. Segregation analysis of our data and of 17 additional multiplex families from the literature led to the conclusion that the autosomal recessive hypothesis cannot be rejected. Multifactorial determination is rejected by the data. The analyses are complicated by several factors, including phenotypic variability, probable genetic heterogeneity, and inadequate description of defects and studies of first-degree relatives. Recurrence risk figures based on a model of multifactorial determination give an underestimate of risk in multiplex families and should not be used until the major gene model is rejected or heterogeneity is clearly demonstrated.

Prosthetic materials and muscle flaps in the repair of extensive diaphragmatic defects: an experimental study

Relative merits of three methods of diaphragmatic hernia repair were evaluated in growing animals. Twenty-five puppies underwent laparotomy. In four controls, the left hemidiaphragm was incised and sutured primarily. In the remaining dogs, it was partially resected sparing the phrenic nerve. The defects were repaired in six with silastic sheeting, in eight with polytetrafluoroethylene (PTFE; trademark, Gore-Tex), and in seven with a thoracoabdominal muscle flap. Dogs were killed at 1, 4, and 7 months for gross and microscopic evaluation of the repair. Diaphragmatic function was evaluated by inspiratory force against a closed airway and by selective phrenic nerve stimulation (PNS). Serial fluoroscopy was used to evaluate diaphragmatic motion. Grossly the diaphragms in all groups showed compensatory growth. Microscopically the silastic was encapsulated without adherence, while PTFE showed tissue ingrowth. Maximal inspiratory force was equivalent in all groups but selective PNS revealed left-sided impairment in all experimental groups. Fluoroscopy showed paradoxical motion of the diaphragm in the muscle flap group for 1 to 2 months, and in the silastic repair group for 2 to 3 weeks, with near normal motion in the PTFE group for the entire postoperative period. These differences disappeared by 6 months. Prosthetic materials or muscle flaps are all safe for repair of large diaphragmatic hernias. Diaphragmatic growth occurs and the prosthesis remains in place. Physiologic impairment is minimal and not of clinical importance. Use of PTFE may be the preferred method as it develops better tissue incorporation and results in more normal diaphragmatic motion in the critical early postoperative period.

Familial congenital diaphragmatic defects: aspects of etiology, prenatal diagnosis, and treatment

We present 14 familial cases from five Finnish families affected with a life-threatening congenital diaphragmatic defect (CDD) and review data on 53 previously published familial cases. CDD occurred in three sibs and their half brother's son, and probably in all four offspring of parents consanguineous as both first and second cousins. In the remaining three Finnish families and in the vast majority of the previously reported familial cases, only two sibs were affected. Two thirds of those affected were males both in the Finnish and the overall series. Pedigree data, delayed fusion of the diaphragm as the primary pathogenetic mechanism, varying anatomical structure of the defective hemidiaphragm, association with other congenital anomalies, and data on animal experiments are more in accordance with multifactorial determination than with recessive inheritance. This does not exclude other genetic causes in some familial cases. The recurrence risk for sibs after one affected sib is about 2%. As the prognosis, especially in familial cases of CDD has remained grave, the development of fetal surgical treatment is desirable. This emphasizes the future role of prenatal diagnosis by ultrasound.