Biomedical subjects

Ioannis Varkarakis

Publications and source records attributed to Ioannis Varkarakis.

11 recordsLinked to original sources

PubMed2006

Bladder lithiasis: from open surgery to lithotripsy.

Bladder calculi account for 5% of urinary calculi and usually occur because of bladder outlet obstruction, neurogenic voiding dysfunction, infection, or foreign bodies. Children remain at high risk for developing bladder lithiasis in endemic areas. Males with prostate disease or relevant surgery and women who undergo anti-incontinence surgery are at a higher risk for developing vesical lithiasis. Open surgery remains the main treatment of bladder calculus in children. In adults, the classical treatment for bladder calculi is endoscopic transurethral disintegration with mechanical cystolithotripsy, ultrasound, electrohydraulic lithotripsy, Swiss Lithoclast, and holmium:YAG laser. Novel modifications of these treatment modalities have been used for large calculi. Open and endoscopic surgery requires anesthesia and hospitalization. Alternatively, extracorporeal shock wave lithotripsy has been demonstrated to be simple, effective, and well tolerated in high-risk patients. Recently, simultaneous percutaneous suprapubic and transurethral cystolithotripsy has been tested as well as percutaneous cystolithotomy by using a laparoscopic entrapment sac.

Humans↗

PubMed2006

Clinical sequelae of radiographic iceball involvement of collecting system during computed tomography-guided percutaneous renal tumor cryoablation.

OBJECTIVES: Percutaneous renal tumor cryoablation is being evaluated as a treatment option for small renal tumors. However, when tumors are located centrally, involvement of the collecting system by the radiographic iceball can occur. We reviewed our series of computed tomography (CT)-guided percutaneous renal tumor cryoablation to identify those cases in which there appeared to be involvement of the collecting system by the radiographic iceball and to determine any clinical sequelae of such involvement. METHODS: Retrospective review of the medical records identified 6 patients who had undergone CT-guided percutaneous renal tumor cryoablation with evidence of collecting system involvement. Measurements of the tumor size, size of the radiographic iceball, and the size of the immediate postprocedure "cryozone" (region of apparent treatment on contrast-enhanced CT) were obtained from the preprocedure, intraprocedure, and immediate postprocedure CT scans. Follow-up imaging was obtained beginning at 3 to 6 months. RESULTS: Six patients were identified who met the inclusion criteria and had at least 3 months of documented follow-up. Despite the apparent involvement of the collecting system during the cryoablation procedure, no patient developed clinical signs or symptoms or radiographic evidence of a urine leak or fistula formation. Furthermore, no evidence of ureteral narrowing or stricture formation has been found to date, with a mean follow-up of 167.7 days (range 90 to 288). CONCLUSIONS: We observed no clinically appreciable urine leaks despite what appeared to be obvious involvement of the collecting system by the radiographic iceball. However, care should be exercised to avoid this insult when possible until additional research has confirmed its safety.

Adult↗

PubMed2005

Exploring the learning curve, pathological outcomes and perioperative morbidity of laparoscopic partial nephrectomy performed for renal mass.

PURPOSE: We investigated the learning curve, pathological results and perioperative morbidity of laparoscopic partial nephrectomy (LPN). MATERIALS AND METHODS: The records of all LPN cases at our institution between January 1999 and March 2004 were reviewed. Of 223 cases 217 (97.3%) were performed for an enhancing renal mass. RESULTS: Mean tumor size was 2.6 cm (range 1 to 10) and 95.4% of patients had a normal contralateral kidney. Transient vascular control was performed in 75.1% of cases. Mean operative time (186 minutes) decreased with surgeon experience (p = 0.003) but was independent of tumor size (p = 0.964). Mean warm ischemia time (27.6 minutes) depended on tumor size (p = 0.005) but not on experience (0.964). Mean blood loss was 385 cc and the perioperative transfusion rate was 6.9%. Postoperative complications occurred in 23 cases (10.6%) with the most common being ileus (1.8%), bleeding (1.8%) and urinary leakage (1.4%). Although the mean serum creatinine change after LPN was a function of tumor size (p <0.001), it was clinically insignificant (0.13 mg/dl). No significant relationship was observed between warm ischemia time and creatinine change (p = 0.262). The final pathological evaluation revealed renal cell carcinoma in 144 patients (66.4%) and the overall positive margin rate was 3.5%. Only 2 renal cell carcinoma recurrences in the operated kidney (1.4%) were identified (mean followup +/- SD 24 +/- 12 months). CONCLUSIONS: LPN is an effective approach for treating small renal masses with low perioperative morbidity. Contrary to previous reports, more than 30% of the enhancing renal lesions excised in this series were found to be benign on final pathological evaluation.

Adult↗

PubMed2005

Long-term survival analysis after laparoscopic radical nephrectomy.

PURPOSE: This report assesses the long-term oncological efficacy of laparoscopic radical nephrectomy compared with open radical nephrectomy in patients with clinically localized renal cell carcinoma. MATERIALS AND METHODS: We analyzed the data from 121 patients who underwent radical nephrectomy between 1991 and 1999 for clinical tumor stage T1/2 N0M0. The medical records of all patients were retrospectively reviewed with emphasis on tumor recurrence and survival. Statistical comparison was performed using Kaplan-Meier analysis. RESULTS: The median followup was 73 months for the laparoscopic group and 80 months for the open group. Of the 67 patients who underwent laparoscopic surgery, 53 survived without any recurrence of disease, 2 are currently alive with metastasis, 2 died of metastatic disease in months 12 and 17, and 10 patients died without any disease recurrence. Laparoscopic port site metastasis did not develop in any patients. Of the 54 who underwent open surgery, 34 survived without any recurrence of disease, 1 currently has metastasis, 6 died of metastasis within 17 to 74 months, and 13 died without any disease recurrence. A comparison of the 5 and 10-year disease-free survival rates of the laparoscopic and open groups revealed no significant differences. In addition, the 5 and 10-year cancer specific and actuarial survival rates were not significantly different. CONCLUSIONS: Based on long-term followup, our evaluation confirmed for clinical tumor stage T1/2 N0M0 that laparoscopic radical nephrectomy is oncologically equivalent to open radical nephrectomy.

Carcinoma, Renal Cell↗

PubMed2005

Laparoscopic specimen extraction: morcellation.

OBJECTIVES: To review our experience with intact extraction and morecellation of nephrectomy specimen, and the advantages and disadvantages of morcellation indicated by current reports. PATIENTS AND METHODS: In a previous study, 56 consecutive patients undergoing radical and simple transperitoneal laparoscopic nephrectomy were prospectively evaluated. Morcellation specimens (33) were extracted at the umbilical or lateral port sites and intact specimens (23) through an infraumbilical incision. Data were obtained on pathology, narcotic requirements, hospital stay, complications, estimated blood loss, size of renal mass based on preoperative imaging, specimen weight and extraction incision length. RESULTS: The mean incision length was 1.2 cm in the morcellation group and 7.1 cm in the intact group (P< 0.001). There were no significant differences in pain or recovery between the groups. In two cases of tumor nephrectomy, microscopic invasion of the perinephric adipose tissue in the intact specimen group were up-staged from clinical T1 to pT3a disease; there was no change in patient treatment based on this information. CONCLUSIONS: With proper technique, morcellation is safe for extracting renal tumours. The specimen can be evaluated for histology but not for pathological staging, limiting its use with transitional cell carcinoma. Port-site seeding is rare, and does not appear to be more frequent than with open nephrectomy. Although morcellation is cosmetically more desirable, there was no significant advantage in operating time, pain or duration of hospital stay. The choice od extraction method depends on the surgeon's preference and patient choice.

Adolescent↗

PubMed2004

Complications of abdominal urologic laparoscopy: longitudinal five-year analysis.

OBJECTIVES: To analyze complications of abdominal laparoscopic surgery of the urinary tract at a single institution during a 5-year period. METHODS: From 1996 to 2000, we identified 894 abdominal laparoscopic procedures performed at a single institution: 600 nephrectomies (live donor, simple, radical, nephroureterectomy, and partial), 112 pyeloplasties, 61 renal biopsies, 35 retroperitoneal lymph node dissections, 31 renal cyst ablations, 18 adrenalectomies, and 37 other abdominal procedures. The charts were retrospectively reviewed for complications, which were classified as operative, postoperative, or medical. Complications were correlated with patient age and American Society of Anesthesiologists score. Statistical analysis was performed with Fisher's exact test and chi-square tests. RESULTS: A total of 118 complications (13.2%) occurred. Two patients (0.2%) died. As a result of operative complications, the procedure of 13 patients (1.5%) was converted to an open one. As a result of postoperative complications, 13 (1.5%) underwent operative and 6 (0.7%) nonoperative intervention. The most common intraoperative complications were vascular (n = 23), adjacent organ (n = 10), and bowel (n = 9) injuries. The most common postoperative complications were neuromuscular pain (n = 12), hematoma (n = 11), urine leak (n = 7), and wound infection (n = 7). The differences in the annual complication rates for all procedures did not attain statistical significance (P = 0.5). Among all procedures, excluding live donor nephrectomy, complications of any kind correlated with a greater patient American Society of Anesthesiologists score (P = 0.01). CONCLUSIONS: Rather than decreasing, the overall incidence of laparoscopic complications did not change significantly during a 5-year period at our institution. The factors contributing to this observation likely included the progression of inexperienced individual surgeons through the learning curve, the introduction of new, more sophisticated laparoscopic procedures, and stable rates of patient comorbidity. This experience may represent the average complication rate for urologic laparoscopy at a large-volume, academic training center.

Adrenalectomy↗

PubMed2004

Long-term results of open transvesical prostatectomy from a contemporary series of patients.

OBJECTIVES: To provide information about the long-term efficacy of transvesical prostatectomy from a contemporary series of patients. When comparing minimally invasive procedures with open prostatectomy, the data for the latter are usually provided from old studies or from recent ones performed in developing countries. However, this procedure is still used frequently for large-size prostates. METHODS: During a 5-year period, 232 patients with large (greater than 75 g) prostates underwent open transvesical prostatectomy for symptomatic benign prostatic hyperplasia. Patient charts were retrospectively reviewed for preoperative and postoperative International Prostate Symptom Scores, postvoid residual urine volumes, maximal flow rates, early and late postoperative complications, and the need for reoperation. The preoperative International Prostate Symptom Score, postvoid residual urine volume, and maximal flow rate were compared with the corresponding postoperative data at 8 to 12 months and at the last follow-up visit. RESULTS: Complete data evaluation was possible for 151 patients, with a mean follow-up of 41.8 +/- 15.6 months. Improvement in International Prostate Symptom Score, postvoid residual urine volume, and maximal flow rate was statistically significant (P <0.001) at 8 to 12 months and remained statistically significant at the last follow-up visit. Long-term complications included bladder neck contraction in 5 (3.3%) occurring at a mean of 10 months (range 5 to 17), urethral strictures in 1 (0.6%), and meatal stenosis in 2 (1.3%) of 151 patients. Re-operation was required in 6 patients (3.9%). CONCLUSIONS: Transvesical prostatectomy in a contemporary series of patients proved to be successful, with a low rate of complications. Its success has a durable effect and only rarely was a corrective procedure necessary. This approach should be included in the list of possible treatments to discuss with the patient with a large prostate.

Aged↗

PubMed2004

Laparoscopic partial nephrectomy: evaluation of long-term oncological outcome.

PURPOSE: Laparoscopic partial nephrectomy (LPN) has emerged as a viable alternative to open surgery for renal tumors less than 4 cm. We present oncological followup of patients treated with laparoscopic nephron sparing surgery at our institution. MATERIALS AND METHODS: Between September 1996 and December 2001, 48 patients who underwent LPN for clinically localized tumors were found to have pathologically proven renal cell carcinoma. Medical and operative records were reviewed for clinical characteristics, pathological findings and followup information. RESULTS: Mean patient age was 59.7 years (range 32 to 81) and mean followup was 37.7 months (range 22 to 84). Mean tumor size was 2.4 cm (range 1.0 to 4.0). Final pathological stage was pT1 in 42 patients (87.5%) and pT3a in 6 (12.5%). Histology revealed clear cell in 32 patients (66.7%), papillary in 10 (20.8%), chromophobe in 3 (6.3%), collecting duct in 1 (2.1%) and unclassified in 2 (4.2%). Intraoperative frozen section biopsies revealed negative margins in all cases. Final surgical margins were positive in 1 patient (2.1%). Followup evaluation consisting of physical examination and yearly cross-sectional imaging, which revealed no recurrences in 46 of 48 patients (95.8%). One patient with von Hippel-Lindau disease was found to have local recurrence 18 months after LPN and observation was elected. The second patient had recurrence in the same kidney away from the original tumor site approximately 4 years later. CONCLUSIONS: LPN is an effective treatment modality for clinically localized renal cell carcinoma. Oncological outcomes at a mean followup of 3 years are promising, although the durability of oncological outcomes must be determined.

Adult↗

PubMed2004

Nerve sparing radical prostatectomy: effects of hemostatic energy sources on the recovery of cavernous nerve function in a canine model.

PURPOSE: To preserve sexual function following radical prostatectomy, one must avoid injury to the neurovascular bundles (NVBs). In the conventional open surgical technique, the use of energy sources for hemostasis is avoided to prevent damage to the cavernous nerves. In contrast, during laparoscopic radical prostatectomy, electrosurgical and ultrasonic energy sources are frequently used for hemostasis during dissection of the prostate. In this study, we evaluated the acute and chronic physiological effects of various hemostatic energy sources on cavernous nerve function in the canine model. MATERIALS AND METHODS: A total of 12 dogs were divided into 4 groups based on the type of energy source used for hemostasis during unilateral dissection of the NVB. The groups included conventional dissection with suture ligatures (group 1), monopolar (group 2) or bipolar (group 3) electrosurgery and ultrasonic shears (group 4). The contralateral NVB was left undissected as a control. Erectile function was assessed acutely and after 2 weeks of survival by measuring peak intracavernous pressures in response to cavernous nerve stimulation. RESULTS: Following conventional techniques of nerve sparing, the erectile response to nerve stimulation was unaffected. In contrast, the use of energy sources in proximity to the NVB during nerve preservation was associated with a substantial decrease in erectile response both acutely (74% to 91% decrease compared to controls) and after 2 weeks (93% to 96% decrease). CONCLUSIONS: In the chronic canine model, use of hemostatic energy sources in proximity to the prostate during dissection of the neurovascular bundle is associated with a significantly decreased erectile response to cavernous nerve stimulation.

Animals↗

PubMed2004

Laparoscopic radical nephrectomy in the elderly.

OBJECTIVE: To evaluate the efficacy and outcome of laparoscopic radical nephrectomy (LRN) in patients aged >75 years, and to compare the results with those obtained from patients younger than this undergoing laparoscopic surgery for the same indication. PATIENTS AND METHODS: From a retrospective review of 33 patients aged >75 years undergoing LRN, 28 were for tumour. A group of 28 consecutive patients aged <75 years undergoing laparoscopy for the same indication were used for comparison. The two groups were compared for American Society of Anesthesiology (ASA) physical status score, comorbidity, previous surgical history, operative duration, estimated blood loss, tumour size, complications during and after surgery, conversion rates, time to oral intake and drain removal, perioperative mortality and hospital stay. RESULTS: Only the initial ASA score was significantly higher for the older patients. All other variables before, during and after surgery were similar for both groups. CONCLUSIONS: The final outcome of laparoscopic surgery in elderly patients was as promising as in their younger counterparts. Therefore, elderly patients should not be excluded from LRN, even though they usually present with more comorbidities.

Aged↗

PubMedDate not supplied

Multifocality of renal cell tumors is a factor to consider before performing a partial nephrectomy.

BACKGROUND: We conducted a retrospective analysis of radical nephrectomies performed in our clinic in order to evaluate the incidence of multifocality in relation to the stage, grade, size and histological type. MATERIALS AND METHODS: Preoperative imaging studies and the final pathological results of surgical specimens were reviewed. Separate primary tumors at a distance of more than one cm from the primary tumor were counted. Of 56 renal cell cancers 10 (17.8%) were multifocal. Of these 10, 3 were found with primary tumors less than or equal to 4 cm, while 7 were found with tumors between 4-10 cm. Three multiflocal tumors were found with TI tumors, none with T2, 4 with T3a and three with T3b primary tumors. Six cases were present where the histological subtype of the largest tumor was clear cell, while 4 had mixed cell histology. No multifocality was observed in the 4 grade I tumors, while 3 of the 32 grade II tumors and 6 of the 20 grade III tumors were multifocal. The only grade IV tumor presented with a separate primary tumor. Statistically significant correlation was found between multifocality and tumor grade stage and clear cell histology subtype. There was no correlation between the primary tumor size and the possibility of multifocality. CONCLUSION: Although partial nephrectomies are justified from their survival rates, close follow-up is necessary because separate primary tumors may still exist in the kidney, left behind, irrespective of tumor size.

Adult↗