Minimally Invasive Management of BPH

Minimally Invasive Management of BPH:

Temporal Stents in BPH

• Temporary stents are designed for short-term use, to relieve bladder outlet obstruction (BOO), and to act as an alternative to an indwelling urethral or suprapubic catheter in high-risk patients considered unfit for surgery.
• Temporary stents are receiving widespread attention, but the original idea that they should be used as a temporary expedient to overcome outflow problems in the medically unfit population is being modified.
• The newer stents, whether biodegradable or not, are being viewed as possible methods of overcoming the temporary retention that can occur secondary to treatments such as laser therapy or high-energy TUMT.
• Intraprostatic stents are confined to alternative therapy for BPH for patients unfit for TURP.

Thermal-based Therapies overview:

• Traditional electrocautery, laser, microwave, and radiofrequency waves can be utilized to resect, vaporize, or cause coagulation necrosis of prostatic tissue.
• Treatments achieving temperatures > 45ºC are known as thermotherapy, while treatments with temperatures less than 45ºC are known as hyperthermia.
• Temperature greater than 45ºC is required to cause coagulation necrosis of normal prostatic tissue

Transurethral Needle Ablation of the Prostate (TUNA)

• Transurethral needle ablation of the prostate (TUNA) uses low-level radiofrequency (RF) energy that is delivered by needles into the prostate and that produces localized necrotic lesions in the hyperplastic tissue.
• Low-level radiofrequency energy (490 kHz) used to produce temperatures ~ 100ºC to result in localized coagulation necrosis in the target area.
• The combination of improved endoscopic visualization of the needles and placement using TRUS, efficacy can be high, with an average improvement in the mean symptom score of 13.1 symptom units and in the mean PFR of 6 mL/sec to be expected at 12 months.
• A treatment by some other modality can be expected in 12.7% to 14% of patients within 2 years. TUNA can be given with the patient under topical anesthesia or local prostatic or perineal block, and so it is useful in poor-risk cases also.
• About 40% of patients have retention within the first 24 hours.
• Other complications include, irritative LUTS, infection, hematuria. 
• The long-term efficacy of the treatment has not been clearly evaluated, with no large series of patients having long-term follow-up.

Transurethral Microwave Therapy (TUMT)

• There has been an evolution in the technology of TUMT from low-energy to high-energy application, perhaps indicating that this technique has a future in the treatment of LUTS.
• Complications are less than with TURP, with prolonged catheterization and infection being the most common.
• The procedure can be performed as a day case with the patient under mild sedation is a benefit of the procedure.
• Changes in IPSS are on average 8 units improved, with approximately 3 cc/sec improvement in peak urinary flow rate.
• Complications: urinary retention, irritative LUTS, infection.
• In general, most effective in those patients without history of urinary retention with mild symptoms looking for alternative to medical therapy. 

Laser Therapy

• The use of the laser to treat symptomatic BPH has evolved to other methods that require smaller pieces of equipment or that can treat a wider range of prostates.
• The difficulties in treating large prostates have been overcome using the newer technology.
• The minimal invasiveness of the laser has been improved, and the complications, particularly prolonged catheterization, bacteriuria, and urethral strictures, have been lowered very considerably.
• The holmium laser and the high-power PVP laser are the most popular instruments and are efficacious in improving PFR and IPSS, and may be comparable to TURP. Long-term studies are required.
• Methods: Vaporization/Coagulation and Transurethral enucleation

Types of lasers and associated outcomes: 

• Neodymium:Yttrium-Aluminum-Garnet (Nd: YAG)
• 1064 nm, deep tissue penetration and coagulation
• Potassium Titanyl Phosphate (KTP)
• 532 nm, intermediate tissue penetration but increased energy resulting in vaporization and coagulation
• Utilized in the GreenLight PV Laser System (American Medical Systems, Minnetonka, MN)
• Holmium:Yttrium-Aluminum-Garnet (Ho:YAG)
• 2100 nm, results in cutting effect by vaporization of water, less hemostatic than other lasers
• Diode
• Smaller, less wasted energy
• Newest diodes utilize up to 200W at 980 nm9
• Initial data shows excellent hemostasis and relief of obstructive symptoms
• Disadvantage of postoperative irritative voiding symptoms
• Holmium Laser Resection
• Utilized the Ho:YAG laser to resect prostatic tissue
• Review of 967 patients showed AUA SS improvement of 13 with Qmax improvement of 13 cc/sec 10
• Holmium Laser Enucleation of Prostate (HoLEP)
• Utilizes laser to enucleate the prostate, requires morcellation of the enucleated prostate tissue in the bladder for removal
• HoLEP may be superior to transurethral resection of prostate in amount of tissue removed, although the procedure may take twice as long to perform
• Photoselective Vaporization of Prostate
• Utilizes side-firing KTP laser, which is absorbed by hemoglobin, resulting in vaporization (GreenLight, American Medical Systems, ENDO)
• 2nd generation system currently in use utilizes 120W (HPS™), although 3rd generation system released in 2010 utilizes up to 180W (XPS™), with resultant increased vaporization area with similar depth of penetration
• 120W system requires water cooling
• A prospective trial of 139 patients over 1 year showed a mean AUA symptom score improvement of 20 units, with a peak urinary flow rate (Qmax) improvement of 11 cc/sec.11
• Advantages of Laser Therapy include:
• decreased bleeding (which may allow treatment of anticoagulated patients)
• decreased risk of TUR syndrome
• Disadvantages include:
• Lack of tissue for pathologic analysis (except for Holmium resection)
• Potentially longer catheterization time with coagulation necrosis
• Prolonged irritative LUTS.
• Cost-effectiveness still remains a question but it quality of life improvement is as good as that achieved with TURP.

Transurethral Resection of the Prostate (TURP)

• TURP is the gold standard of treatment for BPH, particularly in patients with a high “bother” score, those with recurrent urinary tract infections caused by incomplete bladder emptying, or those with outflow obstruction when measured by pressure-flow urodynamic studies.
• TURP is a safe and effective way of treating BPH, with an acceptable side effect profile.
• Performed under general or spinal anesthesia
• Absolute indications for those with obstructing prostate include acute urinary retention, recurrent infection, recurrent hematuria (localized to prostate), and renal insufficiency secondary to bladder outlet obstruction.

Transurethral vaporization of the prostate (TUVP)

• TUVP involves the combination of two electrosurgical effects : vaporization and desiccation. Vaporization steams tissue away using high heat, and coagulation uses lower heat to dry out tissue.
• Other factors are also involved that modify the delivery of electrical energy. These include the voltage production by the generator, the current density of the surface area of contact of the electrode, and the electrical resistance of the tissue being treated (Kaplan et al, 1998).
• Efficacy appears similar to that of TURP, but the studies are short-term evaluations and the glands operated on are relatively small.
• The short-term complication profile appears to be better than with TURP, but further studies are required to prove this because there is a certain variability in the rate of occurrence of some of them.
• In general, although the catheterization time is shorter than with TURP, the operating time is longer.

 References:

• Arai Y, Ishitoya H, Okubo K, et al: Transurethral interstitial laser coagulation for BPH: treatment outcome and quality of life. Br J Urol 1996; 78:93-98.
• Arai Y, Aoki Y, Okubo K, et al: Impact of interventional therapy for benign prostatic hyperplasia on quality of life and sexual function: a prospective study. J Urol 2000; 164:1206-12
• Arrighi HM, Metter EJ, Guess HA, et al: Natural history of benign prostatic hyperplasia and risk of prostatectomy. The Baltimore Longitudinal Study of Aging. Urology 1991; 38(1 Suppl.):4-8.
• Bartsch G, Janetschek G, Watson G, et al: The development of an endoscope and of contact probes for transurethral laser surgery of the prostate. J Urol 1994; 151:333A
• Braf Z, Chen J, Sofer M, et al: Intraprostatic stents (Prosta Kath and Urospiral): more than six years’ clinical experience with 110 patients. J Endourol 1996; 10:555-558.
• Clayman RV: In vitro results with special plastics for biodegradable endoureteral stents. J Urol 2000; 163:1620-1621.
• Dennstedt JD, Razvi HA, Sales JC, et al: Preliminary experience with holmium:YAG laser in urology. J Endourol 1995; 9:255-258.
• Debruyne FMJ, Djavan B, De la Rosette J, et al: Interventional therapy of benign prostatic hyperplasia. In: Chatelain C, Denis L, Foo KT, et al ed. Fifth international consultation on benign prostatic hyperplasia, Plymouth, UK: Health Publications; 2001:399-421.
• Fitzpatrick JM: A critical evaluation of technological innovations in the treatment of symptomatic benign prostatic hyperplasia. Br J Urol 1998; 81(Suppl. 1):56-63.
• Fitzpatrick JM: Will laser replace TURP for the treatment of benign prostatic hyperplasia?. Lancet 2000; 356:357-358.
• Gilling P, Mackey M, Cresswell M, et al: Holmium laser versus transurethral resection of the prostate: a randomised prospective trial with 1-year followup. J Urol 1999;162:1640-1644.
• Kaplan SA, Te AE: A comparative study of transurethral resection of the prostate using a modified electro-vaporising loop and transurethral laser vaporization of the prostate. J Urol 1995; 154:1785-1790.
• Keoghane S, Lawrence K, Gray A, et al: A double-blind randomised controlled trial and economic evaluation of transurethral resection vs contact laser vaporisation for benign prostatic enlargement: a 3-year follow-up. BJU Int 2000; 85:74-78.
• Kumar SM: Photoselective vaporization of the prostate: a volume reduction analysis in patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia and carcinoma of the prostate. J Urol 2005; 173:511-513.
• McAllister WJ, Absalom MJ, Mir K, et al: Does endoscopic laser ablation of the prostate stand the test of time? Five-year results from a multicentre randomised controlled trial of endoscopic laser ablation against transurethral resection of the prostate. BJU Int 2000; 85:437-439.
• McAllister WJ, Karim O, Plail RD, et al: Transurethral electrovaporisation of the prostate: is it any better than conventional transurethral resection of the prostate?. BJU Int 2003; 91:211-214.
• McNicholas TA, Singh S: The use of lasers in benign prostatic enlargement. Curr Urol Rep 2000; 1:124-131.
• Montorsi F, Naspro R, Salonia A, et al: Holmium laser enucleation versus transurethral resection of the prostate: results from a 2-centre, prospective, randomized trial in patients with obstructive benign prostatic hyperplasia. J Urol 2004; 172:1926-1929.
• Reis RB, Te AE, Cologna AJ, et al: Interstitial thermometry in men undergoing electrovaporization of the prostate. J Endourol 1999; 13:53-56.
• Talic RF, El Tiraifi A, El Faqih SR, et al: Prospective randomised study of transurethral vaporization resection of the prostate using the thick loop and transurethral prostatectomy. Urology 2000; 55:886-890.