Microwave Coagulation in Partial Nephrectomy Protocol

A Single Arm Phase 1 Study of Microwave Coagulation Using 2450-MHz Antennae and CO2 Cooling in Partial Nephrectomy for T1 Renal Tumors

Partial nephrectomy (kidney removal) is a standard therapy for clinical T1 renal (kidney) tumors. The goals of surgery are to accurately remove the tumor with no cancer cells at the edge of the remaining tissue, to limit blood loss, and preserve kidney function. The most common technique is to clamp the blood supply to the entire kidney during removal and to surgically repair the tumor bed with suture and agents to stop bleeding. This stops the blood supply to the entire kidney including the healthy tissue, which can cause damage to the remaining tissue due to a shortage of oxygen if left clamped too long. This study uses a microwave pre-coagulation technique using the Certus 140™ to facilitate a bloodless area near the tumor for accurate tumor removal and repair, while avoiding clamping the blood supply, but its effect on the function of kidney adjacent to tumor is unknown. If adequate stoppage of bleeding is achieved using the Certus 140™ with minimal heat spreading to the remaining tissue, clamping and a shortage of oxygen can be avoided. The hypothesis is that microwave pre-coagulation is a safe method for providing the stoppage of bleeding during partial kidney removal.

During the operation: use of Certus 140™ microwave device for pre-coagulation of the kidney tissue adjacent to the tumor.

The Certus 140™ system is used for microwave pre-coagulation of the tissue around the part of the kidney to be removed. This is done in place of the standard clamping to stop blood loss.

To Assess the Effectiveness of Microwave Pre-coagulation Using the Certus 140™ System for Partial Nephrectomy on Renal Function Using the Estimated Glomerular Filtration Rate.

We will be measuring the change in renal function as quantified by pre- and post-surgical estimated Glomerular Filtration Rate. Change = (6 week score - Baseline score)

To assess the safety and efficacy of the Certus 140™ in establishing hemostasis by measuring blood loss. We will calculate the mean, median, standard deviation, and range of values for blood loss.

To assess the safety and efficacy of the Certus 140™ in establishing hemostasis by measuring operative time. We will calculate the mean, median, standard deviation, and range of values for operative time.

To assess the safety and efficacy of the Certus 140™ in establishing hemostasis by measuring clamp time. We will calculate the mean, median, standard deviation, and range of values for clamp time.

To assess the safety and efficacy of the Certus 140™ in establishing hemostasis by measuring the change in renal function by nuclear scan and creatinine clearance. We will calculate the mean, median, standard deviation, and range of values for change in renal function by nuclear scan and creatinine clearance.

To assess the safety and efficacy of the Certus 140™ in establishing hemostasis by measuring the change in functional renal volume as measured by MRI. We will calculate the mean, median, standard deviation, and range of values for change in functional renal volume as measured by MRI.

The percentage of subjects with tumor positive margins will be reported. Tissue pathology will occur during the operation and a final tissue pathology will be performed 6 weeks after the operation.

Inclusion Criteria: Patient must have a solitary, polar, clinical T1 renal mass Patient must have adequate kidney function as measured by eGFR (estimated glomerular filtration rate) greater than or equal to 50 calculated from a standard care serum creatinine performed within 30 days prior to the partial nephrectomy operation. Women of child-bearing potential must have negative serum or urine pregnancy test Patient must be able to give written informed consent Patient must be 18 years or older No blood-thinning medications, including anti-inflammatory medications, herbs and supplements for at least 1 week prior to surgery Exclusion Criteria: T stage greater than clinical T1 Tumor extends beyond kidney into major veins, perinephric tissues, or adrenal gland Prior surgery or radiation therapy to the region of interest Patient has a single functioning kidney Patient has an uncorrectable coagulopathy Patient is not a surgical candidate due to underlying cardiac or other serious comorbid condition