Timothy G. Canty

Injuries of the gastrointestinal tract from blunt trauma in children: A 12-year experience at a designated pediatric trauma center

INTRODUCTION Nonoperative management of solid organ injury from blunt trauma in children has focused concern on potential delays in diagnosis of hollow viscus injury with resultant increases in morbidity, mortality, and cost. This study of a large pediatric trauma database will review the issues of difficulty and/or delay in diagnosis as it relates specifically to definitive treatment and outcome. METHODS We surveyed 11,592 consecutive admissions to a designated pediatric trauma center from 1985 to 1997 to identify children with documented injury of the gastrointestinal (GI) tract from blunt trauma. The records were extensively analyzed specifically in regard to mechanism of injury, type and site of injury, time to diagnosis, operative treatment, complications, and final outcome. RESULTS The 79 children identified, 4 months to 17 years old, included 27 females and 52 males. Mechanism of injury included 15 restrained and 7 unrestrained passengers, 15 pedestrians, 15 child abuse victims, 10 bike handlebar intrusions, 8 discrete blows to the abdomen, 4 bike versus auto, 3 falls, and 2 crush injuries. There were 51 perforations, 6 avulsions, and 22 lesser injuries including contusions. Injury of the small bowel was most common, 44 cases, followed by the duodenum, 18 cases, colon, 17 cases, and stomach, 6 cases. In 45 children, diagnosis was made quickly by a combination of obvious clinical findings, plain x-ray and/or initial computed tomographic findings mandating urgent operative intervention. Diagnosis was delayed beyond 4 hours in 34 children, beyond 24 hours in 17 children and was made by persistent clinical suspicion, aided by delayed computed tomographic findings of bowel wall edema or unexplained fluid. The six deaths were caused by severe head injury. Complications included two delayed abscesses and two cases of intestinal obstruction. All 73 survivors left the hospital with normal bowel function. CONCLUSIONS Injury to the GI tract from blunt trauma in children is uncommon (<1%). The majority of GI tract injuries (60%) are caused by a discrete point of energy transfer such as a seatbelt (19%), a handle bar (13%), or a blow from abuse (19%), or other blows and is unique to this population. Although diagnosis may be difficult and often delayed, this did not result in excessive morbidity or mortality. Safe and effective treatment of GI tract injuries is compatible with nonoperative management of most other injuries associated with blunt abdominal trauma in children, while reducing the risk of nontherapeutic laparotomy.

Primary fascial closure in infants with gastroschisis and omphalocele: a superior approach.

The optimal surgical management of neonates with gastroschisis and omphalocele remains controversial. Early attempts at primary closure were limited by respiratory and vena cava compromise and were gradually replaced by skin closure only, staged reduction of implanted prostheses, and escharification of the intact omphalocele. Advances in surgical technique, neonatal intensive care, and mechanical ventilation have made primary closure a viable alternative once again. We wish to report a consecutive series of 73 infants, including 54 with gastroschisis and 19 with omphalocele, over a 16-year period. Fifty gastroschisis patients were closed primarily, with four deaths (8%), and four with staged prostheses, with one death (25%). Sixteen omphaloceles were closed primarily, with three deaths (19%); two closed with a staged prosthesis, and one patient, closed with skin flaps only, died (100%). Overall survival for primary closure was 59/66 (89%) and for staged reduction, 5/7 (43%). In the past 5 years all patients have been closed primarily with no deaths (100% survival). All survivors were alive and well 1 to 15 years postoperatively. Our current operative technique involves vigorous manual stretching of the abdominal cavity, manual emptying of the entire Gl tract, and primary fascial closure, with no gastrostomy. Key points in postoperative management include total paralysis and mechanical ventilation, as the initially tense abdominal wall softens over 1 to 2 days, followed by weaning from the ventilator, and vigorous fluid support. Gl function returns more rapidly after primary closure (average of 3 days) and hospital stay is not prolonged. Other complications (intestinal obstruction, two patients; fistulae, one patient, etc) are much less frequent.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of integrin-mediated p130(Cas) tyrosine phosphorylation in human B cells. A role for p59(Fyn) and SHP2.

Engagement of β1 integrins in terminally differentiated human B cell lines, such as ARH-77, leads to prominent tyrosine phosphorylation of the p130 Crk-associated substrate (Cas). Cas regulates the assembly of several SH2 and SH3 domain-containing proteins into signaling complexes, which are potentially involved in the propagation of downstream signals. We demonstrate here that immunoprecipitated Cas from β1 integrin-stimulated ARH-77 cells was associated with tyrosine kinase and phosphatase activities and that integrin ligation led to the recruitment of at least p59Fyn tyrosine kinase and SHP2 tyrosine phosphatase in Cas immune complexes. Cotransfection studies in COS-7 cells further indicated that Fyn/Cas physical interaction and Fyn-mediated Cas phosphorylation required amino acids 638–889 in the C-terminal region of Cas. This sequence contains both c-Src SH2 and SH3 domain-binding motifs. In vitro binding studies using glutathioneS-transferase fusion proteins derived from the SH2 or SH3 domains of Fyn suggested that both Fyn domains can participate in Fyn/Cas interaction. These data implicate Fyn and SHP2 as potential modulators of Cas signaling complexes in B cells.

Association of the Cas-like molecule HEF1 with CrkL following integrin and antigen receptor signaling in human B-cells: potential relevance to neoplastic lymphohematopoietic cells

CrkL, a cellular homologue of the v-crk oncogene, belongs to the family of adaptor proteins, containing SH2 and SH3 domains, but no catalytic domain. Stimulation of normal B-cells and B-cell lines through beta1 integrin or - cell antigen receptor (BCR) promoted the association of CrkL with a set of 105-130 kD tyrosine phosphorylated substrates. The principal substrate is a recently identified molecule known as p105HEF1 (HEF1), which is highly homologous to p130Cas (Cas), the major tyrosine-phosphorylated protein detected in fibroblasts after transformation by v-crk. Immunodepletion studies indicated that all the tyrosine phosphorylated HEF1 or Cas was complexed with CrkL. Furthermore, the guanine nucleotide exchange factor C3G, which is thought to be involved in the regulation of the ras pathway and constitutively binds to the C-terminal SH3 domain of CrkL, could be detected in HEF1 immunoprecipitates. Therefore, CrkL is involved in the formation of a HEF1-CrkL-C3G ternary complex in B-cells, suggesting that it is likely to play an important role, allowing the propagation of the stimulation initiated by both BCR and beta1 integrin ligation.

Hydrostatic reduction of ileocolic intussusception: A second attempt in the operating room with general anesthesia

Over a 3-year-period, standard treatment with hydrostatic pressure from a contrast enema failed to reduce ileocolic intussusception in 31 of 62 children. With the child anesthetized in the operating room, a second contrast enema was given before laparotomy. Of the 31 intussusceptions, 21 (68%) were reduced without complication, thereby avoiding the discomfort, longer hospitalization, complications, and expense of surgery. Nine of the remaining 10 intussusceptions were difficult to reduce manually during surgery or required resection. The overall nonoperative reduction rate for the 3-year period was 84%; for the last 2 years it was 90%. Success with the second enema may be related to the effects of general anesthesia. In addition, partial reduction with the first enema may improve blood flow from the intussusceptum so that it becomes smaller and easier to reduce with the second enema. Because it can easily be added to standard management protocols without increased risk, routine use of this second enema with anesthesia is recommended.

The anterior cricoid split procedure for the management of subglottic stenosis in infants and children.

Severe acquired subglottic stenosis occurs most commonly in infants and children who require long-term ventilatory support with indwelling endotracheal tubes for underlying respiratory disease. A variety of operative and endoscopic procedures have been advocated for this problem including endoscopic fulguration, cryotherapy, direct incision or excision, and several types of extensive direct laryngotracheoplasties. The failure rate with these procedures is high. We have treated 22 patients including 12 neonates and 10 older children with acquired airway injury and obstruction with a simple cricoid split. In 15 patients the airway obstruction was completely relieved and these youngsters were extubated without difficulty. An additional 3 patients failed initial extubation which was subsequently successful, however, after repeat intubation for a short period of time. Endoscopic follow-up shows complete healing of the incised area. In 2 neonates the procedure was unsuccessful, and tracheotomy was needed. One of these had additional severe airway injury in the distal tracheobronchial tree secondary to selective bronchial intubation in the newborn period. Two older children also required tracheotomy because of severe airway scarring unrelieved by this procedure. The cricoid split is a simple and successful way of dealing with subglottic stenosis, especially in the newborn premature infant. A significant advantage is that it disturbs the anatomy very little, allowing for more extensive laryngotracheoplasty in the future should it fail.

Acute fluid volume requirements in infants with anterior abdominal wall defects

Abstract Fluid was administered to infants with severe anterior abdominal defects to correct a perfusion deficit detected by muscle surface pH monitoring and not recognized by conventional means of monitoring. Immediate fluid need ranged from 17 to 80 ml/kg. Even in uncomplicated cases these needs were equivalent to or greater than 25% of estimated blood volume. Accurate replacement of volume deficits that appear to be aided by muscle pH monitoring will obviate much of the uncertainty in the care of these infants.

Modified Duhamel procedure for treatment of Hirschsprung's disease in infancy and childhood: Review of 41 consecutive cases

The original Duhamel procedure has undergone several important modifications over the years by Martin, Ravitch, Soper, Talbert, and others. Combining the best features of these various modifications, a modified Duhamel procedure has been developed and utilized in 41 consecutive infants and children with all types of Hirschsprungs disease, including three with long segment involvement. The procedure includes the use of a formal upper and lower anastomosis and division of the spur by the GIA stapling device. There were no deaths and no early complications. At 2-7 yr all children are toilet-trained, continent, and growing well. With appropriate modifications, the Duhamel operation is a very satisfactory definitive procedure for Hirschsprungs disease in infancy and childhood.

Experimental portal hypertension in the rat.

Previous attempts to produce sustained portal hypertension in experimental animals by portal venous obstruction have not been successful. Experiments were designed to study the effects of gradual portal venous occlusion plus hepatic lymphatic ligation in the rat. Adult male Lewis rats were divided into three groups: (A) nonoperated or sham-operated; (B) operated, with hepatic lymphatic ligation only; and (C) operated, with placement of a portal vein ameroid constrictor and hepatic lymphatic ligation. There were no differences noted in portal venous pressures (control 9.6 +/- 0.4 cm H2O) and portovenograms between groups A and B throughout the study. In group C there was greater than doubling of portal venous pressure by 1 wk which remained for 2 mo. Portal pressure then fell but remained elevated at greater than 30% above control values for 1 yr. Three systems of collateral circulation developed rapidly in response to this extrahepatic portal venous occlusion: (A) veins directly bridging across the occluding ameroid reestablishing hepatopetal flow which steadily increased; (B) spontaneous portosystemic shunts at the splenorenal area that occur early and then regress; and (C) retroperitoneal, paraesophageal and submucosal esophageal veins that develop late and remain stable. Quantitative assessment of the lumen size of the submucosal esophageal veins revealed a twofold increase in these veins in group B when compared to controls by 4 wk and a fivefold increase in these veins in group C by 8 wk that persisted for 1 yr. This model appears useful for studying the course and effects of extrahepatic portal hypertension and its gradual alteration by the spontaneous development of portosystemic collaterals in the rat. This model may have enough similarities to the extrahepatic portal hypertension seen in children that its use for future studies may be fruitful.

Upper airway obstruction from foregut cysts of the hypopharynx

T HIS REPORT describes experiences with upper airway obstruction in three neonates caused by cysts of foregut origin within the hypopharynx. Foregut cysts, including esophageal duplications and bronchogenic cysts, have been reported in this location extremely rarely but have not been associated with airway obstruction. Is2 Each of these cases required emergency establishment of an airway before dealing with the lesion.