Pulmonary dysfunction after primary closure of an abdominal wall defect and its improvement with bronchodilators

Respiratory Support Strategies for Surgical Neonates: A Review

Neonates with congenital conditions which require surgical management frequently experience respiratory distress. This review discusses the management of pulmonary complications and the respiratory support strategies for four conditions: oesophageal atresia-tracheoesophageal fistula (OA-TOF), congenital diaphragmatic hernia (CDH), congenital lung malformations (CLM), and anterior abdominal wall defects (AWD). Mechanical ventilation techniques which can reduce the risk of ventilator-induced lung injury (VILI) are discussed, as well as the use of non-invasive respiratory support modes. While advances in perioperative respiratory support have improved outcomes in infants with OA-TOF, managing respiratory distress in premature OA-TOF neonates remains a challenge. In CDH infants, a randomised trial has suggested that conventional ventilation may improve outcomes compared to high-frequency ventilation. Echocardiographic assessment is essential in the management of CDH infants with pulmonary hypertension. Lung-protective ventilation settings may lower the rate of postoperative complications in symptomatic CLM infants, but there remains debate regarding the choice of expectant versus surgical management in neonates with asymptomatic CLMs. Infants with AWDs can require ventilation due to pulmonary hypoplasia, but the effects of this on their long-term respiratory health are poorly understood. As surgical techniques continue to evolve and novel ventilation techniques become available, prospective multi-centre studies will be required to define the optimal respiratory support strategies for neonatal surgical conditions that affect lung function.

Outcomes of patients with exomphalos and associated congenital heart diseases

INTRODUCTION

Exomphalos is an anterior abdominal wall defect resulting in herniation of contents into the umbilical cord. Severe associated chromosomal anomalies and congenital heart disease (CHD) are known to influence mortality, but it is not clear which cardiac anomalies have the greatest impact on survival.

METHODS

We performed a retrospective review of the treatment and outcome of patients with exomphalos over a 30-year period (1990-2020), with a focus on those with the combination of exomphalos major and major CHD (EMCHD).

RESULTS

There were 123 patients with exomphalos identified, 59 (48%) had exomphalos major (ExoMaj) (defect > 5 cm or containing liver), and 64 (52%) exomphalos minor (ExoMin). In the ExoMaj group; 17% had major CHD (10/59), M:F 28:31, 29% premature (< 37 weeks, 17/59) and 14% had low birth-weight (< 2.5 kg, 8/59). In the ExoMin group; 9% had major CHD (6/64), M:F 42:22, 18% premature and 10% had low birth-weight. The 5-year survival was 20% in the EMCHD group versus 90% in the ExoMaj with minor or no CHD [p < 0.0001]. Deaths in the EMCHD had mainly right heart anomalies and all of them required mechanical ventilation (MV) for pulmonary hypoplasia prior to cardiac intervention. In contrast, survivors did not require mechanical ventilation prior to cardiac intervention.

CONCLUSION

EMCHD is associated with high mortality. The most significant finding was high mortality in those with right heart anomalies in combination with pulmonary hypoplasia, especially if pre-intervention mechanical ventilation is required.

Predictors of long-term respiratory insufficiency of exomphalos major

INTRODUCTION

Exomphalos major (EM) is associated with significant morbidity and even mortality with an important risk of long-term pulmonary disease.

AIM

To assess the outcomes of exomphalos in a single tertiary pediatric unit and to identify prognostic factors for patients with respiratory insufficiency who still require ventilatory assistance at six months.

MATERIAL AND METHODS

All infants admitted to our institution over a 10-year period (2005 to 2015) with exomphalos were retrospectively reviewed. EM was defined when the abdominal wall defect measured >= 5 cm and/or contained liver within the sac. Data were collected on patient demographics, prenatal course and imaging, birth information, immediate and long-term outcomes. Those with long-term respiratory insufficiency were identified as the primary outcome and reviewed to assess prognostic factors. A p value of ≤0.05 was regarded as significant. Data are quoted as median(range).

RESULTS

A total of 46 infants were diagnosed with exomphalos during the study period, with most (n = 30, 65%) defined as exomphalos major. Respiratory complications occurred in 16 (35%) with 8 (50%) of these requiring long-term (≥6 months) mechanical ventilation and 5 (31%) required a tracheostomy. On univariate analysis, resuscitation at birth (p = 0.0004), birth weight <3000 g (p = 0.008), use of nitric oxide (p = 0.004), high frequency oscillatory ventilation (HFOV) (p = 0.001), pulmonary hypoplasia (p<0.0001) and pulmonary hypertension (PHTN) (p = 0.02) were significantly associated with respiratory insufficiency. The strongest predictive model for ventilation support at six months was resuscitation at birth in combination with PH (OR = 1.57). Five infants (11%) died at 5(1-122) days.

CONCLUSIONS

In patients with EM, the presence of pulmonary hypertension along with resuscitation at birth are the most important prognostic factors for long-term respiratory insufficiency. Acknowledgement of these factors allows for better parental counselling regarding respiratory outcomes.

[Tissue expansion in management of giant omphalocele parietal sequelae]

OBJECTIVE

According to major difficulty for the giant omphalocele management in the visceral reintegration and the parietal closure, many teams use currently conservative treatment by topical application. These techniques are suppliers of a covered eventration and a scar sequela requiring a complementary treatment. We report the place of the tissue expansion as complementary treatment.

PATIENTS AND METHODS

Two patients with a giant omphalocele benefited from a protocol of cutaneous expansion for the correction of their abdominal scar±of their residual eventration.

RESULTS

An eventration closure was possible thanks to this protocol. The skin expansion allowed the complete excision of the abdominal scar and the defect cover. An additional skin graft was necessary in the first case.

CONCLUSION

The cutaneous expansion in the parietal sequela management of the giant omphaloceles seems to be an interesting alternative. This technique should be realized remotely and except any septic context.

Topical treatment of major omphalocoele: Acacia nilotica versus povidone-iodine: A randomised controlled study

BACKGROUND

Conservative management for major omphalocoele with topical agents as escharotics therapy is well established in practice. Different agents have been used in the past, including mercurochrome and alcohol, proved later to be unsafe. The aim of this study is to evaluate the efficacy and safety of the application of Acacia nilotica paste compared to povidone-iodine solution as a primary non-surgical treatment of major omphalocoele.

PATIENTS AND METHODS

A double-blind, randomised study was conducted on 24 cases of major omphalocoele where they were randomly divided into two equal groups; Group A treated with topical application of A. nilotica paste and Group B treated with topical application of povidone-iodine solution. Cases with gastroschisis, ruptured major omphalocoele or minor omphalocoele were excluded from the study. The evaluating parameters were size of the fascial defect in cm, period of mechanical ventilation if needed, time required for full oral feeding tolerance, duration of hospital stay and any short- or long-term complications.

RESULTS

There was no statistical significant difference between both groups regarding their gestational or post-natal age, weight and the mean umbilical port defect. Patients from Group A tolerated full oral feeding earlier and had shorter total hospital stay duration than those from Group B, but without a statistical significant difference (P = 0.347 and 0.242, respectively). The overall mortality rate was 33.3% without a statistical significant difference between both groups (P = 0.667).

CONCLUSIONS

Application of A. nilotica is a safe and effective treatment of major omphalocoele as it was associated with rapid full enteral feeding tolerance, short duration of hospital stay and low mortality rate.

Pulmonary complications of abdominal wall defects

The abdominal wall is an integral component of the chest wall. Defects in the ventral abdominal wall alter respiratory mechanics and can impair diaphragm function. Congenital abdominal wall defects also are associated with abnormalities in lung growth and development that lead to pulmonary hypoplasia, pulmonary hypertension, and alterations in thoracic cage formation. Although infants with ventral abdominal wall defects can experience life-threatening pulmonary complications, older children typically experience a more benign respiratory course. Studies of lung and chest wall function in older children and adolescents with congenital abdominal wall defects are few; such investigations could provide strategies for improved respiratory performance, avoidance of respiratory morbidity, and enhanced exercise ability for these children.

Abdominal Wall Reconstruction Using De-epithelialized Dermal Flap: A New Technique

Background:

Although autogenous materials have been used in abdominal wall hernioplasty for a long time, the introduction of prosthetic materials diminished their popularity. However, these materials may be expensive, inappropriate or unavailable. The aim of this study is to determine the place of de-epithelialized dermal flap in the reconstruction of abdominal wall hernias.

Materials and Methods:

A five-year prospective, descriptive analysis of eligible patients with difficult abdominal wall hernias closed with de-epithelialized dermal flap in a Nigerian Tertiary Health Institution, from January 2001 to December 2005.

Results:

Over the five-year period, 37 patients were recruited into the study. There were 11 males and 26 females, giving a male: female ratio of 1: 2.4. The ages ranged from 8 months to 47 years (mean = 12.6 years). The defects consisted of 15 incisional hernias, 12 intermuscular/inferior lumbar hernias, nine healed exomphalos major and two giant umbilical hernias. The size of the hernia defects ranged from 4.5 cm to13cm (mean = 6.4 cm). Three patients had bowel resection and end-to-end anastomosis, in addition to the flap reconstruction. Morbidity was minimal and included skin dimpling in 11 patients, seroma in three, and wound infection in two patients. Neither recurrence of herniation nor mortality was recorded during the period of follow-up, which ranged from three months to 4.5 years (mean = nine months).

Conclusion:

The results suggest that this is a useful technique that can easily be applied in many centers with minimal resources. It is cheap, effective and associated with minimal morbidity.

Pulmonary effects of gastroschisis in a fetal rabbit model

Respiratory insufficiency is a significant cause of mortality and morbidity among infants with anterior abdominal wall defects (AWD). The aim of this study was to evaluate the pulmonary effects in a fetal rabbit model where gastroschisis was induced at midgestation. Gastroschisis (GAS) was created in 20 rabbit fetuses on day 22 or 23 of gestation (pseudoglandular phase; term = 31-32 days). The amniotic sacs of 13 fetuses were subjected to hysterotomy and amniotomy only (HYST), while 13 underwent a sham laparotomy which was immediately closed by sutures (SHAM). Eleven nonoperated littermates served as internal controls (CTR). Fetuses were harvested by cesarean section on day 31 of gestation prior to respiration. Pulmonary response was evaluated by left lung to body weight ratio (LWBWR), airway morphometry, and density of type II pneumocytes, as evaluated by the number of surfactant protein B-positive cells. Fetuses from the GAS group had significantly lower body weights than did CTR (P = 0.0129). Of these fetuses, 27% were growth-restricted, i.e., with a body weight under the 10th percentile of the CTR population. There were no differences in left lung weight and LWBWR among the GAS and CTR groups. Moreover, the GAS group had similar alveolar size, alveolar wall thickness, and type II cell density as CTR fetuses. Only mean terminal bronchiolar density (MTBD), which is inversely related to the alveolar space, was slightly increased in the GAS group, but without reaching significance (P = 0.0821). No effect on lung growth and maturation could be demonstrated in this study.

Diaphragmatic function in infants with surgically corrected anomalies

Infants with surgically correctable anomalies, abdominal wall defects (AWD) or congenital diaphragmatic hernia (CDH) may have poor postnatal diaphragmatic function, because the low intra-abdominal pressure experienced by such patients in utero could result in impaired diaphragmatic development. Our objective was to compare postoperative diaphragmatic function of infants with CDH or AWD to that of gestational age-matched controls. Diaphragmatic function was assessed by measurement of the transdiaphragmatic pressure and maximum inspiratory pressure at the mouth generated during crying against an occlusion. In addition, the transdiaphragmatic pressure produced by unilateral and/or bilateral magnetic stimulation of the phrenic nerves (TwPdi) was examined. Lung volume was assessed by measurement of functional residual capacity (FRC) using a helium gas dilution technique. Ten infants with CDH, 26 with AWD infants (19 gastroschisis, seven exomphalos), and 36 gestational age-matched controls were studied. Compared with their matched controls, the eight CDH infants with left-sided defects had significantly lower left (p < 0.01) and right (p < 0.05) TwPdi and FRC (p < 0.01), and the gastroschisis infants, but not those with exomphalos, had significantly lower left and right TwPdi (p < 0.05). There were no significant differences in transdiaphragmatic pressure and maximum inspiratory pressure at the mouth between the CDH or AWD infants and the controls. Diaphragmatic function postoperatively is impaired in infants with CDH or gastroschisis.

Evolution of staged versus primary closure of gastroschisis

OBJECTIVE

Since the introduction of a preformed silo to the authors' practice in 1997, there has been a decrease in primary closure of gastroschisis. To clarify the impact of this change, the authors reviewed their results over the past 10 years.

METHODS

From patient records, the authors abstracted the closure method, mechanical ventilation days, time to full feeds, mechanical and infectious complications, and length of stay. The authors compared groups using the Student t test and the Mann-Whitney test, as appropriate.

RESULTS

Between 1993 and the present, 124 patients were identified. Between 1993 and 1997, 38 children presented with gastroschisis. Thirty-two (84.2%) closures were primary and six (18.8%) were staged. After 1997, the authors treated 80 children with gastroschisis. There were 27 (33.8%) primary and 53 (66.2%) staged closures. Six patients with other lethal anomalies were excluded. Length of stay and ventilator days were higher for the staged closure group, but infection and mechanical complications were less common in the staged closure group. The time to full feeds did not differ.

CONCLUSIONS

A lower incidence of infection and complications related to abdominal compartment syndrome has made staged closure of gastroschisis more common in the authors' practice. While it has resulted in a longer hospital stay, staged closure decreases the risk of long-term bowel dysfunction and need for reoperation.

Thoracoabdominal compression and respiratory system compliance in HIV-infected infants

The thoracoabdominal compression technique (TAC) is used to measure expiratory flow in infants. We investigated whether TAC caused a change in total thoracic compliance (Crs), resistance (Rrs), and respiratory system time constant (Trs). We studied 41 infants (mean age, 12.4 mo; SD, 7.5) from five centers studying longitudinal lung and cardiovascular function of infants from HIV-infected mothers. We measured Crs, Rrs, and Trs before and after TAC. Changes in Crs, Rrs, and Trs after TAC were not dependent on the length of time since TAC. Crs and Trs were reduced after TAC, p = 0.013 and p = 0.003, respectively, whereas Rrs did not change. When compared with uninfected infants, HIV-infected infants had a larger post-pre TAC percent decline in Crs (p = 0.003) and a post-pre TAC rise in mean Rrs (p = 0.03). These differences remained significant after adjusting for sex and age. When performing infant pulmonary function testing, TAC itself produces a temporary decrease in Crs and Trs that is more significant in infants at risk for abnormal lung volume or compliance. Therefore, the sequence of performing the infant lung function parameters should be the same each time the testing is repeated with TAC as the last parameter tested at each testing session.

Temporary impairment of lung function in infants with anterior abdominal wall defects who have undergone surgery

Compliance of the respiratory system (CRS) was measured before and after surgical intervention in 14 infants who had anterior abdominal wall defects (AWD) (7 exomphalos, 7 gastroschisis). The median gestational age was 37 weeks (range, 34 to 40) and median birth weight was 2.38 kg (range, 1.94 to 3.45). The infants had stiff lungs before surgery (median CRS, 0.58 mL/cm H2(O)/kg). During the first and second postoperative days, the median CRS decreased to 0.33 mL/cm H2(O)/kg (P < .05). In seven cases, measurements also were obtained on the third and fourth postoperative days, which showed an increase in the median CRS (day 3, 0.47 mL/cm H2(O)/kg; P < .05). These findings show that in infants with AWD, primary surgical closure is associated with deterioration of lung function, but this effect is temporary.

Nonoperative initial management versus silon chimney for treatment of giant omphalocele

Giant omphalocele is a major clinical challenge for pediatric surgeons. Whereas small- to medium-sized defects can be repaired primarily, larger omphaloceles cannot be closed at birth because the liver and small bowel have lost the right of domain to the abdomen. Two divergent strategies have evolved for treating these giant defects: (1) use of a silon chimney with gradual reduction of the contents of the sac, and (2) initial nonoperative management (epithelialization) of the omphalocele followed by repair of the residual ventral hernia. In an 18-year retrospective study, we have reviewed our experience with these treatment methods. Ninety-four infants underwent treatment for omphalocele between 1975 and 1993. Primary closure (PC) was possible in 55 patients, silon chimney (SC) was used in 15, and 7 had nonoperative management (NM) with epithelialization. In the remaining 17 infants, surgery was believed to be inappropriate because of the lethality of their associated anomalies. Major (but potentially survivable) anomalies were present in 26% of PC, 13% of SC, and 71% of the NM group patients. The majority of the liver was present in 73% of SC- and 86% of NM-treated omphaloceles. There was a decrease in length of stay, time to enteral feeding, and mortality over the 18-year period. However, those patients whose defects could not be closed primarily had consistently longer hospital stays. This was particularly true for the SC patients. The decreased use of total parenteral nutrition seems to reflect a shift from SC to NM rather than a decrease in the interval to full enteral feeding in any given treatment group over time.(ABSTRACT TRUNCATED AT 250 WORDS)