Stuart R. Lacey

Percutaneous translumbar and transhepatic inferior vena caval catheters for prolonged vascular access in children

Central venous access for children with caval occlusion remains a major challenge to pediatric surgeons. Traditionally, children with superior and inferior vena cava (SVC, IVC) thrombosis have often required a thoracotomy to directly cannulate the azygos system or right atrium (RA). Recently, the possibility of placing tunneled RA catheters (RACs) by a percutaneous translumbar or transhepatic approach has become available. We report our experience of seven children with SVC and IVC obstruction who have received 11 transhepatic and 4 translumbar RACs from 1987 to 1991. All but one child was less than 2.5 years old and all were chronically dependent on parenteral nutrition. All catheters were placed in the angiography suite under general anesthesia using ultrasound guidance and Seldinger technique. This technique was successful in all seven children. Perioperative complications included accidental extubation in one patient and aspiration pneumonia in another. Mechanical complications requiring RAC replacement occurred 5 times in three infants (greater than 2,650 catheter days) and included catheter dislodgement (2) and thrombosis (3). In the patients with catheter thrombosis, the existing tract was successfully wired and the catheter exchanged on three occasions. Thrombolytic therapy was effective in restoring catheter patency on three other occassions. Nine episodes of catheter sepsis occurred in five children. Two late deaths occurred from infection. Of the five remaining children, four are dependent on total parenteral nutrition and have a translumbar or transhepatic catheter in situ and one child has adapted successfully to enteral feedings. Percutaneous translumbar or transhepatic IVC catheters provide excellent alternative routes for prolonged central venous access in those patients whose traditional vascular access sites are no longer available. Complications of the technique itself were minimal and although late catheter complications were not infrequent, they appear to be comparable to the standard approaches reported.

Bladder pressure monitoring significantly enhances care of infants with abdominal wall defects: A prospective clinical study

Increased intraabdominal pressure (IAP) has been demonstrated to cause intestinal and renal ischemia in both animals and humans. Neonates undergoing closure of anterior abdominal wall defects are at risk for these complications from markedly increased IAP, which are putatively responsible for a 13% to 20% mortality. In an effort to decrease morbidity and mortality we performed a 4-year prospective clinical study to determine if monitoring IAP using bladder pressure (BdP) measurements would significantly improve perioperative care in infants with abdominal wall defects. Forty-two consecutive infants with gastroschisis (28) and omphalocele (14) were prospectively studied. Intraoperative and serial postoperative measurements of BdP were obtained from an indwelling bladder catheter using a standard pressure transducer. Methods of initial closure, as well as manipulations in sedation, paralysis, and silo reduction, were selected to keep BdP < 20 mm Hg. Bladder pressure monitoring significantly altered the management of 64% of our patients, particularly those with gastroschisis (74%). Thirteen patients with gastroschisis underwent staged closure; in 7 (54%) this decision was based on high BdP even though bowel reduction was mechanically possible. Elevated BdP influenced the closure method and timing of silo reductions in 5 of 14 (42%) infants with omphalocele. There were no episodes of renal failure or refractory oliguria. There were three patients in a single cluster who developed uncomplicated, nonsurgical necrotizing enterocolitis late in their respective courses. One patient whose bowel was placed in a silo had severe hypotension associated with group B streptococcal sepsis and subsequently developed necrotic bowel despite low BdP.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective analysis of urokinase in the treatment of catheter sepsis in pediatric hematology-oncology patients

Use of right atrial catheters (RACs) in children with cancer improves the comfort and efficacy of therapy. However, catheter-related infections are responsible for significant morbidity leading to the removal of approximately 20% of implanted RACs. Sepsis has been linked to thrombus and fibrin sheath formation within the RAC. Gram-negative and fungal infections appear to be particularly resistant to antibiotic therapy alone and most of these infections have required catheter removal. Urokinase has been effectively used for reopening thrombus occluded RACs. Theoretically, thrombolytic agents could improve the treatment of catheter-related infections by removing luminal sites of bacterial/fungal colonization. We prospectively monitored the use of urokinase and antibiotics for catheter-related sepsis in our pediatric hematology/oncology population from 1985 to 1991. Sepsis episodes were treated with 2 doses of urokinase and antibiotics (10 to 42 days) infused through the RAC. One to 2 mL of urokinase (5,000 U/mL) was instilled in the RAC for 1 hour, then removed and repeated 24 hours later. During the study, 224 RACs were placed in 177 children. RACs were in place for a total of 71,134 days (median, 274 days). There were 67 blood culture-positive sepsis episodes occurring in 50 RACs. Fifty-nine sepsis episodes were treated with urokinase and antibiotics and all responded by clearance of organisms from the blood. Three patients (5.1% of urokinase treated) had recurrent sepsis with the same organism within 2 months, were considered treatment failures and had RACs removed. Only 1 of 16 episodes of multiple organism/Candida sepsis led to RAC removal due to inability to cure the infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic lung disease is the leading risk factor correlating with the failure (wrap disruption) of antireflux procedures in children

Recurrent gastroesophageal reflux (GER) after antireflux procedures (ARP) has been correlated with significant neurological impairment (NI). Other major risk factors for recurrent GER have not been extensively characterized. The authors reviewed their experience with ARPs in children to better characterize the risk factors for recurrent GER and identify successful management strategies for these patients. The charts of 281 consecutively treated children who had an ARP at our institution (1985 to 1992) were reviewed. The neurological status of each child was assessed as normal or impaired (cerebral palsy, seizures, mental retardation, spasticity), and other medical diagnoses such as chronic pulmonary disorders (eg, interstitial disease, cystic fibrosis, bronchopulmonary dysplasia, asthma, etc), and congenital malformations and syndromes were identified. The average follow-up period was 3 years (range, 1 to 7.5 years). Patients with symptoms of recurrent GER were evaluated with an upper gastrointestinal study. Patients with a radiologically intact fundoplication and suspected GER were further evaluated with a 24-hour pH probe. Statistical analyses were performed using the Fishers Exact Test. Of the 281 patients who underwent ARP, 39 had documented recurrent GER (average, 16 months after surgery). Twenty-five (64%) of these children had chronic pulmonary disease (CPD). Thirty-two percent of all children with CPD had recurrent GER after ARP, versus 7% of those without CPD (P < .0001). For children with NI and CPD there was an increased risk (P < .0001) of failure when compared with the risk in the normal subgroup (children without CPD or NI) who underwent ARP.(ABSTRACT TRUNCATED AT 250 WORDS)

Microvillus Inclusion Disease In Vitro Jejunal Electrolyte Transport

Microvillus inclusion disease is an inherited intestinal brush border membrane defect that causes severe fluid and electrolyte malabsorption. In an infant with microvillus inclusion disease (confirmed by electron microscopic evaluation of rectal, jejunal, and gallbladder mucosae), basal stool output was massive (greater than 125 mL . kg-1 . day-1) and was not altered by treatment with clonidine or octreotide. A proximal jejunostomy with mucous fistula was placed, allowing separation of proximal from distal tract outputs (60 mL . kg-1 . day-1 and 100 mL . kg-1 . day-1, respectively). A 10-cm jejunal segment was excised during surgery and mounted in Ussing chambers for determination of transepithelial Na+ and Cl fluxes. Compared with intestine of normal infants, this infants epithelium showed transmural conductance and unidirectional ion fluxes that were only 30% of normal. With respect to both Na+ and Cl, the excised jejunum was in a net secretory state. Theophylline (5 mmol/L) increased net Cl secretion slightly. In response to mucosal D-glucose (30 mmol/L), jejunal mucosal-to-serosal Na+ flux doubled. In the infant, glucose-electrolyte solution administered intrajejunally did not significantly change stool output, suggesting that all of the solution (40 mL/kg) was absorbed. Subtotal enterocolectomy, in theory, could have decreased purging by 66% in this infant with microvillus inclusion disease, but diarrhea would still have been significant.

A rat model of ileal pouch-rectal anastomosis.

Summary: After colectomy and ileal pouch‐rectal anastomosis, pouchitis may occur. Pouchitis is a poorly defined condition with unknown etiology. The aim of this study was to develop an animal model of pouchitis. Ileal pouch‐rectal anastomosis was created in Lewis and Sprague‐Dawley rats. Rats were studied 4 and 8 weeks after surgery, and pouchitis was assessed by stool output, histology, and tissue myeloperoxidase (MPO) levels. Some rats were treated with allopurinol or metronidazole beginning the day of surgery. Rats with pouches demonstrated inflammation with a monocytic infiltration, luminal exudate, mucosal ulcerations, and serosal inflammation. Rats with pouches had increased anaerobic bacterial flora compared with normal ileum. After creation of pouches, Lewis rats (histology score = 8.4 ± 1.6; MPO = 17.3 ± 3.6, mean ± SD) developed more severe inflammation than Sprague‐Dawley rats did (histology score = 4.3 ± 1.8; MPO = 5.5 ± 3.6) within 4 weeks, p < 0.001 and 8 weeks after surgery, p < 0.05. Stool output was also greater in Lewis (55 ± 7 g/kg/day) compared with Sprague‐Dawley rats with pouches (43 ± 5 g/kg/day), p < 0.05. Metronidazole treatment reduced histology score (6.0 ± 0.5) p < 0.05 and MPO (5.9 ± 1.6) p < 0.001 in rats with pouches compared with rats with pouches that had no treatment. Allopurinol treatment in rats with pouches reduced histology score (4.0 ± 1.7) and MPO (3.9 ± 1.6), p < 0.001, compared with rats with pouches that had no treatment. Ileal pouch‐rectal anastomosis in rats induced inflammation within 4 weeks, demonstrated differential host genetic susceptibility, and was associated with increased number of pouch bacteria. Anaerobes, especially bacteroides sp. and free radicals, may mediate inflammation. Ileal pouch‐rectal anastomosis surgery in rats may be a useful animal model for the study pouchitis.

Acquired symptomatic bronchial stenosis in infants: Successful management using an argon laser

Acquired bronchial stenosis following prolonged endotracheal intubation is uncommon, but in infants it is associated with significant morbidity. A variety of endobronchial techniques including forceps or cautery resection and balloon dilatation have been used with inconsistent results. Laser therapy seems attractive, but pediatric applications have been very limited. We report the first series of infants with life-threatening acquired bronchial stenosis treated with an argon laser. Eight infants, age 3 weeks to 2 years, presented with symptomatic bronchial obstruction following prolonged intubation. Seven of these patients had at least 90% obstruction of a lobar or mainstem bronchus. Under general anesthesia a 300 or 600 micron quartz laser fiber was passed through the suction channel of a 3.5-mm flexible or 3-mm rigid bronchoscope. The laser was operated at 2.5 to 3.5 W in 0.5-second pulses, to ablate the obstructing tissue. Multiple procedures, spaced no closer than 10 days, were required in three of eight infants. Follow-up bronchoscopy after 2 to 30 months revealed normal findings in five of eight infants. All but one child, who has persistent collapse of the bronchus intermedius due to bronchomalacia at the site of the obstruction, had satisfactory results. The only complication was a pneumothorax in a 1,300 g infant, which developed eight hours after treatment. Our experience suggests that the argon laser is effective in the management of endobronchial lesions in infants and is superior to the CO2 and Neo-dymium-yttrium aluminum garnet (Nd-YAG) lasers for this purpose.(ABSTRACT TRUNCATED AT 250 WORDS)

Endoscopic management of large, postresection bronchopleural fistulae with methacrylate adhesive (super glue)

Bronchopleural fistulae that occur following pulmonary resection are usually managed by direct, operative closure. In complex cases, in which the risk of repeat thoracotomy is great, other means may be preferable. We report two patients, one with cystic fibrosis and one with extensive radiation fibrosis post-Askins tumor, in whom the risk of thoracotomy was considered to be prohibitive. Both had a large fistula between the pleural cavity and a segmental bronchus from the right upper lobe. The cystic fibrosis patient had recurrent massive bleeding from the pleural space. A Teflon catheter was passed through a flexible bronchoscope and Super Glue (butyl or methyl methacrylate) was deposited into the fistula. In both cases, the fistula resolved promptly. One patient developed a large, recurrent granuloma at the site of the fistula requiring endoscopic resection. We believe that tissue adhesive may be a reasonable approach to the management of large bronchopleural fistulas when the risk of operative closure is great.

Munchausen syndrome by proxy: Patterns of presentation to pediatric surgeons

Munchausen syndrome by proxy is an increasingly reported insidious disorder in which illness in a child is fabricated and/or induced by the parent. Over a 5-year period at North Carolina Childrens Hospital 10 such children were identified after having presented to the Pediatric Surgical Service. In reviewing this experience, we have identified two patterns of presentation. Apnea, seizures, and cyanosis comprised the pattern most frequently seen in infants. A history of persistent diarrhea and vomiting, although seen in two infants, was the more common pattern in older children. As they got older, four of the infants subsequently were noted to have the childhood pattern of symptoms. The mother was the perpetrator in all cases with the childs illnesses being induced by a number of different mechanisms. The most useful diagnostic tool proved to be isolation of the child from the parent. Resolution of symptoms in parental absence was a consistent finding especially in fabrication cases and was the key to diagnosis. Video telemetry confirmed the diagnosis in two infants and screens for toxins were diagnostic in three others. Awareness of patterns of presentation and parental behavior is critical to establishing an early diagnosis and avoiding needless diagnostic and operative procedures.

Successful treatment of Candida-infected caval thrombosis in critically III infants by low-dose streptokinase infusion*

Chronic central venous catheters are an important component in the management of chronically ill infants and children. Sepsis and thrombosis are common complications of these catheters. When the combination of Candida sepsis and caval thrombosis occurs, the prognosis is very poor. Lysis of the thrombus is critical to effective therapy and allows preservation of vascular access. We report the successful treatment of four critically ill infants with Candida-infected caval thrombosis treated with low-dose infusion of streptokinase combined with standard antimicrobial therapy. All four infants survived, and in all cases thrombolysis was complete and Candida sepsis resolved. Each of the infants required continued central venous access, which was made possible by resolution of the caval thrombosis. There were no hemorrhagic or other complications of the therapy.