D. Brooke Johnson

Complications of ureteroscopy

Ureteroscopy has undergone a dramatic evolution over the last two decades. Although ureteroscopic injury is the most common cause of ureteral trauma because of the large number of ureteroscopic procedures performed, improvements in instrumentation and technique have resulted in a reduced incidence of serious complications. Despite significant technologic advances, however, surgical misadventures still occur, some of which have lasting consequences. Careful attention to instrument selection and surgical technique are critical to reduce untoward events related to ureteroscopy. As such, adverse sequelae associated with ureteroscopy should be related to the underlying pathology itself rather than to the treatment.

Nephrectomy after radiofrequency ablation-induced ureteropelvic junction obstruction: potential complication and long-term assessment of ablation adequacy

Little information is available concerning the morbidity of radiofrequency ablation (RFA) or the evolution of an RFA lesion over time. We report our findings in a kidney removed 1 year after RFA of a 2.3-cm renal tumor. After RFA, the patient experienced flank pain, followed by hydronephrosis, ureteropelvic junction obstruction, and eventual loss of function in the treated kidney. Nephrectomy revealed no residual renal cell carcinoma. RFA can completely destroy renal cell carcinoma in situ without histologic evidence of persistence or recurrence for up to 1 year after treatment. Care must be taken to avoid concurrent damage to the collecting system.

Cryosurgery and needle ablation of renal lesions.

Laparoscopic renal cryoablation is a minimally invasive alternative for treating renal tumors utilizing narrow probes cooled with a compressed gas such as argon or carbon dioxide. At this time, cryotherapy has shown the most promise as an alternative to partial nephrectomy as a nephron-sparing treatment for renal tumors. Radiofrequency ablation employs needle electrodes placed percutaneously directly into renal lesions to deliver energy, creating high temperatures leading to cell death. High-intensity focused ultrasound is a noninvasive technique in which focused ultrasound energy is applied to cause cell death within the focal zone. Microwave thermotherapy uses small applicators to deliver microwave energy to tissues, resulting in the generation of heat. Although RF, HIFU, and microwave thermotherapy show promise as energy sources for tumor ablation, they are in the early stages of development. Little is known about their acute and chronic histologic effects and long-term efficacy as a treatment for malignant disease. Further work is needed to develop cryosurgery and needle ablation in order to delineate what role these techniques will ultimately play in the management of RCC.

Radiofrequency Interstitial Tumor Ablation: Dry Electrode

With the shift in the treatment of small renal tumors from radical extirpative surgery to nephron-sparing approaches, dry-electrode radiofrequency ablation (RFA) has emerged as one potential modality. This application of RF energy leads to the production of heat within the treatment zone secondary to the native impedance of living tissue. Animal studies and human clinical series have demonstrated that RFA can create controlled, targeted, reproducible, and lethal lesions. Most clinical series have reported promising results, although some authors question the totality of tumor destruction by RFA. With time, the efficacy of RFA, as measured by patient survival, will be determined. Once this is known, RFA may be compared with other therapeutic modalities for small renal tumors to determine its place.

Cryoablation of Renal and Prostate Tumors

During the past decade, cryoablation has been applied to benign and malignant conditions within the prostate and kidney. The essence of cryosurgery lies in producing temperatures low enough to cause necrosis in target tissues while avoiding lethal conditions in healthy peripheral tissues. It works by two main mechanisms: (1) at the cellular level via solute damage and intracellular ice formation; and (2) at the vascular level as a result of thrombosis and subsequent coagulative and ischemic necrosis. Investigation of cryoablation for renal tumors began in 1964, and by the 1990s, attention was turning to its use as a means of treating renal tumors. Modern renal cryosurgery is applied using minimally invasive techniques. Cryotherapy was first applied in the prostate in 1966 and soon thereafter was used to treat prostate cancer. Today, prostate cryosurgical techniques employ ultrasound monitoring and urethral warming to minimize urethral and rectal complications.

Resection of isolated fossa recurrence of renal-cell carcinoma after nephrectomy using hand-assisted laparoscopy

A 72-year-old woman with a body mass index of 33.6 had an apparently isolated renal fossa recurrence of a Grade II, Stage T(3) renal-cell carcinoma. The lesion was resected using hand-assisted laparoscopy with rapid recovery and good short-term results.

Laparoscopic Partial Nephrectomy

Throughout the 1990s, two surgical advances significantly changed the approach to treating renal masses. One of these was the progression of minimally invasive surgery. Clayman et al. accomplished the first laparoscopic nephrectomy in 1990 (1) and since then a number of investigators have reported their experience with laparoscopic nephrectomy using a variety of different approaches (2–4). The other advancement was the acceptance of nephron-sparing surgery (NSS) as a treatment alternative for small renal tumors in patients with a normal contralateral kidney. Partial nephrectomy was initially shown to be effective in the treatment of renal tumors when preservation of renal function was essential (5, 6). Excellent local control was attainable for small renal tumors treated with partial nephrectomy. With further investigation, the role of partial nephrectomy in cases with a normal contralateral kidney has become widespread (7).