Circumferential resection margin involvement after laparoscopic abdominoperineal excision for rectal cancer.

AIM: This study aimed to evaluate circumferential resection margin (CRM) involvement in patients with rectal adenocarcinoma after laparoscopic abdominoperineal excision (APR). METHOD: Prospectively collected data were analyzed on consecutive patients who underwent laparoscopic APR for histologically proven rectal cancer following neoadjuvant chemotherapy, from 1998 to 2006. Patients with no sphincter involvement were not included and underwent intersphincteric resection with coloanal anastomosis. CRM involvement was defined as ≤ 2 mm using a standardized pathology protocol. Data were presented as mean ± SD or as median (range). RESULTS: Seventy-four patients (60 ± 14 years of age; body mass index = 29.7 ± 7.9 kg/m(2) ) underwent laparoscopic APR. The distance of the tumour from the anal verge was 3.1 ± 0.93 cm. All patients had sphincter involvement. The operative time was 180 ± 73 min, and estimated blood loss was 269 ± 149 ml. There were no conversions and no postoperative mortality. The adverse event rate was 11%. There were two reoperations and three readmissions. Seventy-one patients had a T3 tumour and three patients had a T4 tumour. The median tumour size was 3.1 (range, 0-10) × 3 (range, 0-8.5) × 2 (range, 0-3.6) cm, and 26 (range, 3-41) lymph nodes were harvested. The median CRM was 7 (range, 1-11) mm. This was localized at the waist of the specimen in 12 (16.2%) of patients. Adjuvant therapy was given to 92% and 97% of patients with an involved and an uninvolved CRM, respectively. At 50 ± 27 months of follow up of 73 patients, 12 had CRM involvement and had a significantly decreased cancer-specific survival (log rank test, P = 0.002). CONCLUSION: Laparoscopic APR resulted in CRM involvement in 16.2% of patients with rectal cancer.

Factors influencing postoperative adverse events after Hartmann's reversal.

AIM: The study was performed to evaluate factors influencing postoperative adverse events after Hartmann's reversal (HR). METHOD: This was a retrospective study of unselected patients who underwent HR after the Hartmann's procedure (HP) for left colonic perforation with peritonitis at a single institution. Data were retrieved from an Institutional Review Board-approved database. The study end-point was postoperative adverse events, which included mortality, complications, reoperations and 30-day readmission. Lag time was defined as the time from HP to HR. The results are expressed as mean±SD. RESULTS: From 1997 to 2007, 204 (39.1%) of all patients who underwent the HP [60±16 years of age; 58% men; body mass index (BMI) 27.6±5.7; 2% were American Society of Anesthesiology (ASA) 1, 50.2% were ASA 2, 39.9% were ASA 3 and 7.9% were ASA 4) underwent HR at an interval of 158±107 days. There were 24 laparoscopic and 180 open HRs, with no deaths. The operating time was 167±64 min, estimated blood loss was 245±283 ml and the 30-day readmission rate was 4.9%. Eleven (5.4%) patients developed 14 (6.8%) complications and five (2.4%) of these patients required a new stoma at the time of HR or later. On multivariate analysis controlling for confounders, chronic renal failure requiring dialysis (OR=21.0; 95% CI: 1.5-284; P=0.02) was significantly associated with increased adverse events. CONCLUSION: The study showed that chronic renal failure requiring dialysis was the only independent predictor of postoperative adverse event rates following HR.

Is there a post-PPH syndrome?

BACKGROUND: Despite early studies reporting significant decreases in postoperative pain and morbidity with the procedure for prolapse and hemorrhoids (PPH) compared to traditional hemorrhoidectomy, certain complications and long-term efficacy remain uncertain. This study was performed to assess the prevalence of usage of PPH and the observed postoperative complaints and complications. METHODS: A questionnaire was mailed to national and international members of the American Society of Colon and Rectal Surgeons (ASCRS) and the accumulated data were reviewed. RESULTS: The rate of response to the 2,642 questionnaires was 28.5% (n=754). Of the 754 respondents, 531 (70.4%) had performed PPH and 451 (84.9%) continued to perform PPH. The most commonly reported postoperative complaint was delayed postoperative pain. Pain lasting for months was reported by 15.1% of respondents. Persistent bleeding was reported by 34.5%, and 40.9% felt there is a post-PPH syndrome. CONCLUSIONS: Some long-term studies critically examining PPH have come to fruition. A majority of respondents continued to perform PPH. Nearly half of these agreed that there is a "post-PPH syndrome" relating to postoperative morbidities. The most disturbing morbidity was lasting perineal pain of unexplained etiology demanding challenging management. Persistent bleeding from hemorrhoidal disease distal to the staple line requires further management and raises the question as to the use of PPH as a permanent remedial procedure.

Immunohistochemical and functional correlations of renal cyclooxygenase-2 in experimental diabetes.

Prostaglandins (PGs) generated by the enzyme cyclooxygenase (COX) have been implicated in the pathological renal hemodynamics and structural alterations in diabetes mellitus, but the role of individual COX isoenzymes in diabetic nephropathy remains unknown. We explored COX-1 and COX-2 expression and hemodynamic responses to the COX-1 inhibitor valeryl salicylate (VS) or the COX-2 inhibitor NS398 in moderately hyperglycemic, streptozotocin-diabetic (D) and control (C) rats. Immunoreactive COX-2 was increased in D rats compared with C rats and normalized by improved glycemic control. Acute systemic administration of NS398 induced no significant changes in mean arterial pressure and renal plasma flow in either C or D rats but reduced glomerular filtration rate in D rats, resulting in a decrease in filtration fraction. VS had no effect on renal hemodynamics in D rats. Both inhibitors decreased urinary excretion of PGE(2). However, only NS398 reduced excretion of thromboxane A(2). In conclusion, we documented an increase in renal cortical COX-2 protein expression associated with a different renal hemodynamic response to selective systemic COX-2 inhibition in D as compared with C animals, indicating a role of COX-2-derived PG in pathological renal hemodynamic changes in diabetes.

Impact of human immunodeficiency virus on medical and surgical residents.

BACKGROUND--Previous surveys of resident physicians on human immunodeficiency virus (HIV) matters have tended to focus on urban programs serving a patient population with an expected high prevalence of HIV infection. The objective of this study was to survey a community hospital residency program in a nonurban area with a perceived low HIV patient seroprevalence. METHODS--A 32-question survey was completed on an anonymous basis by the entire 74 member multidisciplinary resident physician group at a two-campus university-affiliated hospital program in southeastern Pennsylvania in May 1991. RESULTS--Residents perceived their patient population's HIV seroprevalence rate to be low although they believed their personal risk of occupational exposure to blood-borne infection was moderate to high. House staff most often complied with universal precautions for fear of acquiring a blood-borne illness and most often did not comply because of time constraints. Not perceiving the exposure as a health risk was the primary reason for nonreporting of exposures. Occupational exposure rates were alarmingly high, with suturing using a curved needle being the most common exposure method. Most residents were unfamiliar with HIV legislation. A majority of the house staff wanted improved HIV patient management training and life and disability insurance against occupationally acquired HIV. Many other important issues were addressed in this survey. CONCLUSION--Residents even in low seroprevalence environments do fear occupationally acquired HIV. A great need exists for improved training in universal precautions, acquired immunodeficiency syndrome legislation, and HIV patient management as well as for insurance against occupationally acquired HIV.

Duplex ultrasound and ocular pneumoplethysmography concordance in detecting severe carotid stenosis.

Concordance between two independent tests should serve to increase the accuracy of diagnosis. A combination of ocular pneumoplethysmography and duplex ultrasound, which uses high-resolution B-mode imaging plus spectral analysis, was used to evaluate 289 consecutive patients prior to biplane carotid angiography. Where there was concordance, the noninvasive tests predicted the presence or absence of hemodynamically severe carotid stenosis (75% or greater cross-sectional area reduction) with a sensitivity of 96.8%, a specificity of 95.9%, an accuracy of 96.2%, and positive and negative predictive values of 91.0% and 98.6%, respectively. Of the 538 study arteries, only four (0.74%) angiographically severe lesions escaped detection by both noninvasive tests. Sources of diagnostic error for both tests were defined. We believe that the combination of duplex ultrasound and ocular pneumoplethysmography significantly improves the overall assessment of carotid atherosclerosis.

The delay in reporting symptoms of carotid artery stenosis in an at-risk population. The Asymptomatic Carotid Atherosclerosis Study experience: a statement of concern regarding watchful waiting.

OBJECTIVE: To examine whether patients in the Asymptomatic Carotid Atherosclerosis Study reported symptoms of cerebral and retinal ischemia promptly to the investigating team. DESIGN: Cohort study within the Asymptomatic Carotid Atherosclerosis Study, a prospective, randomized, multicenter clinical trial, with a median follow-up time of 2.7 years. SETTING: Thirty-nine clinical sites across the United States and Canada. PATIENTS: Patients with asymptomatic carotid artery stenosis (> or = 60% reduction in diameter) who experienced either a transient ischemic attack (TIA) (n = 115) or stroke (n = 127) during the follow-up period, as verified by an external committee. MAIN OUTCOME MEASURE: Proportion of patients who reported cerebrovascular symptoms to a study nurse or physician within 3 days of occurrence. RESULTS: Thirty-seven patients (32.2%) experiencing TIA and 57 (44.9%) experiencing stroke reported symptoms to the study staff within 3 days of onset. For TIA, there was a statistically significant inverse association between prompt reporting and the amount of time a patient was enrolled in the study before the event occurred (48% with TIA occurring within 6 months vs 9% with TIA after year 3; P = .04). For stroke, there was a statistically significant association between prompt reporting and treatment arm (56% for the surgical vs 38% for the medical group; P = .05). For either TIA or stroke, none of the other factors examined were significantly associated with prompt reporting. CONCLUSIONS: Despite extensive education and reinforcement, fewer than 40% of all first events were reported within 3 days and fewer than 25% were reported in less than 24 hours. Frequent outpatient evaluation of high-risk patients and careful review of symptoms is necessary to determine when asymptomatic carotid artery stenosis has become symptomatic to offer appropriate forms of therapy.

Risk factors for stroke after coronary artery bypass.

To determine the prevalence of stroke after coronary artery bypass grafting and to evaluate risk factors, we reviewed the records of 1000 patients undergoing coronary bypass within a 1-year time period. Demographic and perioperative data were evaluated by chi 2 analysis. A history of diabetes, evidence of mural thrombus, positive oculopneumoplethysmography findings, increased age, aortic calcification, and postoperative arrhythmias all correlated with increased risk of permanent neurologic deficit for the patient undergoing coronary bypass. Risk factors were analyzed with stepwise logistic regression. A history of diabetes, presence of mural thrombi, and aortic calcification carried a higher probability that the patient would have a permanent neurologic deficit.

Rapid assessment of human immunodeficiency virus seroprevalence in a community-based hospital.

BACKGROUND: To aid in development of patient testing policy, in-service education, and resource planning, it is necessary to have a useful and meaningful tool for determining the population-specific HIV seroprevalence rate for our hospital patients. We were offered by the Centers for Disease Control a newly developed survey tool: "Rapid Assessment of HIV Seroprevalence in Hospital Patients." We subsequently served as one pilot site for this tool. METHODS: A population-based sample of 1000 patients (500 inpatients, 500 outpatients) was stratified into age and sex groups on the basis of admission statistics from the previous year in a general community hospital system in southeastern Pennsylvania that consists of two clinical campuses: an urban site with 343 beds and a suburban site with 506 beds. The study was conducted as an anonymous, unlinked screening for HIV antibody in 1000 serum samples. RESULTS: We found our overall seroprevalence rate to be 2.60% (Poisson 95% confidence interval, 1.77% to 3.81%), or 1 in 38 patient specimens. The highest rates for both sexes were found in the age range 25 to 44 years. CONCLUSIONS: This protocol is a useful survey tool for community hospitals to determine the HIV seroprevalence rate in patient populations, a practical necessity for planning and education. Survey results would aid in implementation of current Centers for Disease Control guidelines for HIV testing of inpatients and outpatients in the acute care hospital setting.

The relationship between the arteriovenous carbon dioxide gradient and cardiac index.

It has been reported that under normal conditions, mixed venous blood gases have approximated arterial samples; however, during cardiac arrest or severe cardiogenic shock, marked differences between arterial and venous blood gases have been noted. To further assess the relationships between arterial and mixed venous blood gases and cardiac index, a study population was chosen consisting of patients with less severe states of cardiac impairment. The differences between arterial and mixed venous PCO2s and pHs were compared with cardiac indexes (CI) of 44 patients in an intensive care unit with arterial lines and Swan-Ganz catheters in place. Twenty-six patients with normal CIs (2.6 to 4.1 L/min/m2) had a mean difference in mixed venous-arterial PCO2 (delta PCO2) of 4.88 +/- 0.40 mm Hg. In patients with low CIs (< 2.6), the delta PCO2 was 7.44 +/- 0.63 mm Hg (P = .001). The difference of mixed venous and arterial pH (delta pH) was 0.027 +/- 0.004 pH units for patients with normal CIs and 0.04 +/- 0.003 pH units for those with low CIs (P < .002). When the CIs of all patients were plotted against the delta PCO2s, there was an inverse linear relationship wherein delta PCO2 increased as CI decreased (r = -.47, P = .0011). There is an inverse relationship between delta PCO2 and CI that has not been previously described. An elevated delta PCO2 may be a marker of a low cardiac index.

Significance of lumbosacral list and low-back pain. A controlled radiographic study.

A prospective study of 43 patients with low-back pain was performed to determine if there exists 1) a significant correlation between lumbosacral list and low-back pain, 2) a significant difference between measured list in patients pretreatment and posttreatment, and/or 3) a significant difference in results obtained using two different measuring techniques. All patients had standing antero-posterior radiographs. The radiographs were analyzed for lumbosacral list using two measurement methods. The results indicated that there was no significant correlation between lumbosacral list and low-back pain and no significant change in measured list in individuals pretreatment and posttreatment. There was a significant difference between the two methods described above. The intercristal line (ICL) method proved most precise.

Rectal prolapse: a search for the "best" operation.

There is a lack of consensus regarding the optimal operative treatment for full-thickness rectal prolapse. We describe our experience in the management of procidentia and evaluate our current practice for improvement of results. The medical records of patients undergoing surgery for rectal prolapse between 1989 to 1999 were retrospectively reviewed. A total of 36 perineal proctosigmoidectomies (PPSs) and 29 abdominal procedures [17 anterior resections (ARs) and 12 Ripstein procedures (RPs)] were performed during the 10-year period. Patients undergoing PPS were significantly older and had more comorbidities. Mean operating time and length of hospital stay were shorter for the PPS group. Early and late postoperative complication rates were also significantly lower in the PPS group. Six patients (16%) in the PPS group developed recurrence at a mean follow-up of 50 months. Operation under general anesthesia or removal of a longer segment of prolapsed bowel did not reduce recurrence after PPS. No full-thickness recurrence was noted after AR or RP. We conclude that abdominal procedures (AR and RP) have the lowest recurrence but at a significantly higher cost in terms of complications. PPS is a valuable option in selected patients and can be performed with minimal morbidity and a relatively low recurrence rate.

Transanal endoscopic microsurgery for excision of rectal lesions: technique and initial results.

The aim of this study was to review experience with transanal endoscopic microsurgery (TEM) and to assess its applicability to an existing practice of colorectal surgeons. Patients undergoing TEM excision of rectal lesions from March 1997 through May 1999 were selected for this study. Medical records were reviewed retrospectively to obtain pertinent data, including indications for TEM, tumor size, distance from anal verge, duration of operation, completeness of tumor resection, postoperative complications, duration of stay and follow-up, and recurrence. Thirty-one patients underwent TEM during the 2-year period. Indications for TEM included benign disease in eight patients and cancer in 23 patients. Mean distance of the tumor from the anal verge was 8.3 cm. Mean size of the lesion was 2.8 cm, and mean specimen size was 4.5 cm. Larger specimen sizes allowed for tumors to be removed with negative margins (97%) in all cases but one. Mean duration of operation was 140 minutes (including set-up time), and mean duration of hospital stay was 1.2 days. Major postoperative complications occurred in one patient. Mean duration of follow-up was 15 months, and recurrence developed in two patients during this period. Transanal endoscopic microsurgery excision of rectal lesions with negative margins was possible in 97% of cases with minimal morbidity and a short-duration hospital stay. Follow-up was too brief to evaluate recurrence, but the thoroughness of resection of tumor in a high proportion of cases is promising.

Thigh muscle size and strength after anterior cruciate ligament reconstruction and rehabilitation.

It is the hypothesis of the senior author (GAA) that high circumference measurements are not an accurate reflection of thigh muscle cross-sectional area or muscle strength after standard rehabilitation following anterior cruciate ligament reconstruction. Likewise, normal quadriceps femoris strength is not achieved in these patients despite aggressive rehabilitation. The purpose of our study was to quantify thigh muscle size and strength and correlate thigh circumference, muscle cross-sectional area by magnetic resonance imaging (MRI), and isokinetic strength in our patients. Thirty-three patients with anterior cruciate ligament repair utilizing autografts of iliotibial band (N = 28), semitendinosus autograft (N = 3), and bone-patellar tendon-bone autograft (N = 2) were retrospectively evaluated 48.7 +/- 6.91 months after surgery. We compared involved operated extremities with uninjured, uninvolved contralateral extremities, measuring thigh circumference, isokinetic peak torque, and cross-sectional area by MRI. We found a significant 1.8% decrease in thigh circumference, a 10% decrease in average quadriceps torque, and a 8.6% decrease in quadriceps cross-sectional area by MRI in the involved extremities compared with the uninvolved extremities. A positive correlation between MRI cross-sectional area, quadriceps, and hamstring peak torque was recorded in involved and uninvolved extremities. A positive correlation between thigh circumference, quadriceps, and hamstring peak torque was found in uninvolved extremities but not in operated extremities. The authors concluded that thigh circumference underestimates atrophy and is not correlated with cross-sectional thigh muscle area by MRI or strength in operated extremities. Persistent quadriceps weakness and decreased cross-sectional area at 49 months postsurgery and rehabilitation continue to challenge our efforts. The pathophysiology of the decrease in thigh muscle size and quadriceps femoris strength is discussed.

A Monte Carlo investigation of the robustness of the Wald, likelihood Ratio, and Median tests with specified symmetric and asymmetric marginal distributions.

The effect of nonnormality on the Type I (tau) error when comparing two independent binomial proportions (P) or the nonparametric alternatives, the Median (Me), Wald (W), and Likelihood Ratio (LR), has not been investigated. If these selected tests are overly conservative the implied loss of power would moderate their practical use. The purpose of the present study was to investigate the impact of nonnormality on small to moderate sample sizes on the estimated tau for alpha = 0.10, 0.05, and 0.01 for the P, Me, W, and LR tests. Samples were generated from nine long-tailed symmetric and asymmetric distributions using a multiplicative congruential generator. For each marginal distribution and for a variety of sample sizes, the proportion of samples for which the test statistic exceeded the 10, 5, and 1 percentage points was tabulated. For data that mimic a symmetric distribution, the median test uniformly yields an empirical alpha considerably less than tau, while the likelihood ratio test consistently overestimates tau for small samples (n < or = 15) over all symmetric distributions and empirical alpha levels. For asymmetric distributions, the median test again yields an empirical alpha significantly less than tau. Similar underestimates of tau were found for the chi-square (2 df), chi-square (4 df) log normal, and gamma (2, 1) distributions. The likelihood ratio test consistently overestimates tau for small samples (n < or = 15) over all asymmetric distributions and empirical alpha levels. The independent proportions test produces an empirical alpha closest to tau for n = 10 for all asymmetric distributions.(ABSTRACT TRUNCATED AT 250 WORDS)

Eliminating bias in randomized cluster trials with correlated binomial outcomes.

Clustered or correlated samples with binary data are frequently encountered in biomedical studies. The clustering may be due to repeated measurements of individuals over time or may be due to subsampling of the primary sampling units. Individuals in the same cluster tend to behave more alike than individuals who belong to different clusters. This exhibition of intracluster correlation decreases the amount of information about the effect of the intervention. In the analysis of randomized cluster trials one must adjust the variance of estimator of the mean for the effect of the positive intraclass correlation p;. We review selected alternative methods to the typical Pearson's chi2 analysis, illustrate these alternatives, and out line an alternative analysis algorithm. We have written and tested a FORTRAN program that produces the statistics outlined in this paper. The program is available in an executable format and is available from the author on request.

Robust analysis of variance with Turbo Pascal.

A program in Turbo Pascal for robust analysis of variance is presented. A typical data file, the Pascal program listing and the corresponding output are given.

Homogeneity of kappa statistics in multiple samples.

The measurement of intra-observer agreement when the data are categorical has been the subject of several investigators since Cohen first proposed the kappa (kappa) as a chance-corrected coefficient of agreement for nominal scales. Subsequent procedures have been developed to assess the agreement of several raters using a dichotomous classification scheme, assess majority agreement among several raters using a polytomous classification scheme, and the use of kappa as an indicator of the quality of a measurement. Further developments include inference procedures for testing the homogeneity of k>/=2 independent kappa statistics. An executable FORTRAN code for testing the homogeneity of kappa statistics (kappa(h)) across multiple sites or studies is given. The FORTRAN program listing and/or executable programs are available from the author on request.

Utility of combining two diagnostic tests.

Methods for evaluating a single diagnostic test with reference to the disease prevalence in a given population include sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Patient disease status and, ultimately, the treatment course is determined by the outcome of these diagnostics. The advantage of ordering a single diagnostic test, or series of diagnostic tests is a concern of physicians. How much information is gained from using the results of two diagnostic tests, each designed to detect the same disease? Combining tests may be the optimal methodology for determining the disease status of the patient. We propose a systematic strategy for optimizing (minimizing alpha and/or beta errors) the combination of two diagnostic tests. This strategy is then illustrated by the use of data from Doppler ultrasound and ocular pneumoplethysmography in detecting carotid artery disease.

Monte Carlo generation of SB and SU distributions.

Generating random variables from specific bounded or unbounded distributions is a problem frequently encountered in Monte Carlo studies. Of particular interest is that of transforming variables from a standard normal distribution to a given Johnson's SB or SU distribution with specified (gamma, delta) parameters. We use a composite standard normal generator N (0.1) to generate Johnson's SB or SU distributions with (gamma, delta) parameters. Goodness-of-fit tests and graphical illustrations demonstrate the adequacy of the empirical distributions.