A Structured Training for Trans Anal Irrigation in Pediatric Patients Improves Outcomes and Reduce Failures: Results of an Interventional Multicenter Prospective Study.

BACKGROUND: Continence issues due to organic causes including previous colorectal surgery or neurological issues might benefit from Transanal irrigation (TAI) that proved to be highly effective but with a number of limitations including a relatively high discontinuation rates. Our study was aimed at evaluating the efficacy of an advanced protocol tailored to each patient to prevent dropout and increase satisfaction, independence, and quality of life. MATERIALS AND METHODS: This was a prospective, interventional, multicenter, nonrandomized study involving children aged 4-18 years with bowel dysfunction unresponsive to conventional treatments who required TAI. TAI was performed in accordance to the best standards of care with a total irrigation volume that was determined based on low emission X-Ray barium enemas performed at the very beginning of the study. All patients underwent training and assessments of continence, patients' perspectives and quality of life were performed at different timepoints from enrollment (T0) up to 6 months since TAI was introduced (T3). RESULTS: A total of 78 patients were enrolled. Male to female ratio was 1.4:1. Mean age at enrollment was 106.1 ± 42.8 months. Discontinuation was reported by 3 patients (3.8 %). Continence, satisfaction and a number of other outcome measures increased from baseline (T0) to the last visit (T3). In particular, mean Rintala total score increased linearly from 7.8 to 14.8 during the study period (T0 to T3 timepoints). On a multivariate analysis, the only parameter that proved to be inversely associated with continence as well as with other outcome measures was the use of laxatives at enrollment and during the study. CONCLUSIONS: This study has demonstrated the high efficacy of this innovative patient-tailored TAI protocol across all assessed scores. Of note, given the negative impact of laxatives, our findings suggest limiting their use in this patient population to further increase the efficacy of the procedure.

[Intestinal transplantation. First experience in Spain]. / Trasplante intestinal. Primera experiencia en España.

UNLABELLED: We present the first case of intestinal transplant (IT) performed in Spacin. CASE REPORT: 28 months old boy with secretory diarrhea since the first month of life, diagnosed of microvillous inclusion disease (MID). He is on total parenteral nutrition (TPN) and had suffered of multiple episodes of catheter related sepsis with lost of standard venous access. An isolated small bowel transplant from a cadaveric donor was performed at the age of 3 years. The native ileocaecal valve and colon were not removed. RESULTS: Enteral feeding was started in the 2nd. week after the IT. On the 25th day he was off TPN. Since the 77th day, he eats regular foods by mouth. At the 6th month post IT the ileostomy was closed. Among the complications, he suffered a rotavirus infection on the 38th post IT day and an episode of mild rejection responsive to methil-prednisolone bolus. CONCLUSIONS: The IT is a therapeutic option that can be already offered with possibilities of success in our country. Although the colonic enterocytes express MVD, the recipient ileocaecal valve and colon can be preserved.

Prenatal dexamethasone rescues heart hypoplasia in fetal rats with congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Patients and rats with congenital diaphragmatic hernia (CDH) have lung and heart hypoplasia. Prenatal steroids improve lung hypoplasia in CDH rats. The current study tests the hypothesis that prenatal dexamethasone could rescue heart hypoplasia in rats with CDH. METHODS: Timed pregnant rats received intragastrically either 100 mg nitrofen or oil on day 9.5, and other animals had the same treatment with, in addition, either 0.25 mg/kg dexamethasone intraperitoneally or no treatment on days 19 and 20. Fetuses were recovered on day 21, and heart weight to body weight ratios, heart DNA, protein, and glycogen were measured in fresh specimens. Left-to-right ventricular diameter and aortic-to-pulmonary diameter ratios were measured after formalin fixation. RESULTS: Wet heart weight to body weight, left-to-right ventricular diameter, and aortic-to-pulmonary root diameter ratios, which were lower in fetuses exposed only to nitrofen than in their oil controls, were similar in those exposed to nitrofen plus dexamethasone than in their corresponding oil plus dexamethasone controls. Total heart DNA, which was decreased in fetuses exposed to nitrofen with CDH in comparison with their controls, was increased in those receiving nitrofen and dexamethasone in comparison with theirs. Protein to DNA ratio was decreased in all rats with CDH irrespective of their exposure or not to dexamethasone. Glycogen to DNA ratio was higher in all dexamethasone-treated fetuses than in those without this treatment. No gross histologic differences were seen among groups. CONCLUSIONS: Heart hypoplasia in rats with CDH is in part rescued by prenatal dexamethasone treatment as expressed by increased number of smaller myocytes with higher glycogen content. Prenatal steroids could modify heart involvement in human fetuses with CDH as well.

Liver transplantation in patients with homozygotic familial hypercholesterolemia previously treated by end-to-side portocaval shunt and ileal bypass.

Familial hypercholesterolemia is the result of mutations in the gene that encodes the synthesis of the cellular receptor for low density lipoprotein (LDL). In the homozygous form of the disease (HFHC), cellular LDL receptors either do not form, or, when present, cannot bond LDL and mediate its cellular uptake LDL, and the cholesterol that it transports accumulate in plasma, producing severe premature atherosclerosis and death from coronary artery disease usually before the age of 20. Currently, the only effective treatment is liver transplantation, which, alone or in association with medications, normalizes plasma cholesterol levels. The authors report the cases of 2 siblings with HFHC who underwent portocaval shunt at the ages of 2.5 and 1.5 years, respectively. Portocaval shunt produced an immediate, but insufficient decrease in cholesterol (by 40% and 35%, respectively), leaving them with cholesterol concentrations of about 500 mg/dL. One year later they each underwent ileal bypass without obtaining any significant response. Liver transplantation at the ages of 18 and 16 years, respectively, reduced plasma cholesterol concentrations to 129 and 225 mg/dL, respectively. The earlier operations seriously increased the technical difficulty of liver transplantation and did not produce a favorable effect on the natural course of the disease, so portocaval shunt and ileal bypass are not indicated in HFHC, not even for the purpose of delaying liver transplantation.

Neural crest-derived defects in experimental esophageal atresia.

Esophageal atresia (EA) is often associated with cardiovascular and other malformations that are likely neural crest derived. The present study tests the hypothesis that the heart and great vessels and the thymus and parathyroids may be abnormal in the rat model of EA as a result of disturbed neural crest development. Time-mated pregnant rats received intraperitoneally on d 8 and 9 of gestation either 2 mg/kg adriamycin or vehicle. Esophageal, heart, and thymic malformations were sought under the microscope in term fetuses. The parathyroids were histologically investigated. Control fetuses had no malformations, whereas 69 of 109 fetuses exposed to adriamycin had EA and 45 of 69 had 15 right aortic arches, nine aberrant right subclavia, eight ventricular septal defects, six narrow pulmonary outflow tracts, five tetralogies of Fallot, three double outflow right ventricles, three double aortic arches, three atrial septal defects, three right ductus arteriosus, and two truncus. The thymus was absent in 19, hypoplastic in 12, and ectopic in five out of 36 fetuses with EA in which it was studied, whereas the parathyroid glands were absent in 16, single in four, and ectopic in one of the 23 fetuses with EA in which they were studied. In conclusion, the nature of the cardiovascular, thymic, and parathyroid malformations associated with EA in rats is consistent with the hypothesis of neural crest participation in their pathogenesis. Mechanisms simultaneously disturbing foregut septation, somitic segmentation, and neural crest development should be sought to explain the combined occurrence of malformations in EA.

Long-term survival expectancy after liver transplantation in children.

PURPOSE: The aim of this study was to assess the long-term survival rate in children who have undergone orthotopic liver transplantation (OLT) in the last 13 years. METHODS: The records of 198 consecutive patients under 18 years of age who underwent 249 OLTs between 1986 and 1998 were reviewed. Actuarial patient survival rates were assessed at 1, 3, 5, and 10 years in the whole series, in the last 5 years, and in patients surviving more than 1 year. Age, weight, and indications were analyzed, as well as type and incidence of posttransplant complications. The median follow-up period was 41 months (0 to 154 months). RESULTS: Biliary atresia was the most common indication (41.9%) followed by alpha-1 antitrypsin deficiency (8.1%), Alagille syndrome (7.6%), and fulminant hepatic failure (6.6%). One hundred forty-six patients (58.6%) were below 5 years, and 46 patients were (18.5%) younger than 1 year at operation. Sixty-eight patients (27.3%) weighed less than 10 kg. One hundred seventy whole organs and 70 reduced, 5 living-related donor, and 4 split-liver allografts were used. Hepatic artery thrombosis (n = 18), primary nonfunction (n = 15), and chronic rejection (n = 14) were the most common causes for allograft failure. Fourteen patients (7%) had posttransplant lymphoproliferative disorders (PTLD) at a median time of 28 months (4 to 124 months) postoperation (3 died). The 1-, 3-, 5-, and 10-year actuarial patient survival rates are 80%, 76%, 74%, and 74%, respectively; over the last 5 years it is 88% at 1 year and 82% at 3 and 5 years. For patients surviving more than 1 year, 3-, 5-, and 10-year actuarial survival rates are 95%, 93%, and 93%, respectively. CONCLUSIONS: (1) Overall results of OLT improve with increasing experience. (2) Children who survive more than 1 year after OLT have an excellent prognosis, although long-term complications of immunosuppression can be expected.

[Kasai operation in the age of liver transplantation. Healing or merely palliative technique?]. / La operación de Kasai en la era del trasplante hepático. Técnica curativa o sólo paliativa?

AIM: To assess the results of portoenteroanastomosis (PEA) and liver transplantation (OLT) in extrahepatic biliary atresia (EHBA). METHODS: Out of a series of 148 EHBA, 92 cases primarily treated by us were selected. Survival with the native liver (end point = death or OLT) and its relationship with the age at PEA, type of EHBA, ductal size and bile flow restablishment were assessed. Patient survival was compared in those patients who had access to OLT when needed (Group I, n = 69) and those in whom only PEA was available (Group II, n = 23). (OLT program started in january 1986). RESULTS: At the end of follow-up, 32 children are alive with their native livers, 22 died and 38 had OLT. 40/85 patients who underwent PEA had complete restablishment of bile flow (47%). The no failure rate (survival of the native liver) at 1, 5, 10 and 20 years, was 91%, 49%, 38% and 21%, respectively. Bile flow restablishment was the only predictor significantly associated with good prognosis (survival of native liver at 5, 10 and 20 years of 89%, 86% and 51%, respectively). Differences in survival were significant (p < 0.001) between patients in groups I and II at 1 year (92% vs 74%), 5 years (78% vs 35%), 10 years (76% vs 30%) and 20 years (76% vs 30%). CONCLUSIONS: Bile flow restablishment after PEA can be obtained in experienced centers in about 50% of cases of EHBA. The combined and sequential use of PEA and OLT allows excellent long-term survival in EHBA.

[Children with intestinal failure as candidates for intestinal transplantation]. / Niños con fallo intestinal candidatos a trasplante intestinal.

Small bowel is not anymore considered a forbidden organ for transplantation, and intestinal transplantation (IT) is currently used as a therapeutic option in selected cases of permanent intestinal failure (PIF). Nevertheless, the experience is still scarce, and despite recent improvements, IT is nowadays only accepted as a life-saving option. However, small children are prone to suffer complications related to TPN, particularly end stage liver disease; moreover, suitable donor for the small baby who needs an IT is seldom available. Subsequently, a high pretransplantation mortality has been reported in the pediatric series. In those cases, the indication of IT shouldn't be delayed, and these children must be referred early for IT. Since we started our IT program, 17 children have been assessed, and 3 are currently on the waiting list; two for combined liver-small bowel transplantation (LSB), both with short bowel syndrome and end stage liver disease, and one patient with microuvillous dysplasia for isolated IT (indication loss of venous access). 3 children were referred too late and died, so did a fourth patient, candidate for LSB, before he could be transplanted.

Skeletal malformations associated with congenital diaphragmatic hernia: experimental and human studies.

BACKGROUND/PURPOSE: Skeletal malformations are seen occasionally in infants with congenital diaphragmatic hernia (CDH). This study examines whether nitrofen, able to produce CDH in fetal rats, also induces skeletal anomalies and, if so, whether these are similar to those seen in CDH patients. METHODS: Pregnant rats received either nitrofen (100 mg, n = 7) or no treatment (n = 2) on gestational day 9.5. Skeletal anatomy was studied in fetuses recovered on day 21 after alcian blue-alizarin red staining. The charts and postmortem records of 117 stillborns or newborns who died of CDH were investigated retrospectively for skeletal defects. The proportions of anomalies found in the different groups were compared. RESULTS: The 15 control rat fetuses were normal, whereas 57 of 90 nitrofen-exposed animals (63%) had CDH accompanied by other malformations. Skeletal defects limited to vertebral segmentation or identity anomalies (split vertebra or absent, hypoplastic, or fused ribs) were seen at low thoracic and high lumbar levels in 68% of animals with CDH and in 57% of those without. Delayed ossification of limbs was seen in treated animals. There were skeletal malformations in 31.6% of the 117 human patients with CDH. Costovertebral defects (malformed, extra or defective vertebral bodies or ribs and spina bifida) were comparably frequent in infants with syndromes and in those without them (31.2% v 17.8%, not significant), whereas limb defects were significantly more frequent in those with syndromes (56.2% v 13.9%, P<.05). CONCLUSION: The nature and location of costovertebral malformations found in both CDH patients and nitrofen-exposed rats suggest that the diaphragmatic defect and the associated organ malformations might be caused by the same early embryonal disturbance involving axial and para-axial mesoderm.

Cardiovascular malformations in congenital diaphragmatic hernia: human and experimental studies.

BACKGROUND/PURPOSE: Cardiovascular malformations (CVM) associated with congenital diaphragmatic hernia (CDH) account in part for the high mortality caused by this defect. The aim of this study is to examine the nature of these malformations in a large series of autopsies and to assess if similar defects are also present in rat fetuses with experimental CDH. METHODS: The incidence of CVM and their nature were examined in the autopsy records of 136 stillborns and neonates with CDH admitted to our institution in the last 30 years. Experimental CDH was induced in rat fetuses by giving 100 mg of nitrofen to their mothers on gestational day 9.5, and the fetuses were harvested on day 21 (near full term). The presence of CDH and the anatomy of the heart and great vessels were studied under dissecting microscope after formalin fixation. Unexposed fetuses were used as controls. RESULTS: Thirty-three newborns with CDH (24%) had CVM, either isolated or associated with other defects, and 7 had heart hypoplasia. Most CVM (ventricular septal defect, tetralogy of Fallot, transposition of the great vessels, double-outlet right ventricle) involved the outflow tract. In our animal experiments, no malformations were found in 21 control pups. Conversely, 80 of 130 nitrofen-exposed fetuses (61%) had CDH, and 59 of them (74%) had CVM. A significant association (Fisher's Exact test, P<.01) was found between CDH and CVM because only 25 of the 50 exposed animals without CDH (50%) had CVM. Again, most defects involved the outflow tract and were similar to those seen in human CDH (tetralogy of Fallot, persistent truncus, ventricular septal defect, double-outlet right ventricle, aberrant right subclavian artery, agenetic ductus, and interrupted aortic arch). Animals with CDH had significantly decreased heart weight to fetal weight ratio in comparison with controls and with those without CDH. CONCLUSIONS: The similar nature of the cardiovascular defects found in babies succumbing to CDH and in nitrofen-exposed rats suggests that a similar disturbance of the regional organogenesis related to the neural crest might be involved in both settings, and further validates the use of this animal model for clarifying the cellular and molecular pathogenetic mechanisms.

Supraceliac aortic clamping during the anhepatic phase of experimental orthotopic liver transplantation.

BACKGROUND: The pig tolerates simultaneous clamping of the liver pedicle and inferior vena cava poorly, so venovenous bypass has to be used during the anhepatic phase of experimental orthotopic liver transplantation (OLT). The aim of this work is to assess whether clamping of the supracoeliac aorta during the anhepatic phase (AP) of experimental OLT in pigs allows transplantation in stable hemodynamic conditions. METHODS: Fourteen pigs (weight, 16 to 18 kg) received whole liver grafts from 14 age-matched donors and were subsequently divided into two groups: group I, OLT without venovenous bypass during the AP, group II, OLT with supracoeliac aortic clamping during the AP. Variables analyzed were cardiac output (CO) and related variables, mean systemic arterial pressure (MAP), mixed venous oxygen saturation (SvO2), hepatic artery and portal vein blood flow, systemic and hepatic O2 supply and uptake (SDO2, SVO2, HDO2, HVO2, respectively), liver enzymes, glucose, creatinine, and electrolytes. RESULTS: In group I, CO, MAP, and SvO2, decreased during the AP (anhepatic) in comparison with baseline (preanhepatic) values (CO, 3.60+/-0.74, preanhepatic, v. 1.21+/-0.25 L x min(-1), anhepatic; P<.05. MAP, 97+/-12, preanhepatic, v. 43+/-17 mm Hg, anhepatic; P<.05. SvO2, 91.6+/-5.6, preanhepatic v. 70.0+/-12.5%, anhepatic; P<.05), and SDO2/SVO2 increased by 16% (preanhepatic) to 33% (anhepatic; P<.05). In group II, CO decreased during the anhepatic phase by only 21% (3.82+/-0.81, preanhepatic, v. 3.07+/-0.99 L x min(-1), anhepatic; not significant), the MAP increased significantly (100+/-8, preanhepatic, v. 135+/-4 mm Hg, anhepatic; P<.05), and SVO2, SDO2, SVO2, and SDO2/SVO2 remained unchanged. After revascularization, none of these variables differed significantly between groups, and levels of liver enzymes, glucose, creatinine, urea, and electrolytes were similar in both groups, both before and aftertransplantation. CONCLUSIONS: Experimental OLT can be carried out in pigs without venovenous bypass, but it leads to severe hemodynamic disturbances. Clamping of the supraceliac artery during the AP is well tolerated and results in excellent hemodynamic stability, so it may prove to be a useful technique in liver transplantation in animals, such as dogs or pigs, that do not tolerate simultaneous clamping of the liver pedicle and inferior vena cava as well as human beings.

Skeletal malformations associated with esophageal atresia: clinical and experimental studies.

BACKGROUND/PURPOSE: Patients with esophageal atresia (EA) often have skeletal malformations. The purpose of this study is to examine if similar defects occur in rat fetuses prenatally exposed to Adriamycin, a chemical capable of causing EA in these animals. METHODS: The charts of 443 babies with EA were reviewed to assess the incidence and nature of these defects in them. Time-mated female rats were given either 2 mg/kg intraperitoneal Adriamycin (experimental group, n = 16) or no treatment (control group, n = 4) on gestational days 8 and 9, and the fetuses were removed near term. Skeletal anatomy was studied after alcian blue and alizarin red staining. RESULTS: A total of 528 skeletal malformations, mainly abnormal segmentation and vertebral identity (extra or defective bodies or ribs), mishaped vertebral bodies, and limb malformations like radial aplasia or hypoplasia were found in 245 babies (55%). Costal fusion and sternal anomalies were present in 17 and 4 babies, respectively. In the animal study, all control fetuses were normal, whereas 83 of 134 experimental fetuses (62%) had EA accompanied by other malformations. No segmentation or vertebral identity anomalies were seen, but butterfly, wedged, and asymmetric vertebral bodies were found at various levels in all animals with EA and in about half of those without it. Three fetuses had rib anomalies, and 3 more had sternal malformations. Ossification of limbs was delayed in treated fetuses and short, thick, and crooked bones were seen in 4 of 31 fetuses with EA and in none of the Adriamycin-exposed ones without EA. CONCLUSIONS: Adriamycin exposure induces in fetal rats, in addition to esophageal, duodenal, and anorectal atresias, high proportions of vertebral malformations and some limb defects of nature not identical but quite similar to that of babies with EA. This further validates this model for investigating the nature of the processes leading to EA and its associated malformations.

Heart hypoplasia in experimental congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Heart hypoplasia is associated with congenital diaphragmatic hernia (CDH) and decisively influences survival rate. This study examines whether nitrofen-exposed fetal rats have heart hypoplasia. METHODS: Pregnant rats received either 100 mg nitrofen or vehicle on gestational day 9.5. The hearts recovered near full term were either formalin fixed for anatomic studies or snap-frozen for biochemical studies. Heart weight, ventricular chamber diameters and aortic-to-pulmonary root diameter ratios were measured in fixed hearts. Protein and DNA were determined in frozen hearts. Analysis of variance (ANOVA) and correlation-regression studies were used for statistical assessment. RESULTS: All control fetuses were normal, whereas 61% of those exposed to nitrofen had CDH. Cardiovascular malformations were found in 73% of CDH and in 50% of non-CDH animals. Wet and fixed heart weights in percent of fetal weight, left-to-right ventricular diameter ratio, and aortic-to-pulmonary root diameter ratio were significantly decreased in fetuses with CDH in comparison with controls. Only wet heart was significantly decreased in nitrofen-treated fetuses without CDH, although all other variables showed a trend in the same direction. Protein to DNA ratios were similar in the three groups. The structure of the myocytes was histologically similar in all groups. CONCLUSIONS: The spectrum of lesions in the nitrofen model of CDH encompasses heart hypoplasia, further validating its use for research on this condition. Heart hypoplasia is related to cardiopulmonary compression, but its presence in treated animals without CDH demonstrates that the teratogen itself participate directly in its pathogenesis, and this finding invites further research on this line.

The tracheobronchial tree is abnormal in experimental congenital diaphragmatic hernia.

Neonates with congenital diaphragmatic hernia (CDH) have other malformations that contribute to the high mortality. The nitrofen rat model allows experimental study of these anomalies. This study examines whether the tracheobronchial tree is also abnormal in this model. Time-mated rats received 100 mg nitrofen on gestational day 9. 5; 90 fetuses were harvested on day 21 (near full term) and dissected. The trachea and bronchi were stained with alcian blue-alizarin red and their anatomy was examined by transillumination under a microscope. The findings were compared with those of 11 suitable controls. Control pups had no malformations. Those with CDH (n = 57) had significantly decreased numbers of tracheal rings in comparison with controls (22.9 +/- 1.9 vs 26 +/- 1.9, P < 0.05) and 40/57 had fragmented rings (0 in controls). Twelve CDH animals had, in addition, tracheal stenoses of variable severity, sometimes related to vascular rings. Nitrofen fetuses without CDH (n = 33) had only short tracheas and 4 had mild stenoses. Nitrofen-exposed fetuses have, in addition to lung hypoplasia and sometimes CDH, severe tracheobronchial anomalies that suggest the involvement of pathogenetic mechanisms capable of acting on various tissue components. The genetic control of organogenesis is most probably disturbed by the teratogen.

Lung hypoplasia caused by nitrofen is mediated by down-regulation of thyroid transcription factor TTF-1.

Prenatal exposure to nitrofen induces lung hypoplasia and diaphragmatic hernias very similar to those in human disease, but the mechanisms are still unknown. Thyroid transcription factor 1 (TTF-1) is involved in lung ontogeny and regulation of the expression of surfactant proteins, and is likely abnormally expressed in nitrofen-induced lung hypoplasia. This study examines the effect of nitrofen on TTF-1 messenger RNA (mRNA) expression in the lungs of prenatal rat fetuses and a human lung-cell line (NCI-H441) that expresses both TTF-1 and surfactant proteins in vivo. Lungs from preterm fetuses harvested from rats with 100 mg nitrofen on gestational day 9.5 and NCI-H441 cells maintained in RPMI medium containing 10% fetal bovine serum and exposed to nitrofen for different times and concentrations were assayed for TTF-1 mRNA by northern blot analysis. mRNA for TTF-1 was decreased in nitrofen-exposed pups in comparison with controls, and exposure to nitrofen caused a dose- and time-related decrease in TTF-1 expression in H441 cell cultures. These results indicate that nitrofen downregulates TTF-1 both in vivo and in vitro. Since this interferes with lung development, it is reasonable to accept that lung hypoplasia in this model is in part due to the direct effect of the teratogen rather than to compression by the abdominal viscera herniated into the thorax. This mechanism should be explored in the clinical setting.

Tracheobronchial malformations in experimental esophageal atresia.

BACKGROUND: Malformations of the tracheobronchial tree may account for postoperative respiratory symptoms in patients with esophageal atresia (EA). This study examines the respiratory tract in fetal rats with EA induced by Adriamycin. METHODS: Time-mated female rats were given either 2 mg/kg intraperitoneal Adriamycin on gestational days 8 and 9 (adria group, n = 6) or no treatment (control group, n = 2), and the fetuses were recovered on day 21. Laryngo-tracheo bronchial tree was studied after transparentation and alcian blue-alizarin red staining that depicts the cartilage in blue and make the surrounding tissues transparent. RESULTS: There were no malformations in any of the 1 1 control animals studied. Conversely, 31 of 46 (67%) Adriamycin fetuses had EA with distal TEF. These had more tracheal rings than controls (32+/-2 v 26+/-1.5, P < .05) at the expense of those of the mainstem bronchi (3.2+/-1 v 6.6+/-1.1 in the right, P< .05 and 6.2+/-2.1 v 11+/-1.1 in the left, P < .05). There were tracheal stenoses in 16 pups with EA (some severe and five double), and all these had fragmented rings in the trachea or bronchi. In six cases there was an ectopic upper right bronchus, and 1 had a grossly abnormal larynx. The malformations in the 15 Adriamycin-exposed fetuses without EA were limited to some fragmented or mishaped rings. CONCLUSIONS: Laryngo-tracheobronchial malformations entailing the whole length of the tract are very constant and severe in rats with EA and tracheoesophageal fistula and correspond to an abnormal development of the tracheobronchial anlage from the ventral foregut. Their nature and extent invite a careful investigation of the respiratory tracts in EA babies in whom they could be underscored.