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Dive into the research topics where Tomas Knutson is active.

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Featured researches published by Tomas Knutson.


Prostate Cancer and Prostatic Diseases | 2009

Insulin and free oestradiol are independent risk factors for benign prostatic hyperplasia

Jan Hammarsten; J-E. Damber; M K Karlsson; Tomas Knutson; Östen Ljunggren; Claes Ohlsson; Ralph Peeker; Ulf Smith; Dan Mellström

The aetiology of benign prostatic hyperplasia (BPH) remains unclear. The objective of the present study was to test the insulin, oestradiol and metabolic syndrome hypotheses as promoters of BPH. The design was a risk factor analysis of BPH in which the total prostate gland volume was related to endocrine and anthropometric factors. The participants studied were 184 representative men, aged 72–76 years, residing in Göteborg, Sweden. Using a multivariate analysis, BPH as measured by the total prostate gland volume correlated statistically significantly with fasting serum insulin (β=0.200, P=0.028), free oestradiol (β=0.233, P=0.008) and lean body mass (β=0.257, P=0.034). Insulin and free oestradiol appear to be independent risk factors for BPH, confirming both the insulin and the oestradiol hypotheses. Our findings also seem to confirm the metabolic syndrome hypothesis. The metabolic syndrome and its major endocrine aberration, hyperinsulinaemia, are possible primary events in BPH.


Scandinavian Journal of Urology and Nephrology | 2003

Relationship Between Age, Prostate Volume, Prostate-specific Antigen, Symptom Score and Uroflowmetry in Men with Lower Urinary Tract Symptoms

Stepan Vesely; Tomas Knutson; Jan-Erik Damber; Mauro Dicuio; Christer Dahlstrand

Objectives: To estimate the relationship between age and the values of different diagnostic tests in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic enlargement (BPE) and to compare prostate growth curves between the normal population sample, healthy men and men with LUTS. Material and Methods: A series of 354 men (mean age 70.2 years; range 45-91 years) with LUTS due to BPE were stratified into seven age groups and reviewed retrospectively. All patients underwent a standard evaluation, involving determination of the International Prostate Symptom Score (IPSS), digital rectal examination, uroflowmetry, determination of the prostate-specific antigen (PSA) level and transrectal ultrasonography. Descriptive statistics were used to describe all the variables and Spearmans correlation test was used to evaluate the relationships between them. Results: The mean prostate volume was 40.1 (±23.9) cm[Formula: See Text] and mean PSA concentration 3.9 (±4.2) ng/ml. Both values increased progressively from 27.5 ml and 1.5 ng/ml, respectively in the <54 years age group to 48.2 ml and 5.4 ng/ml, respectively in the <80 years age group. However, in the 75-79 years age group there was a decrease in both prostate volume and symptom score; PSA concentration remained unchanged and maximal flow rate increased slightly. A statistically significant but weak correlation was found between prostate volume and age (r = 0.25, p < 0.0001) and between PSA and age (r = 0.28, p < 0.0001). Prostate volume correlated positively with serum PSA (r = 0.54, p < 0.0001). The correlations between maximum flow rate and age, prostate volume, PSA and IPSS were r = −0.21, p < 0.0001; r = −0.18, p < 0.0006; r = −0.29, p < 0.0001; and r = 0.14, p < 0.0098, respectively. Conclusions: These data confirm that prostate volume and serum PSA concentration are significantly correlated and increase with advanced age. The correlations between uroflowmetry (Qmax) and age, prostate volume, serum PSA and IPSS were also significant. However, there was no relationship between symptoms and objective measures of BPE. The increase in different parameters of the severity of benign prostatic hyperplasia with advanced age is not continuous. The prostate volume alone is not useful in the estimation of disease severity.


Scandinavian Journal of Urology and Nephrology | 2001

Invasive Urodynamic Studies are Well Tolerated by the Patients and Associated with a Low Risk of Urinary Tract Infection

Yr Logadottir; Christer Dahlstrand; Magnus Fall; Tomas Knutson; Ralph Peeker

Objective: An essential part of investigation of the lower urinary tract is pressure/flow studies (pQS). In fact, pQS is the only way of diagnosing bladder outlet obstruction. There is controversy regarding whether or not prophylactic antibiotic treatment is necessary. This prospective study was carried out in order to determine the frequency of infections and/or distress after pQS performed without the use of antibiotic prophylaxis. Material and Methods: One hundred and twenty-three patients were included in the present study, all males. They were requested to answer a questionnaire 1 week after pQS. Questions were asked concerning symptoms of voiding disorders, dysuria, hematuria, incidence of fever and the patients acceptance of the investigation after the pQS procedure. Urine was obtained for culture immediately before the investigation and 3 and 7 days after the pQS. Results: Forty-six per cent of the patients experienced some degree of transient dysuria after pQS, and 18.5% experienced voiding problems of varying nature. Five per cent of the patients had hematuria and 2.5% reported fever. Fifty per cent of the patients experienced some degree of discomfort during the pQS investigation, and 4.1% had positive culture and symptoms of UTI requiring antibiotic treatment. Conclusions: PQS is well accepted by the patients and the regular use of propylactic antibiotics is not indicated. We recommend, though, that patients at risk for serious complications from infections (e.g. those with prosthetic heart valves) should receive prophylactic antibiotics.OBJECTIVE An essential part of investigation of the lower urinary tract is pressure/flow studies (pQS). In fact, pQS is the only way of diagnosing bladder outlet obstruction. There is controversy regarding whether or not prophylactic antibiotic treatment is necessary. This prospective study was carried out in order to determine the frequency of infections and/or distress after pQS performed without the use of antibiotic prophylaxis. MATERIAL AND METHODS One hundred and twenty-three patients were included in the present study, all males. They were requested to answer a questionnaire I week after pQS. Questions were asked concerning symptoms of voiding disorders, dysuria, hematuria, incidence of fever and the patients acceptance of the investigation after the pQS procedure. Urine was obtained for culture immediately before the investigation and 3 and 7 days after the pQS. RESULTS Forty-six per cent of the patients experienced some degree of transient dysuria after pQS. and 18.5% experienced voiding problems of varying nature. Five per cent of the patients had hematuria and 2.5% reported fever. Fifty per cent of the patients experienced some degree of discomfort during the pQS investigation, and 4.1% had positive culture and symptoms of UTI requiring antibiotic treatment. CONCLUSIONS PQS is well accepted by the patients and the regular use of propylactic antibiotics is not indicated. We recommend, though, that patients at risk for serious complications from infections (e.g. those with prosthetic heart valves) should receive prophylactic antibiotics.


Neurourology and Urodynamics | 1999

Home uroflowmetry: Improved accuracy in outflow assessment

Rudolf Boci; Magnus Fall; Mauritz Waldén; Tomas Knutson; Christer Dahlstrand

To study home uroflowmetry and to compare this method to free or “traditional” uroflowmetry in the evaluation of the patient with symptomatic benign prostatic hyperplasia (BPH), and the relationship between the values of home uroflowmetry parameters and bladder outlet obstruction (BOO). Twenty‐five patients (mean age, 67 years) with symptomatic BPH were examined with home uroflowmetry, free uroflowmetry, and pressure‐flow measurement. The patients were assessed using the International Prostate Symptom score; digital rectal examination; routine blood chemistry, including serum prostate‐specific antigen level; urinanalysis; transrectal ultrasonography; and post‐void residual urine. The 24 hr were divided into “active time” (AT) and “sleep time” (ST). AT home uroflowmetry parameters were compared to ST ones. The home uroflowmetry parameters were compared to respective ones of the free uroflowmetry as well and those obtained by pressure‐flow measurement. The patients were asked about their opinion of home uroflowmetry. Home uroflowmetry was found to be a simpler and more acceptable method than free uroflowmetry. The mean Qmax of AT was significantly greater than the mean Qmax of ST, but the mean voided volume and mean voiding time of ST were significantly larger than those of AT. There was a close relationship between the mean Qmax at home and the Qmax in hospital, but the voided volume and voiding time measured in hospital were significantly larger than those at home. Home uroflowmetry provided an estimation of BOO for 46% of the patients as low if the home mean Qmax was >14 ml/sec, and as high if the home mean Qmax was <10 ml/sec. Home uroflowmetry was well accepted by the patients and gave more information than free uroflowmetry. In 46% of the cases, an estimation of BOO was obtained with home uroflowmetry. Neurourol. Urodynam. 18:25–32, 1999.


European Urology | 2002

The Use of Biodegradable PGA Stents to Judge the Risk of Post-TURP Incontinence in Patients with Combined Bladder Outlet Obstruction and Overactive Bladder

Tomas Knutson; S. Pettersson; Christer Dahlstrand

OBJECTIVE For patients with the combination of severe bladder outlet obstruction (BOO) and severe overactive bladder (OB), no straightforward and safe treatment exists due to the risk of urge incontinence after TURP. In this study we have used a biodegradable polyglycolic stent to simulate the status after TURP and register the risk for urge incontinence. METHODS A total of 37 patients with severe OB, combined with moderate to severe BOO, were asked if they wanted to participate. Under cystoscopic vision a polyglycolic biodegradable stent was inserted in the prostatic urethra. RESULTS Twenty-five of the patients noticed no or only minor leakage and 19 of these have been subjected to TURP with good results. Three patients are on the waiting-list for TURP. Twelve of 37 patients were found to have major leakage after stent insertion. During the stent period, we noted five cases of complications, due to UTI, stent crash and irritation. All of these patients recovered within three weeks. CONCLUSIONS A biodegradable PGA stent seems to be a new and unique tool to test the risk for post-TURP incontinence in patients with combined BOO and severe OB.


Scandinavian Journal of Urology and Nephrology | 2009

One-third of the Swedish male population over 50 years of age suffers from lower urinary tract symptoms

Johan Stranne; Jan-Erik Damber; Magnus Fall; Jan Hammarsten; Tomas Knutson; Ralph Peeker

Objective. To investigate the prevalence of and restrictions in various parts of daily life due to lower urinary tract symptoms (LUTS) in an unselected Swedish male population. Material and methods. A random selection of 3345 men throughout Sweden, aged between 41 and 80, was contacted by telephone and evaluated according to International Prostate Symptom Score (IPSS). The responders were then sent two different questionnaires based on degree of LUTS, IPSS <8 or >7. Results. 2106 men (66%) answered the questionnaire. Of these, 33.4% had an IPSS > 7 and the IPSS increased with age. Of the men with IPSS >7 only 41% had consulted health services for their symptoms and 23% had received treatment. Thirty-seven per cent claimed that their problems had a great negative effect on their quality of life and 77% that they had affected their relationship with their spouse negatively to a great extent. Forty per cent did not consult health services despite their symptoms. In men with an IPSS <8 as many as 33% believed that LUTS would limit them in at least some part of their daily life. Conclusions. LUTS is a common condition among Swedish men with a severe impact on quality of life and everyday life. Despite readily available medical assistance, two out of five men with LUTS still do not try to obtain a remedy. The data presented here identify a need for improved education regarding LUTS, to increase awareness of the condition and the treatment options that are available.


Scandinavian Journal of Urology and Nephrology | 2009

Intraurethral prostate injections with mepivacaine epinephrine: effects on patient comfort, treatment time and energy consumption during high-energy transurethral microwave thermotherapy.

Tomas Knutson; Annika Johansson; Jan-Erik Damber; Magnus Fall; Stepan Vesely; Ralph Peeker

Objective. To investigate the effects of intraprostatic mepivacaine epinephrine injections administered by the Schelin catheter™ during high-energy transurethral microwave thermotherapy (TUMT) using the CoreTherm® Prostalund Feedback Treatment® (PLFT) system. Material and methods. The study included 85 men with lower urinary tract symptoms due to benign prostatic enlargement. One group had intraprostatic injections with mepivacaine epinephrine by the new Schelin catheter, while patients in the other group were treated without intraprostatic injections. All men were treated by TUMT using the PLFT system. Before treatment, transrectal ultrasound (TRUS) volume was measured. During the procedure, treatment time, energy consumption, cell-kill parameter and maximal prostate temperature were recorded. Patients who needed perioperative intravenous analgesics and the rate of perioperative and postoperative complications were registered. Results. The patients who had intraprostatic and periprostatic injections with mepivacaine epinephrine had shorter effective treatment time and reduced energy consumption. There was also a difference between the two groups in that 70% of patients without intraprostatic injections and only 11% of injected patients needed intravenous analgesics. No differences were found in TRUS volume, estimated cell-kill, maximal prostate temperature or complication rates. Conclusions. Intraprostatic injections with mepivacaine epinephrine distributed by the Schelin catheter reduce the number of patients needing intravenous analgesics during PLFT, as well as the treatment time and energy consumption during treatment. Besides improved patient comfort, intraprostatic and periprostatic injections condense the treatment time without side-effects, making PLFT less cumbersome for most patients.


Scandinavian Journal of Urology and Nephrology | 2008

Transurethral microwave thermotherapy of the prostate – Evaluation with MRI and analysis of parameters relevant to outcome

Stepan Vesely; Markus F. Müller; Tomas Knutson; Ralph Peeker; Mikael Hellström; Christer Dahlstrand

Objectives. To evaluate morphological changes in the hyperplastic prostate tissue following transurethral microwave thermotherapy and to investigate the dependence of the treatment outcome on structural and physiological features of the prostate. Material and methods. In this prospective study, 13 patients with chronic urinary retention due to benign prostatic hyperplasia (BPH) underwent Coretherm (ProstaLund, Lund, Sweden) microwave thermotherapy. Prior to the treatment and 1 week and 6 months after, the patients were examined with MRI using morphologic, contrast medium-enhanced perfusion and diffusion-weighted imaging. Such advanced MRI techniques permit an assessment of parameters that have a hypothetical influence on microwave thermotherapy (e.g. prostate blood perfusion, water content and prostate microstructure). Results. Morphologic and perfusion MRI showed a clear prostatic tissue defect in all 13 patients after 1 week and in all 12 patients at 6 months’ follow-up. The mean size of the defect was 22.5 cm3 (27%) (range 3.7–47.3 cm3) and 4.1 cm3 (1.1–10.1 cm3) at 1 week and 6 months, respectively. The cell kill volume was estimated to be 20.5±7.4 cm3 and correlated significantly with the size assessed by MRI at 1 week (r=0.8; p=0.002) and 6 months (r=0.69; p=0.05). At 6 months, the mean decrease in prostate volume was 20.1 cm3 (p<0.0001). The microstructure of the prostate expressed as the apparent diffusion coefficient was shown to have a strong influence on the treatment process. All patients (n=12) were catheter-free at 6 months. Another patient experienced persistent obstruction and underwent transurethral resection of the prostate. Conclusions. Coretherm microwave treatment leads to significant intraprostatic necrosis, which is detectable with MRI even 6 months after the treatment. Diffusion-weighted MRI is capable of identifying structural features of the prostate that can predict the length of treatment and the amount of energy needed.


Urologia Internationalis | 2004

30-MINUTES-TUMT

Mauro Dicuio; Tomas Knutson; Stepan Vesely; Jan-Erik Damber; Christer Dahlstrand

Introduction: Primary objective: to investigate if 30-MINUTES-TUMT can be performed under topical anesthesia and analgesics. Secondary objectives: to evaluate retrospectively analgesics and to study parameters connected with pain. Materials and Methods: Eighty-nine patients underwent TUMT. Patients were divided into four groups with different medications. Paracetamol and tolterodin-L-tartrate were administered in all groups. The first group was also given hydromorphone hydrochloride and atropine sulphate, the second group dextropropoxyphene, the third group morphine and diclofenac, and the fourth group morphine and dextropropoxyphene. Pain during TUMT was registered using the VAS scale. Results: Pain during TUMT was (VAS in mm), respectively, total-first-second-third-fourth group: at 5 min –30, 31, 12, 28, 35; at 15 min –30, 23, 16, 25, 34; at 25 min –30, 28, 18, 25, 35. All patients accepted the treatment. No significant difference between the different drug schedules was noticed. Conclusions: It is possible to treat patients with 30-MINUTES-TUMT with local anesthesia and analgesics. The pain can be accepted by all patients.


Scandinavian Journal of Urology and Nephrology | 2001

Pressure-Flow Studies for Patient Selection in the Treatment of Symptomatic BPH A One-year Follow-up Study

Tomas Knutson; S. Pettersson; Christer Dahlstrand

Objective: Many different treatments for lower urinary tract symptoms (LUTS) due to bladder outlet obstruction (BOO) are available today. To select the most suitable method for each patient is therefore a delicate task. The aim of this study has been to use a standardised systematic investigation schedule including pressure flow studies (pQS) in order to try to use graded treatment according to obstruction. Methods: Ninety-nine patients were systematically examined with routine investigations and pQS to select between 3 treatment options, TURP, TUMT 2.0 (low energy) and watchful waiting (WW). Patients with severe BOO were recommended TURP, patients with moderate BOO were treated with TUMT and patients with no or minor BOO were recommended WW. Results: TURP produced the best improvement in maximum free flow (Q-max), IPS-score and PVR, but only TURP had serious complications. TUMT treatment produced a more moderate improvement in flow rate, IPS-score and PVR, and all of the complications were minor. WW did not improve PVR or Q-max but the IPS-score decreased significantly. One UTI was the only complication in the WW group. Conclusions: pQS can be used to allocate patients with LUTS due to suspected BOO into different treatment arms; TURP, TUMT, WW, all with known different effects of BOO and with different severity of complications. Good symptomatic effect in Q-max, PVR and IPS-score with less serious complications and at low failure rate can thereby be obtained.OBJECTIVE Many different treatments for lower urinary tract symptoms (LUTS) due to bladder outlet obstruction (BOO) are available today. To select the most suitable method for each patient is therefore a delicate task. The aim of this study has been to use a standardised systematic investigation schedule including pressure flow studies (pQS) in order to try to use graded treatment according to obstruction. METHODS Ninety-nine patients were systematically examined with routine investigations and pQS to select between 3 treatment options, TURP, TUMT 2.0 (low energy) and watchful waiting (WW). Patients with severe BOO were recommended TURP, patients with moderate BOO were treated with TUMT and patients with no or minor BOO were recommended WW. RESULTS TURP produced the best improvement in maximum free flow (Q-max), IPS-score and PVR, but only TURP had serious complications. TUMT treatment produced a more moderate improvement in flow rate, IPS-score and PVR, and all of the complications were minor. WW did not improve PVR or Q-max but the IPS-score decreased significantly. One UTI was the only complication in the WW group. CONCLUSIONS pQS can be used to allocate patients with LUTS due to suspected BOO into different treatment arms; TURP, TUMT, WW, all with known different effects of BOO and with different severity of complications. Good symptomatic effect in Q-max, PVR and IPS-score with less serious complications and at low failure rate can thereby be obtained.

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Christer Dahlstrand

Sahlgrenska University Hospital

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Stepan Vesely

Sahlgrenska University Hospital

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Magnus Fall

University of Gothenburg

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Mauro Dicuio

Sahlgrenska University Hospital

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Ralph Peeker

Sahlgrenska University Hospital

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S. Pettersson

Sahlgrenska University Hospital

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Annika Johansson

Sahlgrenska University Hospital

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Christer Edlund

Sahlgrenska University Hospital

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Claes Ohlsson

University of Gothenburg

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