Unilateral agenesis of the diaphragm

Congenital diaphragmatic hernia: review of current concept in surgical management

CONGENITAL DIAPHRAGMATIC HERNIAS (CDHS) OCCUR MAINLY IN TWO LOCATIONS: the foramen of Morgagni and the more common type involving the foramen of Bochdalek. Hiatal hernia and paraesophageal hernia have also been described as other forms of CDH. Pulmonary hypertension and pulmonary hypoplasia have been recognized as the two most important factors in the pathophysiology of congenital diaphragmatic hernia. Advances in surgical management include delayed surgical approach that enables preoperative stabilization, introduction of fetal intervention due to improved prenatal diagnosis, the introduction of minimal invasive surgery, in addition to the standard open repair, and the use of improved prosthetic devices for closure.

Bilateral diaphragmatic defect and associated multiple anomalies

Although congenital diaphragmatic hernia is one of the most common congenital anomalies, complete bilateral agenesis of the diaphragm is a very rare congenital malformation and frequently associated with other major anomalies. We report a case of bilateral diaphragmatic agenesis associated with major congenital anomalies. A 2,240-g male infant was born at 35 weeks of gestation to a 34-year-old mother with a history of minimal prenatal care. Polyhydramnios was reported on prenatal level 1 scan. The patient experienced early respiratory distress requiring intubation. Apgar scores were 2/1/1 at 1, 5 and 20 minutes, respectively, and efforts to resuscitate him were unsuccessful. He died at 2 hours of age. Autopsy revealed bilateral diaphragmatic agenesis associated with right pulmonary hypoplasia, left pulmonary agenesis, multiple cardiac abnormalities and gallbladder agenesis. Cytogenetic studies showed normal male karyotype. Bilateral agenesis of the diaphragm is a life-threatening malformation. Survival of these infants often depends on cardiopulmonary function. Bilateral agenesis of the diaphragm associated with gallbladder and unilateral pulmonary agenesis is a rare entity, and its clinical significance needs further investigation.

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.

Adverse outcome of congenital diaphragmatic hernia is determined by diaphragmatic agenesis, not by antenatal diagnosis

BACKGROUND/PURPOSE

The authors studied their congenital diaphragmatic hernia (CDH) cases retrospectively to ascertain if classical CDH and diaphragmatic agenesis (DA) have separate clinical manifestations, whether antenatally diagnosed cases behave differently from those not diagnosed antenatally, and if antenatal diagnosis before 25 weeks carries a worse prognosis.

METHODS

The authors performed a retrospective review of 23 infants with CDH treated at their institution between January 1996 and March 1999. The patients were divided into 3 groups that were analyzed: DA and classical CDH, antenatally diagnosed and nonantenatally diagnosed, and antenatally diagnosed before 25 weeks and after 25 weeks.

RESULTS

There were 8 cases of DA and 11 cases of classical CDH. Four infants died without operation and could not be classified. Neonates with DA had significantly longer mean duration of preoperative stabilization compared with classical CDH (5.25+/-2.76 days v 1.36+/-1.0 days) and postoperative mechanical ventilatory support (15.7+/-3.0 days v 4.9+/-3.0 days). Fifty percent of DA patients died; all classical CDH patients survived. Twelve cases were diagnosed antenatally, 6 before 25 weeks' gestation. Antenatally diagnosed cases had no statistically significant difference in mortality rates from those not diagnosed antenatally; 50% of those diagnosed before 25 weeks survived.

CONCLUSIONS

DA cases require more preoperative preparation and postoperative ventilation and have a bad prognosis compared with classical CDH. Antenatal diagnosis of CDH does not convey a different prognosis. Fifty percent of CDH patients with antenatal diagnosis before 25 weeks survive.

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.

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.

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.

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.

Incidence and management of gastroesophageal reflux after repair of congenital diaphragmatic hernia

During a period of 6 years, 31 of 54 infants with congenital diaphragmatic hernia survived and were evaluated to study incidence and management of gastroesophageal reflux. At 6 months' follow-up 16 patients had gastroesophageal reflux proven by upper gastrointestinal series; at 12 months' follow-up 11 patients. Three patients having gastroesophageal reflux did not respond to medical treatment and underwent Nissen fundoplication. We conclude that after successful treatment, congenital diaphragmatic hernia is likely to be complicated by gastroesophageal reflux. We could not define a predictive feature for gastroesophageal reflux in the individual patient surviving congenital diaphragmatic hernia.

Delayed surgery for congenital diaphragmatic hernia

Between January 1987 and December 1990, 67 neonates were treated for congenital diaphragmatic hernia, symptomatic within 6 h of birth. The mortality rate was 33 per cent. Preoperative stabilization was achieved in 47 patients, all of whom survived initial treatment, although two died later. Stabilization could not be achieved in 20 neonates, all of whom died within 3 days of birth, 18 without undergoing operation and two after early repair. Intensive resuscitation with controlled, delayed operation for congenital diaphragmatic hernia gives long-term results similar to those of urgent operative repair. This approach avoids operation in the majority of those who subsequently die.

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.