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Biomedical subjects

Patrick P W Luke

Publications and source records attributed to Patrick P W Luke.

14 recordsLinked to original sources
PubMed2007

Treatment of renal transplant complications with a mesh hood fascial closure technique.

Early renal allograft dysfunction may be caused by a number of technical factors including thrombosis, kinking of vessels, and a Page kidney situation in which the allograft is compressed within a shallow false pelvis and limited retroperitoneal space. Without early recognition, compromised graft function, obstruction, or graft loss may ensue. We describe a technique using a polypropylene-assisted mesh hood fascial closure (MHFC) to prevent and treat this potential complication. MHFC was performed both primarily to prevent this phenomenon, and secondarily to treat this complication. Between April 2001 and October 2002, 16 patients undergoing 17 renal transplants underwent MHFC. The mean recipient body weight was 17% less than the mean donor weight. The mean follow-up period was 9 months. The mean serum creatinine level after primary MHFC was 148.4 micromol/L. Three of 4 patients with early allograft dysfunction regained function after secondary MHFC and had a mean serum creatinine level of 155.3 micromol/L. Wound complications were seen in 5 (31%) patients with no wound or mesh infections and 1 patient was diagnosed with a lymphocele. We conclude that the use of mesh in the primary closure of the incision after renal transplantation is safe and has minimal complications.

Compartment Syndromes↗
PubMed2006

Laparoscopic management of advanced renal cell carcinoma with level I renal vein thrombus.

OBJECTIVES: To present our series of laparoscopic radical nephrectomy in patients with level I tumor thrombus. The existence of renal vein tumor thrombus presents a technical challenge in securing hilar control during the resection of a renal mass. To our knowledge, this experience represents one of the largest series of laparoscopic nephrectomy for renal cell carcinoma associated with a macroscopic renal vein thrombus. METHODS: From April 2002 to June 2004, 12 patients (8 men and 4 women) were diagnosed with renal masses. In addition to computed tomography, cavography and magnetic resonance imaging were used to determine the levels of tumor thrombi preoperatively in those who had suspicious involvement of the renal vein on computed tomography. RESULTS: Laparoscopic nephrectomy was performed in a standard fashion. Hand-assisted laparoscopic nephrectomy was used in 6 cases involving large tumors with bulky hilar adenopathy. All renal veins were stapled using an endoscopic vascular stapler. Intraoperative laparoscopic ultrasonography was used to delineate the extent of the vein thrombus in 4 cases to enable proper stapler positioning. No intraoperative complications occurred, and 2 cases were electively converted to open nephrectomy. The postoperative narcotic requirements and hospitalization times were low. Pathologic examination of the tumor specimens demonstrated negative resection margins in all patients. CONCLUSIONS: In carefully selected patients, laparoscopic resection of renal masses with level I renal vein thrombi is feasible. Because of technical considerations that may be identified intraoperatively, early conversion to open nephrectomy should be anticipated. Long-term results regarding oncologic control continue to be assessed.

Carcinoma, Renal Cell↗
PubMed2006

Intravenous immunoglobulin as a treatment for BK virus associated nephropathy: one-year follow-up of renal allograft recipients.

BK virus associated nephropathy (BKVAN) has emerged as an important cause of renal allograft dysfunction and graft loss. Although several treatment strategies have been proposed, the rate of graft loss remains high. We studied the outcome of renal transplant patients with BKVAN treated with IVIG. After 11.4 +/- 3.9 months (mean +/- SEM) from the time of transplantation, 8 renal allograft recipients were diagnosed with BKVAN. In addition to a reduction of immunosuppressive therapy, patients received 2 g/kg IVIG. After a mean follow-up of 15 months, all except one patient are currently off dialysis. In summary, after IVIG therapy, 88% of patients still have functioning grafts, although renal function continues to be impaired. The benefit of concomitant IVIG and reduction of immunosuppressive therapy in BKVAN needs to be further addressed in randomized, multicentered trials.

Adult↗
PubMed2006

Intraoperative laparoscopic renal ultrasonography: use in advanced laparoscopic renal surgery.

OBJECTIVES: To highlight the use of intraoperative laparoscopic ultrasonography (ILUS) in complex renal surgery, as well its impact on management. ILUS has been used to facilitate advanced laparoscopic surgery, but only limited descriptions of the indications for its use have been published. METHODS: All patients undergoing laparoscopic renal procedures requiring ILUS from October 2001 to March 2005 were reviewed. A total of 50 cases, including 35 partial nephrectomies, cryoablation of 6 renal tumors, 6 radical nephrectomies, 2 perinephric explorations, and 1 resection of a renal artery aneurysm were assessed by ILUS. RESULTS: The average tumor size in the patients undergoing laparoscopic partial nephrectomy was 3.1 cm (range 1.4 to 8.0), and all margins were negative. Also, a previously unidentified satellite lesion was found in 1 patient. ILUS was essential in assessing iceball formation during laparoscopic renal cryotherapy. ILUS also proved useful in defining the anatomy during laparoscopic perinephric exploration, assessing renal vein thrombi during laparoscopic nephrectomy, and evaluating renal perfusion during laparoscopic renal artery aneurysm repair. CONCLUSIONS: ILUS can be extremely useful in advanced laparoscopic renal surgery. In a number of situations, it is an essential surgical tool. With expanding indications for laparoscopic surgery, the indications for ILUS continue to grow.

Adult↗
PubMed2005

Aggressive angiomyxoma of the epididymis.

Aggressive angiomyxoma is a rare locally invasive non-metastasizing soft tissue neoplasm that is most commonly located in the female pelvis and perineum. We report a case of aggressive angiomyxoma arising from the epididymis of a young male, which was treated by radical orchiectomy.

Adult↗
PubMed2005

Partial nephrectomy for renal cell carcinoma in long-term renal allografts: operative and post-operative considerations.

The majority of immunosuppressive agents used to prevent rejection in transplant patients have also been shown to increase malignancy risk. Renal transplant patients are dependent upon their solitary allograft kidney in order to remain dialysis free, and the discovery of a primary malignancy within the allograft poses a therapeutic dilemma. We describe two cases of primary renal allograft malignancies and discuss nephron-preserving surgical treatment. Furthermore, we discuss the potential anti-tumor role of the immunosuppressive agent sirolimus in the treatment of these complex patients.

Adult↗
PubMed2004

Hand-assisted laparoscopic resection of the massive autosomal dominant polycystic kidney.

Laparoscopic nephrectomy provides many advantages over open nephrectomy, including pain reduction, hospitalization, and superior cosmesis. However, the bulkiness of massively enlarged polycystic kidneys may preclude access to the renal hilum and therefore prevent safe ligation and division of the renal vascular supply. We describe a hand-assisted technique that facilitates the resection of the massively enlarged kidney.

Humans↗
PubMed2004

Laparoscopic versus open partial nephrectomy.

OBJECTIVES: To compare, retrospectively, the results of laparoscopic partial nephrectomy (LPN) to open partial nephrectomy (OPN) using a tumor size-matched cohort of patients. Limited data are available comparing LPN to OPN in the treatment of small renal tumors. METHODS: Between September 2000 and September 2003, 27 LPNs and 22 OPNs were performed to treat renal masses less than 4 cm. Patient demographics and tumor location and size (2.4 +/- 1.0 cm versus 2.9 +/- 0.9 cm, respectively; P = not statistically significant) were similar between the LPN and OPN groups. RESULTS: Although the mean operative time was longer in the LPN than in the OPN group (210 +/- 76 minutes versus 144 +/- 24 minutes; P <0.001), the blood loss was comparable between the two groups (250 +/- 250 mL versus 334 +/- 343 mL; P = not statistically significant). No blood transfusions were performed in either group. The hospital stay was significantly reduced after LPN compared with after OPN (2.9 +/- 1.5 days versus 6.4 +/- 1.8 days; P <0.0002), and the postoperative parenteral narcotic requirements were lower in the LPN group (mean morphine equivalent 43 +/- 62 mg versus 187 +/- 71 mg; P <0.02). Three complications occurred in each group. With LPN, no patient had positive margins or tumor recurrence. Also, direct financial analysis demonstrated lower total hospital costs after LPN (4839 dollars+/- 1551 dollars versus 6297 dollars+/- 2972 dollars; P <0.05). CONCLUSIONS: LPN confers several benefits over OPN concerning patient convalescence and costs, despite prolonged resection times at our current phase of the learning curve. Long-term results on cancer control in patients treated with LPN continue to be assessed.

Adult↗
PubMed2004

Laparoscopic robotic pyeloplasty using the Zeus Telesurgical System.

We present the initial clinical experience using a robot to perform a laparoscopic dismembered pyeloplasty at a Canadian centre. Five patients were confirmed to have ureteropelvic junction obstructions through nuclear renography, cross sectional imaging and intravenous pyelography. After performing a retrograde ureteropyelography and double J stent placement, laparoscopic dismembered pyeloplasty was performed by a single surgeon at a remote workstation using the ZeusTM Telepresence Surgery System (Intuitive Surgicala). The mean total operative time was 225+/-48 minutes, anastomotic time was 71+/-16 minutes, and the mean time required to set-up the robot was 30+/-17 minutes. The estimated blood loss was less than 100 ml in each case. A mean total of 22+/-10 mg of morphine sulfate equivalents were used for analgesia, and the patients were discharged home after a mean of 58+/-10 hrs. There were no robotic failures, and all evaluable patients are free of pain and demonstrable obstruction. One patient developed a delayed urine leak, which resolved with percutaneous drainage. The robot provides the ability to perform complicated operations with precision through elimination of tremor, scaling of motion, and through the use of 'wristed' instruments that enhance the freedom of movement normally limited by straight-shafted laparoscopic needle drivers. The development of robotic telesurgery is still in its infancy, and the significance of its role in urologic surgery continues to be evaluated.

Adult↗
PubMed2003

Long-term results of pediatric renal transplantation into a dysfunctional lower urinary tract.

BACKGROUND: The authors reviewed their long-term experience with pediatric renal transplantation into a dysfunctional lower urinary tract to evaluate the results of contemporary lower urinary tract evaluation and management on graft survival and function. METHODS: Between 1990 and 1996, 21 renal transplants were performed in 20 children with dysfunctional lower urinary tracts and 61 transplants were performed in 61 patients with normal lower urinary tracts. The minimum follow-up was 36 months (mean, 62.0 +/- 19.6 months). The cause of lower urinary tract dysfunction included posterior urethral valves (n=13), prune belly syndrome (n=4), meningomyelocele (n=2), and urogenital sinus abnormality (n=1). Urodynamics were performed on all children with dysfunctional lower urinary tracts. Using these perioperative assessments, lower tract management strategies were devised, including timed voiding alone (n=6), clean intermittent catheterization (n=8), bladder augmentation (n=4), and supravesical urinary diversion (n=2). RESULTS: Overall 5-year actuarial patient and graft survival rates were 100% versus 95% (P=not significant [NS]) and 83% versus 69% in the dysfunctional and normal urinary tract groups (P=NS), respectively. Mean serum creatinine levels in dysfunctional and normal urinary tract patients with functioning grafts at 3 years were 1.3 +/- 0.5 and 1.3 +/- 0.7 mg/dL, respectively (P=NS). However, 35% of patients with a dysfunctional lower urinary tract experienced urologic complications. CONCLUSIONS: Pediatric renal transplantation into a dysfunctional lower urinary tract yields outcomes comparable to transplantation into the normal lower urinary tract. Because of the high urologic complication rates, careful surveillance of lower urinary tract function by urodynamic evaluation is essential to optimize these outcomes.

Child↗
PubMed2003

Alteration in CD45RBhi/CD45RBlo T-cell ratio following CD45RB monoclonal-antibody therapy occurs by selective deletion of CD45RBhi effector cells.

Tolerance induction by CD45RB monoclonal antibody (mAb) in murine allograft models is associated with an alteration in the CD45RBlo/CD45RBhi T-cell ratio in favor of CD45RBlo T cells, which can function as regulatory cells and promote tolerance. It has been proposed that inversion of the CD45RBhi/CD45RBlo normal T-cell ratio by mAb can occur by down-regulation of CD45RB surface molecules expressed by T cells. Because CD45RB mAb infusion can lead to a reduction in peripheral T cells, we tested whether other mechanisms might participate in the inversion of the CD45RBhi/CD45RBlo ratio, including apoptosis of CD45RBhi cells. We report that CD45RB mAb led to rapid elimination of both CD4+ and CD8+ T cells in vitro. Importantly, CD45RB mAb selectively eliminated CD45RBhi T cells without affecting the viability of CD45RBlo T cells. Furthermore, the death of T cells occurred with a reduction in mitochondrial transmembrane potential and DNA fragmentation but with little evidence of nuclear condensation and cell shrinkage typically found with cells undergoing apoptosis. We propose that CD45RB mAb therapy may promote a dominant regulatory T-cell population that has the capacity to inhibit rejection by the selective elimination of CD45RBhi effector T cells. This occurs by a process that does not involve the classic morphologic features of apoptosis. Strategies that facilitate an inversion of the CD45RBhi/CD45RBlo T-cell subset ratio may improve the efficacy of CD45RB mAb, and therapeutic measures that prevent deletion of CD45RBhi T cells may need to be avoided to achieve tolerance clinically.

Animals↗