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Biomedical subjects

T F Tracy

Publications and source records attributed to T F Tracy.

At least 19 recordsLinked to original sources
PubMed2003

Open and laparoscopic appendectomy are equally safe and acceptable in children.

BACKGROUND: The aim of this study was to evaluate prospectively whether laparoscopic (LA) and open appendectomy (OA) are equally safe and feasible in the treatment of pediatric appendicitis. METHODS: A total of 517 children with acute appendicitis were randomly assigned to undergo LA or OA appendectomy, based on the schedule of the attending surgeon on call. Patient age, sex, postoperative diagnosis, operating time, level of training of surgical resident, length of postoperative hospitalization, and minor and major postoperative complications were recorded. Chi-square analysis and the Student t-test were used for statistical analysis. RESULTS: In all, 376 OA and 141 LA were performed. The two groups were comparable in terms of patient demographics and the incidence of perforated appendicitis. The operative time was also similar (47.3 +/- 19.7 vs 49.9 +/- 12.9 min). The overall incidence of minor or major complications was 11.2% in the OA group and 9.9% in the LA group. CONCLUSION: Pediatric patients with appendicitis can safely be offered laparoscopic appendectomy without incurring a greater risk for complications. Nevertheless, a higher (but not significantly higher) abscess rate was found in patients with perforated appendicitis who underwent laparoscopy.

Abdominal Abscess↗
PubMed2003

Minimal-access fetal surgery for twin-to-twin transfusion syndrome.

BACKGROUND: Laser ablation of placental vessels effectively halts severe twin-to-twin transfusion syndrome (TTTS), but fetal surgery remains a dangerous approach. The authors present the technical aspects of endoscopic fetal surgery in their initial clinical experience. METHODS: Altogether, 11 women underwent endoscopic fetal surgery for severe TTTS. Access to the recipient's sac was obtained by the Seldinger technique via minilaparotomy. A 12-Fr peel-away introducer was used as a cannula to accommodate a custom-curved 9-Fr sheath containing a 1.9-mm semirigid fiber endoscope. Laser ablation was performed on all unpaired vessels crossing the intertwin membrane using a 400- micro m neodymium: yttrium-aluminum-garnet (Nd: YAG) fiber. The cannula was removed over a gelatin sponge plug. RESULTS: The median operating time was 65 min (range, 45-105 min). No patient experienced amniotic leak postoperatively. The length of hospital stay was 2.8 +/- 1.6 days. Immediate improvement of the TTTS was noted in all but two patients. Pneumonia developed, in one mother leading to premature labor. There were no other major surgical complications. Fetal survival at 2 weeks was 73%. CONCLUSIONS: The safety and efficacy of endoscopic fetal surgery for severe TTTS can be optimized with the application of current minimal-access techniques. The superiority of this approach over less invasive means is still being evaluated through prospective studies.

Adult↗
PubMed2002

Laparoscopic gastrostomy in infants and children.

Gastrostomy is a common procedure in children. Percutaneous endoscopic gastrostomy (PEG) is less traumatic than open surgery, but carries a higher risk in small children. We report our experience with laparoscopic gastrostomy, which appears to combine the advantages of the PEG and the safety of an open operation. Operative technique. An umbilical port (5 or 10 mm, depending on the patient's weight) and a left subcostal cannula (site of the future gastrostomy) are used. The stomach is pulled to the abdominal wall with two T-anchors, and the gastrostomy is performed using the Seldinger technique. A 17-Fr peel-away sheath is placed, through which a 5 mm endoscope is introduced to confirm its intragastric position. A 14-Fr balloon gastrostomy tube or button is then introduced. Results. Fifty-one children, aged 0 to 19 years (mean 4.4 +/- 6.4 years), underwent a total of 54 laparoscopic gastrostomies in a 42-month period. Thirty-three patients were younger than 2 years, and 22 weighed less than 5 kg. Thirty-three children had failure-to-thrive, 12 suffered from cerebral palsy and 8 from cystic fibrosis. Operative time was 33.6 +/- 14.3 minutes; in 18 cases, a concomitant Nissen fundoplication was performed (total operative time 76.5 +/- 58.7 minutes). In all cases, gastrostomy feedings were started the following day, and hospital stay in the gastrostomy-only group was 3.3 +/- 0.6 days. There were two (recognized) perforations of the back wall of the stomach, which were repaired laparoscopically, and two tube dislodgments, at 24 hours and at 4 months, requiring reoperation. Conclusions. Laparoscopy allows a quick and simple technique of gastrostomy placement under direct vision in even the smallest newborn and infant. It carries minimal operative risks and allows initiation of feedings within 24 hours.

Adolescent↗
PubMed2001

Institutional Review Board approval for prospective experimental studies on infants and children.

BACKGROUND/PURPOSE: The Declaration of Helsinki requires Institutional Review Board (IRB) approval for experimental studies on human subjects. The authors questioned whether published prospective surgical experimental studies document IRB approval for infants and children. METHODS: Prospective studies were identified in 5 surgical and 2 major pediatric journals from 1997 through 1999. Documentation of IRB approval was recorded. Results were analyzed using Pearson chi(2) tests and a multivariate regression model. Statistical significance was defined as P less than .05. RESULTS: A total of 149 prospective experimental studies on pediatric subjects were evaluated; the majority being interventional or therapeutic studies (105 of 149). More than 75% were from academic medical centers (125 of 149), grant-supported (110 of 149), and appeared in surgical journals (110 of 149). Slightly less than 25% of studies (40 of 149) documented IRB approval. Observational studies, grant support, and publication in nonsurgical journals all correlated positively with IRB approval and were statistically significant variables (P<.001, P<.001, P<.001, respectively). Interventional or therapeutic, institutionally or privately-funded studies found in surgical journals were most likely to avoid IRB documentation (P<.001). CONCLUSIONS: The majority of prospective pediatric studies in the surgical journals omit IRB documentation. Strict requirements for specific IRB approval and documentation in compliance with the Declaration of Helsinki would allow higher ethical standards for the clinical investigation of infants and children.

Chi-Square Distribution↗
PubMed2001

Macrophage phenotype during cholestatic injury and repair: the persistent inflammatory response.

BACKGROUND/PURPOSE: Biliary decompression for congenital or acquired obstruction (eg, biliary atresia) does not uniformly lead to liver repair, restore function, or prevent cholangitis. The authors hypothesize that failed repair is caused by altered macrophage (Mo) phenotypes central to an ongoing inflammatory and fibrogenic response. METHODS: In adult rats, biliary obstruction was performed by suspension of the common bile duct for 5 or 7 days. Decompression followed release of the loop until death during the course of liver repair. To determine Mo phenotype in the presence or absence of resident macrophages, animals were either administered gadolinium chloride or saline before injury and repair. At death, hepatic Mo were isolated, stained with MAC-1 (CD11b/CD 18) and OX-3 (MHC class II), and quantified with flow cytometry. Liver sections were immunostained for ED-1 and ED2; positive Mo were counted per square millimeter of tissue. RESULTS: Obstruction led to bile duct proliferation, fibrosis, and inflammation. Decompression relieved jaundice and ductal hyperplasia. After injury, hepatic Mo showed an 80% phenotypic conversion to MAC-1 and OX-3-positive cells. Cells isolated from livers at 9 days of repair persisted with 60% MAC-1 and 77% OX-3 expression. Gadolinium reduced Kupffer cells at all stages of repair. Recruited Mo in treated animals increased 4-fold greater than controls. CONCLUSIONS: Kupffer cells appear to limit the recruitment and persistence of a systemic macrophage phenotype in liver injury and repair. Cell surface markers for systemic macrophages appear after injury and persist during repair, despite adequate biliary decompression. After biliary decompression, this macrophage phenotype accounts for inflammatory complications such as cholangitis and ongoing fibrosis.

Animals↗
PubMed2001

Preoperative planning with magnetic resonance imaging and computerized volume rendering in twin-to-twin transfusion syndrome.

Our purpose was to illustrate the feasibility of preoperative planning with magnetic resonance imaging, 3-dimensional reconstruction, and volume-rendering techniques in twin-to-twin transfusion syndrome treated by endoscopic laser ablation of communicating vessels. After ultrasonographic determination of the syndrome and the indications for intervention, 2 patients with an anterior placenta underwent magnetic resonance imaging without the need for maternal or fetal sedation. Raw image data were downloaded into a desktop computer and manipulated with 3-dimensional reconstruction, volume rendering, and surgical navigation software. In both patients a virtual rendering of the fetuses, placenta, and uterus could be manipulated to expose all sides, demonstrate the location of the intertwin membrane, and plan the point of entry and curve of the endoscopic instruments. Preoperative planning and virtual surgical navigation in fetal surgery are now possible, as a result of shorter magnetic resonance imaging acquisition times and volume-rendering software. In this manner an entire virtual endoscopic fetal operation can be performed and fine-tuned before the actual procedure is to take place.

Endoscopy↗
PubMed2001

Clinical features of a human Rac2 mutation: a complex neutrophil dysfunction disease.

The case of an infant with multiple, rapidly progressive, soft-tissue infections is presented. Despite features suggesting a neutrophil disorder, results of screening tests of phagocyte function were normal. A novel, multifaceted leukocyte disorder-distinguished by defects in shape change, chemotaxis, ingestion, degranulation, superoxide anion production, and bactericidal activity-was established secondary to a defect in Rac2.

Blood Bactericidal Activity↗
PubMed2001

Aromatase p450 expression in a feminizing adrenal adenoma presenting as isosexual precocious puberty.

A 7-yr-old girl presented with isosexual precocious puberty secondary to a feminizing adrenal adenoma. The adrenal tumor was found to express aromatase messenger ribonucleic acid. Enzyme kinetic studies revealed a high level of aromatase activity in the adrenal tumor, with a K(m) of 45 nmol/L and a maximum velocity of 25.6 pmol/mg.h. Aromatase activity was approximately 500-fold higher in the tumor than in adjacent normal adrenal tissue. Although histopathological examination of the tumor was most consistent with a benign adenoma, the aromatase transcripts present in the tumor corresponded to those previously associated with malignant as well as benign tumors. We consider the pattern of aromatase expression sufficient to warrant continued follow-up for tumor recurrence. Our case demonstrates that isosexual precocious puberty secondary to a feminizing adrenal tumor can be due to estrogen synthesis from the tumor itself rather than peripheral aromatization as had been previously theorized.

Adenoma↗
PubMed2001

Effect of pediatric surgical practice on the treatment of children with appendicitis.

OBJECTIVE: Acute appendicitis in children is managed by both general surgeons (GSs) and pediatric surgeons (PSs). Our objective was to investigate the economics of surgical care provided by either GSs or PSs for appendicitis. METHODS: The outcome of children within our state who underwent operative treatment for appendicitis (January 1994 to June 1997) by board-certified GSs were compared with the results of PSs. Data were sorted according to patient age and diagnosis according to the International Classification of Diseases, Ninth Revision. Analysis of variance was performed on continuous data, and chi(2) analysis was performed on nominal data; data are depicted as mean +/- standard error of the mean. RESULTS: GSs (n = 2178) managed older children when compared with PSs (n = 1018; 11.0 +/- 0.1 vs 9.1 +/- 0.1 years) and less frequently treated perforated appendicitis (18.8% vs 31.9%). Independent of diagnosis (simple or perforated appendicitis), younger children (0-4 years, 5-8 years, and 9-12 years) who were treated by PSs had a significantly shorter hospital stay and/or decreased hospital charge when compared with those who were treated by GSs. However, older children (13-15 years) seemed to have comparable outcomes. CONCLUSIONS: Younger children with appendicitis have reduced hospital days and charges when they are treated by PSs.

Adolescent↗
PubMed2000

Kupffer cell inactivation delays repair in a rat model of reversible biliary obstruction.

BACKGROUND: During cholestatic liver injury, Kupffer cells (KC) and activated macrophages modulate cell proliferation and subsequent matrix deposition. The role of KC in the restoration of cell architecture and matrix metabolism during repair following chronic cholestatic liver injury is unknown. MATERIALS AND METHODS: To determine the effect of KC inactivation, adult male Sprague-Dawley rats underwent bile duct suspension (BDS) for 5 days followed by reversal of the obstruction. Saline (control) and gadolinium chloride (10 mg/kg) were administered 1 day prior to BDS and 1 day prior to reversal, to inactivate KC during both injury and repair. Serum bilirubin and quantitative cell morphometry were compared to verify the reversibility of the model. Collagen content of the liver was measured in trichrome-stained paraffin sections using NIH imaging software. RESULTS: Reversibility of the obstruction was verified by normalization of direct serum bilirubin, which peaked at 8.42 +/- 0.76 mg/dL following 5 days of BDS and returned to sham-operated levels 2 days after reversal, 0.36 +/- 0.15 mg/dL. Hematoxylin and eosin (H&E)-stained paraffin-embedded liver sections from gadolinium-treated animals at 4 and 7 days after reversal exhibited persistent bile duct proliferation, matrix deposition, and inflammation. Gadolinium-treated animals had altered collagen metabolism compared to saline controls. Whereas the collagen content in the saline group slowly returned to sham-operated levels over time, the treatment group demonstrated progressive accumulation of collagen during repair which was statistically significant at 7 days following reversal (8.79%/mm(2) +/- 2.17 in gadolinium group vs 2. 33%/mm(2) +/- 0.34 in saline group, P = 0.0003). CONCLUSIONS: These results demonstrate that inactivation of resident hepatic macrophages during liver repair impairs collagen metabolism, inhibits the resolution of fibrosis, and allows the persistence of inflammatory cell infiltrates in the portal areas. This is the first evidence of profibrogenic responses in the absence of an intact KC compartment during repair after cholestatic injury.

Animals↗
PubMed2000

Morphology of liver repair following cholestatic liver injury: resolution of ductal hyperplasia, matrix deposition and regression of myofibroblasts.

BACKGROUND/AIMS: Myofibroblasts are the primary cells responsible for increased matrix deposition in hepatic fibrosis. Activation of hepatic stellate cells and portal fibroblasts to myofibroblasts during cholestatic liver injury is accompanied by increased expression of the activation marker, alpha-smooth muscle actin (SMA), and collagen genes. In contrast to our understanding of injury, the cellular mechanisms of liver repair are not well defined. This study was designed to examine the morphological relationship between bile duct hyperplasia, matrix deposition and myofibroblast phenotype in a model of chronic cholestatic liver injury and repair. METHODS: Reversible extrahepatic obstruction was accomplished in rats using a soft vessel loop suspended from the anterior abdominal wall: duct manipulation alone was performed in sham-operated controls. After 7 days, rats were either sacrificed or decompressed by release of the loop and subsequently sacrificed 2-10 days after reversal. Liver sections were obtained for in situ hybridization for procollagen alpha1(I) mRNA, immunohistochemical staining for SMA and cytokeratin 19, and histochemical staining for reticulin. RESULTS: Cholestatic livers demonstrated bile duct hyperplasia, which reversed to normal within 10 days after decompression. Fibrosis was also substantially reduced during this period. SMA-positive myofibroblasts were abundant and localized to regions adjacent to proliferating ducts and excess matrix in the obstructed animals. Decompressed livers showed a dramatic time-dependent reduction in the number of SMA-positive cells and in the expression of procollagen I mRNA. CONCLUSIONS: Our results show that the disappearance of bile duct hyperplasia after biliary decompression is accompanied by a similarly rapid loss of SMA-positive myofibroblasts. Both cellular events may abrogate enhanced matrix synthesis and allow repair to occur.

Actins↗
PubMed2000

The unpredictable character of congenital cystic lung lesions.

BACKGROUND: The spectrum of congenital cystic disease of the lung ranges from hydrops and neonatal respiratory distress to asymptomatic lesions. Surgical management is dictated by the presence of symptoms, recurrent infection, and the potential risk of malignant transformation. METHODS: Since 1995, all consecutive patients with congenital cystic lung lesions underwent follow-up for symptoms, treatment, and correlation of presumptive with pathological diagnosis. RESULTS: Twelve cystic lung lesions were identified. Seven were diagnosed with mediastinal shift in utero; in 6 of 7, the shift subsequently resolved. Overall, 6 of 7 lesions that were followed up serially decreased in size. Two patients were symptomatic in utero; 1 underwent thoracoamniotic shunting, 1 pleurocentesis for impending hydrops. Postnatally, these 2, and 2 other newborns required urgent surgery. Five of 8 asymptomatic patients had elective resection by 16 months, and 4 await operation. In 6 of the 9 surgical cases (67%), there was a discrepancy between preoperative and pathological diagnosis. There were 4 hybrid congenital cystic adenomatoid malformation (CCAM)/sequestrations. CONCLUSIONS: At least 6 of 7 congenital cystic lung lesions decreased in size regardless of gestational age or presence of mediastinal shift. Antenatal intervention is therefore rarely indicated. Hybrid morphology may necessitate resection of stable, asymptomatic lesions to prevent the theoretical concern for associated malignancies as well as other complications of CCAM.

Adult↗
PubMed1999

Intra-uterine growth restriction differentially regulates perinatal brain and skeletal muscle glucose transporters.

Employing Western blot analysis, we investigated the effect of maternal uterine artery ligation causing uteroplacental insufficiency with asymmetrical intrauterine growth restriction (IUGR) upon fetal (22d) and postnatal (1d, 7d, 14d and 21d) brain (Glut 1 and Glut 3) and skeletal muscle (Glut 1 and Glut 4) glucose transporter protein concentrations. IUGR was associated with a approximately 42% decline in fetal plasma glucose (p<0.05) and a approximately 25% decrease in fetal body weights (p<0.05) with no change in brain weights when compared to the sham operated controls (SHAM). In addition, IUGR caused a approximately 45% increase in fetal brain Glut 1 (55 kDa) with no change in Glut 3 (50 kDa) protein concentrations. This fetal brain Glut 1 change persisted, though marginal, through postnatal suckling stages of development (1d-21d), with no concomitant change in brain Glut 3 levels at day 1. In contrast, in the absence of a change in fetal skeletal muscle Glut 1 levels (48 kDa), a 70% increase was observed in the 1d IUGR with no concomitant change in either fetal or postnatal Glut 4 levels (45 kDa). The change in skeletal muscle Glut 1 levels normalized by d7 of age. We conclude that IUGR with hypoglycemia led to a compensatory increase in brain and skeletal muscle Glut 1 concentrations with a change in the brain preceding that of the skeletal muscle. Since Glut 1 is the isoform of proliferating cells, fetal brain weight changes were not as pronounced as the decline in somatic weight. The increase in Glut 1 may be protective against glucose deprivation in proliferating fetal brain cells and postnatal skeletal myocytes which exhibit 'catch-up growth', thereby preserving the specialized function mediated by Glut 3 and Glut 4 towards maintaining the intracellular glucose milieu.

Aging↗
PubMed1999

Cost-effectiveness of laparoscopy in children.

BACKGROUND: Laparoscopy may offer fast recovery and improved cosmesis, but its cost has been perceived as excessive. OBJECTIVE: To analyze the total hospital costs of laparoscopy vs open surgery. DESIGN: Retrospective cost-effectiveness analysis evaluating all cases performed in a 36-month period (September 1995 to August 1998). Cases were evaluated for operative time, itemized cost of supplies, and length of hospitalization. SETTING: Operations performed by pediatric surgeons in a tertiary care children's hospital. PATIENTS: Consecutive children undergoing laparoscopic or open appendectomies, cholecystectomies, fundoplications, and splenectomies. Patients were not randomized to laparoscopy, or open surgery. INTERVENTIONS: Laparoscopic procedures performed with a core set of reusable equipment and a limited number of disposable instruments. MAIN OUTCOME MEASURES: Cost surplus of laparoscopy was evaluated, and compared with savings associated with decreased hospital stay, to obtain cost-effectiveness of laparoscopy per procedure. RESULTS: There were 26 laparoscopic and 359 open appendectomies; 33 laparoscopic and 3 open cholecystectomies; 16 laparoscopic and 18 open fundoplications; and 16 laparoscopic and 7 open splenectomies. Excess operating costs per procedure were $442.00 for appendectomy, $634.60 for fundoplication, $847.50 for cholecystectomy, and $1551.30 for splenectomy. Hospital stay was decreased for all laparoscopies, resulting in an overall savings per laparoscopic procedure of $2369.90 for appendectomy, $5390.90 for fundoplication, $1161.00 for cholecystectomy, and $858.90 for splenectomy. CONCLUSIONS: Laparoscopy is cost-effective, particularly for fundoplication, appendectomy, and cholecystectomy. Detailing the costs of supplies, operating time, and length of stay allows interinstitutional comparison and critical cost-analysis of laparoscopy. With a more selective use of reusable instruments and further shortening of operative time, the global savings of laparoscopy may increase.

Adolescent↗
PubMed1999

The impact of intraoperative culture on treatment and outcome in children with perforated appendicitis.

BACKGROUND: Most protocols for the operative treatment of perforated appendicitis use a routine culture. Although isolated studies suggest that routine culture may not be necessary, these recommendations generally are not based on objective outcome data. METHODS: The authors reviewed the records of 308 children who underwent operative treatment for perforated appendicitis between 1988 and 1998 to determine if information gained from routine culture changes the management or improves outcome. Inclusion criteria included either gross or microscopic evidence of appendiceal perforation. RESULTS: Mean patient age was 7.5 years, 51% were boys, and there was no mortality. The majority of children (96%) underwent culture that was positive for either aerobes (21%), anaerobes (19%), or both (57%). Antibiotics were changed in only 16% of the patients in response to culture results. The use of empiric antibiotics, as compared with modified antibiotics, was associated with a lower incidence of infectious complication, shorter fever duration, and decreased length of hospitalization. We also investigated the relationship between culture isolates and antibiotic regimens with regard to outcome. The utilization of antibiotics suitable for the respective culture isolate or organism sensitivity was associated with an increased incidence of infectious complication and longer duration of both fever and length of hospitalization. Finally, the initial culture correlated poorly with subsequent intraabdominal culture (positive predictive value, 11%). CONCLUSION: These outcome data strongly suggest that the practice of obtaining routine cultures can be abandoned, and empiric broad spectrum antibiotic coverage directed at likely organisms is completely adequate for treatment of perforated appendicitis in children.

Adolescent↗
PubMed1999

Rollover injuries in residential driveways: age-related patterns of injury.

BACKGROUND: The major objective of the present study was to determine the severity of nonfatal injuries sustained by children (<16 years old) when a motor vehicle rolls over them. We also sought to determine whether younger children (<24 months old) demonstrated different patterns of injury and/or a worse outcome, compared with older children (>24 months old). METHODS: We reviewed the medical records of 3971 consecutive admissions to a single trauma service at an urban children's hospital between March 1990 and October 1994. During this time period, 26 (0.7%) children presented with rollover injuries incurred by motor vehicles in residential driveways. Outcome was measured by length of both intensive care unit admission and hospitalization. RESULTS: Two children died shortly after admission and were excluded from the remainder of the study. Younger children (<24 months old) had significantly higher injury severity scores and lower pediatric trauma scale scores. Both the duration in the intensive care unit and the length of hospitalization were significantly longer in younger children, compared with children >24 months old. One explanation for these observations was that younger children had a significantly higher incidence of both head and neck and extremity injury but a similar incidence and severity of chest and abdominal trauma, compared with older children. Injuries requiring operative intervention were rare. CONCLUSION: Younger patients sustaining rollover injuries in the residential driveway have a worse outcome, in part, because of the head and neck or extremity injures that they incur. The majority of rollover injuries can be managed conservatively. pediatric trauma, driveway, pedestrian events, rollover injuries, injury severity score, pediatric trauma scale.

Accidents, Home↗
PubMed1998

Perforated appendicitis in children: risk factors for the development of complications.

BACKGROUND: Many aspects of the management of perforated appendicitis in children remain controversial. The objective of this study was to define risk factors associated with the development of postoperative complications in children undergoing treatment for perforated appendicitis. METHODS: We reviewed all children (age < 16 years) who were treated for perforated appendicitis at Cardinal Glennon Children's Hospital between 1988 and 1997. Inclusion criteria included either gross or microscopic evidence of appendiceal perforation. RESULTS: Of 285 children with perforated appendicitis, 279 underwent immediate operative treatment. Mean patient age was 7.7 years and there were no deaths. Major postoperative complications included intra-abdominal abscess (n = 17), ileus (n = 7), mechanical intestinal obstruction (n = 6), and wound infection (n = 4). All children who had a postoperative abscess had more than 5 days of symptoms before operation. Within this subgroup, drain placement was associated with not only decreased postoperative abscess formation and but also shorter duration of fever and length of hospitalization. The incidence of mechanical obstruction or ileus was not increased and the rate of wound infection was actually lower after drainage. CONCLUSIONS: Drain placement appears to be helpful in children with late diagnosis but is of little benefit when the duration of symptoms is less than 5 days. Thus it is likely that drains are most useful in patients with well-established and localized abscess cavities.

Abdominal Abscess↗