Intestinal stoma complications in immunocompromised children.

BACKGROUND/PURPOSE: When performing an urgent gastrointestinal operation on an immunocompromised child, the pediatric surgeon may have to decide between performing an intestinal anastomosis (and risk leakage or sepsis) or creating an intestinal stoma. This study evaluates the postoperative course of those patients treated with intestinal stomas and the long-term survival rate of such patients. METHODS: A 13-year retrospective review of immunocompromised children with intestinal stomas was performed. Patients were assessed as to their diagnosis, indication for surgery, stoma type, postoperative complications (within 30 days of surgery), ostomy-related complications, and survival. RESULTS: 19 stomas (8 ileostomies and 11 colostomies) were created in 18 patients. Six children had immunodeficiency disorders; 12 were immunosuppressed from chemotherapy treatment for cancer. Indications for surgery included infectious complications (n = 8); neoplasm-induced bowel obstruction, perforation, or invasion (n = 10); and Hirschsprung's disease (n = 1). Postoperative complications occurred in 13 cases (68%); two warranted reoperation. Four of six patients with neutropenia had serious postoperative infectious complications. Stoma complications occurred in 6 cases (32%); 1 required revision. All 3 patients in whom bleeding developed from their stoma site were thrombocytopenic. Nine of 18 patients (50%) died, yet no patient died of complications attributable to their stomas. Of the surviving 9 children, 6 underwent stoma takedown at a mean of 19 months after creation; 1 has a permanent colostomy, and 2 currently are undergoing chemotherapy. CONCLUSION: Although immunocompromised children who require intestinal stomas frequently die of their underlying illnesses and their stomas often produce considerable morbidity, stoma creation does not jeopardize their chance of survival.

Long-term survival of patients with coronary artery disease and left ventricular dysfunction: implications for the role of myocardial viability assessment in management decisions.

OBJECTIVES: Our purpose was to evaluate the long-term benefit of myocardial viability assessment for stratifying risk and selecting patients with low ejection fraction for coronary artery bypass grafting and to determine the relation between the severity of anginal symptoms, the amount of ischemic myocardium, and clinical outcome. METHODS: We studied 93 consecutive patients with severe coronary artery disease and low ejection fraction (median, 25%) who underwent positron emission tomography to delineate the extent of perfusion-metabolism mismatch (reflecting hibernating myocardium) for potential myocardial revascularization. Median follow-up was 4 years (range, 0 to 6.2 years). RESULTS: Fifty patients received medical therapy, and 43 patients underwent bypass grafting. In Cox survival models, heart failure class, prior myocardial infarction, and positron emission tomographic mismatch were the best predictors of survival. Patients with positron emission tomographic mismatch receiving bypass grafting had improved 4-year survival compared with those on medical therapy (75% versus 30%; P =.007) and a significant improvement in angina and heart failure symptoms. In patients without positron emission tomographic mismatch, bypass grafting tended to improve survival and symptoms only in those patients with severe angina (100% versus 60%; P =.085), whereas no survival advantage was apparent in patients with minimal or no anginal symptoms (63% versus 52%; P =.462). CONCLUSIONS: Patients with low ejection fraction and evidence of viable myocardium by positron emission tomography have improved survival and symptoms with coronary bypass grafting compared with medical therapy. In patients without evidence of viability, survival and symptom improvement with bypass grafting are apparent only among those patients with severe angina.

Relation of myocardial perfusion at rest and during pharmacologic stress to the PET patterns of tissue viability in patients with severe left ventricular dysfunction.

BACKGROUND: Stress perfusion imaging can assess effectively the amount of jeopardized myocardium, but its use for identifying underperfused but viable myocardium has yielded variable results. We evaluated the relation between measurements of myocardial perfusion at rest and during pharmacologic stress and the patterns of tissue viability as determined by positron emission tomographic (PET) imaging. METHODS AND RESULTS: We studied 33 patients with coronary artery disease and left ventricular (LV) dysfunction (LV ejection fraction, 30%+/-8%). PET imaging was used to evaluate regional myocardial perfusion at rest and during pharmacologic stress with [13N]-ammonia as a flow tracer, and to delineate patterns of tissue viability (i.e., perfusion-metabolism mismatch or match) using [18F]-deoxyglucose (FDG). We analyzed 429 myocardial regions, of which 229 were dysfunctional at rest. Of these, 30 had normal perfusion and 199 were hypoperfused. A severe resting defect (deficit >40% below normal) predicted lack of significant tissue viability; 31 of 35 regions (89%) had a PET match pattern denoting transmural fibrosis. Although regions with mild or moderate resting defects (deficit <40% below normal) showed evidence of metabolic activity, perfusion measurements alone failed to identify regions with PET mismatch (reflecting hibernating myocardium). Reversible stress defects were observed with slightly higher frequency in regions with a PET mismatch (10 of 37) than in those with a PET match (36 of 162) pattern of viability. A reversible stress defect was a specific (78%) marker, but was a relatively insensitive marker (27%) of viable myocardium as defined by the PET mismatch pattern. CONCLUSIONS: In patients with LV dysfunction, the severity of regional contractile abnormalities correlates with the severity of flow deficit at rest. Severe reductions in resting blood flow in these dysfunctional regions identify predominantly nonviable myocardium that is unlikely to have improved function after revascularization. Although dysfunctional myocardium with mild to moderate flow reductions contains variable amounts of viable tissue (as assessed by FDG uptake), flow measurements alone do not distinguish between regions with PET mismatch (potentially reversible dysfunction) and PET match (irreversible dysfunction). The presence of an irreversible defect on stress imaging is a relatively specific (78%) marker of PET match, whereas a reversible stress defect is a rather insensitive (27%) marker of viability, as defined by the PET mismatch pattern.

Risk factors for early infection of central venous catheters in pediatric patients.

BACKGROUND: In an effort to avoid infections that can lead to the premature removal of indwelling central venous catheters (CVCs), the surgical technique and host factors present in pediatric recipients of permanent CVCs were reviewed. STUDY DESIGN: All patients receiving CVCs over a 17-month period were identified. Those patients with fever and positive blood cultures drawn through the CVC within 45 days of line placement were labeled as having early infection. A case-control design was used to select two control patients for each infected patient. Charts from both the infection and control groups were reviewed for several factors present at the time of CVC placement, including fever, neutropenia (absolute neutrophil count [ANC] < 500 and ANC < 1,000), use of perioperative antibiotics, diagnosis, CVC site, and type of CVC. Chi-square test with Yates correction was used to compare the groups. Odds ratios (ORs) and 95% confidence intervals were derived. RESULTS: Among the 473 CVCs placed, early infections developed in 53 patients (12%). The control group consisted of 106 patients. Neutropenia was present in 16 of 53 infected patients versus 8 of 106 controls (p = 0.004, OR = 5.30). Perioperative antibiotics were given to 25 of 53 infected patients versus 72 of 106 controls (p = 0.02, OR = 0.42). Fever was present in 12 of 53 infected patients versus 14 of 106 controls (p = 0.19, OR = 1.92). Factors that were equally prevalent between the groups and that did not appear to influence the CVC infection rate included a diagnosis of malignancy, CVC type, and site of placement. Of the 53 infected catheters, 16 (30%) could not be cleared of infection and were removed. CONCLUSIONS: This study documents that neutropenia and failure to administer prophylactic antibiotics are risk factors for the development of early CVC infection in pediatric patients. To avoid early infection and possible premature CVC removal, we recommend that placement of permanent CVCs be postponed until the ANC is > 1,000. Perioperative antibiotics should be given. A trend toward higher infection rates was seen in patients with preoperative fever.

Value of metabolic imaging with positron emission tomography for evaluating prognosis in patients with coronary artery disease and left ventricular dysfunction.

Patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction have a high but variable annual mortality and some may benefit from myocardial revascularization. This study aimed to evaluate the prognostic value of positron emission tomography (PET), and its interrelation with the choice of medical therapy or revascularization for predicting survival and improvement in symptoms of heart failure in patients with CAD and LV dysfunction. Ninety-three consecutive patients with angiographic CAD and a mean LV ejection fraction of 0.25 who underwent cardiac PET studies for assessment of hypoperfused yet viable myocardium ("mismatch pattern") using N-13 ammonia and 18-F deoxyglucose were followed up for an average of 13.6 months. Fifty patients underwent medical treatment and 43 underwent revascularization. The Cox model analysis showed that the extent of mismatch had a negative effect (p = 0.02), whereas revascularization had a positive effect on survival (p = 0.04). The annual survival probability of patients with mismatch receiving medical therapy was lower than of those without mismatch (50 vs 92%, p = 0.007). Patients with mismatch who underwent revascularization had a higher survival rate than those treated medically (88 vs 50%, P = 0.03). The presence of mismatch also predicted improvement in heart failure symptoms after revascularization (p < 0.001). These results suggest that the presence of mismatch in patients with CAD and severe LV dysfunction is associated with poor annual survival with medical therapy. Revascularization in patients with PET mismatch appears to be associated with improved survival and heart failure symptoms.

Myocardial viability in asynergic regions subtended by occluded coronary arteries: relation to the status of collateral flow in patients with chronic coronary artery disease.

OBJECTIVES: This study aimed to determine whether angiographically visualized collateral vessels in patients with chronic coronary artery disease imply the presence of viable myocardium in asynergic regions subtended by completely occluded coronary arteries. BACKGROUND: Patients with chronic coronary artery disease who are being considered for revascularization frequently exhibit angiographically visualized collateral vessels to completely occluded coronary arteries supplying severely asynergic myocardial regions. However, little is known about the relation between angiographic collateral flow and myocardial viability in these patients. METHODS: We studied 42 patients with 78 completely occluded coronary arteries supplying asynergic territories. Angiographic collateral vessels were interpreted as absent (grade 1) in 14 patients, minimal (grade 2) in 27 and well developed (grade 3) in 37. Myocardial viability was determined with positron emission tomography using nitrogen-13 (N-13) ammonia and fluorine-18 (F-18) deoxyglucose for assessment of regional perfusion and glucose uptake, respectively. Positron emission tomographic patterns were interpreted as mismatch (perfusion defect with enhanced F-18 deoxyglucose uptake); transmural match (severe concordant reduction or absence of both perfusion and F-18 deoxyglucose uptake) or nontransmural match (mild to moderate concordant reduction of both perfusion and F-18 deoxyglucose uptake). RESULTS: There was no significant correlation (p = 0.14) between the severity of perfusion deficit assessed by positron emission tomography and the collateral grade. The extent of mismatch was unrelated to either the presence or the magnitude of collateral vessels. Conversely, with increasing collateral vessels from grade 1 to 3, the total extent of positron emission tomographic match remained similar, whereas the ratio of transmural to nontransmural match decreased. Myocardial viability was usually present in severely hypokinetic regions (82%). It was lower in akinetic-dyskinetic regions (49%). Of the 64 regions with angiographic collateral vessels, 37 (58%) (95% confidence interval [CI] 46% to 70%) showed positron emission tomographic mismatch. In contrast, 7 (50%) of 14 (95% CI 24% to 76%) regions without collateral vessels on angiography exhibited positron emission tomographic mismatch. The presence of angiographically visualized collateral vessels was a sensitive (84%) but not specific (21%) marker of viability. CONCLUSIONS: In patients with chronic coronary artery disease, angiographically visualized collateral vessels to asynergic myocardial regions subtended by occluded coronary arteries do not always imply the presence of viable myocardium, suggesting that revascularization may not always provide a functional benefit.