Ex-vivo comparison of the haemostatic properties of standard transurethral resection and transurethral vaporization resection of the prostate

Overview of Benchtop Models for Comparison of Surgical Treatments for Benign Prostatic Hyperplasia

PURPOSE OF REVIEW

Benign prostatic hyperplasia (BPH) is a disease of the lower urinary tract which often requires surgical treatment. Recently, there has been a deluge of new treatment options, rarely validated or compared to current treatments on a benchtop model. The purpose of this review is to examine the literature and report which benchtop models are currently being used, which therapies have been tested on them, and what outcomes are being studied on each model.

RECENT FINDINGS

There are various benchtop models to choose from, each with their unique benefits and drawbacks. Perfused porcine kidney models are used to assess bleeding on the benchtop, ex-vivo human prostate helps to see specific interactions of devices with the prostatic tissue, and all other models have evaluated tissue ablation rates and depth of coagulation. There are currently no synthetic or non-animal tissues being used for this purpose, and surgical techniques such as enucleation, water-jet ablation, prostate stents, and water vapor thermal therapy have no representation in these benchtop tests. Benchtop testing serves an important role in the evaluation and comparison of surgical treatments for BPH. This testing allows these therapies to be objectively compared to one another, helping novel medical devices in their path to market and urologists make treatment decisions. Future directions may include further validation of the animal models currently being used and development of synthetic models which mimic the prostate on the benchtop.

[Transurethral resection of the prostate and current modifications (bipolar, electrovaporization)]

Transurethral resection of the prostate (TURP) is the surgical standard which is truly minimally invasive by using a natural orifice and is also of durable efficacy. The use of TURP removes tissue from benign prostatic hyperplasia (BPH) and leads to clinically relevant improvement in symptoms and quality of life as well as in micturition parameters and obstruction. Tissue is removed by high frequency (HF) current with synchronous hemostasis. Many modifications of TURP, such as the use of video, have become generally accepted and improved the standard. Other modifications were developed because the balance between cutting and hemostasis needed improvement in favor of hemostasis. Several modifications of TURP, such as modulation of HF pulses, band loops and bipolar resection and new procedures, such as vaporization and enucleation showed improved hemostasis. These modifications and procedures, however, have not yet replaced standard TURP but have become established as additional options.

Evaluation of greenlight photoselective vaporization of the prostate for the treatment of high-risk patients with benign prostatic hyperplasia

AIM

To explore the feasibility and safety of greenlight photoselective vaporization of the prostate (PVP) on high-risk patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH) and to evaluate their clinical and voiding outcome.

METHODS

A total of 85 high-risk patients with obstructive BPH underwent PVP with an 80 W potassium-titanyl-phosphate laser, which was delivered through a side-deflecting fiber with a 23 Fr continuous flow cystoscope. Operative time, blood loss, indwelling catheterzation, international prostate symptom score (IPSS), quality of life score (QoL), uroflowmetry, postvoid residual urine volume and short-term complication rates were evaluated for all patients.

RESULTS

All patients got through the perioperative period safely. The chief advantages of PVP were: short operative time (25.6 +/- 7.6 min), little bleeding loss (56.8 +/- 14.3 mL) and short indwelling catheterization (1.6 +/- 0.8 d). The IPSS and QoL decreased from (29.6 +/- 5.4) and (5.4 +/- 0.6) to (9.5 +/- 2.6) and (1.3 +/- 0.6), respectively. The vast majority of patients were satisfied with voiding outcome. The mean maximal urinary flow rate increased to 17.8 mL/s and postvoid residual urine volume decreased to 55.6 mL. These results are significantly different from preoperative data (P < 0.05). No patient required blood transfusion or fluid absorption. There were few complications and very high patient satisfaction after operation.

CONCLUSION

PVP has a short operative time and high tolerance, and is safe, effective and minimally invasive for high-risk patients, therefore it might be considered as a good alternative treatment for high-risk patients with obstructive urinary symptoms as a result of BPH.

Vaporization of the prostate

PURPOSE OF REVIEW

Transurethral resection of the prostate remains the treatment of choice for men with symptomatic benign prostatic enlargement. Concerns regarding the morbidity of this operation have led to the development of alternative surgical procedures. Vaporization of the prostate can be achieved using either laser energy or electrosurgery. The advantage of these approaches is that they allow tissue removal with reduced blood loss. Vaporization techniques have been around for almost a decade and more powerful lasers have recently become available. This has led to a minor resurgence in interest in laser vaporization. We reviewed articles on all forms of vaporization of the prostate published in the 12 months from August 2002.

RECENT FINDINGS

Electrovaporization of the prostate is an effective treatment for men who require surgery for benign prostatic enlargement. The results are well maintained at 5 years follow-up with low reoperation rates. Scanty data are available for the Gyrus (Gyrus Medical Ltd, Cardiff, Wales) bipolar electrovaporization system but preliminary results suggest there is no significant advantage over transurethral resection of the prostate. Early forms of laser vaporization of the prostate are not as effective as either transurethral resection of the prostate or transurethral electrovaporization of the prostate and have a higher retreatment rate. Newer, more powerful lasers have been recently introduced with encouraging initial results in small numbers of patients.

SUMMARY

Electrovaporization of the prostate is a safe, effective and durable alternative to transurethral resection. Early laser vaporization techniques have high retreatment rates, which limit their cost-effectiveness. Few data are yet available on high-powered lasers for bladder outflow obstruction. Whether any vaporization technique will stand the test of time is unclear.