Clinical and biological acceptance of a fibrocollagen-coated mersylene patch for tracheal repair in growing dogs.

BACKGROUND: Collagen-covered prostheses can be used as a non-circumferential segmental tracheal replacement. However, the applicability of these implants in young subjects has not yet been reported. METHODS: In this experimental, longitudinal study, dogs aged 29-32 days underwent limited segmental tracheal replacement with a polyester prosthesis or were allocated to a control, untreated group. The dogs were evaluated clinically, endoscopically and tomographically for up to one year. RESULTS: Although there was evidence of tracheal growth in the experimental group, tomographic measurements were significantly smaller in this group than in the control group throughout the observation period. At the end of the study, there was no evidence of implant rejection, stenosis or collapse. Normal respiratory epithelium had grown across the implanted membrane in the experimental group. CONCLUSION: The homologous collagen mersylene membrane allowed for limited structural tracheal growth and was functionally integrated into the segmented tracheal wall in growing dogs.

Pharmacokinetics of lidocaine and its metabolite as a hepatic function marker in dogs.

Measuring hepatic metabolic function is critical for detection and treatment of liver failure. Several tests have been widely used to characterize the integrity of liver; however, they do not evaluate the metabolic function of the organ, most requiring multiple blood draws. The purpose of this study was to establish if the ratio of the lidocaine metabolite monoethylglycinexylidide (MEGX) divided by lidocaine concentration at 30 min post intravenous lidocaine administration is a good marker of metabolic activity of the liver. Nine healthy and two partially hepatectomized and auto-transplanted dogs were included in the study. A single 1.5 mg/kg intravenous dose of lidocaine and serum samples were obtained at selected times for 150 minutes. Serum concentrations of lidocaine and MEGX were determined by a validated high-performance liquid chromatographic method. Pharmacokinetic parameters were obtained by non-compartmental methods and ratio of AUC of MEGX divided by AUC of lidocaine was determined for each dog. This ratio was correlated with the ratio of the concentration of the compounds obtained 30 minutes after drug administration. A good concordance was obtained, suggesting that ratio obtained with a single sample may be useful to predict the hepatic metabolism function. To validate the test, dogs hepatectomized and auto-transplanted were plotted and the results obtained were within the values obtained in healthy dogs. These results suggest that ratio of MEGX/lidocaine obtained 30 min after administration could be a good marker of hepatic metabolic function.

Liver transplantation: some advances in liver cancer, live liver donation, and cell transplantation. A literature review.

Organ transplantation represents one of the medical fields with the largest impact and advances. Liver transplantation constitutes a constant challenge in finding viable options to maintain or recover an adequate function when faced with end-stage liver failure. Critical review of the literature was conducted in specific topics on liver transplantation and development in Mexico. We focused our review on medical and surgical topics such as liver procurement from a related living donor, liver transplantation options for patients with liver cancer, especially hepatocellular carcinoma and cholangiocarcinoma, as well as on cellular and molecular biology aspects, such as xenotransplantation and hepatocyte transplantation.

Análisis descriptivo de una población de niños mexicanos con atresia de esófago y alteraciones cromosómicas / Esophageal atresia and chromosomal abnormalities in a mexican children population: descriptive analysis

Introducción. La asociación de alteraciones cromosómicas y atresia de esófago parece tener una morbiletalidad diferente al resto de la población con atresia de esófago (AE). Con el objetivo de conocer las características de esta asociación en una población de niños mexicanos se realizó este estudio. Material y métodos. Ensayo observacional, descriptivo, retrospectivo, transversal que incluyó pacientes con AE y alteraciones cromosómicas, que ingresaron en un hospital de tercer nivel de atención, durante un período de 31 años consecutivos. Se analizó la edad gestacional y de ingreso, sexo, tipo de atresia, alteración cromosómica, malformaciones adicionales, tratamiento, evolución y causa de muerte. Resultados. Se incluyeron 17 pacientes de 368 con AE (4,61%); 12 con trisomía 21 y 5 con trisomía 18; 16 de ellos presentaron de una a tres malformaciones adicionales. Se realizaron 15 diversos procedimientos quirúrgicos por la AE y 6 por malformaciones asociadas. Fallecieron catorce niños en un período de 140 días. Conclusiones. La coexistencia AE, trisomías y otras malformaciones mayores estuvo caracterizada por complicaciones multifactoriales que determinaron una evolución desfavorable a corto plazo (AU)

Introduction. Chromosome alterations are associated with esophageal atresia (EA) in up to 11% of the cases. The morbidity and mortality index of this population is different from other EA patients. The present study was aimed to determine the characteristics of this association in a Mexican infant patient population. Material and methods. Observational, descriptive, retrospective, transversal assay including patients with AE and chromosome alterations over a 31-year period. Gestational age, admittance age, sex, type of atresia, chromosome alteration, additional malformations, treatment, evolution and death cause, were registered. Results. Seventeen patients (4.61%) out of 368 with EA were included. Chromosome 21 trisomy was detected in 12 children and 5 with 18 trisomy. One to 3 additional malformations were found in 16 patients. Fifteen children were subjected to surgical procedures for EA, and 6 for associated malformations. Fourteen children died in a 140-day followup period. Conclusions. Coexistence between AE, trisomys and major malformations was characterized by multifactorial complications which determined adverse evolution in the short term (AU)

[Esophageal atresia and chromosomal abnormalities in a Mexican children population: descriptive analysis]. / Análisis descriptivo de una población de niños mexicanos con atresia de esófago y alteraciones cromosómicas.

INTRODUCTION: Chromosome alterations are associated with esophageal atresia (EA) in up to 11% of the cases. The morbidity and mortality index of this population is different from other EA patients. The present study was aimed to determine the characteristics of this association in a Mexican infant patient population. MATERIAL AND METHODS: Observational, descriptive, retrospective, transversal assay including patients with AE and chromosome alterations over a 31-year period. Gestational age, admittance age, sex, type of atresia, chromosome alteration, additional malformations, treatment, evolution and death cause, were registered. RESULTS: Seventeen patients (4.61%) out of 368 with EA were included. Chromosome 21 trisomy was detected in 12 children and 5 with 18 trisomy. One to 3 additional malformations were found in 16 patients. Fifteen children were subjected to surgical procedures for EA, and 6 for associated malformations. Fourteen children died in a 140-day follow-up period. CONCLUSIONS: Coexistence between AE, trisomys and major malformations was characterized by multifactorial complications which determined adverse evolution in the short term.

Pharmacokinetics of a cephalone (CQ-M-EPCA) in rats after oral, intraduodenal and intravenous administration.

As part of the development of a new series of antibacterial agents derived from coupling a beta-lactamic precursor with a fluoroquinolone and named cephalones, the pharmacokinetics of one derivate: CQ-M-EPCA in rats after intravenous, intragastric and intraduodenal routes, was carried out. After the IV injection of 20 mg/kg or 40 mg/kg of this cephalone, plasma concentrations at the time zero (Cp0) were 3.1 and 11.26 microg/ml, respectively. Plasma concentrations decreased rapidly to almost disappear in both instances. Forty-five minutes later, a surge in concentrations, in the 40 mg/kg group, with a maximal plasma concentration (Cpmax) of 2.97 microg/ml was observed. An elimination half-life (T1/2el) of 2.36 +/- 0.33 h. was calculated. The drug was undetected by the ninth hour. Intragastric administration of the drug resulted in Cpmax of 3.78 +/- 0.26 microg/ml with a time to reach Cpmax (Tmax) of 25 min and T1/2el = 3.22 h. Same variables after intraduodenal administration were Cpmax 4.71 microg/ml; Tmax 1h, and T1/2el 3.41 h. Outstandingly high bioavailabilities after intragastric and intraduodenal administration (169 and 246%, respectively), together with the shape of the concentration versus time profiles after IV administration suggest that the drug undergoes a complex redistribution phenomenon, while showing high tissue diffusion with an apparent volume of distribution of 3.33 l/kg.

Short bowel syndrome in patients studied at the National Institute of Pediatrics in Mexico. Care, cost and perspectives.

BACKGROUND: Short bowel syndrome (SBS) continues to be one of the most challenging problems in pediatric surgery. Intestinal transplantation (IT) seems to be the best form of treatment for this pathology. However, it is thought that the development of an IT program may be more expensive than the present manner of treatment. METHODS: To assess this item, and to identify potential candidates for IT, we reviewed the charts of all the patients with SBS treated at our Institute from 1989 to 1994. RESULT: Nine patients were identified as carriers of SBS; six with intestinal atresia, two with midgut volvulus and one with post-traumatic mesenteric thrombosis. The small bowel remnants varied from 1 to 80 cm, seven patients had remnants shorter than 30 cm, and the ileocecal valve was resected in three. RESULTS: The overall morbidity and mortality was extremely high; four patients died within the first 3 months postresection and those still alive have had several complications: sepsis; hydroelectrolyte imbalances secondary to loose stools; thrombosis or infection of the catheter; TPN-related cholestasis, and malabsorption syndromes, etc. No patient survived with an intestinal remnant shorter than 15 cm. Of the five survivors, four have a weight/age deficit greater than 40%, two have rickets, one still depends on TPN and all, except one, require special enteral diets. Multiple central venous accesses had to be performed in every patient (mean 4.8). They all required multiple readmissions and have spent a considerable part of their lives as inpatients. The mean of the calculated cost per patient was $50,000 USD, while the minimal wage in Mexico is $1,616 USD/year (1). CONCLUSIONS: The shorter the segment of the retained bowel and the longer the survival, the higher the cost. These results may be further improved with the development of IT and, probably, with the same economic burden.

[Comparison of 2 types of experimental transplant in the treatment of lethal short bowel syndrome]. / Comparación de dos tipos de trasplante experimental en el tratamiento del intestino corto letal.

OBJECTIVE: To evaluate the functional response, morbidity and histostructural changes in rats enterectomized and without cecum using two types of syngenic enteral transplants. MATERIAL AND METHODS: Controlled randomized surgical-therapeutic trial. Four groups of male Lewis rats 8-10 weeks old underwent the following procedures: 1. Lethal enteral resection (n = 10). 2. Lethal enteral resection + total yeyuno-ileal transplant (n = 28). 3. Lethal enteral resection + distal segmentary of 40% and cecum transplant (n = 32). 4. Control group (n = 10). RESULTS: 11% of the transplanted animals died due to technical failures; both transplanted groups had a similar proportion of late complications, mostly enteral obstruction. A persistent diarrhea was observed in 20% of the yeyuno-ileal transplanted group, but no significant differences were found between the two groups concerning survival, weight gain, protein and triglycerides serum levels, and a maltose absorption test; villus and crypt hypertrophy was observed in both grafts. The enteral graft integration was followed by structural changes similar to those found in intestinal remnants on deficit conditions after enteral resection. CONCLUSION: The bowel distal segmentary transplant with ileocecal valve and cecum may be a good option in cases of irreversible enteral failure, as the functional response and morbidity are similar to those found with the standard total transplant.

[Experimental enteral segmental transplant. Functional response and surgical complications]. / Trasplante segmentario enteral experimental. Respuesta funcional y complicaciones quirúrgicas.

BACKGROUND DATA: Total enteral transplant associated or not to other abdominal organs has a high degree of morbidity due to immunologic and functional complications that have limited its therapeutic application. Segmentary transplants have demonstrated experimentally to have a better control to immune response, however there are still doubts on its functional effectiveness in terms of other segments. OBJECTIVE: In order to evaluate surgical and functional morbidity without immunologic interference, syngenic segmentary enteral transplants were done, from three different levels in the intestine. METHOD: Growing syngenic Lewis rats were randomly divided into five groups; four of them had 90% enterectomy with a simultaneous transplant of a 30% of the proximal, medial and distal segments in the first three groups and 90% in the fourth one. The fifth group was used as a control. RESULTS: Of the 54 rats that were transplanted, one third developed late complications. Only half of them showed controllable causes, the complications were proportional in all groups. Among surviving four months after transplant, no group had stopped growing, however, the proximal transplant group had significant (P < 0.05) deficit in weight with respect to the other groups. All the other groups showed growth patterns similar to the control group. Plasma concentrations of tryglicerydes, cholesterol and glucose after the maltosa test were similar in all animals. Low albumin concentrations were observed only in the proximal transplant group (P < 0.05). CONCLUSIONS: Medial and listal segmentary transplants showed the best functional adaptability in terms of ponderal growth, similar to animals with total enteral restitution or intestinal integrity.

[Enteral resection in the nursing rabbit (an experimental study)]. / Resección enteral en el conejo lactante. (Estudio experimental).

The response to enteral resection in human newborns and nursing babies depends on the site and magnitude of the resection: usually these patients have a satisfactory recovery although long term supportive measures are required in order to prevent nutritional and digestive complications. This study assessed the post-surgical response of six groups of nursing rabbits with 0, 40, 50, 60, 75 and 90% selective resection of the small intestine. A greater number of surgical complications was observed in those cases with more manipulation and greater resection. Villi hypertrophic was found at the distal extremes of the enteral remnants only with 40% jejunal resection and 75 and 90% jejunum-ileum resections. None of the groups showed growth interruption. Only in rabbits with resections greater than 60% a significant decrease in weight was found. Forty and sixty percent enteral resections, mainly proximal and distal respectively, did not yield weight or length deficits as compared with the control group.

[A technical experimental model for esophageal anastomosis in rabbits]. / Modelo técnico experimental para la práctica de anastomosis esofágica en conejos.

This article has as its main objective to divulge the development and optimization of surgical-technical training procedures for pediatric surgeons required to correct esophageal atresias. Included are the esophageal anastomosis techniques used in New Zealand rabbits, proposed as an experimental model, to later be reproduced and therefore decrease morbiletality as a result of insufficient surgical in this field. The approach, diameter and consistency of the esophagus of the experimental model, shows very similar characteristics as those seen in the newborn with esophageal atresia.

[Bilio-enteric convergent diversion with an antireflux mechanism. An experimental study]. / Derivación bilioentérica convergente con mecanismo antirreflujo. Estudio experimental.

A new biliary-enteric derivation was used in one group of mongrel puppies to avoid reflux and its complications. A Y-en-Roux derivation in one pared group of puppies was used also. There was a substantial complications decrease in the first puppies, but do not stop at all contamination in the bile duct tree and liver.

[Surgical treatment of the patient with atresia of the bile ducts]. / Tratamiento quirúrgico del paciente con atresia de las vías biliares.

Fifty-five cases with bile duct atresia subjected to 56 different bilioenteric diversions seen at the National Pediatric Institute during the last 16 years are studied. The best results were obtained with those patients operated on during the first two months of life and when external bilioenteric diversions were used. The most frequent complication seen in any type of diversion is cholangitis. The main cause of death was due to liver failure based on a parenchymal disease. Depending on how each patient evolved, a classification system was established.

[Behavior of the section and arterial suture site in growing subjects]. / Comportamiento del sitio de sección y sutura arterial en sujetos en crecimiento.

In order to investigate the possible unwanted late effects of vessel cicatrization during growth, especially after the section and terminal-terminal arterial anastomosis, a study was carried out in 28 piglets using three different surgical anastomosis techniques as well as three different types of sutures. Results show that the smaller the diameter of the vessel and when for its surgical correction suture techniques using separate and combined stitches are used, in addition to non absorbent material, a greater amount of suppression is seen at the site of anastomosis during arterial growth. Less suture material is recommended (of lesser thickness) as well as continuous suture techniques as the diameter of the vessels to be sutured decrease.

[Hemangioendothelioma of the pancreas and choledochus, as a cause of cholestatic neonatal and Kasabach-Merrit syndromes]. / Hemangioendotelioma del páncreas y colédoco, como causa de síndromes colestásico neonatal y de Kasabach-Merrit.

Vascular congenital abnormalities are common in children and are often seen in skin and soft tissues. They are rarely observed in internal organs. They may be found singly or in a multiple fashion. The liver is the most frequently affected organ by this disease. The most common histological variety is the hemangioendothelioma. This is a rare neoplasm of the pancreas. The case of a six month old boy with a pancreatic head hemangioendothelioma, associated with thrombocytopenia and digestive track bleeding is presented. The case is clinically interesting due to the vascular malformation and its location. These in turn caused obstructive neonatal jaundice and very severe liver lesions which contributed to the child's death. Paradoxically, the neoplasm is not considered malignant and the secondarily produced liver lesions could have been prevented if the patient would have been diagnosed correctly and at an earlier stage. Hemangioendothelioma; Kasabach-Merrit syndrome; neonatal cholestatic syndrome.

Clinical classification for undescended testes: experience in 1,010 orchidopexies.

A clinical classification for undescended testes based on location, size, and mobility of the testis in the inguinal canal was performed. The latter was artificially divided into three sections. The lower portion was considered position I; the mid part, position II; the upper part, position III; and the abdominal (nonpalpable) part, position IV). Normal-size testes were considered as being size A; testes reduced up to 30% in volume, size B; and gonads reduced more than 30% of the estimated normal, size C. According to these criteria, a case of chryptorchidism can then be classified as I, II, III, or IV and A, B, or C and fixed or movable. This classification was used in 1,010 orchidopexies conducted under a uniform surgical technique by the same surgeon and followed annually up to a maximum of 23 years. Retractile testes were excluded from this series. In most cases, the clinical diagnosis matched the surgical findings. Results are presented in two groups, unilateral and bilateral, since the main problem for the latter is fertility, and they should be considered separately in any study. For both groups, the most frequent finding was the normal-sized testis (size A), in location I. For positions II and III, size B was the most common; and in position IV (intraabdominal), size C had a substantially higher incidence. Surgical technique was simpler and the outcome better, as expected, when the testicles were of good size, located in a low position, and operated at an early age. A worthwhile finding was the long-term cosmetic improvement in an important percentage of the surgically descended B-sized testes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Liver resection in children. Experience in 10 cases]. / Resección hepática en el niño Experiencia en 10 casos

The authors report their experience with ten major hepatic resections; six on the right lobe and four on the left. Six of the resected masses were hepatoblastomas, two were hamartomas, was a hemangioma, and the last one a pheochromocytoma of the right adrenal gland with invasion to the liver next from the affected site. The four patients with major hepatic resection of the left lobe are at present alive, ranging from two months to two years after surgery. Of the six patients with major resection of the right lobe, three died during surgery, another one died late post-operatively and one died a year after surgery from generalized metastasis of an hepatoblastoma. The sixth patient is alive with no complications, four months after surgery. The authors used two types of hepatic resections and they make some recommendations for achieving better results in this type of operation.

[Choledocal cyst. Surgical treatment]. / Quiste de colédoco. Tratamiento quirúrgico

Experience at the Hospital del Niño IMAN in choledochus cysts is reviewed in 13 patients with ages ranging from 3 months to 13 years. Nine were female patients and four were male. Seven cases were managed with cystoduodenostomy and six with cystojejunostomy using Roux's Y operation. Two patients from the cystoduodenostomy group died probably due to the serious hepatic lesion present before surgery and not to the surgical procedure itself. There were no deaths in the group with cystojejunostomy using Roux's Y operation and all patients are asymptomatic at 6 months to 5 years after surgery. Stress is made on the high incidence of cases in our country. Disadvantages of cystoduodenostomy due to the reflux of food contents of the biliary ducts, documented in these cases, are discussed. The possibility of a complete cyst resection is considered, based on reports of late malignancies and poor functioning of the anastomoses mentioned by other authors.