Cost-effective imaging approach to the nonbilious vomiting infant.

OBJECTIVE: To develop a cost- and time-effective algorithm for differentiating hypertrophic pyloric stenosis (HPS) from other medical causes of emesis in infants referred from community-based pediatricians and family practitioners to the imaging department of a tertiary children's care facility. METHODS: Eighty-nine vomiting infants (22 females, 67 males) between the ages of 11 and 120 days (mean, 43.5 days) had received nothing by mouth for at least 1 hour before the study. Each child was assessed for duration of vomiting, status of body weight, time and volume of last ingestion, and time of last emesis. A #8 French (Sherwood Medical, St Louis, MO) nasogastric feeding tube was placed in the child's stomach. The contents were aspirated and measured to determine likelihood of HPS. An aspirated volume >/=5 mL implicated gastric outlet obstruction, and ultrasonography (US) was performed. If this study was positive for HPS, the patient was referred for surgery. If US was negative, an upper gastrointestinal series (UGI) was performed. An aspirated stomach contents volume <5 mL suggested a medical cause for the emesis, and UGI was performed. Pediatric surgeons with no knowledge of the volume results palpated the abdomens of 73 of 89 infants (82%). RESULTS: Twenty-three of 89 patients (25%) had HPS. The aspirate criteria for HPS had a sensitivity of 91%, a specificity of 88%, and an accuracy of 89%. Of the false-positive studies (total = 8), six were related to recent significant ingestion (within 2 hours of the study), and two were attributable to antral dysmotility. The surgeons palpated the mass in 10 of 19 patients (53%). Sensitivity and specificity were 53% and 93%, respectively. Only 6 of 89 infants (7%) required both US and UGI to determine the etiology of the nonbilious vomiting. By performing the UGI in 66 patients, it was also found that 14% had slow gastric emptying and 79% had gastroesophageal reflux. Eighty-one percent of the gastroesophageal reflux was significant. CONCLUSION: The volumetric method of determining the proper imaging study is cost- and time-effective in the evaluation of the nonbilious vomiting infant for pyloric stenosis. If US was performed initially in all patients referred for imaging, two studies would have been performed in 68 of 89 patients (76%) to define the etiology of the emesis. Because we used the volumetric method, 62 fewer imaging studies were performed, representing a savings of $4464 and 30 hours of physician time. If children are given nothing by mouth for 3 to 4 hours before gastric aspiration, the specificity of the volumetric method improves to 94%, and the accuracy improves to 96%.

Hepatic lesions of central pericellular fibrosis in morbid obesity, and after jejunoileal bypass.

Histologic findings in liver biopsy specimens obtained from 88 patients before and one and two years after end-to-end jejunoileal bypass are compared. In addition to the expected fatty changes, mild changes of centrilobular, pericellular fibrosis were present in the initial biopsies in 8.6%; a year later they had become apparent in 46%. Portal-central bridging developed in 6.8%, and early micronodular cirrhosis in 3.4%--always in those with central pericellular fibrosis. Electron-microscopic study of pre-bypass liver biopsies from eight addtional patients showed collagen and electron-dense material resembling basement membranes within the spaces of Disse in seven, although only four had light-microscopic evidence of minimal central pericellular fibrosis. The existence of these light- and electron- microscopic changes before jejunoileal bypass suggests that there is a lesion in morbid obesity that may be exacerbated during the first year after operation.

Can gastrointestinal hormones enhance intestinal absorption?

Recent studies have suggested that certain gastrointestinal peptides exert a trophic effect on the small intestine. We chose to evaluate the effect of glucagon and cholecystokinin-octapeptide (CCK-OP) on absorption of substrates in both developing and mature small intestine. Developing small intestine was evaluated in a rat fetal intestine transplant model, and mature rat small intestine was studied in in situ but isolated 10 cm segments of jejunum and ileum. Glucagon, 10 micrograms/kg/day, and CCK-OP, 45 micrograms/kg/day, were delivered continuously for 14 days through a subcutaneous osmotic pump. Intestinal absorption was determined with labeled substrates (14C-galactose and 14C-glycine) by a recirculation perfusion technique. Absorption results were expressed as percentage increase over control. The fetal intestine response to glucagon infusion was a 13% rise in galactose absorption and a 27% rise in glycine absorption. After CCK-OP infusion, fetal galactose absorption was 11% and glycine absorption rose 17%. Mature jejunal galactose absorption rose 53% and glycine absorption rose 55% after glucagon infusion. The ileal response to glucagon was a 271% rise in galactose absorption (p less than 0.05) and a 21% increase in glycine absorption. Infusion of CCK-OP decreased jejunal galactose absorption 3% but increased glycine absorption 41%. The ileal response was a 224% increase in galactose absorption (p less than 0.05) and a 19% increase in glycine absorption. Our data suggest that chronic administration of glucagon and CCK-OP can increase substrate absorption in developing and mature rat small intestine. Perhaps manipulation of the gastrointestinal hormone environment may result in increased absorption in man.

Management of congenital arteriovenous malformations.

Twenty-five patients with congenital arteriovenous malformations (AVMs) involving the head, neck, trunk, or extremities were treated over a 10-year period. In patients with more extensive lesions, selective angiography was essential to delineate the extent of the AVM and its vascular anatomy. AVMs that produced congestive heart failure, hemorrhage, pain, or cosmetic embarrassment were excised if possible. Intra-arterial embolization is useful in the reduction of vascularity before operation or as the primary treatment for unresectable lesions. Incomplete excision or embolization of the AVM often results in a recurrence. However, nonsymptomatic lesions may be observed, and extremity varicosities can be treated by external compression.

Growth and function of transplanted fetal rat intestine: effect of cyclosporine.

After transplantation of fetal rat small intestine in rat strains with major genetic differences, the effectiveness of cyclosporine (CyA) as an immunosuppressive agent and its effect on intestinal function were evaluated. Substrate absorption, disaccharidase activity, DNA concentration, and histologic appearance were measured and compared with those of fetal intestine transplanted in syngeneic animals. Sixteen of 20 grafts survived in the control (syngeneic) group and 14 of 20 grafts survived in the nonsyngeneic group when treated with CyA (25 mg/kg/day). None of the 10 nonsyngeneic grafts survived when no CyA was administered. Absorption of 14C-galactose in the syngeneic transplants was 0.70 +/- 0.70 mumol/cm2 intestine compared with 1.03 +/- 0.16 mumol/cm2 intestine in the nonsyngeneic transplants treated with CyA. Absorption of 14C-glycine in the respective groups was 1.63 +/- 0.22 mumol/cm2 intestine (syngeneic group) and 1.75 +/- 0.20 mumol/cm2 intestine (nonsyngeneic group treated with CyA). DNA concentration was 410 +/- 43 micrograms/mg intestine mucosa (syngeneic group) and 477 +/- 27 micrograms/mg intestine mucosa (nonsyngeneic group). There was a significant decrease in maltase and sucrase activity in the group treated with CyA but lactase activity was comparable in both groups. Evidence of mild to moderate cellular rejection was seen in only 25% of the nonsyngeneic grafts treated with CyA. When this rat fetal intestine transplant model is used, CyA appears to be an effective immunosuppressive agent and does not significantly impair growth and development of the intestine.

The effect of portacaval shunt on plasma lipids and tissue cholesterol synthesis in the dog.

Portacaval shunt (PCS) has been proposed as a therapy for hyperlipidemia; however, its lipid-lowering mechanism is unknown. In this study PCS was performed on ten mongrel dogs to measure its effect on plasma lipids and on the cholesterol synthesizing ability of the liver and intestines, the major indodenous cholesterol synthesizing tissues. Plasma was analyzed for total cholesterol (CHOL), triglycerides (TG), and the CHOL content of three plasma lipoprotein fractions. Jejunal, ileal, and hepatic cholesterol synthetic rates were determined by 14C-acetate incorporation to CHOL in tissue slices obtained at operation before PCS and 44 +/- 4.1 (S.D.) days after PCS. Plasma CHOL decreased by 18 +/- 7 (S.E.), 34 +/- 8 (S.E.), and 57 +/- 14 (S.E.) mg. per 100 ml. by 4, 6, and 16 weeks after PCS, respectively. TG decreased by 13 +/- 5 (S.E.), 27 +/- 5 (S.E.), and 30 +/- 9 (S.E.) mg. per 100 ml. at corresponding time intervals. Paired Student's test analysis of CHOL and TG changes are significant at the p less than 0.05 level. CHOL content of the three plasma lipoprotein fractions decreased correspondingly. Intestinal tissue CHOL synthesis rates changed only slightly. Hepatic synthetic rates increased by 30 to 40%; however, no synthetic rate changes were statistically significant at the p less than 0.05 level. PCS is associated with decreased in plasma CHOL [42% (see article)] AND TG [53% (see article)] in dogs up to 16 weeks following operation. Statistically significant changes in endogenous CHOL synthesis were not demonstrated by this study. The mechanism by which PCS affects plasma lipids in the dog is unknown as yet.

Complications of prematurity that may require surgical intervention.

Many complications related to prematurity may require surgical intervention. Between July 1981 and July 1987, treatment of patent ductus arteriosus (PDA) (228 patients), necrotizing enterocolitis (NEC) (49 patients), and complications of high-pressure ventilation (eight patients) was reviewed. A PDA was ligated in 136 patients, with one death and one complication. Ninety-two patients had treatment with indomethacin, with 35 failures. A PDA was associated with NEC in 37 of the 49 patients, with a 73% mortality when they occurred within 72 hours of each other. Two patients died following pulmonary resection for lung cysts. The two patients with pneumoperitoneum and pneumopericardium were successfully treated with tube drainage. A PDA ligation was successful, with low mortality and morbidity. Treatment with indomethacin was unsuccessful in 38% of patients. There is a high mortality when NEC and PDA occur within 72 hours of each other.

Primary repair without routine gastrostomy is the treatment of choice for neonates with esophageal atresia and tracheoesophageal fistula.

Gastrostomy and staged repair are techniques frequently recommended for the management of esophageal atresia with distal tracheoesophageal fistula (EA-TEF), especially for those infants at high risk. We describe 42 consecutive patients with EA-TEF treated during the past 8 years. Staged repair and preliminary gastrostomy were not routinely employed. Fifteen infants were considered to be at high risk (Waterston class C). Surgical treatment via an extrapleural approach consisted of fistula division and primary single-layer end-to-end esophageal anastomosis. Four patients required proximal esophageal circular myotomy. Four patients early in the series received a gastrostomy at or before definitive repair for various life-threatening indications. One patient had fistula division only and died before esophageal anastomosis was possible. Two neonates died before repair and another died after repair. The deaths in this series of patients were unrelated to EA-TEF. One patient developed a clinically significant anastomotic leak. Four patients required multiple dilatations for anastomotic stricture. Fundoplication was necessary in 3 patients with symptomatic gastroesophageal reflux. Our data demonstrate that excellent overall survival (90%) with low morbidity (15%) can be achieved using primary repair without preliminary gastrostomy in most neonates with EA-TEF. We believe that mortality in high-risk patients with EA-TEF is due to associated life-threatening anomalies.

Influence of epidermal growth factor on intestinal function in the rat: comparison of systemic infusion versus luminal perfusion.

Epidermal growth factor may be a trophic substance for the small intestine. Previous studies had not evaluated intestinal absorption after long-term continuous administration of epidermal growth factor or compared luminal perfusion with systemic infusion. Epidermal growth factor (150 micrograms/kg/day) was continuously infused either systemically or luminally for 14 days into young adult Fisher strain rats. Luminal studies were performed by creating 10 cm Thiry-Vella loops. At the conclusion of the 14 day infusions, mucosal DNA concentration and absorption of carbon-14 galactose and carbon-14 glycine were determined. The increase in DNA concentration after systemic or luminal infusion of epidermal growth factor was not statistically significant. However, galactose absorption increased 1.9-fold (p less than 0.05) after systemic epidermal growth factor infusion and glycine absorption increased 4.4-fold (p less than 0.01). Luminal epidermal growth factor perfusion increased galactose absorption 2.4-fold (p less than 0.05) and glycine absorption 4.1-fold (p less than 0.01). Thus, both systemic and luminal administration of epidermal growth factor can significantly increase substrate absorption. Additional studies on the physiologic implications and clinical usefulness of these data are warranted.

A possible serum marker for rejection after small intestine transplantation.

Frequent histologic evaluation of mucosal biopsies remains the most reliable method of monitoring and diagnosing rejection after small intestine transplantation, but lengthy processing time can result in delay in diagnosis. Unfortunately, a serum marker for monitoring small intestine transplantation rejection has not been identified. Hexosaminidase, a lysosomal acid hydrolase, has been shown to increase in serum in association with intestinal ischemia, a finding also associated with acute rejection after small intestine transplantation. We measured N-acetyl hexosaminidase levels after transplantation in three groups of five rats each as follows: Group I, Lewis strain small intestine to Lewis recipients; Group II, Wistar small intestine to Lewis recipients; and Group III, Wistar small intestine to Lewis recipients treated with 25 mg/kg per day of cyclosporine. Serum N-acetyl hexosaminidase levels and mucosal biopsies were obtained on days 0, 2, 4, 6, 8, 10, 12, 14, and 21. Rats in Groups I and III survived without gross evidence of rejection. Three rats in Group II died between 8 and 10 days, and serum N-acetyl hexosaminidase levels increased 24 to 48 hours before death. In the remaining Group II rats, the N-acetyl hexosaminidase levels were significantly higher on days 10, 12, and 14 after transplantation (p less than 0.05). In two of five rats, the histologic changes of rejection occurred later than the increase in N-acetyl hexosaminidase levels. Because measurement of N-acetyl hexosaminidase levels is a rapid and simple serum assay, it may be useful for monitoring rejection after small intestine transplantation.

Significance of pneumatosis cystoides intestinalis after jejunoileal bypass.

In 148 radiographs taken two weeks to twenty-seven months postoperatively in a series of 402 jejunoileal bypass patients at the University of Minnesota, twenty-four patients demonstrated roentgen evidence for pneumatosis intestinalis on twenty-eight separate episodes. This primarily involved the right colon. Clinical signs and symptoms were reviewed in association with the roentgen findings. Symptoms of nausea, vomiting, fever, and abdominal stress were noted but were not universal. Six patients had no significant change in abdominal complaints at the time the pneumatosis was seen and seven patients had similar clinical findings without roentgen evidence for pneumatosis. Thus, the radiographic findings of pneumatosis intestinalis do not represent a specific sign for bypass enteritis.

Unusual peptide-secreting tumors in adolescents and children.

Endocrine tumors of the pancreas and intestine are uncommon but challenging lesions. Those tumors that arise in the pancreas are typically derived from one of the various cell types of the islet of Langerhans and secrete the peptide associated with the cell type. In general, the primary tumors are small, relatively slow growing, and many are benign. However, certain tumors are malignant, more aggressive, and metastasize early, such as gastrinomas, glucagonomas, and VIPomas. Many of these tumors can be multicentric, and some may arise in the duodenum of small intestines. Tumors that arise more often in the intestine are carcinoids and VIPomas. The endocrine effects of many of these tumors such as VIPomas or gastrinomas can be life-threatening. A markedly elevated level of a specific peptide will generally be sufficient to establish the diagnosis. Often, the greatest challenge is localizing the tumor(s). The only opportunity for cure is complete surgical excision. Palliation can be accompanied through tumor reduction, surgically of with antineoplastic agents (eg, doxorubicin and 5-fluorouracil). Palliation from symptoms also can be accomplished by blockade of the peptide's secretion of effects. The prognosis is variable and depends on cell type, resectability, and presence of metastases.

Acute abdomen. Laboratory evaluation and imaging.

The child with an acute abdomen requires a thorough history and physical examination followed by a focused laboratory and imaging evaluation. The laboratory evaluation is more beneficial in determining management than in establishing diagnosis. Ultrasonography has become increasingly useful in the evaluation of the child with acute abdominal pain.

Pharmacotherapy and growth factors in the treatment of short bowel syndrome.

A review of the pharmacologic substances and growth factors that have been studied experimentally and administered clinically for the management of short bowel syndrome is presented. The medical management of short bowel syndrome is multifaceted. In the acute phase, efforts focus on fluid and electrolyte management and the reduction of gastric acid output. As enteral feeding is initiated, antimotility and antisecretory agents may be effective in reducing gastrointestinal losses. Additional modalities of management, including nutrients and growth factors, may be directed at maximizing absorptive function beyond that which occurs with intestinal adaptation. Continued research aimed at further elucidating the process of intestinal adaptation may allow us to use the various peptides and hormones that act as growth factors for the bowel mucosa. Knowledge gained from these studies combined with gene therapy techniques will result in the permanent enhancement of intestinal function beyond the normal adaptation process, eliminate the dependence on total parenteral nutrition, and avoid the need for intestine transplantation.

Short bowel syndrome in infants and children.

This article defines short bowel syndrome and reviews the pathophysiology, medical management, and surgical manipulations proposed to improve intestinal absorption. Emphasis is also placed on possible future methods of management.

An improved technique for circular myotomy in long-gap esophageal atresia.

Circular myotomy has allowed the surgeon to establish esophageal continuity in early infancy in patients with long-gap esophageal atresia. This report describes the use of a #5 Fogarty balloon catheter, passed by the surgeon into the proximal esophagus to facilitate the myotomy. The catheter is passed through a pursestring suture placed at the tip of the proximal esophagus. The balloon is inflated to fill but not distend the lumen. The myotomy is performed approximately two cm proximal to the esophageal end and; upon its completion, it will provide 1 to 1.5 cm of additional length. The advantages of the surgeon placing the catheter into the esophagus include: complete control of the balloon size and position, and the ability to use the catheter to manipulate the proximal esophagus atraumatically.

An alternate method for intraoperative cholangiography in infants with severe obstructive jaundice.

Differentiation between biliary atresia, biliary hypoplasia and severe neonatal hepatitis continues to require direct visualization of the biliary ducts. This is usually accomplished by operative cholangiography using radiographic contrast material. Recently, we have employed an alternate technique of operative cholangiography using methylene blue. This method identifies patent biliary ducts by direct visualization. Methylene blue cholangiography (MBC) has been used in 16 infants with severe obstructive jaundice. In contrast to the radiopaque cholangiogram, MBC more accurately demonstrated biliary hypoplasia in two patients. In addition to the better resolution obtained by MBC, it can be performed in considerably less time than that usually required for x-ray cholangiography.

Splenic injury in children after blunt trauma: blood transfusion requirements and length of hospitalization for laparotomy versus observation.

Nonoperative management (observation) of blunt injury to the spleen under the appropriate conditions has been shown to be successful and safe. However, concern has been raised that this approach may lead to longer hospitalizations and more frequent and greater volumes of blood transfusion and, therefore, increased risk of blood-borne infection when compared with laparotomy for blunt splenic injury. At the University of California, Davis Medical Center, two separate management teams provide trauma care to patients under 16 years of age, one of which is more oriented to nonoperative care. This provided the opportunity for a retrospective review in which length of hospitalization and blood transfusion requirements were compared for patients undergoing laparotomy and those being observed. From July 1988 to January 1992, 36 patients under the age of 16 were evaluated after blunt trauma and found to have an injury to the spleen. Eleven children were managed nonoperatively. The mechanisms of injury were similar in the operative and nonoperative groups. The average age and hematocrit for the operative and nonoperative groups (respectively) were 9.1 years, 30.6 g%, and 6.9 years, 34.4 g%. Comparing the operative and laparotomy groups, the length of hospital stay (9.9 v 8.4 days) and intensive care unit stay (5.1 v 4.3 days) were similar. The average blood transfusion volumes for the observed group was 0.5 U compared with 5.3 U for the laparotomy group. A subgroup of patients (n = 9) who were stable but underwent abdominal exploration received an average of 1.4 U.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of gastrin on gastrointestinal function.

To improve intestinal function in children with short bowel syndrome, our laboratory has focused on identifying substances, which may enhance the function of small intestine epithelium. Previous studies have demonstrated that gastrin appeared to exert a trophic effect on the gastrointestinal tract. We chose to evaluate the influence of chronic, systemic, and luminal administration of gastrin-17 on substrate absorption in both fetal and mature rat small intestine. Transplanted fetal small intestine, mature small intestine in situ, and isolated mature small intestine segments were the surgical preparations used. Saline (control) or gastrin-17 (13.5 nmol/kg/d) was administered continuously for 14 days either systemically or luminally using osmotic pumps. The response to the saline or gastrin-17 infusions was determined by measuring absorption of radiolabeled substrates (14-C-galactose and 14-C-glycine). Following transplantation of fetal small intestine to a syngeneic host, galactose absorption rose 250% (P less than .01) and glycine absorption rose 130% (P less than .05) when compared with controls (N = 10). The response of mature jejunum and ileum following systemic gastrin infusion was a mild to moderate rise in galactose and glycine absorption, although statistical significance was not achieved. However, following luminal gastrin infusion into mature small intestine segments, there was a 4.54 fold rise in galactose absorption (P less than .01) and a 4.79 fold rise in glycine absorption (P less than .01) when compared with controls. These data suggest that gastrin can enhance substrate absorption in rat fetal and mature small intestine and that luminal perfusion appears to induce the greatest response.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital malformations of the lung and mediastinum--a quarter century of experience from a single institution.

Congenital malformations of the lung are rare and vary widely in their presentation and severity. The authors reviewed 25 years of experience with specific reference to diagnosis, treatment, and outcome. From July 1970 to June 1995, 70 patients were diagnosed with congenital malformations of the lung, which included sequestration (n = 20), foregut anomalies (n = 20), congenital lobar emphysema (CLE; n = 10), congenital cystic adenomatoid malformation (CCAM; n = 5), benign lung cysts (n = 6), lung aplasia/ hypoplasia (n = 4), and other miscellaneous disorders (n = 5). All patients with pulmonary hypoplasia presented at birth. With the exception of one patient, infants with CCAM and CLE presented before 5 months of age. All other patients presented from birth to 16 years of age. A prenatal diagnosis was accurate in two patients. Although prompt surgical management is the rule, the exceptions were children with bilateral lung involvement. Corrective surgery was delayed in some patients in whom extended respiratory support was required or in whom the delay led to an increase in pulmonary reserve. Extracorporeal membrane oxygenation (ECMO) was used in two patients pre- and postoperatively to manage persistent pulmonary hypertension. This review, representing the largest series of congenital lung lesions, showed that (1) prenatal diagnosis is useful but generally does not change the outcome; (2) computerized tomography (CT) is the optimum postnatal diagnostic imaging modality if chest radiography is not definitive; (3) ECMO can be an adjunct in treating associated pulmonary hypertension; (4) pulmonary resection (lobectomy) is the surgical procedure of choice for most lesions; (5) expected survival is good; and (6) pulmonary hypertension is the most common cause of mortality.