Biomedical subjects

K Taari

Publications and source records attributed to K Taari.

26 records · Page 2Linked to original sources

PubMed1993

Contact fibre Nd:YAG laser for partial nephrectomy: experimental study in pigs.

Thirty-two partial nephrectomies were performed without renal cooling on 13 pigs with a contact fibre Nd:YAG laser (10 W) or a steel scalpel with or without a vascular pedicle clamp. Nine pigs had a 2-week follow-up with an abdominal ultrasound 1 week postoperatively. The time for haemostasis was 6.9 +/- 5.2 min (mean +/- SD) with the laser and 9.1 +/- 5.8 min with the steel scalpel when the clamp was used (P = 0.028). There was no significant difference in the total operating time (13.2 +/- 4.5 min with the laser vs 12.6 +/- 4.6 min with the steel scalpel, P = 0.203). Intraoperative blood loss was similar in the two groups when the clamp was used. Clamping the renal pedicle decreased the blood loss by 61% in the laser group and 31% in the steel scalpel group. The number of ligatures used was significantly lower in the laser group (3.7 +/- 2.6) compared with the steel scalpel group (6.6 +/- 3.4) (P = 0.013). Five urinomas developed on the laser side and four on the steel scalpel side. These results indicate that the contact fibre Nd:YAG laser method can be used in partial nephrectomy, but it offers no definitive advantage over the conventional technique.

Aluminum↗

PubMed1993

Intra- and peri-hepatic effects of ethanol injections in the pig liver.

We studied the intrahepatic (spread and scarring) and perihepatic effects of percutaneous ethanol injection therapy and its dose-necrosis relationship in normal pig livers. Ethanol (99.5%) was injected in volumes of 0.5-2.0 ml into the livers of six pigs during laparotomy. The livers were dissected and studied histopathologically 30 min and 2 weeks after the injections. Ethanol-induced liver necrosis, the diameter of which could roughly be calculated by dividing the injected dose by 2 (inversely: volume (ml) = 2 x diameter (cm)). Two weeks after the injections all pigs showed intra-abdominal adhesions and severe intrahepatic scar formation, unlike three control pigs similarly operated on without ethanol injections. The 30-min lesions showed thin projections extending into the neighboring liver tissue. Major escape of ethanol outside the needle tip area in the liver occurred twice. Uncontrolled spread of ethanol may be a potential hazard of this treatment.

Animals↗

PubMed1993

Parenchyma-conserving surgery for renal cell carcinoma.

Between 1969 and 1992, 32 patients underwent conservative surgery (partial nephrectomy or enucleation) for renal cell carcinoma (RCC). Elective parenchyma-conserving surgery (n = 10) was done in patients with small, peripheral kidney tumors and a normal contralateral kidney. Cancer in a solitary kidney, bilateral tumors, dysfunctional contralateral kidney or chronic renal failure were imperative indications (n = 22) for conservative surgery. In the elective group the tumors were 15-100 mm (mean 37 mm) in diameter, in the imperative group 5 to 200 mm (mean 41 mm). The follow-up was 0.2-192 months (mean 48.7 months). Nine of 22 (41%) patients in the imperative group have died of RCC. There were no renal cancer related deaths in the elective group. The 5-year cause-specific survival rates for the elective and imperative groups were 100% and 46%, respectively. Two patients in the elective group have died of unrelated causes. Local recurrences developed in three of 22 patients in the imperative group after a mean of 5.4 years; two of them had von Hippel-Lindau disease with bilateral RCC. Conservative surgery seems to be a feasible option in small peripheral kidney tumors.

Carcinoma, Renal Cell↗

PubMed1992

Morphological effects of photodynamic therapy on rabbit bladder using Photofrin II and Photosan intravesically and intravenously.

Photodynamic therapy (PDT) has proved effective against superficial papillary bladder tumours and focal and diffuse carcinoma in situ. Effective topical administration of the sensitiser would be a welcome improvement. The morphological effects of PDT on the normal bladder were examined in 13 rabbits when 2 photosensitisers (Photofrin II and Photosan III) were applied intravesically (5 mg/kg for 1 h) and compared with intravenous administration (3 or 5 mg/kg). Four animals served as controls without a sensitiser. Intravesical red light (630 nm) from an argon dye laser was used to activate the photosensitiser, using light doses of 12 or 24 J/cm2. The animals were sacrificed either 1 or 5 to 7 days after the laser treatment. Intravenous dosage induced bladder wall oedema/haemorrhage and total necrosis of the epithelium. There was no difference between the effects of the 2 sensitisers. Intravesical application induced superficial epithelial necrosis. The control animals treated with laser light alone showed slight superficial injury to the cell layer.

Administration, Intravesical↗

PubMed1992

Healing of bladder wall after contact and non-contact Nd-YAG laser photocoagulation. Experimental study in piglets.

The healing process of the bladder wall after contact and non-contact Nd-YAG laser irradiation was studied in 18 piglets. The animals were sacrificed 1 h, and 2, 5 and 14 days after photocoagulation. The lesions were examined histologically by light and scanning electron microscopy. Immunohistochemical stains were prepared for visualization of lactate dehydrogenase. Perforation of the bladder wall was found in 2 cases where a contact probe was used (15 W/2 s). A crater in the bladder wall resulting from tissue ablation was seen in all cases immediately after contact laser irradiation. Photocoagulation using a non-contact laser led to white necrosis in the bladder wall. Minimal tissue ablation was evident at the highest power setting used (35 W/2 s). After 2 days inflammation around the lesion was marked. Inflammation with fibroblasts invading the damaged area was seen 5 days after photocoagulation. Fourteen days after photocoagulation minor scar formation was evident beneath the histologically normal epithelium. It is concluded that lesions caused by contact or non-contact Nd-YAG laser photocoagulation will heal within 2 weeks with minor scar formation.

Animals↗

PubMed1991

Renal function after partial nephrectomy with the Nd-YAG laser. Experimental study in piglets.

Twelve partial nephrectomies were performed in 12 piglets using either the combination (contact and non-contact) Nd:YAG laser technique or a steel scalpel. Additional haemostasis was attempted with ligatures. The renal artery was not clamped and renal cooling was not attempted. Total nephrectomy was performed on the contralateral side. Serum creatinine and urea levels were measured, and 99mTc-DTPA renography was performed pre-operatively and 1 and 2 weeks post-operatively. One week post-operatively the mean serum creatinine level was 35% higher than the pre-operative level in the laser group and 30% higher in the steel scalpel group. Two weeks post-operatively the respective differences were 34 and 24%. The mean urea level 1 week after operation was 50% higher than the pre-operative level in the laser group and 17% higher in the steel scalpel group. Two weeks post-operatively the respective differences were 38% in the laser group and 20% in the steel scalpel group. The mean DTPA disappearance rate was 34% lower 1 week after operation in the laser group and 23% lower in the steel scalpel group when compared with the preoperative state. Two weeks post-operatively the respective changes were 48 and 25%. These data indicate that there is no significant difference in renal function when the Nd: YAG combination laser technique is used in partial nephrectomy as compared with the steel scapel.

Animals↗

PubMed1991

Efficacy and complications of the Nd:YAG laser in partial nephrectomy: experimental study in piglets.

Twenty-four partial nephrectomies were performed in 18 piglets using either the combination Nd:YAG laser technique (contact and noncontact) or a steel scalpel. Additional haemostasis was attempted with ligatures. Blood loss, operation time, and number of ligatures were compared in the two treatment groups. Twelve piglets had a two-week follow-up. The mean blood loss with the laser was 72 +/- 10 g and 83 +/- 13 g with the steel scalpel (no significant difference). The resection time until complete haemostasis was 9.8 +/- 0.9 min with the laser and 14.3 +/- 1.3 min with the steel scalpel (p = 0.0076). The number of ligatures needed for complete haemostasis was 2.8 +/- 0.4 with the laser and 7.5 +/- 1.0 with the steel scalpel (p = 0.0051). Three piglets in the steel scalpel group developed urinomas. There were two perirenal abscesses, one in each group. In the steel scalpel group there was one intussusception. In conclusion, it seems that the combination Nd:YAG laser method offers no definitive advantage over the standard technique for partial nephrectomies in the pig.

Animals↗

PubMedDate not supplied

Bacterial adherence to self-reinforced polyglycolic acid and self-reinforced polylactic acid 96 urological spiral stents in vitro.

The aim of this study was to evaluate the bacterial adherence to biodegradable self-reinforced polyglycolic acid (SR-PGA) and self-reinforced poly-DL-lactic acid (SR-PLA 96) spiral stents in vitro. They are used as temporary urethral stents in urology. Gold-plated metal wire, polyurethane and latex were used as controls. Materials were incubated up to 28 days in artificial urine, after which a bacterial suspension was added. After detaching by sonication the adhesive bacteria were analysed as colony forming units (CFUs) and by scanning electron microscopy (SEM) analysis. Adhesion was more significantly correlated to stent bacterial type than to the tested material in both assays. No encrustation was seen on SR-PGA or SR-PLA 96. SR-PGA and SR-PLA 96 had no effect on the bacterial growth. In conclusion, the bacterial properties are equally or more important than the material properties in the adhesion process.

Bacterial Adhesion↗