High accuracy plasma density measurement using hybrid Langmuir probe and microwave interferometer method.

High spatial resolution plasma density measurements have been taken as part of an investigation into magnetic nozzle physics at the NASA/MSFC Propulsion Research Center. These measurements utilized a Langmuir triple probe scanned across the measurement chord of either of two stationary rf interferometers. By normalizing the scanned profile to the microwave interferometer line-integrated density measurement for each electrostatic probe measurement, the effect of shot-to-shot variation of the line-integrated density can be removed. In addition, by summing the voltage readings at each radial position in a transverse scan, the line density can be reconstituted, allowing the absolute density to be determined, assuming that the shape of the profile is constant from shot to shot. The spatial and temporal resolutions of this measurement technique depend on the resolutions of the scanned electrostatic probe and the interferometer. The measurement accuracy is 9%-15%, which is on the order of the accuracy of the rf interferometer. The measurement technique was compared directly with both scanning rf interferometer and standard Langmuir probe theory. The hybrid technique compares favorably with the scanning rf interferometer, and appears more accurate than probe theory alone. Additionally, our measurement technique is generally applicable even for nonaxisymmetric plasmas.

Diagnosis and treatment of urethral prolapse in children.

OBJECTIVES: To review published reports on urethral prolapse in the pediatric population, with a focus on diagnosis and management, and to do a retrospective review of 20 cases of urethral prolapse at an urban hospital. METHODS: A retrospective chart review of 20 consecutive cases of urethral prolapse in the pediatric population at Kings County Hospital was done. A review of the published reports on urethral prolapse from 1937 to the present was included in this study. RESULTS: Twenty patients with urethral prolapse were treated at Kings County Hospital during a 10-year period. Patients were identified by perineal bleeding and diagnosed by physical examination. All patients were successfully treated by excision of the prolapsed urethral mucosa and suturing of the remaining mucosa to the vestibule. CONCLUSIONS: Urethral prolapse is an uncommon entity that occurs primarily in prepubertal black girls. Patients may be successfully treated by excision of the prolapsed mucosa and suturing of the proximal urethra to the vestibule.

Peritoneal drainage as definitive treatment for intestinal perforation in infants with extremely low birth weight (<750 g).

BACKGROUND: Advances in neonatal intensive care have improved the survival of the extremely premature infant. However, survival at less than 25 weeks' gestational age remains tenuous, with intestinal perforation presenting a significant mortality. METHODS: During an 18-month period from 1995 to 1996, nine patients weighing less than 750 g (range, 485 to 740 g; mean, 615 g) presented with intestinal perforation. All patients were treated with peritoneal drainage. Drains were removed after clinical improvement and the cessation of peritoneal drainage. RESULTS: Seven patients survived the initial drainage procedure (78%). At a mean follow-up of 12 months, the six long-term survivors are all tolerating full enteral feeds, and none developed intestinal strictures or intraabdominal abscess. No patient required subsequent celiotomy. Peritoneal drainage has previously been considered in some centers as temporary therapy in extremely ill neonates deemed unlikely to survive operation. The authors have adopted drainage as the sole treatment in selected patients. CONCLUSION: Peritoneal drainage alone may be considered definitive therapy for intestinal perforation in the majority of micropremature infants.

Sampling Bacterial Flora.

All clinicians involved in wound care are at some time or another required to send a specimen to a laboratory. However, this often involves considerable uncertainty and debate as to which specimen should be taken, where from and how.

Access techniques in endoscopic fetal surgery.

Endoscopic surgery may in the future become an attractive alternative to open fetal surgery. Herein, we present our evolving experience with minimal access techniques in sheep and nonhuman primate models. Fifty-two pregnant sheep (term = 145 d) were used. All underwent laparotomy. Cannulas were 5 mm diameter with balloon fixation device. In group I (95-105 d, n = 22, and 70-74 d, n = 19), a total of 119 cannulas were placed by open hysterotomy and pursestring suture through myometrium and membranes. In group II (n = 11), access was obtained by Seldinger guidewire technique. Eight cannulas were introduced over a dilator and 7 were radially expanding endoscopic cannulas. Fifteen cannulas were also placed in 5 pregnant Rhesus monkeys using Seldinger and radially expanding techniques. Cannula removal was followed by insertion of a collagen sponge plug and oversewing of the myometrium. Mini-hysterotomies with purse-stringing provided excellent access to the amniotic cavity, without dissection of the membranes. Classic Seldinger technique with forward dilatation was equally effective, but caused stretching of membranes. In sheep and in primates, Seldinger technique with radial dilatation allowed safe access without membrane separation. Leak-proof removal of the cannulas was achieved in all primates. Open hysterotomy with purse-string and balloon-tipped cannula provides efficient and safe access to the gravid sheep uterus. Seldinger technique allows equally secure access, and alleviates the need for hysterotomies. Radial dilatation of the porthole eliminates forward dissection of the membranes, both in sheep and primate models. This method, and collagen plug insertion upon completion of the endoscopic procedure, may provide a truly minimally invasive approach to in-utero surgery.

The successful treatment of symptomatic, refractory hepatic hydrothorax with transjugular intrahepatic portosystemic shunt.

Hepatic hydrothorax is a rare complication of portal hypertension. Conservative therapy may be successful but refractory hepatic hydrothorax is not uncommon. Management of refractory hydrothorax is usually ineffective and can result in a worsened clinical status. Transjugular intrahepatic portosystemic shunts (TIPS) lower portal pressure and have been used in the treatment of refractory ascites. The aim of this study was to determine the efficacy of TIPS in the treatment of symptomatic refractory hepatic hydrothorax. A TIPS was placed in 24 consecutive cirrhotic patients with symptomatic refractory hepatic hydrothorax. Five patients (20.8%) were Child's/Pugh class B and 19 (79.2%) were class C. All had undergone multiple thoracenteses and were hypoalbuminemic. Mean follow-up was 7.2 months (range, 0.25-49 months). Fourteen (58.3%) of 24 patients had complete relief of symptoms after shunt placement and did not require further thoracentesis. Five (20.8%) additional patients required fewer thoracenteses. Five (20.8%) patients developed worsening liver function and died within 45 days. In eight (66.7%) of 12 patients with > or = 60 days of follow-up, the serum albumin increased by a mean of 1.2 g/dL (range, 0.1-2.2 g/dL). The Child's-Pugh score improved in 7 (58.3%) of these 12 patients and two patients improved from class C to class A. These two patients no longer require liver transplantation. This study shows that TIPS can be effective in the management of symptomatic, refractory hepatic hydrothorax. Clinical and laboratory improvement may be seen and liver transplantation may become unnecessary.

A modified feeding Roux-en-Y jejunostomy in the neurologically damaged child.

PURPOSE: Feeding tube access with an antireflux procedure is frequently necessary in children with severe neurological deficits. Fundoplication in this particular group of patients has many complications and a reported failure rate of 40% to 50%. Recently, the use of a feeding Roux-en-Y jejunostomy has been advocated in this population. METHODS: Since December 1993, over a 6-month period, the authors performed 12 Roux-en-Y jejunostomies. All children had documented gastroesophageal reflux. One patient had a prior failed Nissen fundoplication, and none of these patients were feeding significantly by mouth. Postoperative follow-up has been 12 months. RESULTS: There were no deaths in this series. One patient required early revision of the stoma because of marked prolapse. One 11-month-old infant required reoperation 7 days postoperatively because of tube dislodgment. Eight of the 12 patients required out-patient procedures to unplug or replace the jejunostomy tube. CONCLUSION: The operation may be beneficial in a subset of neurologically impaired children who will never be able to ingest significant calories by mouth. It may also be useful after a failed fundoplication. The main postoperative complications were plugging and dislodgment of the jejunostomy tube, which if they occurred early, required x-ray confirmation for catheter placement.

Pearls and perils in the management of prolonged, peculiar, penetrating esophageal foreign bodies in children.

BACKGROUND/PURPOSE: Most retained esophageal foreign bodies (FB) are identified soon after ingestion and are easily extracted. A minority of FB ingestions are not identified for weeks to years and present significant problems for retrieval. The purpose of this study was to describe the diagnostic and therapeutic strategies needed to care for children who have chronic esophageal FBs. METHODS: Five children were identified as having retained esophageal FBs 2 months to 2 years after ingestion. During the same 3-year period, 100 children who had acute FBs were identified and had their foreign bodies removed endoscopically. The average age of the children was 3 years (range, 2.4 to 3.5). RESULTS: The average age of the five children identified in this study was 3 years. The items ingested included coins, a heart pendant, a clothespin spring, and a toy soldier. Complications from chronically retained foreign bodies were bronchoesophageal fistula, mediastinitis, esophageal diverticulum, and lobar atelectasis. One patient died from an aortoesophageal fistula. In all children, endoscopic removal was attempted. Barium esophagram was then performed, and foreign bodies were eventually removed via right thoracotomy. CONCLUSIONS: Long-retained esophageal FBs are extremely morbid and life threatening. History most often identifies excess salivation, new onset asthma, and/or recurrent upper respiratory infections. Three diagnostic adjuncts are helpful in identifying the presence of a long retained FB: (1) Chest x-ray (PA and lateral), (2) barium swallow, and (3) esophagoscopy. Indications for thoracotomy for removal of foreign body include (1) Poor endoscopic visualization of FB because of inflammatory tissue and (2) Herald bleeding during endoscopy.

Should iodine be reconsidered in wound management?

A report of a consensus meeting on the use of iodine in wound care.

Child abuse as a cause of traumatic chylothorax.

Chylothorax is an uncommon condition that may be associated with significant morbidity and mortality. The authors report a case of traumatic chylothorax attributed to child abuse and describe our management with tube thoracostomy and nutritional support with medium-chain triglycerides. Child abuse should be suspected in any case of chylothorax when no other etiology is evident and particularly when other signs of abuse are present.

Management of thoracolaryngopelvic dysplasia.

We report a family in which three members have thoracolaryngopelvic dysplasia (Barnes' syndrome). This family illustrates the phenotypic variability seen in this rare clinical entity and highlights the medical and surgical management necessary in such cases.