Ultrasound and magnetic resonance imaging assessmentof active bowel segments in Crohn's disease

AIM

Determining bowel disease activity in Crohn's patients can be difficult on clinical and laboratory assessment. Endoscopy is invasive and barium studies use ionising radiation. The aim of this study was to compare ultrasound and magnetic resonance imaging (MRI) in detecting Crohn's disease activity in the small or large bowel.

MATERIALS AND METHODS

Thirty patients, previously diagnosed with Crohn's disease, had bowel ultrasound and MR imaging, and were deemed active or inactive on each test. The 'gold standard' was based on clinical assessment and one or more of the following: endoscopy, barium studies or surgery.

RESULTS

For determining Crohn's disease activity, the sensitivities and specificities of bowel ultrasound and MRI were 87 percent and 100 percent, and 87 percent and 71 percent, respectively. Significant parameters that defined disease activity were bowel wall thickening on ultrasound and MRI, and contrast enhancement of the bowel wall and mesenteric vascularity/stranding on MRI.

CONCLUSION

Ultrasound and MRI were both sensitive for determining Crohn's disease activity in the bowel, but MRI with gadolinium enhancement was less specific.

MR imaging evaluation of the activity of Crohn's disease

OBJECTIVE

The purpose of this study was to evaluate the sensitivity and specificity of MR imaging in assessing the activity of Crohn's disease.

SUBJECTS AND METHODS

Thirty symptomatic patients with Crohn's disease but uncertain disease activity were prospectively examined using MR imaging. Twenty-nine patients were scored using the Crohn's disease activity index. Six hundred milliliters of water orally and 1 mg of glucagon intramuscularly were given before imaging. Breath-hold images were obtained using T2-weighted turbo spin-echo, T1-weighted fast low-angle shot, and fat-suppressed gadolinium-enhanced T1-weighted fast low-angle shot sequences. Images were assessed by two radiologists who were unaware of the patient's symptoms, clinical scoring, and other imaging tests, and who reached a consensus about the imaging findings (bowel wall thickening, bowel wall enhancement, and perienteric changes) and determined the absence or presence of active disease in each patient. MR imaging findings were correlated with endoscopy and surgery.

RESULTS

Twenty-three patients had active disease and seven patients had inactive disease. One hundred twenty-four of a total of 168 bowel segments were examined with both MR imaging and endoscopy or surgery. On a per patient basis, MR imaging had an overall sensitivity of 91% and a specificity of 71% for active disease. The Crohn's disease activity index had a sensitivity of 92% and a specificity of 28%. On a per segment basis, MR imaging had a sensitivity of 59% and a specificity of 93%. Bowel wall thickening of greater than 4 mm, bowel wall enhancement (ratio of signal intensity of abnormal to normal bowel > 1.3:1), and increased mesenteric vascularity were useful in identifying active disease. A layered enhancement pattern after the IV administration of gadolinium was highly specific for active inflammation.

CONCLUSION

MR imaging is useful in assessing the activity of Crohn's disease and may be helpful when clinical scoring is equivocal.

Hemidiaphragmatic paralysis increases postoperative morbidity after a modified Fontan operation

OBJECTIVES

After a Fontan procedure, forward pulmonary blood flow is augmented during inspiration because of negative intrathoracic pressure. Total pulmonary blood flow is higher during inspiration. With hemidiaphragmatic paralysis, inspiratory augmentation of pulmonary flow is lost or diminished. The objective of this study was to compare early postoperative morbidity after the modified Fontan operation in patients with and without hemidiaphragmatic paralysis.

METHODS

A case-control analysis was performed comparing 10 patients with documented hemidiaphragmatic paralysis against 30 patients without paralysis who were matched for diagnosis, fenestration, and age. The following early postoperative outcomes were assessed: duration of ventilator support, duration of hospital stay, incidence of ascites, prolonged effusions, and readmission.

RESULTS

Preoperatively, there were no significant differences between the 2 groups. However, among the postoperative outcomes, the duration of hospital stay (25.4 +/- 16.6 days vs 10.8 +/- 6.3 days; P =.03), incidence of ascites (70% vs 3%; P <.001), prolonged pleural effusions (60% vs 13%; P =.007), and readmission (50% vs 7%; P =.007) were significantly greater in patients with hemidiaphragmatic paralysis than in those without hemidiaphragmatic paralysis.

CONCLUSIONS

Hemidiaphragmatic paralysis after the modified Fontan operation is associated with an increase in early morbidity. Care should be taken to avoid injury to the phrenic nerve. Patients with prolonged effusions should be evaluated for hemidiaphragmatic paralysis.

Mycobacterium tuberculosis Beijing genotype strains associated with febrile response to treatment

DNA fingerprinting has demonstrated predominance of the Beijing genotype among Mycobacterium tuberculosis strains isolated in Southeast Asia. We prospectively examined the occurrence of Beijing genotype strains in tuberculosis patients in Indonesia. Early in treatment, patients infected with Beijing genotype strains more often had fever unrelated to disease severity, toxicity, or drug resistance, indicating that Beijing genotype strains may have specific pathogenic properties.

Poor micronutrient status of active pulmonary tuberculosis patients in Indonesia

Malnutrition is observed frequently in patients with pulmonary tuberculosis (TB), but their nutritional status, especially of micronutrients, is still poorly documented. The objective of this study was to investigate the nutritional status of patients with active TB compared with that of healthy controls in Jakarta, Indonesia. In a case-control study, 41 out-patients aged 15-55 y with untreated active pulmonary TB were compared with 41 healthy controls selected from neighbors of the patients and matched for age and sex. Cases had clinical and radiographic abnormalities consistent with pulmonary TB and at least two sputum specimens showing acid-fast bacilli. Anthropometric and micronutrient status data were collected. Compared with the controls, TB patients had significantly lower body mass index, skinfold thicknesses (triceps, biceps, subscapular, suprailiac), mid-upper arm circumference, proportion of fat, and concentrations of serum albumin, blood hemoglobin, plasma retinol and plasma zinc, whereas plasma zinc protoporphyrin concentration, as a measure of free erythrocyte protoporphyrin concentration, was greater. When patients and controls were subdivided on the basis of nutritional status, concentrations of serum albumin, blood hemoglobin, and zinc and retinol in plasma were lower in malnourished TB patients than in well-nourished healthy controls, well-nourished TB patients and malnourished healthy controls. In conclusion, the nutritional status of patients with active pulmonary TB was poor compared with healthy subjects, i.e., significantly more patients were anemic and more had low plasma concentrations of retinol and zinc. Low concentrations of hemoglobin, and of retinol and zinc in plasma were more pronounced in malnourished TB patients.

Coronary arterial size late after the atrial inversion procedure for transposition of the great arteries: implications for the arterial switch operation

BACKGROUND

Coronary flow reserve in the hypertrophied ventricle is reduced. One contributing factor may be the size of the proximal coronary arteries. In patients who undergo atrial inversion procedures for transposition of the great arteries, the left coronary artery supplies the pulmonary ventricle and may be smaller than the right coronary artery. We hypothesized that the dimensions of the coronary arteries may correlate with symptomatic status after atrial inversion and may be an important factor when these patients are considered for the arterial switch operation.

METHODS

The proximal left and right coronary arteries were measured in 9 patients with transposition and failure of the systemic right ventricle after atrial inversion, 10 asymptomatic patients after atrial inversion, and 10 patients with normal hearts. The diameters of the coronary arteries were indexed to body surface area and compared.

RESULTS

The absolute and indexed diameters of the right coronary artery were greater in symptomatic patients than in asymptomatic patients (indexed: 3.1 +/- 0.6 vs 2.4 +/- 0.4 mm/m(2), P <.001) or control patients (2.0 +/- 0.3, P <.001), and the absolute diameter of the left coronary artery was smaller (2.9 +/- 0. 7 vs 3.6 +/- 0.5 mm, P =.003 [asymptomatic], 3.6 +/- 0.5 mm, P =.01 [control]). In symptomatic patients, the absolute and indexed diameters of the left coronary artery were smaller than those of the right (indexed: 2.1 +/- 0.6 vs 3.1 +/- 0.6 mm/m(2), P <.001). By contrast, there was no difference in asymptomatic patients (2.2 +/- 0.5 vs 2.4 +/- 0.4 mm/m(2), P =.44), and the left coronary artery was larger in normal control patients (2.2 +/- 0.4 vs 2.0 +/- 0.3 mm/m(2), P <.001).

CONCLUSIONS

Differences in the sizes of the proximal coronary arteries may be related to symptomatic status in patients with transposition of the great arteries who have undergone an atrial inversion procedure, as well as to the efficacy of ventricular retraining. When pulmonary artery banding and subsequent arterial switch are considered for patients with a Mustard or Senning procedure and a failing systemic right ventricle, the size of the proximal coronary arteries may be an important factor and should be evaluated with preoperative imaging studies.

A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms

BACKGROUND AND AIMS

To determine the sensitivity and specificity of computed tomography (CT) pneumocolon in the detection of colorectal neoplasms.

METHODS

A total of 201 consecutive patients with colorectal symptoms or requiring surveillance for colorectal neoplasms underwent both conventional colonoscopy and CT pneumocolon.

RESULTS

On conventional colonoscopy 13 invasive colorectal carcinomas were detected in 13 patients, and 118 polyps in 63 patients (14 polyps were > or =1 cm in diameter, 25 were 6-9 mm, and 79 were < or =5 mm). CT pneumocolon detected all 13 cancers, two false positive cancers, but only 20 polyps (seven were > or =1 cm). This resulted in a sensitivity of 100% (95% confidence interval (CI) 87-100%) and specificity of 99% (95% CI 97-100%) for detection of invasive carcinoma, and a sensitivity of 73% (95% CI 56-90%) and specificity of 94% (95% CI 91-98%) for detection of invasive carcinoma and/or > or =1 cm polyps. CT pneumocolon also identified invasive carcinoma not seen at colonoscopy because of incomplete examination in three patients, and detected metastases in six colorectal carcinoma patients and extracolonic carcinoma in a further seven patients.

CONCLUSIONS

CT pneumocolon had a high sensitivity and specificity for detection of invasive colorectal carcinoma but not colorectal polyps. CT pneumocolon may be suitable for initial investigation of patients with symptoms of colorectal malignancy.

Q methodology--a journey into the subjectivity of human mind

AIMS

This paper introduces a relatively new research methodological tool, known as Q method, useful in exploring issues related to human subjectivity.

DESCRIPTION

Q methodology is unique as it combines the strengths of both qualitative and quantitative research traditions. The sequential steps involve generation of ideas about the research topics, clarification and refinement of the ideas, and rank ordering these ideas by the respondents in a quasinormal distribution. The data are extracted with by-person factor analysis and useful in exploring arrays of attitude either cross-sectionally or longitudinally over a period of time.

CONCLUSION

Q methodology can be used to analyse opinions, perceptions, and attitudes in both clinical and non-clinical settings. It is a preferred method of human subjectivity study as it provides more in-depth analysis of complex subjectivity issues.

Transcatheter closure of membranous ventricular septal defects with a new nitinol prosthesis in a natural swine model

Transcatheter closure of a membranous ventricular septal defect (MVSD) is much more difficult than closure of other intracardiac defects because of the proximity to the aortic and tricuspid valves and their relatively large size in small children. In this report, transcatheter closure of naturally occurring membranous VSDs was attempted in 12 Yucatan minipigs. The prosthesis is constructed from fine Nitinol wires in the shape of two buttons and a connecting waist filled with polyester fiber. Two kinds of prosthesis were used in this study: concentric and eccentric left-sided retention disks. A 6 or 7 Fr delivery sheath was advanced across the membranous VSD over a wire from femoral vein. The prosthesis was inserted through the sheath by pushing the delivery cable to deploy a button into left ventricle and the second button was then deployed into right ventricle by withdrawing the sheath. Successful implantation of the device was achieved in all animals except one. Complete closure rate was 58.3% immediately after placement, 100% at 1 week, 90.9% at 1 month and 3 months, and 100% at 6 months. An associated aneurysm of the membranous septum increased significantly in size in two of three animals using the concentric device, and in none of the animals using the eccentric device. A trace to mild aortic regurgitation was present in two of the three animals using the concentric device, and only in one of the eight animals using the eccentric device. Five animals developed a trace to mild tricuspid regurgitation. Pathologic examination showed all devices to be covered by smooth neoendothelium at 3 months. This report presents the first experimental study where closure of membranous ventricular septal defects in a swine model was attempted by specially constructed devices. Procedural success and occlusion rates are very encouraging but overall results cannot equal surgery. Further experimentation is needed with devices that are redesigned according to the experience gained from this study.

Coronary to pulmonary artery collaterals in patients with pulmonary atresia and ventricular septal defect

BACKGROUND

The frequency, distribution, and surgical importance of coronary artery to pulmonary artery (CAPA) collaterals have not been established. The aim of this study was to establish prevalence, anatomical pattern, and significance of CAPA in patients with pulmonary atresia and ventricular septal defect (PA/VSD).

METHODS

We reviewed cardiac catheterization and operative data of 87 consecutive, unselected patients who underwent one-stage complete unifocalization for PA/VSD and assessed major systemic to pulmonary collaterals from July 1992 to June 1998.

RESULTS

CAPA collaterals were diagnosed in 9 of 87 patients (10%). The collaterals originated from the left coronary artery system in 7 patients and the right in 2. Collaterals from the left coronary system arose from the left main coronary artery in 3 patients and the circumflex in 4. All collaterals joined the central pulmonary artery, which bifurcated and supplied both lungs. One collateral from the right coronary system joined the stump of the main pulmonary artery and the other gave origin to a true left pulmonary artery, which was the sole supply to 75% of the left lung. Coronary artery enlargement was seen in 2 patients only. No patient had evidence of myocardial ischemia. Coronary collaterals comprised a dual source of pulmonary blood flow in all but 1 patient. During unifocalization, the CAPA collaterals were ligated at its origin in all cases, and the collateral from the right coronary to the left pulmonary artery was unifocalized.

CONCLUSIONS

The prevalence of CAPA collaterals in patients with PA/VSD is approximately 10%. The diagnosis may be missed without appropriate angiograms. We recommend selective ascending aortogram or selective coronary angiogram in all patients.

How do our new graduates prefer to learn?

BACKGROUND

Learning preference refers to one's choice of specific learning situations or environments over the other. It is one of the factors needed to be considered in planning curriculum and in designing instructional units.

OBJECTIVES

The primary objectives of this study were to characterize the learning preference of recent medical graduates of the National University of Singapore (NUS) and to identify any possible gender differences. This study is likely to be first of its kind in this learner population.

INSTRUMENT

Rezler's Learning Preference Inventory.

METHODS

Rezler's Learning Preference Inventory was administered among twenty-eight 1997 graduates (male 16, female 12) of NUS. The independent variable was the gender and the dependent variables were the scores in each of the learning categories: abstract, concrete, teacher-structured, student-structured, interpersonal, and independent.

ANALYSIS

Frequency distribution of the learning preferences was counted manually. Independent samples t-test was used to compare two groups of dependent variables.

RESULTS

Ninety-two percent female and sixty-nine percent male respondents preferred concrete learning. Only one male respondent and none of the female respondents preferred abstract learning. Among all the respondents, differences between concrete and abstract categories reached statistical, as well as meaningful, significance (p < 0.0001 and mean score difference of 19.9). Differences between student-structured and teacher-structured, and between interpersonal and independent categories did not reach statistical significance (p value of 0.51 and 0.78 respectively). Female respondents generally showed a trend towards greater preference for concrete and teacher-structured learning than their male counterparts.

CONCLUSION

The learning preferences of recent graduates of the NUS is characterized by high inclination towards concrete learning. The results can be utilized in designing instructional methods for this group of learners.

Theory and practice in continuing medical education

INTRODUCTION

Continuing medical education (CME) represents the final and often most poorly understood stage of physician education. The understanding of contemporary theories of physician education and characteristics of effective CME interventions will help CME providers and physician learners to plan productive CME activities and improve learning. This article aims to provide readers with emerging evidences on effective CME, particularly in relation to theories of physician learning and their implications for CME planning. The article also summarises attributes of effective CME interventions.

METHODS

The data and evidence were collected from contemporary medical education journals and published books on medical education. Two electronic databases, Medline and ERIC (Educational Research Information Clearinghouse) were searched for suitable articles.

RESULTS

Physician learning is a distinct phenomenon with high inclination towards autonomy and self-directed learning. CME interventions are more likely to be fruitful if they are modelled with strong theoretical background, catered towards individual learning needs and preferences, and focused on the learning component of education. Many widely practised CME interventions fail to be effective as those are not based on the above principles.

CONCLUSION

Evidence suggests that careful planning and evaluation of CME will improve the key measure of physician's performance and health care outcome.

Early and intermediate outcomes after repair of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries: experience with 85 patients

BACKGROUND

Pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collaterals (MAPCAs) is a complex lesion with marked heterogeneity of pulmonary blood supply. Traditional management has involved staged unifocalization of pulmonary blood supply. Our approach has been to perform early 1-stage complete unifocalization in almost all patients.

METHODS AND RESULTS

Since 1992, 85 patients with pulmonary atresia, VSD, and MAPCAs have undergone unifocalization (median age, 7 months). Complete 1-stage unifocalization and intracardiac repair were performed through a midline approach in 56 patients, whereas 23 underwent unifocalization in a single stage with the VSD left open, and 6 underwent staged unifocalization through sequential thoracotomies. There were 9 early deaths. During follow-up (1 to 69 months), there were 7 late deaths. Actuarial survival was 80% at 3 years. Among early survivors, actuarial survival with complete repair was 88% at 2 years. Reintervention on the neo-pulmonary arteries was performed in 24 patients.

CONCLUSIONS

Early 1-stage complete unifocalization can be performed in >90% of patients with pulmonary atresia and MAPCAs, even those with absent true pulmonary arteries, and yields good functional results. Complete repair during the same operation is achieved in two thirds of patients. There remains room for improvement; actuarial survival 3 years after surgery is 80%, and there is a significant rate of reintervention. These results must be appreciated within the context of the natural history of this lesion: 65% of patients survive to 1 year of age and slightly >50% survive to 2 years even with surgical intervention.

A novel use of Amplatzer duct occluder

This report describes the use of the Amplatzer patent ductus arteriosus occluder to close a left ventricle to descending aorta conduit. The patient was a 10-year-old male who was born with critical aortic stenosis and left ventricular outflow tract obstruction. After initial valvotomy, he underwent left ventricular to descending aorta conduit placement. At the age of 10, he had a Konno procedure to enlarge the left ventricular outflow tract and 21-mm St. Jude aortic valve placement. Closure of the conduit was not addressed because it was inaccessable from median sternotomy. Postoperatively, echocardiogram revealed significant flow through the conduit with a wide pulse pressure. Cardiac catheterization was performed with the premise to close the conduit with an Amplatzer patent ductus arteriosus occluder device.

New device for closure of muscular ventricular septal defects in a canine model

BACKGROUND

Repair of muscular ventricular septal defects (MVSDs) has always been challenging to the surgeon. Long-term morbidity and mortality are significantly increased if the defects are closed via left ventriculotomy or if they are associated with other complex congenital anomalies. The purpose of this study was to close MVSDs with the Amplatz ventricular septal defect device. This device is constructed from 0.004-in nitinol wire mesh filled with polyester fibers. It is retrievable, repositionable, self-centering, and of low profile.

METHODS AND RESULTS

MVSDs were created with the help of a sharp punch in 10 dogs. The location of the defects was anterior muscular (n=3), midmuscular (n=3), apical (n=3), and inlet muscular (n=1). The diameter of the defects ranged from 6 to 14 mm. All defects were closed in the catheterization laboratory. The device was placed with the help of transesophageal echocardiography and fluoroscopy. A 7F sheath was used to deploy the device from the right ventricular side in 8 and the left ventricular side in 2 dogs. Placement was successful in all animals. The complete closure rate was 30% (3/10) immediately after placement and 100% at 1-week follow-up. Pathological examination of the heart revealed complete endothelialization of the device in dogs killed after 3 months.

CONCLUSIONS

The Amplatz ventricular septal defect device appears highly efficacious in closing MVSDs. The advantages include a small delivery sheath, complete retrievability before release, and the fact that it is self-centering and self-expanding, thereby making it an attractive option in smaller children.

Perventricular [correction of Periventricular] closure of ventricular septal defects without cardiopulmonary bypass

BACKGROUND

Minimally invasive techniques are currently in use to close atrial and ventricular septal defects (VSD). Cardiopulmonary bypass (CPB) is instituted via the femoral vessels, which may cause injury to these vessels, especially in younger patients. The objectives of this study were to demonstrate the feasibility of perventricular [corrected] closure of muscular VSD (MVSD) and paramembranous VSD (PVSD) without CPB, using the Amplatz VSD device.

METHODS

Five Yucatan pigs with naturally occurring PVSD (3- to 7-mm diameter) and 5 dogs with surgically created MVSD (6- to 14-mm diameter) were subjects of this study. The VSDs were closed intraoperatively with a 7-French delivery sheath inserted through the free wall of the right (n = 5) or left ventricle (n = 5), under epicardial echocardiogram guidance. The animals were followed for 3 months.

RESULTS

There was no operative mortality. All MVSD closed after placement of the device. Closure rate of PVSD was 4 of 5 after placement and 3 of 5 after 3 months. One pig developed aortic incompetence at the last follow-up.

CONCLUSIONS

Perventricular closure of MVSD and PVSD is feasible. Avoidance of CPB can decrease recovery time, its complications, and trauma to the femoral vessels.

Aggressive approach in the treatment of acute lead encephalopathy with an extraordinarily high concentration of lead

OBJECTIVE

To report a case of a 3-year-old child with an extraordinarily massive lead concentration, 26.4 micromol/L (550 microg/dL), following environmental exposure to lead paint in the home.

LITERATURE REVIEW

The relevant literature concerning the treatment of lead encephalopathy was reviewed during the treatment of this child and preparation of the manuscript. To our knowledge, the landmark article written by Julian Chisolm in 1968 is the only recent article that reported similarly high levels of lead concentration. This case, however, is the first in which 3 chelating agents were used for the treatment of lead encephalopathy. We also reviewed the literature on the use of whole bowel irrigation in heavy metal intoxications.

CONCLUSIONS

In this case, aggressive gut decontamination with whole bowel irrigation and triple chelation therapy with British anti-Lewisite, EDTA, and oral succimer was well tolerated and seemed effective for rapidly deleading the child. The extent to which her lead concentration increased while being treated with oral succimer alone necessitated further chelation with EDTA. Further evaluation is necessary to determine if triple chelation therapy is an appropriate method for severe lead intoxication, and if the use of whole bowel irrigation should be considered in heavy metal intoxication.

Repair of coarctation with resection and extended end-to-end anastomosis

BACKGROUND

Our surgical strategy for infant coarctation changed from subclavian flap aortoplasty to resection with extended end-to-end anastomosis in 1991. The purpose of this review was to evaluate the results of that strategy.

METHODS

From 1991 through 1997, 55 infants underwent repair of coarctation of the aorta using resection with extended end-to-end anastomosis. Isolated coarctation of the aorta was present in 26 patients, 20 patients had a ventricular septal defect, and 9 patients had other associated intracardiac lesions. Mean age at surgery was 0.20+/-0.24 years (median, 21 days). In 34 patients (62%), arch reconstruction was performed through a left thoracotomy. Twenty patients (36%) had median sternotomy with simultaneous repair of coarctation of the aorta and intracardiac repair of associated lesions. One patient had recoarctation repair through a median sternotomy. All coarctation and ductal tissue was resected and the anastomosis was constructed starting opposite the left carotid artery with running polypropylene suture.

RESULTS

There was one early death 26 days after coarctation of the aorta and ventricular septal defect repair in a child on extracorporeal membrane oxygenation for meconium aspiration and 2 late deaths owing to pneumonia and pulmonary hypertension (1) and interventricular hemorrhage (1). There were no instances of paraplegia. Follow-up in survivors ranges from 10 to 76 months (mean, 39.8+/-17.2 months). Recoarctation has developed in 2 patients, who have had successful balloon dilation 6 and 14 months after the operation. This yields a low recoarctation rate of 3.6%.

CONCLUSIONS

Resection with extended end-to-end anastomosis yields a low mortality and particularly a low recoarctation rate and is our procedure of choice for infants with coarctation of the aorta.

Does banding the pulmonary artery affect pulmonary valve function after the Damus-Kaye-Stansel operation?

BACKGROUND

The Damus-Kaye-Stansel (DKS) operation can be an effective palliation in patients who have single-ventricle physiology and systemic outflow obstruction. Pulmonary artery banding (PAB) may be used as a preliminary procedure in these patients to limit overperfusion of the pulmonary circulation. In some series, the DKS operation has been associated with pulmonary insufficiency (PI). We retrospectively analyzed medical records of our patients who had PAB and later DKS to determine the incidence of PI in these patients.

METHODS

Between 1982 and 1996, 15 patients underwent PAB before DKS. Median age at PAB placement was 7 days and median duration of PAB was 7 months. Echocardiograms obtained before PAB, before DKS, and at the most recent post-DKS follow-up were reviewed.

RESULTS

Follow-up ranged from 1 to 15 years (mean follow-up, 7.5 years). One patient had trivial PI before PAB, which progressed to moderate PI at the last follow-up. Only 1 other patient had mild PI, but only at the last follow-up after DKS.

CONCLUSIONS

These findings suggest that prior PAB does not appear to cause significant PI in patients slated for DKS, and the incidence of significant PI after the DKS operation is relatively low.

Helical CT pneumocolon to assess colonic tumors: radiologic-pathologic correlation

OBJECTIVE

The objective of this study was to determine the accuracy of helical CT pneumocolon in the staging of colonic carcinomas.

SUBJECTS AND METHODS

Fifty-two patients (27 men, 25 women; age range, 40-88 years old; mean age, 67 years old) with known or strongly suspected colonic disorders underwent CT pneumocolon. After bowel cleansing, administration of smooth muscle relaxant, and rectal air insufflation, CT pneumocolon was performed with 5-mm collimation, 2.5-mm reconstruction interval, and a pitch of 1.5. Two contrast administration protocols were used. Twelve patients received 100 ml of i.v. contrast material that was injected at 3 ml/sec; scan delay was 45 sec. The other 40 patients received 150 ml of contrast material at 5 ml/sec; scan delay was 25 sec. Images were prospectively evaluated. All patients had pathologic confirmation: 46 patients had resections and six patients had endoscopic biopsies.

RESULTS

Diagnostic images were obtained in 47 of 52 patients. In the 47 patients, there were 38 colonic carcinomas (one synchronous), nine diverticular strictures, eight polyps, one ischemic stricture, and one normal study. Thirty of 38 carcinomas were correctly staged by CT. Sensitivity and specificity for serosal infiltration were 100% (35/35 carcinomas) and 33% (one of three carcinomas), respectively; sensitivity and specificity for lymph node involvement were 56% (nine of 16 carcinomas) and 95% (21/22 carcinomas), respectively. Four polyps that were smaller than 5 mm in diameter were not revealed by CT. Twelve of 14 benign lesions were correctly diagnosed and two were believed to be malignant. No malignant lesion was misdiagnosed.

CONCLUSION

CT pneumocolon gave an overall staging accuracy of 79% in 38 carcinomas.