Agenesis of the right diaphragm: repaired with marlex

Newly designed bioabsorbable substitute for the treatment of diaphragmatic defects

PURPOSE

Earlier studies have investigated the suitability of various materials and autologous grafts for the repair of diaphragmatic defects. Our group investigated the feasibility of using an artificial diaphragm (AD) to repair wide diaphragmatic defects.

METHODS

Twelve pigs were laparotomized and, in each pig, a defect was fashioned by resecting a round 8-cm diameter hole in the left diaphragm. Next, the defect was repaired by implanting an AD. The animals were relaparotomized 8 or 24 weeks after implantation for gross, histological and radiological observation of the implanted sites.

RESULTS

All recipient animals survived until killing for evaluation. Chest X-ray examinations showed no differences between the preoperative diaphragms and the grafted diaphragms at 8 and 24 weeks after implantation. At 8 weeks after implantation, the implanted sites exhibited fibrous adhesions to the liver and lungs without deformities or penetrations. Parts of the surface tissue at the graft sites had a varnished appearance similar to those of the native diaphragm. Histology performed at 8 weeks detected no trace of the ADs in the graft sites; however, numerous inflammatory cells and profuse fibrous connective tissue were observed. At 24 weeks after implantation, no differences were found in the thorax between the areas with the grafts and the unaffected areas. Histology of the graft sites in the thorax confirmed growth of mesothelial cells similar to that observed in the native diaphragm.

CONCLUSIONS

Artificial diaphragms can be a novel substitute for diaphragmatic repair.

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.

Permacol: a potential biologic patch alternative in congenital diaphragmatic hernia repair

PURPOSE

Recurrence is a well-known complication after patch repair of congenital diaphragmatic hernia (CDH). We propose that a newer, "bioprosthetic" material may lower recurrence rates. The purpose of this study is to compare outcomes of CDH repair with synthetic Gore-Tex (W. L. Gore and Associates, Neward, Del) to the bioprosthetic Permacol (Tissue Science Laboratories Inc, Andover, Mass).

METHODS

We performed a retrospective review of 100 consecutive patients with CDH with survival more than 30 days at Children's Medical Center of Dallas (Dallas, Tex) from 1999 to 2007. The incidence and timing of recurrence, as well as comorbidities were assessed.

RESULTS

Primary repair was performed in 63 patients and patch repair in 37, divided between Gore-Tex (29) and Permacol (8). Overall recurrences were as follows: 1 (2%), 8 (28%), and 0 in the primary, Gore-Tex, and Permacol groups, respectively. Median follow-up was 57 months for Gore-Tex and 20 months for Permacol. Median time to recurrence in the Gore-Tex group was 12 months, with no Permacol recurrences. Both the Gore-Tex and Permacol groups had similar comorbidities, including prematurity, congenital heart disease (76% and 63%, respectively), and the need for extracorporeal membrane oxygenation support (38% and 25%).

CONCLUSION

Our results suggest that Permacol may have lower recurrence rates compared to Gore-Tex and is a promising alternative biologic graft for CDH repair.

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.

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.

Abdominal muscle flap repair for large defects of the diaphragm

Repair of a large diaphragmatic defect in congenital diaphragmatic hernia (CDH) and eventration of the diaphragm (DE) is difficult, especially when this is an unexpected finding at surgery. A patch of synthetic material may not be available at short notice, especially in developing countries. We describe the repair of nine such defects by using an abdominal muscle flap comprising the transversus abdominis and internal oblique muscles based on the intercostal and subcostal vessels. Although reports of similar flap repairs have been published in the literature [1-5], these employed a subcostal incision for abdominal entry, which we believe jeopardizes the flap's vascularity. Thus, we prefer to use an upper abdominal midline incision for abdominal entry in all cases of CDH and DE.

Evaluation of small intestine submucosa and acellular dermis as diaphragmatic prostheses

BACKGROUND/PURPOSE

The repair of large congenital diaphragmatic defects in the neonate continues to be a challenge. Polytetrafluoroethylene (PTFE) is the synthetic material most widely used for reconstruction in instances of partial and complete diaphragmatic agenesis. Recurrent hernia is a frequent complication, because this material does not grow with the infant. This study evaluates two novel materials; small intestine submucosa (SIS; Cook Biotech, Lafayette, IN), and acellular dermis (AlloDerm; Lifecell Corp, The Woodland, TX) for diaphragm reconstruction in growing animals.

METHODS

Sprague-Dawley rats (100 g, n = 87) were anesthetized and underwent laparotomy. The control group (n = 18) underwent a sham laparotomy with a left subcostal incision and closure. The other two groups underwent central excision of the left hemidiaphragm (50% loss) and reconstruction with either a SIS (n = 35) or AlloDerm (n = 19) patch sutured circumferentially with 6-0 prolene. Seventy-two animals survived the operation, and were killed at five separate time intervals (2 weeks, 1, 2, 3, and 4 months). Chest radiographs were performed monthly and before death. Radiographs were reviewed in a blinded fashion by two observers as were the necropsies, and rib deformity was noted if present. Histological examination of the diaphragm patch was performed in each animal.

RESULTS

There was no evidence of rib deformity noted on gross examination at necropsy or on chest radiograph in either experimental group. At necropsy, all patches were intact without hernia, eventration, or contraction. Histology findings initially showed acute and chronic inflammatory changes in both patch materials that lessened at the 2-month time interval. Both prosthetic patches began to thin at 3 months and was most prominent in the SIS rats. At 4 months, both SIS and AlloDerm remained viable without evidence of necrosis. Each patch showed evidence of fibroblastic incorporation and small capillary ingrowth. These changes were more prominent in the AlloDerm group. There was no evidence of skeletal muscle ingrowth.

CONCLUSIONS

These data indicate SIS and AlloDerm may be useful materials for prosthetic repair in instances of partial or total agenesis of the diaphragm. Further investigation in a large animal model over a longer duration is indicated.

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)

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.

Unusual varieties of diaphragmatic herniae

Unusual varieties of diaphragmatic herniae can be classified into two major groups, congenital and acquired. The late-presenting Bochdalek herniae often present difficulties in diagnosis which may lead to inappropriate treatment. The prime example is the herniated stomach, which is mistaken for a tension pneumothorax. Strangulation is a rare, but an important, complication of Bochdalek herniae. A number of techniques for closure of large diaphragmatic defects are described with recommendation of those procedures which can be performed rapidly and effectively in a critically ill infant. The literature concerning eventration is confusing due to different definitions of the condition by different authors. It may be difficult to distinguish preoperatively between this condition and congenital diaphragmatic hernia with a sac. Such distinction is often not important as the decision for intervention is based on evaluation of clinical and radiological considerations. The majority of Morgagni herniae are asymptomatic and only rarely does strangulation supervene. There is a small group of infants with Morgagni hernias who present in early infancy with respiratory symptoms. Paralysis of the diaphragm due to phrenic nerve palsy recovers spontaneously in the majority of patients. The selective use of diaphragmatic plication for this condition is widely accepted, but the decision and appropriate timing for surgical intervention is often difficult. The results of surgery are very good both in the early postoperative period and also on long-term follow-up. The diagnosis of traumatic diaphragmatic hernia is often overlooked in the presence of other major injuries. The danger of strangulation of contents of this hernia is ever present and repair should be undertaken without delay once the diagnosis is made.

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.

The reverse latissimus dorsi flap for congenital diaphragmatic hernia repair

The reverse latissimus dorsi muscle flap was successfully used for the repair of recurrent congenital diaphragmatic hernia in three neonates. This muscle flap can be rapidly raised on a reliable blood supply, and provides sufficient vascularized tissue to replace the whole hemidiaphragm without tension. It should be considered at the first reparative operation when insufficient tissue is available for safe repair by direct suture.

Agenesis of the left diaphragm: surgical repair and physiologic consequences

Agenesis of the hemidiaphragm is an unusual congenital anomaly associated with a high mortality. This paper presents the fourth patient to survive the neonatal period with agenesis of the hemidiaphragm. He was an identical twin, weighing 1.5 kg and his clinical course was characterized by ipsilateral pulmonary hypoplasia, large alveolar-arterial gradient for oxygen, persistent fetal circulatory pattern and ventilator dependence. These abnormalities suggest a pathophysiology similar to that observed in patients with Bochdalek hernia. The surgical correction, postoperative care and observation of pulmonary function following repair of agenesis of the left diaphragm are described.