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PURPOSE: The authors present and describe an original adaptation for the use of "boatman's knot" in renal vein ligation during laparoscopic nephrectomy. This procedure may replace the need for the endovascular stapler, which is considered the standard of care, but not available in several institutions in Brazil. The knot presented is also known as the " pig's knot" in several farms in Brazil. METHODS: Fourteen laparoscopic nephrectomies were performed by the same surgeon in a standard fashion in seven female pigs. Both the renal artery and vein were ligated using the "boatman's knot" as the only method for hemostasis with conventional intracorporeal technique. Two knots were applied in each artery and vein; one knot was tied proximally and the other distally. The vessels were then sectioned in between both knots. This technique is based on the intracorporeal confection of two loops by the right hand pair of dissectors with the help of the left hand. The arteries and the veins were then sectioned and the capability to accomplish full hemostasis was observed. RESULTS: All the laparoscopic nephrectomies were performed successfully. The "boatman's knot" was performed by the same surgeon with neither complications nor difficulties during the confection of the knot. In all cases hemostasis was fully achieved using only the "boatman's knot" as the hemostatic method. CONCLUSION: The "boatman's knot" is feasible and safe for hilum control during laparoscopic nephrectomy in pigs and total hemostasis can be achieved using it as the only method of hemostasis. However, the safety and the capacity of others to learn how to apply it should be tested before it may be advised to use it routinely.

Objective The purpose of this study is to establish a method for the diagnosis and grading of transitional cell carcinoma (TCC), which is responsible for 90% of bladder tumors, using a recently developed ultrasensitive assay for the measurement of hyaluronan (HA). Materials and methods Urine samples were collected prior to surgery (cystoscopy, transurethral resection for bladder cancer (TURBT), and cystectomy) in 350 patients. After the procedure, pathologic examination revealed that 160 patients had TCC. HA was measured directly in the urine by a noncompetitive enzyme-linked immunosorbent assay (ELISA)-like fluorometric assay. Using the receiver operator characteristic curve (ROC), t -test, Dunn test, Kruskal-Wallis test, and Mann-Whitney test, we evaluated the differences between groups (those with TCC vs. those without TCC). Results By analyzing the ROC curve, we chose a urinary HA cutoff value of 13.0 μg/l for indicating risk of TCC. Using the value this of 13.0 μg/l, we found that this test had an overall sensitivity of 82.3% and an overall specificity of 81.2%. The positive predictive value of this assay was 78.9%, the negative predictive negative value was 84.2%, and the predictive accuracy was 81.7%. Logistic regression analysis revealed that every 1 μg/l increase in HA increased a patient's likelihood of having TCC by 3.9%. The sensitivity of this test to detect superficial tumors was 76.6%, whereas its sensitivity for detecting invasive tumors was 94.6%. The urinary HA excretion of patients with TCC, classified according to the TNM staging system and the World Health Organization (WHO) grading system, were compared, and a significant difference was observed between the HA levels of patients with superficial tumors compared with invasive tumors ( P = 0.005) as well as between patients with low- vs. high-grade carcinomas ( P 35 μg/l had a 4.63 times increased risk of having an aggressive, invasive, high grade tumor ( P = 0.005). Conclusions Our results support the postulate that urinary HA may be used as a tumor marker to aid in the diagnosis and grading of TCC. Additionally, more invasive tumors produce and release more HA in urine than superficial tumors, thus higher HA levels indicate more aggressive disease.

To evaluate the possibility of shrinking the kidney by perfusion with hypertonic solution to facilitate organ removal in laparoscopic surgery.After 18 open nephrectomies (ONs) in 9 pigs, one of four saline solutions (5%, 7.5%, 10%, and 15%) was infused through a catheter into the renal artery for 5 minutes in four kidneys each. The volumes and weights of the kidneys were measured before and after renal perfusion; the kidneys were then sent for histologic evaluation. Eight ONs were performed, and the kidneys were removed from the abdominal cavity in a plastic bag in order to mimic organ entrapment during laparoscopy. The kidneys were perfused with hypertonic solution and were again put in a plastic bag and removed from the same animal's abdomen through another incision. The incisions were measured with calipers before and after extraction of the unperfused and perfused organs.The kidneys that underwent perfusion with 5% saline had the greatest decrease in both weight and volume, an average of 16% and 17.8%, respectively. The average incision needed for extraction of unperfused kidneys was 44.9 mm (range 40-58 mm), whereas the mean size of the incision needed to remove perfused kidneys was 26.6 mm (range 20-30 mm) (P0.001). The relative reduction in the necessary incision size therefore was 44.3% (range 33.3%-55%).Perfusion with 5% saline is able to shrink the kidney volume slightly with mild histologic changes. In the pig, it is possible to decrease the renal incision necessary for kidney removal by 44% using this method.