Effect of hospital case volume on outcome in congenital diaphragmatic hernia: the experience of the Canadian Pediatric Surgery Network

Purpose

Despite advances in neonatal care of congenital diaphragmatic hernia (CDH), a significant variation exists in the mortality rates reported by individual centers. Center experience (reflected by case volume) may contribute to this variation in outcome. The aim of the study was to determine whether CDH mortality is affected by hospital case volume.

Methods

The CDH cases were abstracted from a disease-specific, 16-hospital, national network. Thirteen hospitals participated in this study. Anonymized hospitals were categorized as either high (>6 cases) or low-volume (≤6 cases) centers (HVC, n = 6; LVC, n = 7) according to the median case number per center. Risk-adjusted (Score for Neonatal Acute Physiology, version II [SNAP-II] score) mortality rates were compared between HVC and LVC.

Results

One hundred twenty-one CDH cases were identified. Overall in-hospital survival was 81%. No significant difference in SNAP-II score was observed between HVC and LVC. Of 97 (15%) infants treated in 6 HVC, 15 (15%) died compared to 8 (33%) of 24 in 7 LVC (P < .05).

Conclusion

Hospital case volume may be partially responsible for mortality rate variation in CDH. This result requires careful analysis, as case volume may merely be a surrogate for other predictive variables.     

Neonatal thoracoscopic repair of congenital diaphragmatic hernia: selection criteria for successful outcome

Background/Purpose

Complications of open conversion, hypercarbia, and intestinal injury have plagued minimally invasive approaches to congenital diaphragmatic hernia (CDH) repair in neonates. To safely begin using minimally invasive techniques for neonatal CDH repair, we formulated preoperative selection criteria and operative techniques that would enhance chances for successful thoracoscopic primary diaphragm repair and uncomplicated outcome.

Methods

During the period from January 2003 to October 2004, neonates were selected for thoracoscopic CDH repair using anatomic and physiologic criteria. Anatomically, all patients were required to have stomach in the abdomen by radiography. Physiologically, all patients were required to be on minimal ventilator support with preoperative ventilator peak inspiratory pressures in the low 20s mm Hg. No patient could have clinical evidence of pulmonary hypertension at the time of surgery. Thoracoscopic CDH repair was performed using 3 trocars (3 and 5 mm). The hernia contents were reduced into the abdomen using 5-mm Hg insufflation, and the diaphragms were repaired primarily using interrupted 3-0 Ethibond simple sutures (Ethicon, Inc, Piscataway, NJ). Posterolateral diaphragm stitches were passed around the posterolateral ribs and tied extracorporeally.

Results

Thirty neonates with CDH were admitted to Children's Hospital Boston and Vanderbilt Children's Hospital during the study period. Eight patients (27%) met selection criteria and 7 underwent thoracoscopic CDH repair. Primary diaphragmatic repair was successfully accomplished thoracoscopically in all neonates without perioperative complication. Preoperative anatomic criteria correlated accurately with intact esophageal hiatus and primary diaphragm repair. Physiologically, each patient tolerated intrathoracic insufflation and CDH repair without clinical pulmonary hypertension or blood pressure lability. Three patients had intraoperative respiratory acidosis that was reversed with ventilator changes. Operative times averaged 152 minutes and ranged from 212 to 106 minutes. Postoperative mechanical ventilation ranged from 0 to 7 days, and the length of hospitalization ranged from 5 to 32 days. Longest follow-up has been 17 months. One patient required reoperation for recurrent CDH at 10 months after repair, but there have been no other long-term complications.

Conclusions

Neonatal thoracoscopic CDH repair is safe in selected patients who have good preoperative pulmonary function and anatomy amenable to primary diaphragmatic repair. A wider range of neonates may be acceptable for thoracoscopic CDH repair with increasing surgical experience.     

Late-onset congenital diaphragmatic hernia: A case report

INTRODUCTIONA Bochdalek hernia is a posterior congenital defect of the diaphragm, usually on the left hemidiafragm, caused by a lack of closure of the pleuroperitoneal canal between the eighth and tenth week of fetal life during the embryonic development. It typically presents in the neonatal period with severe respiratory failure.PRESENTATION OF CASEIn this paper we present a 35 year old man with a 5-year history of episodes of severe dyspnea who arrived to the emergency room, during his medical work-up we incidentally found an intrathoracic gastric bubble, a laparoscopy was performed, founding a necrotic stomach and for defect correction.DISCUSSIONThis pathology is infrequent in adults, among this age group, there are two different clinical presentations: asymptomatic patients who are diagnosed incidentally when abdominal organs are found in the thorax in a chest X-ray, and symptomatic patients due to side effects of incarceration, strangulation, hemorrhage and visceral perforation in the chest cavity.CONCLUSIONDiaphragmatic hernias are rare among adult population, and they are usually asymptomatic, in this case we presented a symptomatic patient, diagnosed with a chest X-ray and treated surgically. The surgical approach for the resolution of this pathology is variable and it depends on the presence and severity of visceral complications.     

Thoracoscopic repair in congenital diaphragmatic hernia: patching is safe and reduces the recurrence rate

Purpose

Congenital diaphragmatic hernia (CDH) has traditionally been repaired via a laparotomy. More and more reports on thoracoscopic repair are being published. The aim of this study was to evaluate our series of thoracoscopic CDH repair and compare this group to an open repair group treated during the same period in the same institute.

Patients and Methods

Between June 2006 and December 2008, 49 children with posterolateral CDH were admitted, of whom 23 (47%) were operated thoracoscopically and 23 (47%) using an open repair, depending on the discretion of the attending surgeon and the clinical condition of the patient. Three patients (6%) with CDH were not treated because of associated anomalies (twice Cornelia de Lange syndrome and once hypoplastic left heart syndrome). Six thoracoscopic operations (26%) were converted to open surgery. Nine defects (39%) were closed thoracoscopically without a patch. In 8 (35%) patients, a patch was used. We used a patch in 20 open procedures (87%).

Results

Three (33%) of the 9 thoracoscopic repairs without patch and 1 (12%) of the 8 with a patch developed a recurrence. All these recurrences were repaired thoracoscopically. The 3 recurrences from the thoracoscopic primary repair were repaired using a patch. In the open group, 3 patients (13%) developed a recurrence, of whom 2 were repaired thoracoscopically.Mean operative time was significantly longer in the thoracoscopic patch repair group (158 minutes), when compared to the open repair group (125 minutes).

Conclusion

As in open repair, it seems wise to use large patches liberally, not only to reconstruct the dome of the diaphragm but also to avoid undue tension on the repair and prevent recurrences. The thoracoscopic approach is also considered feasible in case of a recurrence from either a thoracoscopic or open repair.     

Bilateral congenital anterior diaphragmatic hernia: a case report

The anteromedial diaphragmatic hernias of Morgagni and Larrey are the least common defects that occur in this organ. Simultaneous occurrence has been described but remains an absolute rarity. We herein present a case of this bilateral herniation with a unique presentation. The paper refers to the basic anatomic, diagnostic and therapeutic considerations for this entity.     

Laparoscopic repair of late presenting congenital diaphragmatic hernia

Congenital diaphragmatic hernia usually presents in the neonatal period, with delayed presentation being uncommon. Traditionally repair was performed by laparotomy or thoracotomy. We have performed laparoscopic repair of a previously undiagnosed congenital diaphragmatic hernia that presented acutely in a 10-year-old male. Laparoscopic repair of late-presenting congenital diaphragmatic hernia is a safe and effective approach even in an emergency. The laparoscopic approach has advantages including reduced hospital stay, excellent visualisation of the defect even for obese patients, and improved cosmesis.     

Predictors of outcome in patients with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation

Background

The role of extracorporeal membrane oxygenation (ECMO) in patients with congenital diaphragmatic hernia is still evolving. The use of ECMO is invasive with potential complications during instrumentation for cannulation and heparinization. There are no reliable predictors of outcome in patients requiring ECMO. We aimed to identify (a) the factors that could predict outcome and (b) the incidence and relation of complications during ECMO to outcome.

Methods

“Pre” ECMO (age, sex, birth weight, blood gasses, and ventilator settings) and “on” ECMO variables (mode of ECMO, use of nitric oxide, surfactant, liquid ventilation, inotropes, timing of repair, and complications on ECMO) were analyzed to identify predictors of outcome.

Results

Fifty-two patients were included. The overall survival was 58%. Mean duration of ECMO (181 ± 120 vs 317 ± 156 hours, P = .001), use of nitric oxide (6 vs 10, P = .049), and renal complications (4 vs 14; P < .001) differed between survivors and nonsurvivors. The survival of patients requiring ECMO support for more than 2 weeks is significantly lower than that of patients requiring ECMO support for less than 2 weeks (18% vs 68%, P = .005). Multiple logistic regression revealed ECMO duration of 2 weeks or more and renal complications to be associated with mortality.

Conclusion

No pre-ECMO variable could be identified as predictor of mortality. Prolonged duration of ECMO and renal complications on ECMO were independently associated with mortality.     

Laparoscopic repair of congenital diaphragmatic hernia with prosthesis: a case report

We report here our experience in the treatment of a large congenital diaphragmatic hernia, an uncommon pathology, approachable by laparoscopy. The patient was a 33-year-old woman with trisomy 21 syndrome, who only complained of colicky abdominal pain and a cough for 7 months before the hospitalization. Thoracic and abdominal CT scans showed a large anteromedial diaphragmatic hernia with slippage of the colon into the mediastinum and posterior displacement of the cardiovascular structures. The patient underwent laparoscopic repair of the hernia. The colon was put back in the abdomen; the defect (8×4 cm) was repaired by a Composix mesh (PTFE-polypropylene), fixed to the diaphragm by nonabsorbable stitches and staples. The patient was discharged on the third postoperative day. The postoperative course was uneventful. Follow-up at 18 months didn't show any complications or recurrence. We believe laparoscopic repair of diaphragmatic hernia to be the elective surgical choice, because of its technical feasibility and certain intra- and postoperative advantages. Electronic Publication     

Survival of severe congenital diaphragmatic hernia has morbid consequences

Background/Purpose

Fetal tracheal occlusion (TO) was developed in an attempt to enhance prenatal lung growth and improve survival in fetuses with severe congenital diaphragmatic hernia (CDH). We conducted a randomized, controlled clinical trial in 24 fetuses with severe left CDH (liver herniated into the thorax and low lung-to-head ratio) to compare survival after endoscopic fetal TO vs standard perinatal care (control) and prospectively followed up the 16 survivors (9 control, 7 TO) to compare neurodevelopmental, respiratory, surgical, growth, and nutritional outcomes.

Methods

At 1 and 2 years old, subjects underwent evaluation consisting of medical and neurological history and physical, developmental testing, nutritional assessment, oxygen saturation and pulmonary function testing, chest radiograph, and echocardiogram. Growth and developmental measures were corrected for prematurity. Data were analyzed by Mann-Whitney rank sum test, Fisher's Exact test, and logistic and linear regression.

Results

Infants with TO were significantly more premature at birth (control vs TO, 37.4 ± 1.0 vs 31.1 ± 1.7 weeks; P < .01). Growth failure (z score for weight <2 SDs below mean) was severe in both groups at 1 year of age (control vs TO, 56% vs 86%; P = .31). There was considerable catch-up growth by age 2 years (growth failure: control vs TO, 22% vs 33%; P = .19). There were no differences in other growth parameters. There were also no differences in neurodevelopmental outcome at 1 and 2 years. Supplemental oxygen at hospital discharge was a significant predictor of worse neurodevelopmental outcome at 1 and 2 years old (P = .05 and P = .02, respectively). Hearing loss requiring amplification has been diagnosed in 44% of the group (control vs TO, 44% vs 43%; P = 1.0).

Conclusions

In this group of infants with severe CDH, there were no differences in outcome at 2 years old despite significant prematurity in the TO group. Oxygen supplementation at hospital discharge identified the most vulnerable group with respect to neurodevelopmental outcome, but all infants had significant growth failure, and hearing impairment is a substantial problem in this population. Severe CDH carries significant risk of chronic morbidity.     

Main bronchus occlusion for treatment of congenital diaphragmatic hernia in fetal lambs

Purpose

The present study investigates a new surgical approach in the treatment of left diaphragmatic hernia in fetal sheep. We postulated that unlike tracheal occlusion where both lungs are occluded, selective left main bronchus occlusion (LMBO) would accelerate growth of only the left lung, reduce left visceral herniation, and recover space in the both thoraces necessary for lung development.

Methods

Left-sided congenital diaphragmatic hernia (CDH) was surgically created in 8 fetal lambs at approximately 65 days of gestation; in 4 of these animals, LMBO was performed at approximately 118 days. Four sham-operated animals served as controls. Lambs were delivered by hysterotomy at 137 days. We measured lung-to-body weight ratios, alveolar surface area, septal wall thickness, and AE2 cell density in the left and right lungs.

Results

Left main bronchus occlusion increased (P < .05) left lung growth causing severe right mediastinal shift but failed to reduce herniated abdominal viscera in 3 of 4 lambs. Wet lung-to-body weight ratio in LMBO group was similar to that of the control group; however, this was achieved by overgrowth of left lung, whereas the right wet lung-to-body weight ratio remained low. In the LMBO group, right lung AE2 cell density was higher than that of control group and not different to that of the CDH group.

Conclusions

Left main bronchus occlusion failed to restore normal pulmonary development in CDH.     

Mortality prediction in congenital diaphragmatic hernia

Background

A validated risk stratification tool for congenital diaphragmatic hernia (CDH) is required for accurate outcomes analyses. Existing mortality-predictive models include those of the CDH Study Group (CDHSG) based on birth weight and 5-minute Apgar score, the Canadian Neonatal Network (CNN) based on gestational age and admission score in Score for Neonatal Acute Physiology version II, and the Wilford Hall/Santa Rosa clinical prediction formula (WHSR_PF) derived from blood gas measurements. The purpose of this study was to evaluate the calibration and discrimination of these predictive models using the Canadian Pediatric Surgical Network dataset.

Methods

Neonatal risk variables and birth hospital survivorship were collected prospectively in 11 perinatal centers, between May 2005 and October 2006. Actual vs predicted outcomes were analyzed for each equation to measure the calibration and discrimination of each model.

Results

Twenty (21.2%) of 94 infants with CDH died during birth hospitalization. The CDHSG model demonstrated superior discrimination (area under the receiver operator characteristic curve = 0.85; CNN = 0.79; WHSR_PF = 0.63). Model calibration reflected by the Hosmer-Lemeshow P value was poorest with the WHSR_PF = 0.37 and comparable between CDHSG and CNN (0.48 and 0.46, respectively).

Conclusion

Predictive outcome models are essential for risk-adjusted outcome analysis of CDH. The ideal predictive equation should prove robust across CDH datasets.     

Intrapericardial diaphragmatic hernia: a rare type of congenital diaphragmatic hernia

An extremely rare case of congenital intrapericardial diaphragmatic hernia is presented. Since 1981, only 14 cases have been reported in the literature. A 5-year-old girl presented with dyspnea on exertion and easy fatigability. Computed tomography was suggestive of an anterior diaphragmatic hernia. Laparoscopy followed by successful open repair of hernia was performed.     

Right congenital diaphragmatic hernia: Prenatal assessment and outcome

Purpose

To understand the natural history of right congenital diaphragmatic hernia (CDH), the authors retrospectively reviewed 27 cases of right CDH that presented for prenatal evaluation or postnatal treatment.

Methods

Between 1995 and September 2002, a total of 194 cases of fetal CDH were evaluated and included 22 right-sided defects. The authors reviewed prenatal diagnostic studies (ultrasound scan, magnetic resonance imaging [MRI] echocardiography) and pre- and postnatal outcomes in these 22 cases of right CDH. Five additional cases of right CDH without a prenatal diagnosis were reviewed.

Results

The mean gestational age at evaluation was 26.1 weeks. The lung area to head circumference ratio (LHR) ranged from 0.32 to 2.5. In all cases, the fetal liver was herniated into the right chest. Associated anomalies were common. There were no karyotype abnormalities (17 of 22 tested). There were 4 terminations. Nine of the 18 (50%) continuing pregnancies had polyhydramnios, premature rupture of membranes, or preterm labor. The mean gestational age at birth was 36.8 weeks. One patient underwent tracheal occlusion at 27 weeks, and 2 patients died before postnatal repair. Overall survival rate (22 prenatal plus 5 postnatal diagnoses) was 19 of 27 (70%). Postnatal survival rate was 19 of 23 (83%). A Gore-tex (W. L. Gore and Associates, Flagstaff, AZ) patch was utilized in 14 of 21 neonates undergoing surgery. Twelve of 23 (52%) required extracorporeal membrane oxygenation (ECMO) with a 75% survival rate. Significant morbidity occurred in 10 of 19 survivors and included neurologic sequelae in 6 of 19 (32%).

Conclusions

MRI was helpful in the determination of liver position and confirmation of diagnosis. The high incidence of preterm complications, frequent need for ECMO, and high prevalence of comorbidities are indicative of the severity of this CDH population and warrant close prenatal surveillance and delivery at a tertiary care center with ECMO capability.     

Successful thoracoscopic staged repair of bilateral congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) occurs in 1 of every 2000 to 3000 live births and accounts for 8% of all major congenital anomalies. Bilateral hernias account for no more than 1% of all types of CDH; furthermore, they are usually fatal prenatally. Those that survive are identified through a limited number of case reports. We are presenting an unusual case of bilateral CDH hernia in a neonate that was repaired successfully using a staged thoracoscopic approach. To our knowledge, this represents the first case in the world literature of bilateral CDH that was repaired thoracoscopically. In carefully selected patients, appropriate use of disruptive new technologies such as thoracoscopy can be achieved.     

Right congenital diaphragmatic hernia: an 18-year experience

Background

Prenatal diagnosis and outcome of right congenital diaphragmatic hernia (RCDH) are far less well known than the more common left CDH (LCDH). In addition, onset of RCDH beyond the neonatal period with a spectrum of atypical symptoms is not unusual. A retrospective analysis of RCDH treated at a single center over 18 years has been reviewed with regard to outcome after the introduction of a new treatment protocol for CDH.

Methods

All charts of patients with CDH between 1987 and 2004 were reviewed. Twenty-nine patients with RCDH were identified. The patients were divided into 2 historical groups: group 1, from 1987 to 1998 (16 patients), and group 2, from 1999 to 2004 (13 patients). From 1999, at the Department of Pediatric Surgery of Padua, the management of a baby born with CDH has been standardized and includes planned delivery at term, high-frequency oscillatory ventilation since birth, inhaled nitric oxide if required, extracorporeal membrane oxygenation as a “last resort,” and delayed repair once the infant is hemodynamically stable. Patients with either prenatal diagnosis of RCDH or early onset of symptoms (<6 hours of life) were considered “high risk,” and those with late onset (>6 hours) were considered “low risk.”

Results

Of 29 patients, prenatal diagnosis was available in 8 (27.5%) and major associated malformations in 8 patients (27.5%). Eight (50%) of 16 cases from group 1 and 9 (69.2%) of 13 cases from group 2 were high-risk patients. There was a trend in favor of a higher survival among high-risk patients from group 2 (25% vs 44%), although this was not statistically significant. As expected, all low-risk patients survived (P = .0001). Plain thorax x-ray was diagnostic in 23 (82.1%) cases, initially normal in 3, not performed in 1, and misinterpreted as right lower lobe pneumonia in 2. At operation, the prosthetic patch was required in 2 (9%) of 22 cases and the peritoneal sac was found in 4 (13.7%).

Conclusions

(1) The rate of prenatal diagnosis of RCDH was low and remained stable throughout the examined period. (2) The introduction of a treatment protocol, using high-frequency oscillatory ventilation since birth, improved the survival of high-risk patients with RCDH, although the data did not reach statistical significance. (3) The majority (75%) of low-risk patients presented beyond the first week of life with a variety of aspecific gastrointestinal or respiratory symptoms that accounted for initial misdiagnosis. (4) Even in these cases, the outcome was excellent.     

Creation and repair of diaphragmatic hernia in the fetal lamb: techniques and survival

Diaphragmatic hernias were created in 54 fetal lambs at 72 to 82 days gestation via a left thoracotomy. The diaphragmatic hernia was repaired in 30 lambs at 106 to 123 days gestation, and 14 of these lambs subsequently aborted. The majority of those surviving to term were delivered for survival. Four lambs with an unrepaired diaphragmatic hernia were intensively resuscitated at delivery and their diaphragmatic hernias repaired; survival in these lambs ranged from 20 minutes to 89 hours. Nine lambs with repaired diaphragmatic hernia were resuscitated following delivery; survival times ranged from one hour, 45 minutes to 123 days, with three lambs surviving to be sacrificed at 43, 62, and 123 days. Three of the lambs that died before sacrifice, died of causes unrelated to their lung function. These results show that in-utero repair of the diaphragmatic hernia in the fetal lamb results in improved survival. We feel, however, that direct application of these results in humans would be premature.     

Bronchopulmonary innervation defects in infants and rats with congenital diaphragmatic hernia

Introduction

Pulmonary morbidity in survivors of congenital diaphragmatic hernia (CDH) is caused by hypoplasia, barotraumas, or other reasons. We have previously shown deficient tracheal innervation in rats with CDH. Now we examine whether bronchopulmonary innervation is also abnormal in both infants and rats with CDH.

Material and Methods

Sections of E15, E18, and E21 rat lungs were immunostained for Protein gene product 9.5 and S100 antibodies. Similar immunostaining was performed on tissue from infants dying from CDH (n = 6) and other causes (n = 6) with Neurofilament, S100, and Rearranged during transfection antibodies. Nerve trunks/bronchus were counted, and the proportion of glial and RET-positive cells/bronchial surface was calculated. Glial cell-line derived neurotrophic factor protein and mRNA were measured in rat lungs.

Results

Nerve trunks/bronchus were decreased in infants and rat fetuses with CDH. In contrast, glial and RET-positive cells/bronchial surface were increased in infants and rats with CDH. Both lungs were equally affected. GDNF protein was high, whereas GDNF mRNA was decreased in preterm animals with CDH.

Conclusions

The lungs of infants and rats with CDH have decreased neural components compensated by increased supporting glial cells and persistence high expression of RET and GDNF protein. Because bronchopulmonary innervation controls airway smooth muscle, vessels, and glandular secretions, it is tempting to hypothesize that these deficiencies might play a role in respiratory morbidity in CDH.     

Abnormal intrinsic esophageal innervation in congenital diaphragmatic hernia: a likely cause of motor dysfunction

Purpose

Patients with congenital diaphragmatic hernia (CDH) often have dilated esophagus and gastroesophageal reflux. Sparse intrinsic esophageal innervation has been described in rats with CDH, but this issue has not been investigated in patients with CDH. The present study tests the hypothesis that innervatory anomalies could account for motor dysfunction in human CDH.

Methods

The esophagi of CDH (n = 6) and control babies dead of other causes (n = 6) were included in paraffin, transversally sectioned, and immunostained with antineurofilament and anti-S-100 antibodies. The proportion of the section surface occupied by neural structures, the ganglionar surface, and the number of neurons per ganglion were measured in 2 to 5 low-power fields from the proximal and distal esophagus with the assistance of image analysis software. Mann-Whitney tests were used for comparing the results using a threshold of significance of P < .05.

Results

The percentage of neural/muscle surface was similar in the upper esophagus in both groups, but it was significantly decreased in the lower esophagus of patients with CDH in comparison with controls. There was a relative scarcity of neural tissue in the intermuscular plexus of the lower esophagus. On the other hand, the ganglionar surface and the number of neurons per ganglion were identical in both groups. These results were similar with both immunostainings.

Conclusion

Intrinsic innervation of the lower esophagus in CDH is abnormal in terms of decreased density of neural structures in the intermuscular plexus. These neural crest-derived anomalies could explain in part the esophageal dysfunction in survivors of CDH.