Observer variation in the detection of colorectal neoplasia on double-contrast barium enema: implications for colorectal cancer screening and training

AIM: To assess inter-observer error for the diagnosis of neoplasia on double contrast barium enema (DCBE) in the light of claims that no additional interpretative training would be needed for implementation in a national screening programme. MATERIALS AND METHODS: 10 experts, 10 consultants, and 10 experienced trainees each reported 20 DCBE studies, of which two showed cancer, three showed large polyps, four showed small polyps, and 12 were normal. Inter-observer variation was compared using odds ratios with the trainee group as reference (baseline group). RESULTS: Experts were significantly more likely to correctly identify neoplasia on DCBE than trainees. The odds of a correct diagnosis for experts were 2.79 (95% CI 2.04, 3.81) for cancer, 2.36 (1.88, 2.97) for large polyps, and 3.50 (1.98, 6.18) for small polyps. While consultants were more likely to correctly diagnose a large polyp than trainees, 1.45 (1.15, 1.84), there was no significant difference between these two groups for the correct diagnosis of either cancer, 1.24 (0.52, 2.96), or small polyps, 1.26 (0.83, 1.90). A cancer was missed by 6 (60%) experts, 9 (90%) consultants, and 8 (80%) trainees. Large polyps were missed by 4 (40%) experts, 5 (50%) consultants, and 6 (60%) trainees. There was no significant difference between any group when false positive diagnoses were considered. CONCLUSIONS: There is considerable inter-observer perceptive error for the diagnosis of neoplasia on DCBE. Experts performed significantly better than other observers but the overall standard of performance was poor, even amongst experts.     

Shunt nephritis

Six children with shunt nephritis are reported of whom two did not show complete recovery of renal function. Follow up and outcome in relation to the delay in diagnosis and renal biopsy appearances are discussed.     

Inflammatory pseudotumors in children

Inflammatory pseudotumors are so named because they mimic malignant tumors clinically and radiologically. Most often seen in the lungs of young adults, they consist of localized proliferations of mononuclear inflammatory cells and myofibroblasts. There are scattered reports of these tumors occurring in various sites in children. We report five cases of these rare lesions in children; four arising intraabdominally and one in the lung. In contrast to the usual presentation in adulthood, these children were all previously healthy. One child, with the tumor arising from the urinary bladder, was originally diagnosed as having a malignant sarcoma and underwent pelvic exenteration and chemotherapy for this subsequently-proven benign lesion. Local recurrence occurred in one case. Total excision is indicated and is usually possible without unacceptable morbidity. Our cases and a review of the literature point out the importance of pathologic differentiation of these lesions from malignancy with early appropriate surgery.     

Prolongation of xenograft survival after combination therapy with 15-deoxyspergualin and total-lymphoid irradiation in the hamster-to-rat cardiac xenograft model.

Adequate immunosuppression remains a major obstacle to successful xenotransplantation, with early xenograft rejection appearing to be mediated by humoral factors. Total-lymphoid irradiation (TLI) and 15-deoxyspergualin (DOSP) have been shown to be effective immunosuppressive agents in allografs. In this study, TLI alone and in combination with DOSP and cyclosporine were evaluated in the hamster-to-rat heterotopic cardiac xenograft model. The animals were divided into four groups: group 1--control (n = 9); group 2--TLI alone, administered pretransplant at 125 cGy/day, four days per week, for three weeks (n = 12); group 3--TLI plus CsA at 10 mg/kg/day (n = 17); and group 4--TLI plus DOSP at 2.5 mg/kg/day (n = 10). Tissue sections were taken from rejected xenografts in all treatment groups for histological examination. Complement-dependent cytotoxicity assays were performed on the control group and also the TLI-DOSP group. The control animals were found to have a mean graft survival of 3.2 +/- 0.4 days. TLI alone (5.8 +/- 0.7 days) did not significantly improve graft survival in comparison with the control group. Combination of TLI with DOSP (26.3 +/- 5.9 days) results in significantly improved survival (P less than 0.05) in comparison with the control, TLI alone, and combination of TLI and CsA (13.6 +/- 8.6 days). Complement-dependent cytotoxicity assays revealed that control groups have low rat antihamster lymphocytotoxic antibody titer (1/1-1/10) prior to xenografting, and that these antibody titers show a precipitous rise to a level of 1/640-1/1280 by day 3, the time at which rejection occurred. This correlates with the histological findings of the rejected hearts showing a severe humoral type of rejection and no evidence of cellular rejection. In contrast, animals in the TLI-DOSP group had markedly lowered rat antihamster lymphocytotoxic antibody titers (1/20-1/40) on day 3, and these titers only increased to 1/160 at time of rejection. This correlates with the histological findings of a lesser degree of humoral rejection in the TLI-DOSP group. Combination therapy with TLI and DOSP results in a marked increase of survival in xenografts in this model not seen with any other drug combination studied in over 500 xenografts in our laboratory. This study indicates that TLI combined with DOSP results in prolonged suppression of the antixenograft antibody response. This combination of agents appears to have the potential to prevent early xenograft rejection.     

Simultaneous operative repair of multilevel lower extremity occlusive disease

Sixty-two patients (39 men (63%), 23 women (27%), mean age 68 years) with multilevel lower extremity arterial occlusive disease underwent simultaneous inflow and outflow operative arterial repair consisting of aortofemoral bypass in 22 (35%), axillofemoral bypass in 17 (28%), femorofemoral bypass in 15 (24%), iliac endarterectomy in 7 (11%), and unilateral aortoiliac bypass in 1 (2%), combined with 69 outflow procedures (unilateral in 55 patients, 89%), including above-knee femoropopliteal in 12 (17%), below-knee femoropopliteal in 35 (51%), femoroinfrapopliteal in 20 (29%), popliteal tibial in 1 (1%), and femoropedal bypass in 1 (1%). Multiple criteria were used to identify patients with multilevel disease likely to benefit from multilevel procedures. The operations were performed by two operating teams in a median time of 240 minutes. Prosthetic grafts were used for eight (13%) distal bypasses, the remainder were autogenous vein. There was one operative death (1.8%). The mortality rate, morbidity rate, and operative time were not significantly different from a group of patients who underwent concurrent, isolated inflow operations (aortofemoral, axillobifemoral, femorofemoral bypass or iliac endarterectomy). Mean follow-up was 14.9 months (range, 0 to 120). The life-table primary patency for the inflow procedures was 92.6% at 24 months, the outflow was 94.9% at 24 months. Cumulative limb salvage was 90.9% at 48-month follow-up. All patients with claudication were relieved of their symptoms. We conclude that complete correction of multilevel disease can be accomplished with operative time, morbidity rate, and patency equal to that of single level repair. Multilevel procedures provide complete relief of symptoms in a higher percentage of patients than has been reported after single level repair.     

Twenty-four hour esophageal pH monitoring by telemetry. Cost-effective use in outpatients

Of 366 cases of portal hypertension in adult patients referred for evaluation and management in the past 15 years, the cause was not related to cirrhosis or hemachromatosis in 41. No specific cause was demonstrated for portal hypertension in four cases, which were excluded from further evaluation. Of the remaining 37 patients, 26 had a presinusoidal block characterized primarily by bleeding from esophagogastric varices, and 9 had a postsinusoidal block characterized by the rapid development of intractable ascites. In two cases an arteriovenous fistula was the cause of portal hypertension. Treatment was operative or nonoperative depending on the nature and prognosis of the basic disease. The various approaches to therapy include shunting procedures for the control of ascites or esophagogastric varices, the use of a type of portal-azygous disconnection and a direct approach to a valve or a fistula. In the absence of a rapidly fatal primary disease, portal hypertension is not a threatening problem and may be controlled with minimal mortality by appropriate surgical management.     

Effect of exercise on hemodynamic conditions in the abdominal aorta

PURPOSE: The beneficial effect of exercise in the retardation of the progression of cardiovascular disease is hypothesized to be caused, at least in part, by the elimination of adverse hemodynamic conditions, including flow recirculation and low wall shear stress. In vitro and in vivo investigations have provided qualitative and limited quantitative information on flow patterns in the abdominal aorta and on the effect of exercise on the elimination of adverse hemodynamic conditions. We used computational fluid mechanics methods to examine the effects of simulated exercise on hemodynamic conditions in an idealized model of the human abdominal aorta. METHODS: A three-dimensional computer model of a healthy human abdominal aorta was created to simulate pulsatile aortic blood flow under conditions of rest and graded exercise. Flow velocity patterns and wall shear stress were computed in the lesion-prone infrarenal aorta, and the effects of exercise were determined. RESULTS: A recirculation zone was observed to form along the posterior wall of the aorta immediately distal to the renal vessels under resting conditions. Low time-averaged wall shear stress was present in this location, along the posterior wall opposite the superior mesenteric artery and along the anterior wall between the superior and inferior mesenteric arteries. Shear stress temporal oscillations, as measured with an oscillatory shear index, were elevated in these regions. Under simulated light exercise conditions, a region of low wall shear stress and high oscillatory shear index remained along the posterior wall immediately distal to the renal arteries. Under simulated moderate exercise conditions, all the regions of low wall shear stress and high oscillatory shear index were eliminated. CONCLUSION: This numeric investigation provided detailed quantitative data on the effect of exercise on hemodynamic conditions in the abdominal aorta. Our results indicated that moderate levels of lower limb exercise are necessary to eliminate the flow reversal and regions of low wall shear stress in the abdominal aorta that exist under resting conditions. The lack of flow reversal and increased wall shear stress during exercise suggest a mechanism by which exercise may promote arterial health, namely with the elimination of adverse hemodynamic conditions.     

Association between left ventricular mass index and cardiac function in pediatric dialysis patients

Background  

Left ventricular mass index (LVMI) is a surrogate of left ventricular hypertrophy and a predictor of cardiac morbidity and mortality in adults with hypertension. LVMI has not been linked to cardiovascular endpoints in children. The aim of this study was to identify an association between elevated LVMI and echocardiographic markers of systolic and diastolic function.