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Biomedical subjects

M L Blakely

Publications and source records attributed to M L Blakely.

At least 19 recordsLinked to original sources

The role of laparoscopy in the management of common bile duct obstruction in children.

BACKGROUND: Laparoscopic common bile duct exploration is commonplace in adults; however, this procedure is not often performed in children. The goal of this study was to evaluate the results of laparoscopic common bile duct exploration in children. METHODS: Of 50 patients undergoing laparoscopic cholecystectomy, six patients (12%) had obstructing lesions of the common bile duct (CBD). Five children underwent laparoscopic common bile duct exploration, and one child had a preoperative endoscopic sphincterotomy and stone removal. RESULTS: The mean age at laparoscopic CBD exploration was 11.6 years (range, 5-16). The obstructing lesion was visualized by intraoperative cholangiography in all five patients. The mean operative time for laparoscopic cholecystectomy along with CBD exploration was 215 min (range, 160-282). The transcystic laparoscopic CBD exploration was performed using a 7-Fr, multichannel rigid, or 10-Fr flexible fiberoptic cystoscope. The stones were either pushed into the duodenum with the scope or extracted through the cystic duct using a 3-Fr Segura basket. In one patient, a candidial ball disintegrated during an attempt to remove it with the basket. A repeat cholangiogram at the end of each procedure showed an anatomically normal CBD with free flow of contrast into the duodenum. All patients enjoyed a quick recovery. They were started on a regular diet on the same day of surgery and discharged on the 1st or 2nd postoperative day. One patient with sickle cell disease developed a pulmonary infarction and required 5 additional days of hospitalization. One patient developed recurrent choledocholithiasis 6 months after laparoscopic exploration and was treated successfully with endoscopic sphincterotomy and stone extraction. CONCLUSIONS: Laparoscopic CBD exploration can be performed safely at the time of the cholecystectomy in children. Endoscopic sphincterotomy before cholecystectomy is not necessary. We recommend laparoscopic CBD exploration for obstructing lesions of the CBD. Endoscopic sphincterotomy should be reserved for recurrent lesions of the CBD after laparoscopic cholecystectomy.

Adolescent↗

Laparoscopic pancreatectomy for persistent hyperinsulinemic hypoglycemia of infancy.

BACKGROUND: A 4-week-old male infant (4.9 kg) with persistent hyperinsulinemic hypoglycemia of infancy (PHHI) underwent a laparoscopic pancreatectomy to evaluate its feasibility. Preoperative medications included diazoxide and glucagon to maintain adequate blood glucose levels. METHODS: Laparoscopic pancreatectomy was performed using a 5-mm cannula at the umbilicus, external fixation, transcutaneous suture-assisted gastric retraction to expose the lesser sac, and three additional 3.5-mm cannula sites. The pancreas was resected from the splenic hilum to the mesenteric vessels. The splenic vein was dissected from the under surface of the pancreas using electrocautery, and the spleen was easily preserved. Surgery time was 75 min, and minimal blood loss occurred. RESULTS: The child required no narcotic medication and tolerated a regular diet immediately after surgery. Serum glucose levels did decrease postoperatively, and the child required diazoxide, dextrose infusion, glucagon, and octreotide. On postoperative day 7, the child underwent an open near-total pancreatectomy, after which he remained asymptomatic. Essentially no scarring was found in the lesser sac, and the remaining pancreatic remnant was resected without difficulty. CONCLUSIONS: Laparoscopic pancreatectomy can be performed safely, even in a newborn patient, without prolonged operative time or unnecessary risk. The technique using external fixation and transcutaneous suture-assisted gastric retraction provides excellent exposure to the pancreas and lesser sac. In patients with PHHI, in whom reoperative additional pancreatectomy is very likely, this technique is the ideal initial surgical approach.

Humans↗

The association of elevated percent bands on admission with failure and complications of interval appendectomy.

BACKGROUND/PURPOSE: The routine use of interval appendectomy for the treatment of perforated appendicitis, with or without abscess, remains controversial. The purpose of this study is to confirm the efficacy of this approach and to identify factors associated with failures and complications. METHODS: All patients (n = 101) with their clinical diagnosis of perforated appendicitis confirmed with imaging were treated prospectively with fluids and intravenous antibiotics (clindamycin, ceftazidime) and were discharged home on oral fluids and analgesics regardless of fever. Intravenous antibiotics were continued at home until the patients were afebrile for 48 hours, and their white blood cell and differential counts were normal. Patients were readmitted at 8 to 12 weeks for an interval appendectomy. Failure to improve by 72 hours of antibiotic therapy mandated an early appendectomy. P values were determined by chi(2) analysis and Student's t test. RESULTS: The 79 patients (78%) successfully treated with interval appendectomy had an overall 6.3% complication rate, and total hospitalization averaged 5.2 days. The treatment in 21 of 22 patients (22%) requiring early appendectomy failed because of a clinical picture suggesting small bowel obstruction. The patients with the failed procedures had a complication rate of 50% and were hospitalized an average of 12.8 days. The overall complication rate for the 101 patients was 15.8%, and the overall total hospitalization was 6.9 days. Patients requiring early appendectomy had a more frequent finding resembling a small bowel obstruction on their initial x-ray (50% v 13%, P = .004) and a higher percent band count on their initial differential blood cell count (22.6% v 7.6%, P<0.0001) than did those successfully treated with interval appendectomy. An initial band count <15% was predictive of an uncomplicated course (84% positive predictive value). CONCLUSIONS: Interval appendectomy without complications is successful in the majority of patients with perforated appendicitis. An elevated initial band count > or =15% is associated with an increased likelihood of failure and complications.

Adolescent↗

Surgery-associated complications in necrotizing enterocolitis: A multiinstitutional study.

PURPOSE: This study was designed to evaluate the wound and stomal complication rate associated with surgical intervention in infants with necrotizing enterocolitis (NEC). METHODS: Comprehensive demographic and perioperative data were collected prospectively from 4 separate university hospitals on 51 infants with surgically treated NEC. The postoperative complication rate included wound (infection, dehiscence) and stomal (prolapse, retraction, necrosis, stricture) problems. For analysis, patients were grouped based on gestational age less than 28 weeks (group I, n = 30) and >/=28 weeks (group II, n = 21). Z-score analysis was used for intergroup evaluation. RESULTS: Significantly more infants in group I (21 of 30 [70%] versus group II, 6 of 21 [29%]; P <.001) were treated initially with Penrose drainage alone, but most eventually underwent laparotomy (group I, 28 of 30 [93%] versus group II, 19 of 21 [91%]; P value, not significant). The combined stomal/wound complication rate was significantly higher in group I (14 of 30 [47%]) versus group II (6 of 21 [29%]; P <.025). Of 51 patients, one operation was required in 23 (45%), 2 in 18 (35%), 3 in 8 (16%), and 4 in 2 (4%). CONCLUSIONS: Although the stomal/wound complication rate was significantly higher in group I, both groups had very substantial complication rates, emphasizing the vulnerability of this infant population. Parents, especially of very premature babies, should be advised that multiple operations are likely and that complications should be expected.

Enterocolitis, Necrotizing↗

Controversies in the management of Wilms' tumor.

Wilms' tumor is the most common malignant renal tumor of childhood; it represents 5% to 6% of childhood cancers in the United States. The survival rate of children with Wilms' tumor has improved dramatically, partly due to large multicenter studies conducted by the National Wilms' Tumor Study Group and the International Society of Pediatric Oncology. To ensure optimal patient outcome, the surgical management of these patients must be appropriate. Controversial issues in the management of Wilms' tumor include the value of preoperative chemotherapy; whether pre-resection biopsy is indicated and if so, how this is best performed; indications for partial nephrectomy; the treatment of low-risk patients with surgery only; and the reliability of preoperative imaging to assess the contralateral kidney.

Chemotherapy, Adjuvant↗

The impact of margin of resection on outcome in pediatric nonrhabdomyosarcoma soft tissue sarcoma.

BACKGROUND/PURPOSE: Because the management of pediatric nonrhabdomyosarcoma soft tissue sarcomas (NRSTS) is determined by extrapolation from adult studies, the effect of margin of tumor resection and postoperative radiation therapy (RT) on local tumor recurrence in children has not been assessed. METHODS: Records of NRSTS patients from a single institution were reviewed with regard to demographic data, TNM staging, grade, histological type and site of primary tumor, RT, and local tumor recurrence. The margin of resection was determined by pathological review and did not necessarily reflect operative margins. RESULTS: Eighty-eight clinical group I patients were treated over a 30-year period. The most common histological tumor subtypes were synovial cell sarcoma (n = 26), malignant fibrous histiocytoma (n = 17), and fibrosarcoma (n = 7). The mean age was 9.4 years (range, 0 to 29 years). Thirty-four patients had high-grade tumors. Two of ten patients with low-grade tumors and margins less than 1 cm, including one of five who had received RT, had a local recurrence. Patients with low-grade tumors and margins greater than 1 cm (n = 44) had a lower recurrence rate (2 of 44, 4.5%). None of these patients had received RT. Fourteen patients with high-grade tumors had margins less than 1 cm. Seven of these had RT and had no recurrence. Three of the seven patients who received no RT had a recurrence (42.9%). None of the 20 patients with high-grade tumors and margins greater than 1 cm received RT; four of these patients had recurrences (20%). Seven of the 12 irradiated patients (58.3%) had serious radiation-associated complications (wound dehiscence, fracture, growth retardation, and joint dysfunction). CONCLUSIONS: Grade alone does not determine the rate of local recurrence. In both low- and high-grade tumors, a pathological margin of resection greater than 1 cm reduced local recurrence. Radiotherapy provided no advantage in low grade tumors but did decrease local recurrence rates in high-grade tumors with less than 1 cm pathological margins.

Adolescent↗

Does debulking improve survival rate in advanced-stage retroperitoneal embryonal rhabdomyosarcoma?

UNLABELLED: BACKGROUND, METHODS, AND PURPOSE: The authors examined demographic and clinical features, therapy, and outcome of patients with advanced (group III or IV) rhabdomyosarcoma (RMS) of the retroperitoneum and nongenitourinary pelvis treated in the Intergroup Rhabdomyosarcoma Study Group (IRSG) III (1984 to 1991, n = 41) or IV pilot (1987 to 1991, n = 53) studies to assess the role of initial debulking surgery. RESULTS: Ninety-four patients with retroperitoneal primary tumors and gross locoregional residual tumor (group III, n = 53) or metastatic disease (group IV tumors, n = 41) were treated with combination chemotherapy (ie, vincristine, dactinomycin, and cyclophosphamide with or without other agents plus radiation therapy, RT) after biopsy only or subtotal resection. These retroperitoneal tumors usually were invasive (T2, 76%). Most patients were younger than 10 years of age (n = 69, 73%), the male to female ratio was 1.4, and tumors usually were embryonal (n = 64, 68%). Overall 4-year failure-free survival (FFS) was 50%; survival was 60%. Survival rate was better for girls (4-year survival rate, 75% v49% for boys; P = .05) and was not significantly different for patients treated in IRS-III (66%) or IRS-IV pilot (52%). However, it was better for patients with embryonal versus alveolar or undifferentiated tumors (4-year survival rate, 70% v 42%; P = .002). In adolescents, RMS is different from that seen in children less than 10 years old; most cases are alveolar or undifferentiated (16 of 29, 55%). Surgery for most (21 of 24) patients with alveolar tumors comprised biopsy only. By contrast, of 64 patients with embryonal tumors, 39 (61%) underwent biopsy only, whereas 25 (39%) had debulking surgery. Patients whose tumors were debulked fared better than those whose tumors underwent biopsy only (4-year FFS rate, 72% v48%; P = 0.03). Patients with group IV embryonal tumors fared unexpectedly better than those with group IV alveolar or undifferentiated tumors (70% versus 42% 4-year survival rate, P < .05), and patients less than 10 years of age with group IV embryonal tumors had 4-year survival rate of 77%, indicating the importance of the biology of these tumors. CONCLUSIONS: Multimodal therapy, including multiagent chemotherapy plus RT, appears to improve survival rate in patients with advanced embryonal RMS arising in the retroperitoneum. These data suggest that debulking tumors of embryonal histology improves outcome further. This approach will be assessed in IRSG V.

Adolescent↗

Physiologic consequences of pneumonectomy. Long-term consequences of pneumonectomy done in children.

Lung resections in children are performed for a variety of reasons including congenital malformations, infections, bronchiectasis, and tumors. There are no long-term reports on pneumonectomy alone in children, but those on lung resection as a group state that children tolerate these operations well, with mild sequelae if any, and that the majority of them in adulthood can perform non-physically demanding jobs adequately. The authors' findings concur with the reports that younger patients can endure pulmonary resections with minimal functional limitations.

Adolescent↗

Current status of laparoscopic appendectomy in children.

Appendectomy is the most common surgical emergency in children. Laparoscopic appendectomy (LA), first performed by Semm in 1983, has increased in popularity for both uncomplicated and ruptured appendicitis. The authors perform early laparoscopic appendectomy for acute uncomplicated appendicitis, but use aggressive antibiotic therapy for obvious ruptured appendicitis. Patients presenting with accessible abscesses have drainage using image guidance. Antibiotic therapy is continued at home until the fever has resolved and the white blood cell and differential counts have normalized. An interval appendectomy is performed 2 to 3 months later. Children with ruptured appendicitis for whom aggressive medical management had failed usually had a persistent pattern of small bowel obstruction noted 72 hours after initiation of treatment. The authors' preferred technique for laparoscopic appendectomy employs linear stapling of the mesoappendix and appendix. LA patients had a shorter hospital stay and a lower wound infection rate. The operating times for open and laparoscopic appendectomy were similar.

Appendectomy↗

Current status of laparoscopic appendectomy in children.

Acute appendicitis is the most common surgical emergency in children. Open appendectomy has been the standard treatment for decades, with excellent results. Owing to advances in pediatric laparoscopic instrumentation and increased experience with the technique of laparoscopy, however, many centers are routinely performing laparoscopic appendectomy in children. Most studies show a marginal advantage of laparoscopic appendectomy over open appendectomy with regard to length of hospitalization, postoperative analgesia use, length of time until return to full activity, and wound infection rate. There is a wide range of clinical presentation in children with acute appendicitis, from mild inflammation of the appendix to ruptured appendicitis with diffuse peritonitis or localized abscess formation. Patients with ruptured appendicitis have many more complications regardless of the surgical approach. Prospective, randomized studies specifically in children are needed to answer remaining questions regarding any potential benefit of laparoscopic appendectomy and for which patients this technique is best suited.

Appendectomy↗

Laparoscopic appendectomy in children.

Laparoscopic appendectomy is a common surgery in most pediatric surgical centers. Many studies, mostly retrospective reviews in adults, show the advantages of the laparoscopic approach to be less wound infections, shortened postoperative recovery, and faster return to normal activities. In addition, less analgesic medication is required postoperatively. Potential disadvantages of laparoscopic appendectomy include an increased operative time, elevated costs when disposable instruments are used, and possibly more infectious complications when performed for complicated appendicitis. There are no prospective, randomized trials comparing laparoscopic versus open appendectomy in children. Until these studies are completed, questions will persist regarding the benefits of laparoscopic appendectomy in children.

Adult↗

Activation of intragraft endothelial and mononuclear cells during discordant xenograft rejection.

Most studies of discordant xenograft rejection have focused on the roles of recipient xenoreactive antibody and complement as mediators of hyperacute rejection; there are essentially no data from in vivo studies as to the contribution of endothelial cell responses to the pathobiology of xenograft rejection. We hypothesized that the mechanism by which xenoreactive natural antibodies and complement of the recipient are involved in rejection of a discordant, immediately vascularized xenograft involves donor organ endothelial cell activation, with the consequences of such activation contributing significantly to the rejection process. We performed a kinetic analysis of rejection of guinea pig hearts by untreated Lewis rats or recipients depleted of complement activity that underwent delayed xenograft rejection. We report that in both hyperacute rejection and delayed xenograft rejection there is widespread evidence of endothelial cell activation, including expression of P-selectin and E-selectin, upregulation of tissue factor, and downregulation of thrombomodulin and antithrombin III expression. Many of these changes occur very early posttransplantation in grafts that are not completely rejected until approximately 3 days. In delayed xenograft rejection, an intense cellular infiltrate is seen that results from progressive accumulation of activated macrophages and natural killer cells. T cell receptor alpha/beta+T cells are present only at relatively low levels. This cellular infiltrate is associated with dense expression of pro-inflammatory cytokines, including interferon gamma, interleukin 1, and tumor necrosis factor-alpha. We conclude that both endothelial cell activation and infiltration by activated macrophages and natural killer cells may play an important role in xenograft rejection. These newly described features of the xenogeneic rejection response may require targeting by future therapeutic regimens aimed at prolonging xenograft survival.

Animals↗