What is the Prevalance of Tuberculous Fistula in Ano in a Tertiarycare Centre? ; How Useful Is PCR as a Diagnostic Tool for Tuberculous Fistula in Ano?

INTRODUCTION : Fistula in ano is a common surgical problem encountered in the out patient clinic. It is a condition which can be often diagnosed clinically with meticulous examination. It is mostly due to a benign cause which can be treated with surgical therapy therapy. The treatment, although mainly surgical, involves consideration of certain systemic causes and prompt diagnosis and treatment of the same. Tuberculosis is one such ubiquitous cause , especially in developing countries. Various studies have found tuberculosis to be the cause to varying extents in cases of fistula in ano. However, the exact magnitude of the disease burden is not known. Another problem with tuberculosis, in any form, is the difficulty in making a prompt diagnosis in order to start anti-tuberculous therapy. Even though a battery of tests exist, only some tests have stood the test of time and have been considered as gold standard. These tests are microscopy and culture demonstrating presence of M. tuberculosis in the specimen in question. However, even these tests have their shortcomings, a fact which has led to the quest for faster and more accurate tests. One such test is Polymerase Chain Reaction (PCR), a test which allows the amplification of a specific strand of DNA in a sample by enzymatic reaction, such that trace amounts this DNA (which represents the Nucleic acid of the species to be detected) are picked up and amplified, thus confirming the diagnosis. Fistulae caused by M.tuberculosis are difficult to diagnose because of low concentration of the acid fast bacilli in the tissue. Another factor is the overlap in the histopathological appearance between tuberculosis and other infections causing granulomatous inflammation. The present study tries to answer two of the questions regarding tuberculous fistula in ano. It tries to determine the prevalence of tuberculosis as a cause of fistula in ano. It also tries to look at how useful PCR is in diagnosing tuberculous fistula in ano. AIMS & OBJECTIVES : AIMS : 1. To evaluate the prevalence of tuberculous fistula in ano in patients attending a tertiary care centre. 2. To determine the sensitivity and the specificity of PCR in the diagnosis of Tuberculous fistula in ano. OBJECTIVES : 1. To establish the disease burden of tuberculous fistula in ano among patients seen in the out patient department of a tertiary care centre (Christian Medical College) in Vellore. 2. To establish the role of PCR as a reliable method to diagnose tuberculous fistula in ano. The study aims at evaluating PCR as a tool for quick and reliable diagnosis of Tuberculous fistula in ano where the histopathology of the tract is indeterminate, thus saving the patient a 6-8 week wait before initiation of Anti - Tuberculous Therapy. MATERIALS AND METHODS : Study design – The study was a prospective blinded crossectional study with the evaluation of a diagnostic tool. Patients, clinical information, and clinical specimens. Patients with fistula in ano were drawn from those attending the Out patient department of General surgery Units II and V of the Christian Medical College, Vellore over a period of 20 months (from September 2007 to April 2009). A detailed clinical history, physical examination, baseline laboratory investigations to asses fitness for surgery were conducted for all patients. At the time of the operation, a sample of the curetted fistulous tract was obtained and was cryo preserved at -196 degree C for later use. Bits from the same fistulous tract curettage were sent for AFB smear and culture examination and hematoxylin and eosin histopathological examination (HPE). The HPE reports were followed up subsequently. The AFB culture were followed up for a period of 10 weeks for growth of Mycobacterium tuberculosis. The cryopreserved specimens were subjected to PCR for the presence of IS6110 amplification target. The clinical diagnosis was not known to the laboratory personnel conducting the PCR tests. RESULTS : A total of 231 samples were included in the study. These samples were derived from 228 patients. The mean age of the patients was 42 years, with a range of 12-69 years of age. The majority of the patients were males and only 11 (4.8%) were females. None of the patients were HIV positive. However, 3 patients were HbsAg positive and one patient was HCV positive. 7 patients were diagnosed to have tuberculous fistula in ano based on either histopathology or AFB culture. Therefore, a prevelance of 3.07% was determined. The mean duration of symptoms before the patients presented was 31 months with a range of half a month to 20 years. 58 patients had greater than one tract at the time of presentation. 50 patients had undergone three or more perianal procedures at the time of presentation at various centers including ours. However, only 12 of these patients had more than one tract. Tuberculosis was diagnosed in 7 out of the 228 patients. This gave a prevelance of 3.07 % for tuberculosis among patients of fistula in ano. All these patients were males with an average age of 44 years of age. Most of the patients (n= 6) diagnosed to have tuberculosis had single tracts. The average duration of symptoms among the tuberculous fistula in ano patients was 18 months, with a range of 4 months to 3 years. 3 patients were biopsy positive. 3 patients were culture positive. One patient was biopsy and culture positive. A total of 176 samples were subjected to PCR, of which 77 samples were found to be PCR positive for tuberculosis. Six of these samples were positive for tuberculosis by culture or histopathology. The other biopsy reports encountered were adenocarcinoma (1 patient), Crohn's disease (1 patient) , and granular cell tumour (1 patient). CONCLUSIONS 1. Tuberculosis is an rare but definite cause of fistula in ano. It should be actively ruled out by testing specimens by histopathological as well as microbiological (Culture) means. 2. Fistula in ano is a chronic disease affecting mostly males. 3. Tuberculous fistula in ano can exist as and entity independent from pulmonary or other systemic involvement of the disease. 4. TBPCR does not appear to be an useful test in diagnosing tuberculous fistula in ano due to a high rate of false positive results. However, in culture positive samples, TBPCR is 100% sensitive in detecting the same

PCR for Diagnosing Tuberculous Fistula in Ano

INTRODUCTION: Fistula in ano is a common surgical problem encountered in the out patient clinic. It is a condition which can be often diagnosed clinically with meticulous examination. It is mostly due to a benign cause which can be treated with surgical therapy therapy. The treatment, although mainly surgical, involves consideration of certain systemic causes and prompt diagnosis and treatment of the same. Tuberculosis is one such ubiquitous cause, especially in developing countries. Various studies have found tuberculosis to be the cause to varying extents in cases of fistula in ano. However, the exact magnitude of the disease burden is not known. Another problem with tuberculosis, in any form, is the difficulty in making a prompt diagnosis in order to start anti-tuberculous therapy. Even though a battery of tests exist, only some tests have stood the test of time and have been considered as gold standard. These tests are microscopy and culture demonstrating presence of M. tuberculosis in the specimen in question. However, even these tests have their shortcomings, a fact which has led to the quest for faster and more accurate tests. One such test is Polymerase Chain Reaction (PCR), a test which allows the amplification of a specific strand of DNA in a sample by enzymatic reaction, such that trace amounts this DNA (which represents the Nucleic acid of the species to be detected) are picked up and amplified, thus confirming the diagnosis. Fistulae caused by M.tuberculosis are difficult to diagnose because of low concentration of the acid fast bacilli in the tissue. Another factor is the overlap in the histopathological appearance between tuberculosis and other infections causing granulomatous inflammation. The present study tries to answer two of the questions regarding tuberculous fistula in ano. It tries to determine the prevalence of tuberculosis as a cause of fistula in ano. It also tries to look at how useful PCR is in diagnosing tuberculous fistula in ano. AIMS & OBJECTIVES: Aims: 1. To evaluate the prevalence of tuberculous fistula in ano in patients attending a tertiary care centre. 2. To determine the sensitivity and the specificity of PCR in the diagnosis of Tuberculous fistula in ano. Objectives: 1. To establish the disease burden of tuberculous fistula in ano among patients seen in the out patient department of a tertiary care centre (Christian Medical College) in Vellore. 2. To establish the role of PCR as a reliable method to diagnose tuberculous fistula in ano. The study aims at evaluating PCR as a tool for quick and reliable diagnosis of Tuberculous fistula in ano where the histopathology of the tract is indeterminate, thus saving the patient a 6-8 week wait before initiation of Anti-Tuberculous Therapy. MATERIALS AND METHODS: Study design – The study was a prospective blinded crossectional study with the evaluation of a diagnostic tool. Patients, clinical information, and clinical specimens. Patients with fistula in ano were drawn from those attending the Out patient department of General surgery Units II and V of the Christian Medical College, Vellore over a period of 20 months (from September 2007 to April 2009). A detailed clinical history, physical examination, baseline laboratory investigations to asses fitness for surgery were conducted for all patients. At the time of the operation, a sample of the curetted fistulous tract was obtained and was cryo preserved at -196 degree C for later use. Bits from the same fistulous tract curettage were sent for AFB smear and culture examination and hematoxylin and eosin histopathological examination (HPE). The HPE reports were followed up subsequently. The AFB culture were followed up for a period of 10 weeks for growth of Mycobacterium tuberculosis. The cryopreserved specimens were subjected to PCR for the presence of IS6110 amplification target. The clinical diagnosis was not known to the laboratory personnel conducting the PCR tests. Sample size: The sample size was calculated by using the prevalence as established by a previous retrospective study done in the Department of General Surgery Unit V which had determined the prevalence of tuberculous fistula in ano as 6.6%. (ref. unpublished data). The formula used for calculation of the sample size was 4pq/d2, where P is the expected prevalence, Q is (1-P), and D is the degree of accuracy expected out of the study. It was decided to do the study with an expected degree of accuracy of +/- 3%, as this would need a sample size which could be completed in the study period. Therefore, using this formula, a sample size of 263 was calculated. Statistical Analysis: The patients whose samples are used in the study were analyzed by way of their distribution of age, sex, number of fistulae found on clinical examination and total number of procedures done for the same complaints. The prevalence of tuberculosis was thus calculated based on the number of patients positive for the gold standard tests divided by the total number of patients examined over the study period. The number of samples which were positive for AFB smear and/or are positive for tuberculosis on histopathological examination were grouped together as positive for the gold standard test. CONCLUSIONS: 1. Tuberculosis is an rare but definite cause of fistula in ano. It should be actively ruled out by testing specimens by histopathological as well as microbiological (Culture) means. 2. Fistula in ano is a chronic disease affecting mostly males. 3. Tuberculous fistula in ano can exist as and entity independent from pulmonary or other systemic involvement of the disease. 4. TBPCR does not appear to be an useful test in diagnosing tuberculous fistula in ano due to a high rate of false positive results. However, in culture positive samples, TBPCR is 100% sensitive in detecting the same

Soft lithography meets self-organization: some new developments in meso-patterning

This is a brief review of our recent and ongoing work on simple, rapid, room temperature, pressure-less and large area (˜ cm2) imprinting techniques for high fidelity meso-patterning of different types of polymer films. Examples include soft solid polymer films and surfaces like cross-linked polydimethylsiloxane (PDMS) and polyacrylamide (PAA) based hydrogels, thermoplastics like polystyrene (PS), polymethylmethacrylate (PMMA) etc both on planar and curved surfaces. These techniques address two key issues in imprinting: (i) attainment of large area conformal contact with the stamp, especially on curved surfaces, and (ii) ease of stamp detachment without damage to the imprinted structures. The key element of the method is the use of thin and flexible patterned foils that readily and rapidly come into complete conformal contact with soft polymer surfaces because of adhesive interfacial interactions. The conformal contact is established at all length scales by bending of the foil at scales larger than the feature size, in conjunction with the spontaneous deformations of the film surface on the scale of the features. Complex two-dimensional patterns could also be formed even by using a simple one-dimensional master by multiple imprinting. The technique can be particularly useful for the bulk nano applications requiring routine fabrication of templates, for example, in the study of confined chemistry phenomena, nanofluidics, bio-MEMS, micro-imprinting, optical coatings and controlled dewetting

A retrospective study on maternal and perinatal outcome in pregnancy requiring DJ stent and PCN during pregnancy

Background: Gestational hydronephrosis (GH) is result of dilatation effect of the progesterone and mechanical compression of the gravid uterus. Management during pregnancy is challenging as routine radiological investigations and surgical treatments cannot be applied due to the potential harm to the fetus. Intervention is indicated in women who fail to respond to conservative management. Acute hydronephrosis and renal colic are common etiologies for loin pain, and can lead to severe form of urinary tract infection affecting perinatal outcome. Ureteric stenting and percutaneous nephrostomy (PCN) during pregnancy are safe, requiring no intra-operative imaging, and inserted under local anaesthesia. It provides good symptom relief, low complication rate, efficient and safe modality for women with refractory symptoms.Methods: A retrospective study of pregnant women admitted under obstetric units with acute hydronephrosis requiring DJ stenting and/or PCN. Aim was to evaluate the course and pregnancy outcomes in a tertiary center of Southern India over a period of five years.Results: Descriptive statistical analysis was done in 12 women with acute hydronephrosis in pregnancy. 66.7% were nulliparous and mean gestational age at admission was 31 weeks. Diagnosis was done by USG. One-fourth had pyelonephritis and calculus being the main pathology (n=9;75%).Women requiring DJ stent and PCN were 41.6% and 58.4% respectively. 41.7% had preterm labour. 66.7% delivered vaginally, birth weight was more than 2.5kg in 50%.Conclusions: Maternal and neonatal outcome mainly depends on the early diagnosis. In this study we emphasize on the importance of multidisciplinary team approach in the management of women with acute hydronephrosis. DJ stent and PCN are efficient and safe modalities in women with refractory symptoms

The negative pyelogram in urinary obstruction

A case of chronic ureteral obstruction secondary to radiation-related ureteral stricture producing a classic “negative pyelogram” on intravenous urography is presented

Soft lithography meets self-organization: Some new developments in meso-patterning

This is a brief review of our recent and ongoing work on simple, rapid, room temperature, pressure-less and large area (~ cm2) imprinting techniques for high fidelity meso-patterning of different types of polymer films. Examples include soft solid polymer films and surfaces like cross-linked polydimethylsiloxane (PDMS) and polyacrylamide (PAA) based hydrogels, thermoplastics like polystyrene (PS), polymethylmethacrylate (PMMA) etc both on planar and curved surfaces. These techniques address two key issues in imprinting: (i) attainment of large area conformal contact with the stamp, especially on curved surfaces, and (ii) ease of stamp detachment without damage to the imprinted structures. The key element of the method is the use of thin and flexible patterned foils that readily and rapidly come into complete conformal contact with soft polymer surfaces because of adhesive interfacial interactions. The conformal contact is established at all length scales by bending of the foil at scales larger than the feature size, in conjunction with the spontaneous deformations of the film surface on the scale of the features. Complex two-dimensional patterns could also be formed even by using a simple one-dimensional master by multiple imprinting. The technique can be particularly useful for the bulk nano applications requiring routine fabrication of templates, for example, in the study of confined chemistry phenomena, nanofluidics, bio-MEMS, micro-imprinting, optical coatings and controlled dewetting

Attitude and perceived barriers towards the practice of evidence-based urology amongst urological trainees in India

Introduction: Evidence-based medicine requires systematic access and appraisal of contemporary research findings, followed by their application in clinical practice. It assumes an even greater significance in the current era of aggressive, industry-driven marketing. Methods: A questionnaire was designed combining the McColl questionnaire and Barrier scale with relevant modifications and was administered to the urology trainees attending a continuing urological education program. Statistical analysis was performed using SPSS version 25. Results: The meeting was attended by 110 urological trainees from 55 urological training centers all over India. One hundred and three of them agreed to participate in the study. About 92% of the questionnaires were fully completed. Less than half of the participants (47%) had access to reliable urological literature at work. Only 11% of the respondents claimed to have been formally trained in evidence-based urology (EBU). The inability to understand statistical analysis was the most common (67.4%) perceived barrier to EBU. Conclusion: The urological trainees in India are positively inclined towards EBU. The lack of formal training in appraising the available literature and lack of protected time, and portals to access the literature at workplaces hinder them from improving their compliance to EBU