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Biomedical subjects

C G Howell

Publications and source records attributed to C G Howell.

35 records · Page 2Linked to original sources
PubMed1989

Bypass circuits as the source of thromboemboli during extracorporeal membrane oxygenation.

To determine the presence and extent of thrombus formation in the apparatus used for extracorporeal membrane oxygenation we studied various portions of the polyvinylchloride circuit from five infants who received extracorporeal membrane oxygenation for 70 to 330 hours. All infants had right-sided cannulation. Sections were cut from the circuit at the time of decannulation and subjected to light and scanning electron microscopy. The site that contained the most thrombus formation was the membrane oxygenator bypass circuit, which is subjected to repeated periods of unclamping and clamping to direct blood flow through the membrane oxygenator. Autopsy results from nonsurvivors showed evidence of pulmonary and renal infarcts, a left frontal lobe infarct, a thromboembolus of the left external and internal carotid arteries, and thrombi in the lungs, kidney, brain, and coronary arteries. One survivor had computed tomographic evidence of infarction of the left middle cerebral artery distribution. We suggest that the areas of the extracorporeal membrane oxygenation circuit subjected to repeated changes in flow dynamics may be the source of microemboli.

Catheters, Indwelling↗
PubMed1988

Successful gastrorrhaphy on ECMO.

From April 1985 to November 1987, over 100 infants were evaluated for extracorporeal membrane oxygenation (ECMO) in the treatment of respiratory failure. Of these infants, 40 underwent ECMO after failure of conventional treatment. Four developed gastroduodenal perforations. One developed a perforation prior to going on ECMO and died after several hours on ECMO, one developed a perforation while being treated conservatively for respiratory failure that never required ECMO, and two developed perforations requiring laparotomy while on ECMO. These two infants constitute the first report of successful gastrorrhaphy in infants while being supported by ECMO and anticoagulation with heparin. Particular measures helpful in the management of these infants included near-total cardiopulmonary bypass, reduction of the activated clotting time to 170 to 200, transverse abdominal incision for exposure, use of electrocautery, appropriate drainage of the operative site, insertion of a gastrostomy for gastric decompression and irrigation, rapid weaning from ECMO as soon as respiratory support could be provided by conventional methods, and the use of massive blood and platelet transfusions. In summary, 33 of 40 infants undergoing ECMO survived. Furthermore, two of the three infants with intestinal perforation who underwent ECMO have survived without significant short-term sequelae, and are 24 and 30 months of age, respectively. Therefore, we believe that despite severe respiratory failure requiring ECMO and anticoagulation with heparin, infants with intestinal perforation can be managed surgically with anticipated survival and good long-term prognosis.

Duodenal Diseases↗
PubMed1988

Right common carotid artery ligation in extracorporeal membrane oxygenation.

The effect of right common carotid artery ligation required for arteriovenous extracorporeal membrane oxygenation (ECMO) was investigated in 35 infants. Their neonatal course was reviewed for evidence of right-sided ischemia of the brain, as suggested by the presence of focal seizures, hemiparesis, focal abnormalities on electroencephalography, or infarct or hemorrhage demonstrable on neuroimaging studies. A significant incidence of left focal seizures (9/35) versus right focal seizures (2/35) was noted, suggesting an effect of the carotid ligation on right hemisphere function. Computed tomographic scans (20/35 infants), electroencephalograms (18/35), ultrasound scans (31/35), and neurologic examinations did not reveal an increased incidence of right hemisphere abnormalities. These data suggest that systematic evaluation of the effects of right common carotid ligation should proceed as discussion continues on expanding the use of ECMO.

Brain↗
PubMed1988

Childhood farm injury: the role of the physician in prevention.

Farm-related trauma occurs in more than 25,000 children per year with almost 300 patients dying from these preventable injuries. The incidence of associated farm-machinery injuries and fatalities is increasing at an alarming rate with the majority occurring in young boys during the summer months. Between 1979-1985, 234 patients with traumatic injuries were admitted to our Pediatric Surgery Service. Seven of these, six boys and one girl, age ranges from 2-15 years were treated for severe farm-related injuries. Modified injury severity score was calculated with an average score of 31.5 (range 9-66). Four patients sustained or required amputation of a major extremity(ies) as a result of the injury. Two patients had multiple long bone fractures with associated neurologic or abdominal injury. One patient exsanguinated from massive liver lacerations. Five of the six surviving patients are disabled to varying degrees because of their injuries. This report provides support for the establishment of federal safety standards for farm-related equipment. Guidelines for prevention are outlined. We believe that the child physician is obliged to encourage education programs in farming communities on safety measures and further should endorse the application for farms.

Accidents, Home↗
PubMed1987

Primary repair of esophageal atresia: how long a gap?

Primary esophagoesophagostomy is the treatment of choice for repair of esophageal atresia, particularly the more common type C atresia. Debate continues, however, regarding repair of the type A, or long-gap esophageal atresia. Since the pioneering work of Livaditis, Howard and Myers, the frequency of primary repair of long-gap atresia has increased. Interposition grafting, however, remains as the treatment for gaps longer than 6 cm or with absence of a distal intrathoracic esophageal segment. We report a case of primary esophagoesophagostomy with proximal esophagomyotomy in a 1,900-g infant with an absent distal intrathoracic esophageal segment and an eight vertebral body gap. Utilizing daily bougienage of the proximal and eventually the distal segment, a 1-cm gap was present at 6 months of age. With intraoperative fluoroscopy, the distal intra-abdominal esophageal segment was manipulated thru the esophageal hiatus. Thru an extrapleural approach with a proximal esophagomyotomy, a delayed primary anastomosis was successfully performed. She is currently 3 years old and has a normal barium swallow without stricture or gastroesophageal reflux.

Dilatation↗
PubMed1987

Esophageal stricture secondary to Stevens-Johnson syndrome.

We report a 7-year-old male with ampicillin-induced Stevens-Johnson syndrome with subsequent extensive skin, conjunctival, oropharyngeal, and laryngeal involvement. Over the next 5 months, he developed complete blindness and dysphagia. A barium swallow revealed absence of both right and left pyriform sinus, and a stricture involving the entire esophagus. Retrograde dilatations, complicated by malignant hyperthermia, have subsequently allowed for the difficult progression from an eight to a 40 French bougie. Eighteen months since the diagnosis of esophageal stricture, he has a normal appearing esophagus and is swallowing without difficulty.

Ampicillin↗
PubMed1986

Hemodialysis access: elevated basilic vein arteriovenous fistula.

Vascular access in the pediatric patient with endstage renal disease (ESRD) can be a surgical challenge to perform as well as maintain. We have recently developed a new technique of elevating the basilic vein in the upper arm for the arteriovenous (AV) fistula instead of using a polytetrafluoroethylene (PTFE) graft. During the past 2 years, 66 patients with ESRD and unsuitable superficial veins have had basilic vein elevation. Of these 66 patients, four have been in children, aged 11 to 19 years. The technique of mobilization of the vein from the elbow to the axilla was similar to that described by Dagher et al except that we used one long incision. The new feature of this technique is that the vein is not rerouted laterally through a subdermal tunnel. Instead, after the AV fistula to the side of the brachial artery is created, the vein is elevated within the incision by closing the subcutaneous fascia beneath, and the skin over, the vein. Most veins could be used in 2 to 4 weeks. Of the entire group, the patency rate has been 55 of 66 (83.3%), with no infections or long-term morbidity. Of the four pediatric patients, there have been no thromboses or infections. We believe the operation to be easier to perform than the standard PTFE bridge graft. The subsequent AV fistula is easy to access, less likely to cause a "steal syndrome," less likely to become infected, and if it does become infected, more likely to respond to treatment with antibiotics.

Adolescent↗
PubMed1984

High resolution computed tomography in neonatal nasopharyngeal teratoma.

A case of neonatal teratoma of the nasopharynx associated with polyhydramnios and respiratory distress is presented. Surgical excision was carried out after preoperative evaluation with high resolution CT. Computed tomography is valuable in distinguishing a teratomatous tumor and in searching for intracranial extension and malignant characteristics.

Female↗
PubMed1983

Jejunal mucosal graft for biliary tract disruption following traumatic trisegmentectomy of the liver.

A patient with near-fatal blunt trauma to the liver was subsequently found to have complete disruption of the left hepatic and common ducts. Establishment of biliary-enteric drainage by means of Roux-en-Y jejunal limb required the use of a specially designed Silastic transhepatic stent. This stent provided direct contact between the jejunal mucosal graft and the recessed left hepatic duct. Guidelines for biliary tract reconstruction are discussed.

Bile Ducts↗
PubMed1983

Antenatal diagnosis and early surgery for choledochal cyst.

The pathogenesis and optimal treatment of choledochal cyst have long remained questions of considerable speculation and dispute. Because the pregnancy of a 37-year-old woman was felt to be at risk, five antenatal ultrasound examinations were made. The fourth examination at 31.5 weeks of gestation demonstrated a choledochal cyst. Following birth, the child was studied with repeat ultrasound examinations and scintigraphy. The results of these studies plus the findings at surgery contributed new evidence regarding the possible pathogenesis and optimal treatment of choledochal cysts. Although the time at which the cyst originated is compatible with the concept of reflux of pancreatic juice into the common duct, no abnormal junction of the pancreatic and common duct was identified. No evidence of obstruction as part of the pathogenesis could be demonstrated. Progressive changes in the choledochal cyst in the first ten days of life suggested that delay in diagnosis and treatment of a choledochal cyst may contribute to early complications such as cholangitis. Early excision of the cyst in the newborn is considered to be the optimal treatment and may pose less risk to the patient than delayed surgical exploration.

Common Bile Duct Diseases↗
PubMed1983

Rectosigmoid perforation and intestinal evisceration from transanal suction.

Transanal suction injuries were sustained in 1981 by five children when they sat upon uncovered swimming area drain sites. Tears of the rectosigmoid areas occurred in each with associated evisceration and loss of substantial amounts of small intestine because of mesenteric separation. These cases are reviewed.

Child, Preschool↗
PubMed1982

Therapy and outcome in 51 children with mesoblastic nephroma: a report of the National Wilms' Tumor Study.

Mesoblastic nephroma is a distinctive pathologic renal tumor with unique clinical, therapeutic, and prognostic patterns. This report reviews 51 patients (2.8% of 1905 patients submitted to NWTS with renal tumors) with this diagnosis from the NWTS contrasting this disease entity with Wilms' tumor. There were 33 males and 18 females, predominantly term babies born after uncomplicated pregnancies. The mean age at tumor excision was 3.44 +/- 0.6 mo (one child 9 yr). A palpable mass was the predominant presentation in 48 patients and in addition hematuria (9), hypertension (2), vomiting (3), and jaundice (1) were noteworthy. Diagnostic studies included IVP (49 positive, 2 negative) and ultrasound (15 positive, 1 negative). Adequate operative excision was achieved in 43 of 51 patients while 8 children had local extension and 10 had tumor spillage. Operation alone (23), predominantly since 1978, surgery plus chemotherapy (24), prior to 1978, and surgery, chemotherapy, and radiation therapy (4), prior to 1976, were the modes of therapy. The follow-up ranges from 4 mo to 11.5 yr. Survival was excellent; 50 patients survive (98%), only 1 dying of sepsis. These data suggest that mesoblastic nephroma contrasts with Wilms' tumor in that it occurs in a younger age group, has a benign biologic behavior, and a more favorable outcome. Aggressive multimodal treatment though utilized in the early years of the study is not essential to achieve this outcome.

Age Factors↗