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1.
Am Surg ; 88(3): 447-454, 2022 Mar.
Article En | MEDLINE | ID: mdl-34734550

BACKGROUND: Pediatric traumatic brain injury (TBI) affects about 475,000 children in the United States annually. Studies from the 1990s showed worse mortality in pediatric TBI patients not transferred to a pediatric trauma center (PTC), but did not examine mild pediatric TBI. Evidence-based guidelines used to identify children with clinically insignificant TBI who do not require head CT were developed by the Pediatric Emergency Care Applied Research Network (PECARN). However, which patients can be safely observed at a non-PTC is not directly addressed. METHODS: A systematic review of the literature was conducted, focusing on management of pediatric TBI and transfer decisions from 1990 to 2020. RESULTS: Pediatric TBI patients make up a great majority of preventable transfers and admissions, and comprise a significant portion of avoidable costs to the health care system. Majority of mild TBI patients admitted to a PTC following transfer do not require ICU care, surgical intervention, or additional imaging. Studies have shown that as high as 83% of mild pediatric TBI patients are discharged within 24 hrs. CONCLUSIONS: An evidence-based clinical practice algorithm was derived through synthesis of the data reviewed to guide transfer decision. The papers discussed in our systematic review largely concluded that transfer and admission was unnecessary and costly in pediatric patients with mild TBI who met the following criteria: blunt, no concern for NAT, low risk on PECARN assessment, or intermediate risk on PECARN with negative imaging or imaging with either isolated, nondisplaced skull fractures without ICH and/or EDH, or SDH <0.3 cm with no midline shift.


Brain Concussion/therapy , Medical Overuse/prevention & control , Patient Transfer , Trauma Centers , Algorithms , Ambulances/statistics & numerical data , Brain Concussion/epidemiology , Brain Concussion/mortality , Brain Concussion/surgery , Brain Injuries, Traumatic/epidemiology , Brain Injuries, Traumatic/therapy , Child , Critical Care , Emergency Medical Services , Emergency Treatment/economics , Health Care Costs , Humans , Injury Severity Score , Intensive Care Units, Pediatric , Medical Overuse/economics , Medical Overuse/statistics & numerical data , Patient Discharge , Patient Transfer/economics , Patient Transfer/statistics & numerical data , Time Factors , Triage/statistics & numerical data , United States/epidemiology
2.
JBJS Case Connect ; 11(1): e20.00250, 2021 02 12.
Article En | MEDLINE | ID: mdl-33587485

CASE: The patient is a 16-year-old girl with history of dermatomyositis in remission for several years who presented with complaints of right thigh pain and elevated inflammatory markers. She presented to the Emergency Room (ER) on separate occasions and was diagnosed with right lower extremity necrotizing fasciitis secondary to ruptured appendix. She underwent 11 surgical procedures and extended hospital stay. CONCLUSION: This case is a unique presentation of ruptured appendicitis without abdominal pain that presented as right lower extremity necrotizing fasciitis and posed a diagnostic challenge. This case illustrates the importance of diligent evaluation and aggressive surgical management in musculoskeletal infections.


Appendicitis , Fasciitis, Necrotizing , Abdominal Pain , Adolescent , Appendicitis/complications , Appendicitis/diagnosis , Appendicitis/surgery , Fasciitis, Necrotizing/etiology , Fasciitis, Necrotizing/surgery , Female , Humans , Leg , Thigh
4.
Acad Emerg Med ; 28(1): 5-18, 2021 01.
Article En | MEDLINE | ID: mdl-32888348

OBJECTIVES: Child abuse is a significant cause of morbidity and mortality in preverbal children who cannot explain their injuries. Fractures are among the most common injuries associated with abuse but of themselves fractures may not be recognized as abusive until a comprehensive child abuse evaluation is completed, often prompted by other signs or subjective features. We sought to determine which children presenting with rib or long-bone fractures should undergo a routine abuse evaluation based on age. METHODS: A systematic review searching Ovid, PubMed/Medline, Scopus, and CINAHL from 1980 to 2020 was performed. An evidence-based framework was generated by a consensus panel and applied to the results of the systematic review to form recommendations. Fifteen articles were suitable for final analysis. RESULTS: Studies with comparable age ranges of subjects and sufficient evidence to meet the determination of abuse standard for pediatric patients with rib, humeral, and femoral fractures were identified. Seventy-seven percent of children presenting with rib fractures aged less than 3 years were abused; when those involved in motor vehicle collisions were excluded, 96% were abused. Abuse was identified in 48% of children less than 18 months with humeral fractures. Among those with femoral fractures, abuse was diagnosed in 34% and 25% of children aged less than 12 and 18 months, respectively. CONCLUSION: Among children who were not in an independently verified incident, the authors strongly recommend routine evaluation for child abuse, including specialty child abuse consultation, for: 1) children aged less than 3 years old presenting with rib fractures and 2) children aged less than 18 months presenting with humeral or femoral fractures (Level of Evidence: III Review).


Child Abuse , Rib Fractures , Aged , Child , Child Abuse/diagnosis , Child, Preschool , Humans , Infant , Retrospective Studies , Rib Fractures/diagnosis , Rib Fractures/epidemiology
5.
Pediatr Infect Dis J ; 39(12): 1116-1120, 2020 12.
Article En | MEDLINE | ID: mdl-32826725

BACKGROUND: Neonates with abdominal wall defects are at an increased infection risk because of the defect itself and prolonged neonatal intensive care unit (NICU) stays. Antibiotic prophylaxis until closure of the defect is common. However, infection risk and antibiotic use have not been well quantified in these infants. METHODS: A retrospective cohort study of infants with abdominal wall defects (gastroschisis and omphalocele) admitted to a single-center NICU from 2007 to 2018. Demographic and clinical information, including microbiologic studies, antibiotic dosing and surgical care, were collected. Antibiotic use was quantified using days of therapy (DOT) per 1000 patient-days. Sepsis was defined as culture of a pathogen from a normally sterile site. RESULTS: Seventy-four infants were included; 64 (86%) with gastroschisis and 10 (14%) with omphalocele. Median day of closure was 8 days [interquartile range (IQR) 6-10, range 0-31]. All infants received ≥1 course of antibiotics; median antibiotic DOT/infant was 24.5 (IQR 18-36) for an average of 416.5 DOT per 1000 patient-days. Most antibiotic use was preclosure prophylaxis (44%) and treatment of small intestinal bowel overgrowth (24%). Suspected and proven infection accounted for 26% of all antibiotic use. Skin and soft tissue infection (13/74, 18%) and late-onset sepsis (11/74, 15%) were the most common infections; 2 infants had sepsis while on antibiotic prophylaxis. All infants survived to discharge. CONCLUSIONS: Most antibiotic use among infants with abdominal wall defects was prophylactic. Infection on prophylaxis was rare, but 35% of infants had infection after prophylaxis. Improved stewardship strategies are needed for these high-risk infants.


Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Gastroschisis/pathology , Hernia, Umbilical/pathology , Drug Utilization , Female , Humans , Infant, Newborn , Male , Retrospective Studies
6.
Dis Colon Rectum ; 58(3): 358-62, 2015 Mar.
Article En | MEDLINE | ID: mdl-25664716

BACKGROUND: Colonic stenting has failed to show an improvement in mortality rates in comparison with emergency surgery for acute large-bowel obstruction. However, it remains unclear which patients are more likely to benefit from this procedure. OBJECTIVE: The aim of this study is to identify factors that may be predictive of successful outcome of colonic stenting in acute large-bowel obstruction. DESIGN: All patients undergoing colonic stenting for acute large-bowel obstruction between 1999 and 2013 were studied. The demographics and characteristics of the obstructing lesion were analyzed. SETTINGS: This investigation was conducted at a district general hospital. PATIENTS: A total of 126 (76 men; median age, 76 y; range, 42-94 y) with acute large-bowel obstruction were included in the analysis. INTERVENTION: The insertion of a self-expanding metal stent was attempted for each patient to relieve the obstruction. MAIN OUTCOME MEASURES: The primary outcomes measured were technical success in the deployment of the stent, clinical decompression, and perforation rates. RESULTS: Technical deployment of the stent was accomplished in 108 of 126 (86%) patients; however, only 89 (70%) achieved clinical decompression. Successful deployment and clinical decompression was associated with colorectal cancer (p = 0.03), shorter strictures (p = 0.01), and wider angulation distal to the obstruction (p = 0.049). Perforation was associated with longer strictures (p = 0.03). LIMITATIONS: This study was limited by its retrospective nature. CONCLUSION: Colonic stenting in acute large-bowel obstruction is more likely to be successful in shorter, malignant strictures with less angulation distal to the obstruction. Longer benign strictures are less likely to be successful and may be associated with an increased risk of perforation.


Colonic Diseases/complications , Endoscopy, Gastrointestinal , Intestinal Obstruction , Intestinal Perforation , Intestine, Large , Postoperative Complications/epidemiology , Stents , Acute Disease , Aged , Cohort Studies , Colonic Diseases/classification , Colonic Diseases/pathology , Decompression, Surgical/methods , Endoscopy, Gastrointestinal/adverse effects , Endoscopy, Gastrointestinal/instrumentation , Endoscopy, Gastrointestinal/methods , Female , Humans , Intestinal Obstruction/diagnosis , Intestinal Obstruction/epidemiology , Intestinal Obstruction/etiology , Intestinal Obstruction/physiopathology , Intestinal Obstruction/surgery , Intestinal Perforation/epidemiology , Intestinal Perforation/etiology , Intestine, Large/injuries , Intestine, Large/pathology , Intestine, Large/surgery , Male , Outcome Assessment, Health Care , Prognosis , Risk Adjustment , Risk Factors , United Kingdom
7.
J Pediatr Surg ; 46(1): 128-30, 2011 Jan.
Article En | MEDLINE | ID: mdl-21238653

BACKGROUND/PURPOSE: Intestinal anastomosis in children has traditionally been performed using hand-sewn techniques. Little data exist evaluating the efficacy of stapled intestinal anastomoses in the infant and pediatric populations. METHODS: A review of a 5-year experience using a mechanical stapler to treat 64 consecutive children requiring intestinal anastomoses was performed. An intestinal stapler was used to complete a side-to-side functional end-to-end anastomosis. Postoperative outcomes and modifications made to the technique were identified. RESULTS: Since 2004, 64 children (median age, 3 months; range, newborn to 24 months) underwent procedures requiring intestinal anastomosis. Twenty-six children (41%) were 1 week or less in age. Twenty-seven children (42%) underwent a stoma closure using a stapler. Thirty-seven children (58%) underwent bowel resection and stapled anastomosis in treating a variety of surgical disorders. Complications included wound infection (n = 2) and anastomotic stricture (n = 1). No issues suggesting anastomotic dilatation and subsequent stasis/overgrowth were identified. CONCLUSIONS: These results suggest that stapled bowel anastomosis is an effective approach applicable to a variety of surgical diseases in newborns and infants.


Anastomosis, Surgical/methods , Digestive System Surgical Procedures/methods , Intestines/surgery , Surgical Stapling/methods , Age Factors , Anastomosis, Surgical/instrumentation , Child, Preschool , Constriction, Pathologic/etiology , Constriction, Pathologic/surgery , Digestive System Surgical Procedures/instrumentation , Humans , Infant , Infant, Newborn , Postoperative Complications/etiology , Postoperative Complications/surgery , Surgical Stapling/instrumentation , Suture Techniques , Treatment Outcome
8.
PLoS One ; 5(1): e8807, 2010 Jan 20.
Article En | MEDLINE | ID: mdl-20098718

BACKGROUND: Vascular endothelial cadherin (VE-cad) is essential for endothelial barrier integrity and vascular sprouting. However, the role of this important protein in cardiovascular development is only recently becoming apparent. METHODOLOGY/PRINCIPAL FINDINGS: To characterize the role of VE-cadherin in cardiovascular development, we analyzed cardiovascular development in a zebrafish VE-cad knockdown model. Embryos deficient in VE-cad show profoundly impaired cardiac development despite having apparently normal peripheral vasculature. Initial formation of the heart proceeds normally in knockdown embryos, but subsequent looping morphogenesis is impaired. Consistent with these results, VE-cad knockdown embryos demonstrate impaired cardiac function and early circulatory arrest. Histologic examination of knockdown embryos shows persistent, abnormal separation of the endocardial and myocardial layers. Using transmission electron microscopy, we demonstrate that endocardial junctions form poorly in VE-cad knockdown embryos, with resulting leak across the endothelial layer and reduction in the density of the cardiac jelly. CONCLUSIONS: Our results demonstrate a significant role for VE-cadherin in cardiac development independent of its effects on the formation of the peripheral vasculature.


Antigens, CD/metabolism , Blood Vessels/embryology , Cadherins/metabolism , Zebrafish/embryology , Animals , Animals, Genetically Modified , Antigens, CD/genetics , Base Sequence , Blood Vessels/metabolism , Cadherins/genetics , DNA Primers , Gene Knockdown Techniques , In Situ Hybridization
9.
Mol Cancer Ther ; 9(1): 190-201, 2010 Jan.
Article En | MEDLINE | ID: mdl-20053778

Patients with anaplastic thyroid carcinoma (ATC) typically succumb to their disease months after diagnosis despite aggressive therapy. A large percentage of ATCs have been shown to harbor the V600E B-Raf point mutation, leading to the constitutive activation of the mitogen-activated protein kinase pathway. ATC invasion, metastasis, and angiogenesis are in part dependent on the gelatinase class of matrix metalloproteinases (MMP). The explicit targeting of these two tumor markers may provide a novel therapeutic strategy for the treatment of ATC. The MMP-activated anthrax lethal toxin (LeTx), a novel recombinant protein toxin combination, shows potent mitogen-activated protein kinase pathway inhibition in gelatinase-expressing V600E B-Raf tumor cells in vitro. However, preliminary in vivo studies showed that the MMP-activated LeTx also exhibited dramatic antitumor activity against xenografts that did not show significant antiproliferative responses to the LeTx in vitro. Here, we show that the MMP-activated LeTx inhibits orthotopic ATC xenograft progression in both toxin-sensitive and toxin-resistant ATC cells via reduced endothelial cell recruitment and subsequent tumor vascularization. This in turn translates to an improved long-term survival that is comparable with that produced by the multikinase inhibitor sorafenib. Our results also indicate that therapy with the MMP-activated LeTx is extremely effective against advanced tumors with well-established vascular networks. Taken together, these results suggest that the MMP-activated LeTx-mediated endothelial cell targeting is the primary in vivo antitumor mechanism of this novel toxin. Therefore, the MMP-activated LeTx could be used not only in the clinical management of V600E B-Raf ATC but potentially in any solid tumor.


Antigens, Bacterial/therapeutic use , Bacterial Toxins/therapeutic use , Carcinoma/blood supply , Matrix Metalloproteinases/metabolism , Neovascularization, Pathologic/drug therapy , Thyroid Neoplasms/blood supply , Xenograft Model Antitumor Assays , Animals , Antigens, Bacterial/pharmacology , Bacterial Toxins/pharmacology , Benzenesulfonates/pharmacology , Carcinoma/drug therapy , Carcinoma/enzymology , Carcinoma/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Endocytosis/drug effects , Humans , Mice , Mice, Nude , Mitogen-Activated Protein Kinases/metabolism , Niacinamide/analogs & derivatives , Phenylurea Compounds , Pyridines/pharmacology , Sorafenib , Survival Analysis , Thyroid Neoplasms/drug therapy , Thyroid Neoplasms/enzymology , Thyroid Neoplasms/pathology , Time Factors
10.
Am J Surg ; 198(2): 277-82, 2009 Aug.
Article En | MEDLINE | ID: mdl-19362285

BACKGROUND: The purpose of this study was to determine whether third-year medical students can become proficient in open technical skills through simulation laboratory training. METHODS: A total of 204 students participated in a structured curriculum including bladder catheterization, breast examination, and knot-tying. Proficiency was documented using global rating scales and validated, objective, model-based metrics. RESULTS: For catheterization and breast examination, all trainees showed proficiency, and self-rated comfort increased in more than 90%. For knot-tying, 83% completed the curriculum; 57% and 44% of trainees showed proficiency for 2- and 1-handed tasks, respectively. Objective performance scores improved significantly for 2- and 1-handed knot-tying (62.9-94.4 and 49.2-89.6, respectively; P < .001) and comfort rating also increased (28%-91% and 19%-80%, respectively; P < .001). CONCLUSIONS: Objective scores and trainee self-ratings suggest that this structured curriculum using simulator training allows junior medical students to achieve proficiency in basic surgical skills.


Clinical Competence , General Surgery/education , Manikins , Students, Medical , Breast , Clinical Clerkship , Curriculum , Educational Measurement , Female , Humans , Male , Physical Examination , Prospective Studies , Suture Techniques , Texas , Urinary Catheterization , Videotape Recording
11.
J Pediatr Surg ; 43(12): 2161-4, 2008 Dec.
Article En | MEDLINE | ID: mdl-19040926

PURPOSE: Recurrence is a well-known complication after patch repair of congenital diaphragmatic hernia (CDH). We propose that a newer, "bioprosthetic" material may lower recurrence rates. The purpose of this study is to compare outcomes of CDH repair with synthetic Gore-Tex (W. L. Gore and Associates, Neward, Del) to the bioprosthetic Permacol (Tissue Science Laboratories Inc, Andover, Mass). METHODS: We performed a retrospective review of 100 consecutive patients with CDH with survival more than 30 days at Children's Medical Center of Dallas (Dallas, Tex) from 1999 to 2007. The incidence and timing of recurrence, as well as comorbidities were assessed. RESULTS: Primary repair was performed in 63 patients and patch repair in 37, divided between Gore-Tex (29) and Permacol (8). Overall recurrences were as follows: 1 (2%), 8 (28%), and 0 in the primary, Gore-Tex, and Permacol groups, respectively. Median follow-up was 57 months for Gore-Tex and 20 months for Permacol. Median time to recurrence in the Gore-Tex group was 12 months, with no Permacol recurrences. Both the Gore-Tex and Permacol groups had similar comorbidities, including prematurity, congenital heart disease (76% and 63%, respectively), and the need for extracorporeal membrane oxygenation support (38% and 25%). CONCLUSION: Our results suggest that Permacol may have lower recurrence rates compared to Gore-Tex and is a promising alternative biologic graft for CDH repair.


Biocompatible Materials , Collagen/therapeutic use , Hernia, Diaphragmatic/surgery , Abnormalities, Multiple , Animals , Child, Preschool , Extracorporeal Membrane Oxygenation , Female , Heart Defects, Congenital , Hernias, Diaphragmatic, Congenital , Humans , Infant , Male , Polytetrafluoroethylene , Prostheses and Implants , Recurrence , Retrospective Studies , Treatment Outcome
12.
Surgery ; 142(6): 900-5; discussion 905.e1, 2007 Dec.
Article En | MEDLINE | ID: mdl-18063074

BACKGROUND: A subgroup of patients with adrenal cortisol hypersecretion fails to meet the biochemical criteria for Cushing's syndrome. Appropriate therapy for this entity, subclinical Cushing's syndrome (subclinical CS), is unclear. We examined outcomes for patients who underwent unilateral adrenalectomy for subclinical CS. METHODS: Between 2003 and 2006, all patients who underwent adrenalectomy for cortisol hypersecretion caused by an adrenal mass were examined. We analyzed biochemical, metabolic, and clinical outcomes. RESULTS: Overall, 24 patients underwent adrenalectomy for adrenal cortisol hypersecretion, of which 9 were found to have subclinical CS. Median serum cortisol was 2.0 microg/dL (range, 1.1-6.1) after 1-mg overnight dexamethasone suppression testing. Suspicious clinical findings on preoperative examination included skin bruising, unexplained weight gain, proximal muscle weakness, abnormal fat pads, skin thinning, fatigue, and facial plethora. During a median follow-up period of 5 months (range, 1-30 months), all 8 patients with easy bruising noted resolution postoperatively. Fatigue improved in 4 of 5 patients, muscle weakness in 6 of 8 patients, and weight in 7 of 9 patients, with a median body mass index change of -2.0 kg/m(2) (range, -7.1 to +0.5 kg/m(2)). CONCLUSION: Adrenalectomy improves clinical and metabolic parameters for many patients with subclinical CS.


Adrenalectomy , Cushing Syndrome/surgery , Severity of Illness Index , Adenoma/metabolism , Adenoma/pathology , Adenoma/surgery , Adrenal Cortex/metabolism , Adrenal Cortex/pathology , Adrenal Cortex/surgery , Adrenal Cortex Neoplasms/metabolism , Adrenal Cortex Neoplasms/pathology , Adrenal Cortex Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Cushing Syndrome/metabolism , Cushing Syndrome/pathology , Female , Humans , Hydrocortisone/metabolism , Hyperplasia , Male , Middle Aged , Retrospective Studies , Treatment Outcome
13.
Oncologist ; 12(2): 168-74, 2007 Feb.
Article En | MEDLINE | ID: mdl-17296812

An increasing number of patients with a history of solid organ malignancy now undergo surveillance imaging as part of their follow-up or for evaluation of other conditions. This imaging has led to both greater identification of asymptomatic adrenal masses and subsequent confusion among clinicians regarding the evaluation and treatment. Although established algorithms exist for treating such "incidentalomas" in otherwise healthy patients, the most effective way to do so in patients with known prior or concurrent malignancies is unclear. In this review, we explore methods of biochemical testing in such patients and discuss the role of imaging techniques in their ability to differentiate benign versus malignant lesions. In this population, we examine the increasing use of biopsy and discuss current data on both surveillance and resection of lesions based on their identity. Finally, we propose an algorithm to aid the clinician in evaluating and treating these complex patients efficiently.


Adrenal Gland Neoplasms/secondary , Adrenal Gland Neoplasms/therapy , Neoplasms/pathology , Adrenal Gland Neoplasms/diagnosis , Adrenalectomy , Antineoplastic Agents/therapeutic use , Biopsy, Needle , Diagnostic Imaging , Humans , Neoplasms/therapy
14.
Int J Radiat Oncol Biol Phys ; 63(3): 745-52, 2005 Nov 01.
Article En | MEDLINE | ID: mdl-16199310

PURPOSE: This study set out to determine the impact of a positive circumferential resection margin (CRM) (R1-R2) and pathologic downstaging on local recurrence and survival in patients with borderline resectable or unresectable rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy (CRT). METHODS AND MATERIALS: A total of 150 patients with locally advanced rectal cancer were treated with long-course neoadjuvant CRT using low-dose folinic acid and 5-fluorouracil. CRT was followed 6-12 weeks later by surgical excision. The CRM rate and incidence, site, and pattern of local and systemic recurrences were recorded. The median follow-up was 25 months. RESULTS: The overall median survival was 37 months, with a 5-year overall survival rate of 34%. Of the 150 patients, 122 underwent curative resection; 12% had a complete pathologic response, and downstaging to pT1-T2 occurred in an additional 16%. A negative CRM (R0) was achieved in 65% overall (98 of 150). Local recurrence occurred in 10% of those with R0 resection and 62% of those with R1-R2 resections. Distant metastases occurred in 29% of those with R0 resections and 75% of those with R1-R2 resections. The 3-year disease-free and 3-year overall survival rate was 9% and 25% and 52% and 64%, respectively, for patients with and without a histologically positive CRM. CONCLUSION: After 5-fluorouracil-based CRT, a positive CRM predicted for a high risk of subsequent local recurrence and a 3-year disease-free survival rate of only 9%. For this reason, the CRM should be considered a major prognostic factor and should be validated in future trials as an early alternative clinical endpoint.


Antimetabolites, Antineoplastic/therapeutic use , Fluorouracil/therapeutic use , Rectal Neoplasms/pathology , Rectal Neoplasms/therapy , Adult , Aged , Aged, 80 and over , Analysis of Variance , Combined Modality Therapy , Disease-Free Survival , Female , Follow-Up Studies , Humans , Leucovorin/therapeutic use , Male , Middle Aged , Mitomycin/therapeutic use , Neoadjuvant Therapy , Neoplasm Recurrence, Local , Neoplasm Staging , Neoplasm, Residual , Radiotherapy Dosage , Rectal Neoplasms/mortality , Survival Rate
15.
Int Semin Surg Oncol ; 2: 22, 2005 Oct 20.
Article En | MEDLINE | ID: mdl-16242026

Diverting stomas are being used increasingly in the management of rectal cancer, particularly with low anterior resection following neoadjuvant therapy. We describe a simple anchorage method for loop colostomy using a rectus fascial sling. This has been used successfully in fifteen patients with no complications or evidence of significant spill over of faecal contents into the efferent loop.

16.
Radiology ; 230(2): 359-68, 2004 Feb.
Article En | MEDLINE | ID: mdl-14752181

PURPOSE: To test the feasibility and safety of a percutaneous magnetic resonance (MR) imaging-guided technique for radiofrequency (RF) interstitial thermal ablation of the tongue base and to correlate MR appearance of induced thermal lesions with histopathologic findings in pigs in acute and chronic porcine models. MATERIALS AND METHODS: A 1-cm-tip RF electrode was inserted percutaneously into the tongue in 10 pigs with 0.2-T real-time MR guidance. The RF electrode was advanced up the midline between lingual arteries and stopped short of tongue mucosa. RF interstitial thermal ablation was performed at 90 degrees C +/- 2 and lasted 10 minutes. Postablation images were obtained with a 1.5-T MR imager. Five pigs were sacrificed immediately (acute model), while five were followed up for 1 month (chronic model) before they were sacrificed. MR-compatible fiducial coils were inserted into tongues with MR imaging guidance prior to RF ablation in the chronic group. Tongues were harvested for histopathologic analysis. Mean thermal lesion volume was compared with the Student t test on images obtained immediately, 2 weeks, and 1 month after RF ablation. Interclass correlation coefficients of lesion diameters at gross pathologic analysis and corresponding diameters with each pulse sequence were calculated. RESULTS: Successful MR imaging-guided electrode positioning was achieved in all procedures without intra- or postprocedure complications because there was high vascular conspicuity and tissue contrast. Thermal lesions appeared hypointense with hyperintense surrounding rims with all sequences in both groups. At pathologic analysis, acute lesions appeared as pale necrotic areas surrounded by hyperemic rims, while chronic lesions demonstrated progressive circumferential fibrosis and significant volume shrinkage (P <.01). Thermal lesion diameters measured at gross pathologic analysis best agreed with corresponding diameters measured on short inversion time inversion-recovery images (interclass correlation coefficient = 0.85). CONCLUSION: The results of this investigation demonstrate MR imaging-guided RF interstitial thermal ablation of the tongue base is feasible and safe and illustrate imaging and pathologic phenomena associated with creation and evolution of the induced thermal lesions.


Disease Models, Animal , Hyperthermia, Induced/instrumentation , Magnetic Resonance Imaging/instrumentation , Sleep Apnea, Obstructive/therapy , Therapy, Computer-Assisted/instrumentation , Tongue , Animals , Feasibility Studies , Humans , Swine , Tongue/pathology , Treatment Outcome , Wound Healing/physiology
17.
Radiology ; 224(2): 452-62, 2002 Aug.
Article En | MEDLINE | ID: mdl-12147842

PURPOSE: To test the hypotheses that (a) magnetic resonance (MR) imaging-guided radio-frequency (RF) thermal ablation of the vertebrae is feasible in porcine models, (b) procedure safety depends on the location of ablation within the vertebra, and (c) MR imaging allows accurate monitoring of induced thermal lesion size and shape. MATERIALS AND METHODS: Ten percutaneous MR imaging-guided RF thermal ablations were randomized over various lumbar vertebral levels and locations in seven pigs. Animals were followed up for 2, 7, or 14 days before sacrifice. Thermal lesion size and shape as measured on MR images obtained immediately after ablation and at follow-up were compared with gross pathologic findings. Mean absolute differences between lesion diameters at pathologic examination and MR imaging were evaluated by using a paired t test, as were differences between lesion-to-vertebra contrast-to-noise ratios obtained for each sequence. Clinical and imaging data were correlated with histologic findings. RESULTS: Successful RF electrode placement in the targeted part of the vertebra was achieved in all procedures. Ablations performed away from neural elements were safe to perform. Pedicular ablations resulted in radiculopathy, whereas ablations performed directly over the posterior cortex resulted in paraplegia. Lesion sizes measured on T2-weighted images were closest to those measured at gross pathologic examination (mean absolute difference, 0.72 mm +/- 0.83 [SD]), followed by those measured on contrast material-enhanced T1-weighted (1.27 mm +/- 0.83) and short inversion time inversion-recovery (STIR) (1.5 mm +/- 1.84) images. Size measurements obtained on T2-weighted images were significantly closer to gross pathologic measurements than were those obtained on contrast-enhanced T1-weighted images (P =.013) but were not different from those obtained on STIR (P =.27) images. The contrast-to-noise ratio was significantly higher for contrast-enhanced T1-weighted images than for T2-weighted (P <.001) or STIR (P <.001) images. CONCLUSION: MR imaging-guided RF thermal ablation of the vertebrae is feasible in porcine models, but the safety of the procedure depends on the location of ablation within the vertebra. MR imaging allows accurate monitoring of thermal lesion size and shape.


Catheter Ablation , Lumbar Vertebrae/surgery , Magnetic Resonance Imaging , Animals , Female , Lumbar Vertebrae/pathology , Swine
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