Biomedical subjects

G Alivizatos

Publications and source records attributed to G Alivizatos.

At least 19 recordsLinked to original sources

PubMed2006

Treatment characteristics and inherent prostatic features do not predict patient outcome after high-energy transurethral thermotherapy: a prospective study of prostalund feedback treatment.

PURPOSE: To determine whether treatment characteristics, intrinsic prostatic factors, and clinical parameters predict the outcome in patients treated with high-energy transurethral microwave thermotherapy (HE-TUMT). PATIENTS AND METHODS: A series of 48 consecutive patients, 28 with an indwelling catheter, underwent ProstaLund Feedback Treatment (PLFT). The 12-month International Prostate Symptom Score response rate (IPSS < or = 7 or > or =50% improvement), peak flow rate response rate (Q(max) > or = 15 mL/sec or > or =50% improvement), and bladder outflow obstruction index response rate (BOOI <40) were correlated with treatment characteristics such as duration, average intraprostatic temperature, time with therapeutic intraprostatic temperatures (>45 degrees C), average intraprostatic blood flow, consumed energy, and recorded prostate mass destruction. Baseline parameters such as age, serum prostate specific antigen concentration, prostate volume, and pretreatment IPSS, quality of life (QOL), Q(max), postvoiding residual urine volume (PVR), and BOOI were included in the logistic regression analysis. RESULTS: Treatment characteristics did not discriminate responders and nonresponders to HE-TUMT. For the patients without a catheter, the IPSS response (75%) was predicted by higher pretreatment IPSS (P = 0.041; relative risk [RR] = 3.4) and higher pretreatment PVR (P = 0.026; RR = 1.1). The Q(max) response (85%) was predicted by higher grades of pretreatment obstruction (P = 0.009; RR = 1.02). The BOOI response (60%) was not related to any of the factors tested. For the patients with a catheter, no outcome predictors could be identified. CONCLUSIONS: According to our results, the intraprostatic temperature, the duration of intraprostatic temperatures in the therapeutic range, and the pattern of blood flow did not predict HE-TUMT outcome. Treatment duration, consumed energy, and the magnitude of tissue necrosis did not translate into clinical efficacy. Clinical parameters were important predictors of outcome in patients not in retention.

Aged↗

PubMed2005

Present practice and treatment strategies in endourological stone management: results of a survey of the European Society of Uro-technology (ESUT).

OBJECTIVES: The European Society of Urological Technology (ESUT) conducted a survey in order to assess and record the current trends between urologists with regard to the application of endourological stone management to identify trends and differences in treatment strategies among urologists. METHODS: A total of 695 certified urologists and urological residents answered the ESUT Endourological Stone Management Questionnaire. There were 136 (28.7%) chief urologists, 240 (50.6%) staff urologists and 98 (20.7%) residents. The respondents were classified according to both the geographical origin (in four groups: Northern Europe (NE), Southern Europe (SE), Eastern Europe (EE) and Outside Europe (OE)), and department size (number of urological beds per department: small < or = 25, medium 26-50 beds, large > 50 beds) in order to identify any differences in the replies. RESULTS: On average, 40.1 newly diagnosed patients and 73.6 revisits with urolithiasis are seen a month per department. According to the replies, there are no significant differences in total numbers of treatments in ESWL and/or endourological stone managements amongst the geographically based groups. Monthly, on average 68.5 ESWL treatments and 23.0 URS are performed per department. A significant majority of surveyed urologists performs URS with a rigid or semi-rigid instrument (79%) instead of a flexible instrument (21%, p = 0.003). URS is more frequently performed outside Europe (p = 0.02) with a more frequent use of dormia catheters (p < 0.001). On average, 20.9 double g-stents are placed monthly in each department, most commonly before or after endourological procedures (p < 0.001). Percutaneous procedures are performed by 69.6% of the respondents with a mean of 16.8 PNL procedures a month. PNL for stone management is mainly performed in Eastern Europe and non-European countries (p = 0.017). Nephrostomy tubes are used by 77.7% of the responding urologists. Monthly, 13.1 nephrostomy tubes are placed, mostly during PNL or after endourological procedures (40.7%). CONCLUSION: The data obtained from the 695 urologists and residents provides information on the performed procedures and the use of material. In general, respondents from different geographical locations perform similar procedures and use identical material; however URS and PNL are performed more frequently outside of Europe, whereas laser lithotripsy is frequently used in Northern European counties.

Data Collection↗

PubMed2005

Percutaneous nephrolithotomy and its legacy.

OBJECTIVE: We review the indications of Percutaneous Nephrolithotomy (PNL), its safety and efficacy when applied to various patient groups as well as the different points of technique, giving emphasis on new tips and ongoing debates. METHODS: A literature search was performed using MEDLINE database on PNL between 1980 and 2004. RESULTS: Percutaneous nephrolithotomy (PNL) has been successfully and safely used to treat patients with renal stones for more than a quarter of a century. Still, the use of PNL in treating renal stones in different patient groups, such as children, obese patients, patients with renal congenital anomalies, patients who had previous open renal surgery and patients who have undergone renal transplantation are always of high interest. Simultaneous bilateral percutaneous nephrolithotomy seems to have a certain role in treating bilateral renal stones, especially when proficiency is achieved for unilateral PNL. Various aspects of the procedure such as patient positioning, renal access, the ideal dilating method, the type of nephrostomy tube used, as well as the actual need for drainage, have been debated. CONCLUSION: PNL is currently the procedure of choice for removal of large renal calculi. The need for well designed prospective randomized trials comparing PNL with alternative treatment modalities arises through the literature review.

Humans↗

PubMed2004

Retrograde acucise endopyelotomy: is it worth its cost?

PURPOSE: To identify patients with ureteropelvic junction (UPJ) obstruction who will benefit from endoscopic Acucise incision of the stenosis and to compare the open Hynes-Anderson pyeloplasty with this minimally invasive technique. PATIENTS AND METHODS: In a prospective trial, 22 patients with primary and secondary UPJ obstruction were treated by Acucise endopyelotomy, and 18 patients were treated by Hynes-Anderson pyeloplasty. Preoperative and postoperative renal scans were used to determine the degree of obstruction and intravenous urography, ultrasound scanning, or both to assess the degree of dilation. RESULTS: There was a vast difference in the cure rate of the two groups: Hynes-Anderson pyeloplasty cured 94.5% of the patients, while in the Acucise group, the cure rate was only 32%. There was some improvement in another 22% of the patients, but the renal scan curve remained obstructed. The remaining 45% of patients failed to show any improvement. CONCLUSION: Acucise endopyelotomy will improve or cure only patients with good renal function and mild dilation of the pelvicaliceal system. Patients with severe dilation should be treated by Hynes-Anderson pyeloplasty.

Adolescent↗

PubMed2001

Transurethral hot water balloon thermoablation.

The inclusion of a determinate technique among the "minimally invasive treatments" of the symptoms due to benign prostatic hyperplasia is a long and careful process. The technique has to be more patient-friendly than conventional techniques, but also needs to be time-tested against older methods. Most of these minimally invasive treatments are based upon distinct types of thermoablation; the method discussed here, hot water balloon thermoablation, is based on the heat conductive properties of the prostatic tissue.

Catheter Ablation↗

PubMed2001

EAU Guidelines on benign prostatic hyperplasia (BPH).

OBJECTIVE: To establish guidelines for the diagnosis, treatment, and follow-up of BPH. METHODS: A search of published work was conducted using Medline. In combination with expert opinions recommendations were made on the usefulness of tests for assessment and follow-up: mandatory, recommended, or optional. In addition, indications and outcomes for the different therapeutic options were reviewed. RESULTS: A digital rectal examination is mandatory in the assessment for the diagnosis of BPH. Recommended tests are the International Prostate Symptom Score, creatinine measurement (or renal ultrasound), uroflowmetry, and postvoid residual urine volume. All other tests are optional. The aim of treatment is to improve patients' quality of life, and it depends on the severity of the symptoms of BPH. The watchful waiting policy is recommended for patients with mild symptoms, medical treatment for patients with mild-moderate symptoms, and surgery for patients who failed medication or conservative management and who have moderate-severe symptoms, and/or complications of BPH which require surgery. Regarding non-surgical treatments, transurethral microwave thermotherapy is the most attractive option. These treatments should be reserved for patients who prefer to avoid surgery or who no longer respond favourably to medication. Finally, recommendations for follow-up tests and a recommended follow-up time schedule after BPH treatment are provided. CONCLUSIONS: Recommendations for assessment, possible therapeutic options, and follow-up of patients with BPH are made.

Follow-Up Studies↗

PubMed2001

Encrusted cystitis and pyelitis.

Encrusted cystitis (EC) and encrusted pyelitis (EP) are rare chronic inflammatory diseases of the bladder and renal pelvis, respectively, and are characterized by mucosal inflammation with deposits of ammonium magnesium phosphate on the urothelium. Corynebacterium urealyticum is the pathogen responsible in the vast majority of cases. We report 4 cases of EC and 1 case of EP. In 1 case of EC Ureaplasma urealyticum was isolated as the microorganism responsible. To the best of our knowledge, U. urealyticum-induced EC has never been reported previously.

Adult↗

PubMed2000

Prostate specific antigen and benign prostatic hyperplasia.

Benign prostatic hyperplasia is a common condition in males over 50 years, but prostate cancer can develop in the same population. Prostate specific antigen, the best marker for prostate cancer, is also produced by benign epithelial cells, and there is an overlapping phenomenon between both conditions. The better we understand the relationships between benign prostatic hyperplasia and prostate specific antigen, the higher will be the discrimination power of prostate specific antigen measurement as a marker for prostate cancer. Our scope includes a review of the latest published material to date on this subject.

Age Factors↗

PubMed1998

The effect of ESWL of renal calculi on pancreatic function.

Fifteen patients were treated by ESWL for renal calculi. The sagittal size of the head, neck and tail of the pancreas, and serum amylase, insulin, c-peptide and 24-hour urine amylase levels were estimated pre and post-treatment. Serum glucose, serum amylase and urinary levels remained within normal limits. Serum levels of insulin, c-peptide and the size of the gland increased but this was not statistically significant. There may be some danger to the pancreas during ESWL as there are some morphological changes even though there are no evident peptide changes. Caution should be taken if patients have a history of pancreatitis.

Adult↗

PubMed1998

Efficacy of escalating doses of intravesical interferon alpha-2b in reducing recurrence rate and progression in superficial transitional cell carcinoma.

OBJECTIVE: To compare the efficacy of three different doses of intravesical interferon alpha-2b (IFN alpha-2b) in reducing recurrence and progression rates in superficial grade II, transitional cell carcinoma (TCC). PATIENTS AND METHODS: Eighty-nine patients with primary or recurrent TCC stage Ta/T1, grade II, were randomly allocated into four groups after transurethral resection (TUR) of the tumour. Group A (20 patients) received no further treatment, serving as the control group; group B (22 patients) received 40 MU of IFN alpha-2b, group C (24 patients) 60 MU and group D (23 patients) 80 MU. The instillations started within 48-72 h after TUR and were performed weekly for 2 months, bimonthly for the next 4 months and thereafter monthly for 6 months. The patients were followed for 36 months. The four groups were compared for the number of recurrences (simple recurrence rate), progression in stage, disease-free interval and recurrence rate per 100 patient-months. RESULTS: During the follow-up, 33 patients had recurrence (13, eight, seven and five in groups A to D, respectively). The simple recurrence rate was 65% for group A, compared with 36% (P = 0.06), 29% (P < 0.05) and 22% (P < 0.01) for groups B, C and D, respectively. The differences in simple recurrence rates between the groups treated with IFN alpha-2b were not statistically significant. Eleven patients experienced progression in stage, with six, there, one and one in groups A to D, respectively. The differences were statistically significant only between groups A and C (P < 0.05) and groups A and D (P < 0.05). The disease-free interval was 15 months for group A, compared with 21.4 (P < 0.05), 26.1 (P < 0.001) and 30 months (P < 0.001) for groups C to D, respectively. The disease-free intervals of the groups treated with IFN alpha-2b were significantly different between all patients in groups B and D (P < 0.01) and only for those with stage T1 between groups C and D (P < 0.01). Finally the recurrence rate per 100 patient-months was 2.91, 1.19, 0.88 and 0.63 for groups A to D, respectively (all P < 0.001). The results were always in favour of the patients treated with the high dose, the only exception being the difference between groups C and D (P = 0.026). No side-effects of the drug were noted, nor was any adverse reaction reported from any patient. CONCLUSION: These results show a significant advantage for adjuvant intravesical IFN alpha-2b treatment over TUR alone for the 36 months of follow up and indicate that IFN alpha-2b can modify the clinical course of superficial TCC at least in the short term. The appropriate dose was apparently 80 MU, for although 40 MU was better than TUR alone, it was less effective than 60 MU and 80 MU; the 80 MU dose was slightly better than 60 MU and thus this regimen is recommended.

Administration, Intravesical↗

PubMed1997

Oral estramustine and oral etoposide for hormone-refractory prostate cancer.

OBJECTIVES: Estramustine and etoposide have been shown to inhibit the growth of prostate cancer cells in experimental models. An in vivo synergism of the two agents, when administered to patients with metastatic prostate cancer refractory to hormone therapy, has been reported. To confirm these results, we administered this combination to a large number of patients with hormone-refractory prostate cancer (HRPC). METHODS: Fifty-six patients with metastatic HRPC were treated with oral estramustine 140 mg three times a day and oral etoposide 50 mg/m2/day for 21 days. Therapy was discontinued for 7 days and the cycle was then repeated. Therapy was continued until evidence of disease progression or unacceptable toxicity occurred. To control for the possible interference of an antiandrogen withdrawal effect, all patients discontinued antiandrogen therapy and were not enrolled in the study unless there was evidence of disease progression. RESULTS: Forty-five percent of 33 patients with measurable soft tissue disease demonstrated an objective response, which included five complete and ten partial responses. Among 52 patients with osseous disease 17% showed improvement and 50% showed stability of bone scan. Thirty patients (58%) demonstrated a decrease of more than 50% in pretreatment prostate-specific antigen (PSA) levels. The median survival of all patients was 13 months. Good pretreatment performance status, measurable disease response, improvement or stability of bone scan, and PSA response were important predictors of longer survival. CONCLUSIONS: We conclude that the combination of estramustine and etoposide is an active and well-tolerated oral regimen in HRPC.

Adenocarcinoma↗

PubMed1996

Does free to total ratio of prostate-specific antigen alter decision-making on prostatic biopsy?

OBJECTIVES: For patients with prostate specific antigen (PSA) values of 4-10 ng/mL, some urologists perform prostatic biopsies depending upon the findings of digital rectal examination (DRE) and transrectal ultrasonography (TRUS), and others perform biopsies on most of these men regardless of the findings of DRE and TRUS. The purpose of this study was to examine whether the information given by the measurement of the ratio of free to total (F/T) PSA can alter decision-making on prostatic biopsy. METHODS: One hundred and two (102) men with PSA values between 4 and 10 ng/mL, were included in this study. All men were examined with DRE and TRUS; a F/T PSA ratio was also measured, and six prostatic biopsies were taken from each patient. RESULTS: In 102 men who were biopsied, 22 (21.5%) prostatic carcinomas were identified. Among these 22 cancer patients, 13 had abnormal findings in DRE and/or TRUS and would have been biopsied and diagnosed anyway. If we use only the F/T PSA ratio (cut-off value 0.20) to decide whom to biopsy, we would have diagnosed 16/22 cancers; the difference between these two procedures was not statistically significant (P = 0.17). If we decide to biopsy those patients who have abnormal findings in DRE and/or TRUS and those who have a F/T PSA ratio < 0.20, we would diagnose 20/22 cancers (P = 0.05) and at the same time, reduce the unnecessary biopsies from 80 to 41 (48%). With a PSA value between 4 and 10 ng/mL and no findings in DRE and TRUS and at the same time with a F/T PSA ratio > or = 0.20, we would have to perform biopsies in 20.5 men to find one cancer. On the other hand, in patients with suspicious findings in DRE and/or TRUS and a F/T PSA ratio < 0.20, in every two men that we biopsy we would find one cancer. CONCLUSION: We believe that among patients with PSA values between 4 and 10 ng/mL after performing DRE and TRUS, the additional information of F/T PSA ratio can help since it increases the number of cancers detected and reduces the number of unnecessary biopsies.

Adult↗

PubMed1996

Double-pigtail stents for distal ureteral calculi: an alternative form of definitive treatment.

In this study, we treated patients with a solitary distal ureteral stone of less than 10 mm in maximum diameter by placing a double-pigtail stent and subsequently removing it allowing the calculus to pass spontaneously. A total of 40 patients were enrolled in the study with a mean stone size of 5.1 x 3.5 mm (range 2-8 mm in length and 2-7 mm in width). The indication for intervention was intractable pain in 5 patients, infection due to obstruction in 2, highly obstructed urinary tract in 10, absence of progression for 30 days in 21 and desire of the patient to be free of stone in 2. A double-pigtail stent was inserted in the involved ureter under local anesthesia and left in place for 2 weeks. After stent removal, 34 patients succeeded in passing the stone within an average time of 5.8 days. The overall success rate was 85%. We suggest this method as an alternative form of treatment for distal ureteral calculi to extracorporeal shockwave lithotripsy of ureterolithotripsy under selected clinical circumstances.

Adult↗

PubMed1995

The value of prostatic specific antigen in the early diagnosis of prostatic cancer: a Greek view.

OBJECTIVE: To assess whether it is worthwhile to screen asymptomatic men for prostate cancer using serum prostate specific antigen (PSA) and to determine how many patients could be cured of prostatic carcinoma if detected by screening. PATIENTS AND METHODS: Between June 1992 and January 1994 the serum PSA level of 1400 asymptomatic men over 50-years-old was assessed. Those men with PSA levels < 4 ng/mL were not evaluated further. Those men with PSA levels of 4-10 ng/mL underwent digital rectal examination (DRE) and transrectal ultrasonography (TRUS) and biopsies were taken when there were significant findings on DRE and/or TRUS. If the PSA levels were > 10 ng/mL patients were submitted for DRE and TRUS and, even if both examinations were negative, random biopsies were taken. Where cancer was detected the tumour was staged and if it was a clinically confined tumour a radical retropubic prostatectomy was performed. The pathological and clinical stages of the disease were then compared. RESULTS: The majority of patients (95%) had PSA levels of < 4 ng/mL. Forty-nine men had PSA levels of 4-10 ng/mL and of these 28 were biopsied, which detected 12 (24.5%) carcinomas. There were 20 men with PSA levels > 10 ng/mL and among them 11 (55%) were found to have carcinomas. Combining these figures, among the 1400 men there were 69 cases with PSA levels > 4 ng/mL and, using DRE and TRUS, 23 patients (33%) were diagnosed as having prostatic adenocarcinomas. Among these, one had metastatic disease, three had lymph node micrometastases during surgical exploration and 19 underwent radical prostatectomies. The pathological and clinical stages agreed in only eight patients. CONCLUSION: Only eight patients can be considered as cured because of the screening protocol and even this result is overoptimistic, as the future biological behaviour of these tumours is unknown. Therefore we cannot recommend screening for prostatic carcinoma among asymptomatic men in Greece.

Aged↗

PubMed1994

Transurethral microwave thermotherapy (TUMT) in benign prostatic hyperplasia: placebo versus TUMT.

OBJECTIVES: A prospective, randomized placebo-controlled study was designed to exclude a placebo response in transurethral microwave thermotherapy (TUMT). METHODS: During a sham procedure, the microwave applicator was installed in the urethra as in the real TUMT treatment and a complete procedure was simulated by the microwave delivery system (Prostatron). Any patient who entered this study had the option to request a second real TUMT treatment if, 3 months after the initial procedure, his condition had not improved. RESULTS: A total of 48 patients were available for evaluation at 3 months and 28 at 6 months. The TUMT group had an average decrease of 7.3 points (from 13.2 to 5.9) in the Madsen symptom score, an average increase in flowrate of 3.4 mL/s (9.6 to 13.0), and an increase in voiding percentage of 9.6% (81.7 to 91.3). All improvements were statistically significant. In the sham group, the average Madsen score decreased from 12.1 to 8.2 points, the average flowrate decreased from 9.7 to 9.5 mL/s, and the voiding percentage increased from 80.8% to 84.3%. Only the change in symptom score was significant. In both groups, observations at the 3-month follow-up were similar to those after 6 and 12 months. Patients who had TUMT after sham treatment showed similar significant changes in symptom score and peak flow as observed in the original TUMT group. Patients who did not respond favorably to a first TUMT did not experience improvement after a second TUMT. CONCLUSIONS: A placebo effect, although minimal, exists. This placebo response, however, accounts for little of the observed benefit of TUMT.

Aged↗

PubMed1994

Influence of digital examination, cystoscopy, transrectal ultrasonography and needle biopsy on the concentration of prostate-specific antigen.

The influence of various prostatic manipulations, including digital rectal examination, cystoscopy, transrectal ultrasonography and transrectal needle biopsy, on the serum prostatic-specific antigen (PSA) levels in 170 men, were examined. We found that digital rectal examination, cystoscopy and transrectal ultrasonography had no significant effect on PSA levels, except for transrectal needle biopsy, which caused an immediate increase of serum PSA in 96.2% of the patients lasting more than 2 weeks in 42.3% of the cases. In conclusion, serum PSA determination after digital rectal examination, after cystoscopy and after transrectal ultrasonography is accurate and reliable. On the other hand, we must wait about 6 weeks after needle biopsy before measuring PSA in the serum of patients with prostatic diseases.

Biopsy, Needle↗

PubMed1994

Laser ablation of the prostate: experience with an ultrasound guided technique and a procedure under direct vision.

Twenty-four patients with benign prostatic hyperplasia were treated with the Nd:YAG laser. We review our experience with two different techniques: the ultrasound-guided transurethral laser-induced prostatectomy (TULIP) and the visual laser ablation of the prostate (VLAP). Our experience with these two different laser systems shows that the treatment is relatively simple, speedy and performed with virtually no blood loss. The results, of both the TULIP and VLAP procedures, are excellent. The symptom scores decrease from 43 to 19 (TULIP) and 48 to 9 (VLAP). Furthermore, there is a marked increase in average uroflow from 7.9 to 18.6 ml/s (TULIP) and from 8.1 to 18.0 ml/s (VLAP). The patients with the TULIP procedure, however had more pronounced posttreatment complaints. These patients more often received antibiotics. Laser therapy of the prostate, although still in its infancy, gives excellent results and has substantial advantages over conventional transurethral resection of the prostate (TURP). Laser therapy may replace TURP within several years.

Humans↗

PubMed1993

Update of hormonal treatment in cancer of the prostate.

Prostate carcinomas are heterogeneous tumors composed of hormone sensitive and hormone insensitive cells. Although all androgens have an effect on prostatic cells, it is believed that dihydrotestosterone (DHT) is the active metabolite primarily utilized by prostatic cancer cells for growth and division. Hormonal therapies are therefore designed to lower tissue levels of DHT or prevent its binding to receptors on prostatic cancer cells. The Veterans Administration Cooperative studies in the 1960s and 1970s laid the groundwork for the use and timing of hormonal therapy. Until recently orchiectomy and estrogens were the two main alternatives, but new compounds such as luteinizing hormone releasing hormone analogs and antiandrogens have shown to be as effective and less toxic than estrogens. Today, important controversies concerning the selection of the best primary treatment and the timing of initiating the hormonal therapy still exist. Second line hormonal strategies are used, but they still have to prove their impact on overall survival.

Clinical Trials as Topic↗