Toshio Sawai

Anomalies of the tracheobronchial tree in patients with esophageal atresia

To examine associated anatomic anomalies of the tracheobronchial tree and structural abnormalities of the trachea, and their clinical consequences, bronchoscopic examination and follow-up studies were performed in 32 patients with esophageal atresia (EA) and tracheoesophageal fistula (TEF) over a 5-year period. To evaluate structural abnormalities of trachea, the ratio of circumferential length of cartilaginous trachea to circumferential length of membranous trachea (C:M ratio) was determined before surgical repair. In patients examined before and after surgical repair, the motion of the posterior tracheal wall was observed under spontaneous respiration. Fifteen of the 32 patients (47%) had abnormalities of the tracheobronchial tree such as ectopic right upper bronchus (12), congenital bronchial stenosis (4), and absence of the right upper bronchus (2). The C:M ratio of the 27 patients with EA (2.0 +/- 0.6) was significantly lower than that of controls (3.0 +/- 0.3); the ratio for the 10 cases with ectopic right upper bronchus (1.7 +/- 0.4) was significantly lower than that of other cases (2.2 +/- 0.5). The C:M ratio for the 12 patients who had atelectasis (1.7 +/- 0.3) was significantly lower than that of the 15 who did not have atelectasis (2.2 +/- 0.6). Of 24 infants, nine had bulging of the posterior tracheal wall synchronized with expiration, and their C:M ratio (1.8 +/- 0.2) was significantly lower than that of the 15 patients without bulging (2.2 +/- 0.6). These data show an association between anatomic anomalies of the tracheobronchial tree and structural abnormalities of the trachea in patients with EA. Because these abnormalities may be related to the occurrence of respiratory disorders such as tracheomalacia and atelectasis, early bronchoscopic examination, including measurement of the C:M ratio and observation of the motion of the posterior tracheal wall under spontaneous respiration, may be useful in the care of patients with EA.

Experience in tracheobronchial reconstruction with a costal cartilage graft for congenital tracheal stenosis

Although successful surgical management of congenital tracheal stenosis has been reported, it is still controversial as to the best operative procedure. Eleven infants with congenital tracheal stenosis were evaluated to confirm the efficacy of tracheobronchial reconstruction with costal cartilage graft. Symptoms ranged from recurrent respiratory infection to severe respiratory failure. All infants had other congenital anomalies in addition to tracheal stenosis. Notably, five infants had pulmonary artery sling and four infants had patent ductus arteriosus. Definitive diagnosis was made by bronchoscopy, results of which showed complete tracheal rings in all patients with severely compromised tracheobronchial lumens. Five infants had elongated stenosis involving nearly the whole length of the trachea, and five infants had segmental stenosis involving nearly one half the length of the trachea. One infant had bilateral stenosis of the main bronchi. Early experience included two deaths from problems related to the repair. The involvement of the carina and the distal portion of the trachea was associated with increased complications and a higher mortality rate. Currently, our preferred technique facilitated by extracorporeal membrane oxygenation (ECMO) includes carinal reconstruction with a thin-wall intraluminal stent. Bronchoscopy is essential for accurate intraoperative incision of the trachea, post-operative airway management for several weeks, and removal of the intraluminal stent.

Prenatal diagnosis of abdominal wall defects and their prognosis

To determine whether associated anatomic features may be useful in predicting fetal prognosis, 43 fetuses who had ultrasonographic evaluation for abdominal wall defects during a 13-year period were reviewed. Thirty-one fetuses had omphalocele and were classified into three groups according to fetal ultrasonography results: ruptured omphalocele with exposed liver, giant omphalocele with exposed liver, and small omphalocele without liver herniation. Twelve fetuses had gastroschisis. Ten of the 12 fetuses with gastroschisis survived; one died in utero. Nine of the 12 with a small omphalocele survived. Ten of 12 fetuses with giant omphalocele survived, but six of the seven with ruptured omphalocele died of pulmonary hypoplasia and respiratory insufficiency. Ruptured omphalocele recognized in utero was accompanied by intrauterine growth retardation and liver herniation and frequently was associated with deformity of the spine, diaphragmatic defects, vesicointestinal fissure, and meningocele. These results indicated that, together with the deformity of the spine, rupture and absence of the covering membrane with an exposed liver (noted through fetal ultrasonography) may suggest a poor prognosis because of pulmonary hypoplasia.

Nitric oxide inhalation therapy for an infant with persistent pulmonary hypertension caused by misalignment of pulmonary veins with alveolar capillary dysplasia

Misalignment of pulmonary veins with alveolar capillary dysplasia (MPV) has been reported to be a rare cause of persistent pulmonary hypertension of the newborn (PPHN) and to be fatal despite extracorporeal membrane oxygenation (ECMO). A full-term female neonate with PPHN was brought to the hospital for ECMO therapy at 2 days of age. On the 14th day of life, she was extubated early after the second run of ECMO, and underwent nitric oxide (NO) inhalation therapy in the incubator. She died of catheter-related sepsis on the 61st day of life. After autopsy findings revealed MPV, the longest survival with this disease was documented. NO inhalation therapy in the incubator may provide time for lung transplantation.

Prolonged preoperative stabilization using high-frequency oscillatory ventilation does not improve the outcome in neonates with congenital diaphragmatic hernia

Abstract Although delayed repair with preoperative stabilization using high-frequency oscillatory ventilation (HFOV) has been advocated in neonates with congenital diaphragmatic hernia (CDH), improved survival has not been reported. We compared survival between neonates undergoing delayed repair after prolonged stabilization for more than 48 h using HFOV and those undergoing immediate repair following short stabilization using HFOV in subjects with high-risk CDH. Patient selection was made by two criteria: fetuses with the lung/thorax transverse area ratio (L/T) below 0.26 and neonates who presented with respiratory distress significant enough to require intubation within 6 h after delivery. Selection of the strategies differed by era and medical center. Stabilization failed in 11 of 18 patients with delayed repair and only 7 patients (38.9%) in this group survived, but 18 of 23 patients (78.3%) in the immediate-repair group survived (P < 0.05). Although lower values of Apgar scores, best postductal PO2 (BPtDPO2), gestational weeks, and L/T and more frequent patch repair were observed in the delayed than in the immediate repair group, significant differences in survival among the subpopulations were also observed in the prenatally diagnosed group, including the group with L/T < 0.15 and the group that required ECMO, the group with the best preductal PO2 (BPrDPO2) ≥ 100 torr, and the group with BPtDPO2 < 100 torr. These results indicate that prolonged stabilization for more than 48 h using HFOV does not improve survival in patients with high-risk CDH.

Prenatal diagnosis of congenital diaphragmatic hernia and pulmonary hypoplasia and therapeutic strategy

The outcome of fetuses with congenital diaphragmatic hernia (CDH) has been reported to be fatal when pulmonary hypoplasia (PH) is severe. As an indicator of PH, we attempted to measure the lung-thorax transverse area ratio (L/T) using ultrasonic echography. Immediate postnatal surgery was performed using high-frequency oscillatory ventilation (HFOV) and sometimes followed by extracorporeal membrane oxygenation (ECMO). Eighteen fetuses were treated and 14 survived. L/T correlated well with the best preductal arterial blood gas data before surgical reduction during manual ventilation and HFOV, while preductal PO2 and alveolar-arterial oxygen differences from patients managed with HFOV were better than those in patients with manual ventilation. Although L/T also correlated with the duration of O2 therapy and hospitalization in survivors without major anomalies, there was no significant difference between L/T in survivors and nonsurvivors. Because delayed institution of ECMO and complications related to ECMO management seemed to be a major cause of death in non-survivors, the unsalvageable L/T due to PH was estimated to be below 0.06 for HFOV and below 0.1 for conventional ventilation based on the correlation between L/T and preductal P02. These results suggest that L/T is a useful indicator of PH in patients with CDH and also that HFOV is advantageous in treating CDH with PH. The advantage of prenatal diagnosis in predicting unsalvageable L/Ts, should be considered in the therapeutic strategy.

Extralobar pulmonary sequestration with venous drainage to the portal vein: a case report.

Abstract Venous drainage to the portal vein in pulmonary sequestration is rare. A 7-month-old girl was referred to our hospital following surgery for ventricular septal defect because of a left upper abdominal mass with a large feeding artery from the abdominal aorta and venous drainage to the portal vein. She had had frequent pulmonary infections and was growth retarded. MRI demonstrated that the mass was above the left diaphragm, suggesting extralobar sequestration. An extralobar sequestered lung was resected at thoracotomy. Diagnostic problems and clinical features are presented.

Umbilical Cord Ulcer Associated with Fetal Jejunal Atresia: Report of 2 Cases

We report 2 cases of umbilical cord ulcer associated with fetal jejunal atresia. Both of them developed a severe intrauterine hemorrhage, followed by fetal heart rate decelerations, and underwent emergency cesarean section. Bloody amniotic fluid and umbilical cord ulcers were observed in both cases. Although both cases were successfully resuscitated, neurological impairment and renal failure developed in 1 case due to prolonged asphyxia. In a review of the literature, umbilical cord ulcer was associated only with congenital duodenal atresia or jejunal atresia, but not with ileal atresia. Although the prenatal diagnosis of duodenal or upper jejunal atresia has been established, the prenatal diagnosis of this complication has not been reported. In such cases, detailed examination of the umbilical cord by ultrasonography may be useful for the prenatal diagnosis of this disease.

Clinical significance of the lung/thorax transverse-area ratio in fetuses with cystic lung disease

Abstract We examined the clinical significance of the lung-thorax transverse-area ratio (L/T) in fetuses with cystic lung disease (CLD). The transverse section of the thorax was analyzed at the level of the 4-chamber view of the heart. L/T was calculated as the bilateral normal lung area divided by the thoracic area. Within a 9-year period, ultrasonography was performed in 15 fetuses with CLD, 13 of which were histologically diagnosed: congenital cystic adenomatoid malformation of the lung (CAM; n = 8), pulmonary sequestration (n = 4), and bronchial atresia (n = 1). Although the initial L/T measurement (29.6 ± 4.2 weeks) showed significantly lower values than in the controls, the final measurement (36.4 ± 1.6 weeks) indicated that the L/T in CLD excluding CAM was significantly higher than that in CAM. Six patients with a final L/T of less than 0.21 required mechanical ventilation immediately after birth. Two of these patients died, and the autopsy findings indicated pulmonary hypoplasia. In these cases, a significant correlation was observed between the maximal value of L/T and preductal alveolar-arterial oxygen difference (A-aDO2), although the final L/T was not correlated to A-aDO2. These results indicate that serial measurements of L/T may be useful in the diagnosis of CLD and may help to predict postnatal respiratory conditions.

Bilateral diaphragmatic hernia followed by fetal ultrasonography. A report of two cases.

Two cases of bilateral congenital diaphragmatic hernia (CDH) followed by fetal ultrasonography were described. Although many cases of CDH are diagnosed by fetal ultrasonography, it is difficult to diagnose bilateral CDH in utero, which is a relatively rare and fatal condition. Two fetuses were diagnosed as having left CDH associated with severe anomalies. However, a retrospective review of fetal ultrasonography indicated elevation of the liver in the right posterior chest. Both patients died shortly after surgical repair for left CDH despite the use of extracorporeal membrane oxygenation. Diagnosis of bilateral CDH by fetal ultrasonography and the evaluation of its prognosis were discussed.