eMedicine Specialties > Urology > Benign Prostatic Hypertrophy

Transurethral Resection of the Prostate

Author: Stephen W Leslie, MD, FACS, Founder and Medical Director of the Lorain Kidney Stone Research Center, Clinical Assistant Professor, Department of Urology, Medical College of Ohio
Contributor Information and Disclosures

Updated: Oct 3, 2006

Introduction

For most of the 20th century, from 1909, when Hugh Hampton Young performed his first cold-cut prostatic punch operation, until the late 1990s, when effective medical therapy and newer, less invasive technologies for prostatic obstruction were developed, the premier treatment for symptomatic benign prostatic hypertrophy (BPH) was transurethral resection of the prostate (TURP). It was the first successful, minimally invasive surgical procedure of the modern era. To this day, TURP remains the criterion standard therapy for obstructive prostatic hypertrophy and is both the surgical treatment of choice and standard of care when other methods fail.

Since the advent of medical therapy for symptomatic prostatic hypertrophy with 5-alpha reductase inhibitors and alpha-adrenergic blockers, the need for immediate surgical intervention in symptomatic prostatic obstruction has been reduced substantially. However, alpha-blockers do not modify prostate growth, and even the use of prostatic growth inhibitors such as finasteride (Proscar) or dutasteride (Avodart) often fails to prevent recurrent urinary symptoms of BPH and retention. In the past, these patients would almost certainly have undergone transurethral prostate surgery years earlier.

The modern role of transurethral prostatectomy and the current status of urology residency training in TURP was perhaps best stated by J. Curtis Nickel in a recent editorial.

"Because of successful medical treatment and minimally invasive therapy, our transurethral prostatectomy numbers have significantly decreased during the last decade. Our residents and new urologists may not be as expert at doing the procedure as urologists were previously. Yet the operation continues to be required in many patients worldwide and urologists must remain competent in the procedure. Transurethral prostatectomy remains the "criterion" standard by which all BPH management strategies must be compared."

History of the Procedure

Urinary obstruction from prostatic hypertrophy has been described for many centuries, starting with the ancient Egyptians in the 15th century BC. The prostate was first described anatomically by Vesalius in 1538 but was not called "prostate" until it was so named by Casper Bartholin in 1611. The word "prostate" comes from the Greek prostat, which means "one who stands before or in front of", which, in this case, means in front of the bladder.

The earliest useful therapy for urinary obstruction from prostatic enlargement was a catheter, which was first used by the Romans Celsus and Galen in the first century AD. The earliest known description of a flexible catheter was by Avicenna of Persia in 1036. Since then, some type of urinary catheter made from a large variety of materials, including hollow leaves (eg, Allium fistulosum used by the ancient Chinese), bamboo, wood, metal, and rubber, has been the primary therapy for prostatic obstruction until the beginning of the 20th century.

Ambroise Pare performed the first transurethral operation for obstructed bladder outlet disease in the 16th century, blindly using a curette and a sharpened hollow sound. The obstruction was from urethral strictures, which were successfully opened by this maneuver.

The most successful surgical technique in the 18th and 19th centuries was described by La Faye of Paris in 1726. It involved the use of a curved hollow sound with a sharp pointed stylet, which was forcibly passed through the obstructing prostate into the bladder using a finger in the rectum for guidance. The sound was left in place for several days to allow the false passage to epithelialize. At about the same time, Lorenz Heister described his experience using a suprapubic trocar for both temporary and permanent bladder drainage in cases of urinary retention. Intermittent self-catheterization, with catheters made of various materials and using oil or butter as a lubricant, was the standard treatment of the day. This "catheter life," even in the early 20th century, had a reported mortality rate of 8% during just the first month.

In 1909, Hugh Hampton Young (see Image 1) developed a cold-cut punch for prostate resection, which essentially was used blindly. A fenestration or hole near the end of a hollow tube allowed prostatic tissue to enter (see Image 2). An internal cylinder with a sharp leading edge was then passed through the inside of the tube, slicing off a small section of prostatic tissue. While it did remove prostate tissue, it failed to control bleeding.

Electrical cautery that could work underwater was first demonstrated by Edwin Beer in 1909, when it was used experimentally on bladder tumors. This was quickly added to Young's cold punch in 1911, but the diathermy and resulting hemostasis was still of poor quality, which limited its usefulness. In 1931, Thomas J. Kirwin designed a modification that allowed placement of a needle for electrical coagulation prior to the resection. This modified version of the cold-punch device produced minimal bleeding and was reasonably successful.

Several factors were critical to the development of modern TURP. These included the following:

• Adequate endoscopic, transurethral, and intravesical illumination with the incandescent lamp cystoscope (Phillip Bozzini, Antonin Jean Desormeaux, Maximilian Nitze, Josef Leiter)
• Electrical tissue resection using cutting current (Heinrich Hertz, Lee DeForest, Reinhold Wappler, George Wyeth)
• Electrical cauterization using coagulating current (Edwin Beer, W.T. Bovie, G.H. Leibel)
• Wire loop resecting electrode (Maximilian Stern, Theodore M. Davis)
• Telescopic wide-field visualization and magnification (foroblique lens by Reinhold Wappler, Hopkins rod lens system by Harold Hopkins)
• Consolidation of instrumentation into a single, practical, workable resectoscope (Maximilian Stern, Joseph F. McCarthy)
• Detailed description of prostatic vascular supply (Rubin Flocks)
• Description of proper technique of transurethral resection (Reed M. Nesbit, William A. Milner)
• Recognition and preventive treatment of postoperative complications such as dilutional hyponatremia or transurethral resection syndrome (TUR syndrome) (Creevy and Webb)
• Modern refinements and improvements (Hopkins lens, fiberoptics, continuous flow, and video)

The first true endoscope was designed and built by German physician Phillip Bozzini in 1805. It was called the lichtleiter (light conductor) and consisted of various examining tubes, including a special cannula for the urethra and bladder, plus a wax candle in a special holder or cradle for illumination. While rudimentary, the lichtleiter did allow direct visual examination of various internal body cavities, including the bladder, which was not otherwise possible at that time. Unfortunately, the device was harshly ridiculed by Bozzini's medical contemporaries, which effectively halted endoscopic development for almost 50 years.

In 1853, French surgeon Antonin Jean Desormeaux used a modified lichtleiter to examine patients primarily for urological problems. A system of mirrors and lenses improved visualization. Instead of a wax candle, he used a much brighter lamp flame from a burning mixture of alcohol and turpentine as a light source, which unfortunately resulted in numerous burns. Nevertheless, this version of the lichtleiter was considered reasonably successful.

The first electrically illuminated endoscope was made by Gustave Trouve in 1869. It used an electrical current to create illumination from a white-hot, glowing, platinum wire and had the light source at the distal tip of the instrument. His polyscope electrique used a rheostat to regulate the electrical current from a battery to adjust the light intensity. It was not very successful as a cystoscope because of heat production, limited duration of battery life, and the need for a dry environment, but it was a start.

German physician Maximilian Nitze designed the first successful modern cystoscope in 1877 and is credited as the father of cystoscopy. Built by Josef Leiter of Vienna and used exclusively for bladder examinations, it also used incandescent lighting provided by an electrically heated platinum wire; however, it added a cooling system of flowing ice water and telescopic lenses for visualization, which solved many of the problems with earlier instruments.

Enrico Bottini performed the first electrical prostate surgery in 1874, when he used galvanocautery to remove median bar tissue. Two insulated parallel brass arms were passed together blindly through the prostate, and then a direct electrical current was applied. This caused coagulative necrosis of the bladder neck and median bar tissue with relatively minimal bleeding and complications. In 1897, Albert Freudenberg improved on this instrument by adding a telescope so the procedure could be performed under direct vision, but it was still suitable only for smaller prostates and median bars. Larger prostates were handled by open surgical suprapubic prostatic removal at that time. The first successful total suprapubic prostatectomies were performed by Eugene Fuller of New York in 1895.

Another important milestone was Heinrich Hertz's 1888 discovery regarding spark transmission and spark-gap circuitry. This led others, such as D'Arsonval, Thompson, and Tesla, to recognize some early clinical effects developed by Hertz's spark gap. This type of circuit was used to generate heat and, therefore, could provide limited hemostasis.

Cutting currents were discovered much later, by accident, by Lee DeForest when he was using an awkward Poulsen arc generator. DeForest invented the vacuum tube in 1906, which could generate a continuous high-frequency current. However, its high manufacturing cost made it impractical for medical applications at the time. DeForest suggested that this current could be used to cut tissue during surgery. Not until improvements were made by Reinhold Wappler, W.T. Bovie, and George Wyeth in 1924 did vacuum tube based electrosurgical generators become available; however, they were initially of insufficient power to reliably cut under water. Wappler also later built the excellent foroblique telescope used in the 1932 Stern-McCarthy resectoscope.

In 1926, Maximilian Stern designed an instrument he called a resectoscope, which featured a movable electrified tungsten wire loop that could cut out a cylinder of tissue when a high frequency current was passed through it. To create a cutting current, a continuously alternating high-power electrical sine wave was generated. As the thin leading edge of the wire loop electrode passed through tissue, cells were quickly heated, causing them to explode into steam, leaving a vaporized space into which the cutting loop could then be easily advanced.

In 1931, Theodore M. Davis, who had been an electrical engineer before entering the field of urology, combined the cutting current with a diathermy machine for hemostasis and reported good results and no operative deaths in 230 patients using a modified version of Stern's resectoscope. He thickened the movable tungsten wire cutting loop on Stern's resectoscope, which made it stronger and less prone to breakage. He added additional insulation, which was badly needed. Davis also introduced the first dual-action foot switch, allowing direct control of either cutting or coagulating current, which is still in use today.

A reliable coagulating generator, using a heavily dampened electrical current for hemostasis, was developed by W.T. Bovie of Harvard and G.H. Leibel of Cincinnati, Ohio. Coagulating current uses relatively low power to generate short bursts of electrical sine waves with brief intermittent pauses. A single unit with two separate generators, including an improved and more powerful vacuum tube based cutting current that reliably cut tissue underwater, were combined into a single electrosurgical unit (see Image 3) for the first time by Reinhold Wappler (see Image 4) in 1931. This unit became the standard electrosurgical device until the 1960s, when modern solid-state units became available.

In 1932, Joseph F. McCarthy introduced the first modern resectoscope (see Image 5) with a 2-handed rack-and-pinion–style working element, improved Stern-type tungsten wire cutting loop, Davis' dual-control foot switch, the Wappler foroblique direct-vision telescope, and an improved Wappler electrical unit with both dampened spark-gap coagulating and vacuum tube–based cutting currents.

One of McCarthy's major innovations was the addition of an insulating Bakelite resectoscope sheath, which made possible directly visualizing and precisely controlling the movements of the cutting loop safely, even while current was applied, without electrical risk to the surgeon. However, the key to the success of this instrument was the wonderful foroblique telescope developed by Reinhold Wappler. It provided both a wide-angle view and sufficient magnification to allow for precise placement and manipulation of the cutting loop. The tip of the resectoscope sheath was redesigned into a beak to make better use of this new telescope. This unit is essentially the same one in use today. Its development marks the beginning of the modern era of transurethral prostate surgery.

When first introduced, the standard transurethral prostate resection with the Stern-McCarthy instrument involved removal of only a few segments from an obstructing median bar or lateral lobe. A typical operative report of the era would state "adequate channel made,5 pieces burned out," or "3 segments of prostate removed." Mortality rates from early transurethral prostate surgeries were as high as 25%. Nathaniel Alcock described his experience with 50 cases in 1931. Twelve patients died and all had problems with bleeding and infection, but this was still an improvement over the even worse outcomes from open surgical prostatectomies of the time.

Common complications of early TURP surgery, as reported by John R. Caulk in 1933, included rectourethral fistula, incontinence, excessive bleeding, sepsis, stricture formation, bladder rupture, abscess formation, and even electrocution. The task of developing the techniques necessary to safely remove large quantities of obstructive prostatic tissue by transurethral resection remained for others, such as Reed M. Nesbit (see Image 6) of Ann Arbor, Michigan and William A. Milner (see Image 7) of Albany, New York. This development was facilitated by the detailed description of the arterial blood supply of the prostate by Rubin Flocks in 1937.

Further improvements followed. Notable among these was the development of the Foley hemostatic bag (balloon) catheter in 1937, which allowed not only for self-retention but also for tamponade of the prostatic fossa and the application of traction to help control venous bleeding by direct compression. In 1939, Reed M. Nesbit placed an internal spring in the handle of the working element to allow for one-handed operation (see Image 8). Jose Iglesias de la Torre designed a more reliable external spring-loaded model that is the most popular resectoscope working element style used today.

The main advantage of a resectoscope that allows the resection to be performed with a single hand, as in the Nesbit and Iglesias designs, is that it leaves the second hand free to place a finger in the rectum to help raise the apex and floor of the prostate. The primary disadvantage is that some of the sensory perception from cutting the tissue is lost. The Iglesias working element uses the thumb and the spring to do the actual cutting, while the older Stern-McCarthy model allows the resection to be controlled by the thumb and first 2 fingers using a rack-and-pinion mechanism, which provides finer motor control and excellent tactile sensory feedback. Most urologists today use the Iglesias model, but a few prefer the original Stern-McCarthy design for these reasons.

Once modern transurethral surgical instruments became available in the early 1930s, the demand for this new prostatic surgery was quite high by both physicians and patients. Broad dissatisfaction with traditional surgical treatments for prostatic hypertrophy made any new procedure seem attractive by comparison. The standard technique of prostatectomy before transurethral resection involved a 2-stage procedure, as described by Pilcher in 1914, which started with the placement of a suprapubic cystostomy. If the patient survived, an open suprapubic prostatectomy was performed a few weeks later. Hospitalization typically lasted 6-8 weeks, and the reported mortality rate was 50%. Many of these patients undoubtedly had uremia secondary to their urinary obstructions, which would explain why some may have done better with a 2-stage procedure. A number of somewhat unreliable early reports had created the erroneous impression that TURP surgery was technically simple to perform with few complications.

What happened next is best described by Reed M. Nesbit in his landmark 1943 book on transurethral prostatectomy.

"It soon became apparent, however, that the prostatic millennium had not actually arrived. Resectionists throughout the country discovered that the operation could not be performed with ease; that its technique was exceedingly difficult to acquire as well as to execute; that the incidence of morbidity and mortality could be alarmingly high following transurethral resection; and that unexpectedly poor end results were observed in a disconcerting number of patients.

The refined techniques which are now available, allow transurethral resection to be employed for the treatment of all types of prostatic obstruction with the expectation of minimal postoperative morbidity and mortality, and uniformly good functional results. Modern transurethral prostatic resection is an exceedingly difficult operation to perform, and requires that one spend a long and painstaking apprenticeship in acquiring its technique."

The next major development was the discovery of the danger in using distilled water as an irrigating solution. This was first pointed out by Creevy and Webb in 1947 when they reported on the danger of water intoxication leading to intravascular hemolysis causing increased morbidity and death rates. They had observed bloody urine from intravascular hemolysis coming through the ureteral orifices during resections while using water as an irrigating solution. They recommended using a solution of 4% glucose for irrigation. In 1956, Harrison described hyponatremic shock and dilutional hyponatremia. The benefit of nonhemolyzing solutions was confirmed in 1969 by Emmett, who compared 2 large series from the Mayo Clinic and reported that the nonhemolyzing solutions produced much better morbidity and mortality rates compared to plain-water irrigation.

Fiberoptic lighting systems, based on the 1956 work on fiberoptics by Lawrence E. Curtis, and the Hopkins wide-angle rod lens telescopes were both introduced in the early 1970s. In particular, the optical system designed by Harold Hopkins vastly improved visualization by substituting optical-quality solid-glass rod lenses for the air spaces used in previous telescopes.

Continuous-flow transurethral resection using a suprapubic trocar was introduced first in Europe by Hans Joachim Reuter in 1968 and then in the United States by Paul O. Madsen, but it never became widely accepted despite its theoretical advantages and reported clinical success. The first successful continuous-flow resectoscope was reported by Iglesias in 1975, but it was not until the mid and late 1990s that practical continuous-flow resectoscopes using a coaxial sheathing system became popular and widely available. Modern coaxial continuous-flow resectoscopes are currently the overwhelming first choice of urologists for TURP instrumentation.

Problem

The prostate has been described as the organ of the body most likely to be involved with disease of some sort in men older than 60 years. This statement characterizes any histological evidence of BPH as a disease, which is certainly debatable, but there is no argument that BPH is an extremely common clinical entity.

As the hyperplastic process increases the volume of the prostate, the urethral lumen is compressed, causing outlet obstruction. An enlarged median lobe may cause relatively more severe symptoms than lateral lobe hyperplasia of similar magnitude because it can act as a valve at which increased bladder pressure may actually cause further obstruction. Intravesical extension of the lateral lobes may act in a similar fashion. At the same time, a dynamic component involving the stromal prostatic tissue and bladder is present, which is often more significant in causing urinary symptoms than simple mechanical obstruction from an enlarged prostate. The precise interaction of these two mechanisms, mechanical and dynamic, is not well understood.

Bladder trabeculation often follows because isolated muscle bundles hypertrophy in response to the need for a higher intravesical pressure to overcome the increased resistance to voiding. The spaces between these hypertrophied bundles tend to become thinner, with less functional muscle. Eventually, this can progress to the point at which the bladder becomes almost nonfunctional. Bladder trabeculation is usually graded on a scale of I-IV. When seen on cystoscopy images, it is a relative indicator of the degree and duration of any bladder outlet obstruction (eg, BPH), although any detrusor hyperactivity problem can possibly produce bladder trabeculations, even without an identifiable obstruction. Initial symptomatic changes include increased bladder instability and irritability, which can eventually progress to muscular decompensation with permanent loss of detrusor contractile ability.

The goal of prostate surgery for BPH is to remove the obstructing tissue while minimizing damage to surrounding structures, with as little discomfort to the patient as possible. The accessibility of the obstructing prostate via transurethral endoscopy affords the opportunity to remove the obstruction without open surgery. It also protects the surrounding organs from injury by removing the tissue from the intraluminal surface of the prostate.

TURP is a surprisingly challenging procedure technically, with a protracted learning curve. The procedure tends to be required in older, less healthy men. Continuing improvements in instrumentation and technique allow accomplishment of this procedure more easily for the surgeon and less dangerously for the patient.

Frequency

Once one of the most commonly practiced urological procedures, TURP is now performed much less frequently because of the new availability of reasonable alternative medical and surgical treatment options. In 1962, TURP operations accounted for more than 50% of all major surgical procedures performed by urologists in the United States. By 1986, this had declined to 38%.

The 1985 Veterans Administration Normative Aging Study estimated the lifetime probability of surgical intervention for prostatic enlargement at 29%, and the 1986 National Health Survey estimated that 350,000 patients in the Medicare age group had a TURP that year, compared to fewer than 200,000 in that same age group by 1998. These numbers should be considered within the context that the median age of the typical patient is rising, the size of the average resected prostate gland is increasing, and the typical patient has more comorbidities and is generally less healthy than surgical patients of the past.

This decrease in the number of TURP procedures performed is even more dramatic when the general aging of the population and the larger number of older men in society are considered. In the United States, the number of older men with BPH-related symptoms is expected to increase from 5 million to 9 million persons by the year 2025.

A comprehensive review of transurethral prostatectomy in the Medicare age group by Wasson and associates from Dartmouth compared a national sample of Medicare beneficiaries from 1991-1997 to a similar group for the period 1984-1990. They found the more recent group demonstrated a substantial decline in the number of TURP surgeries of 50% for white men and 40% for black men. Compared to the peak period of TURP use in the 1980s, a higher proportion of the men undergoing the procedure were older in the more recent period, with 53% aged 75 years or older.

Another factor that must be considered when evaluating the general decline in the number of TURP procedures performed is the significant reduction in financial reimbursement to urologists for TURP surgeries in the United States. Physician reimbursement from Medicare for a TURP has dropped from a high of $2000-$3000 in the past to approximately $700 today, with a 90-day global period that covers all postoperative care by the surgeon for 3 months. In many instances, performing a TURP is simply not profitable for the urologist when office overhead, billing, and malpractice costs are considered, especially when complications occur.

Alternative surgical procedures, such as microwave therapy and prostatic laser surgery, are reimbursed at much higher levels, even though they may not be as durable or effective. This creates a strong financial disincentive for urologists to perform TURP procedures, except when no reasonable alternatives exist. A recent article by Donnell examines the history of Medicare policies and the effect of changes in Medicare reimbursement on TURP.

In one large Canadian series reported by Borth and colleagues, the number of TURP procedures dropped by 60% between 1988 and 1998, presumably because of medical therapy, despite an increase of 16% in the male population older than 50 years. While the number of patients presenting with urinary retention was significantly higher in the 1998 group compared to the earlier cohort (55% in 1998 vs 23% in 1988), no significant difference was noted in their average age, medical comorbidities, operative parameters, average size of prostate tissue resected, or complication rates.

The criteria for performing TURP surgery are now more stringent than before. In general, TURP surgery is reserved for patients with symptomatic prostatic hyperplasia who have acute, recurrent, or chronic urinary retention; in whom medical management and less-invasive prostatic surgical procedures failed; who have prostates of an unusual size or shape (eg, a markedly enlarged median lobe, significant intravesical prostatic encroachment); who have azotemia or renal insufficiency due to prostatic obstruction; or who have the most severe symptoms of prostatism. Less common uses of TURP include intractable prostatitis or for tissue sampling when standard biopsy techniques cannot be used.

African Americans more typically present for TURP surgery with urinary retention or urinary infections and have a higher incidence of preexisting medical problems compared to the general population. According to Kang et al, reports from the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial indicate that Asian and Asian American men have the lowest overall risk of clinical BPH and eventual TURP.

The average age of patients currently undergoing TURP is approximately 69 years, and the average amount of prostate tissue resected is 22 grams. Risk factors associated with increased morbidity include prostate glands larger than 45 grams, operative time longer than 90 minutes, and acute urinary retention as the presenting symptom. The 5-year risk rate for a reoperation following TURP is approximately 5%. Overall mortality rates following TURP by a skilled surgeon is virtually 0%.

The relative frequency of TURP compared to open prostatectomy in surgical patients varies from country to country. In 1990, the relative frequency rate of TURPs in surgical patients with BPH in the United States was 97%, with similar rates in Denmark and Sweden. The lowest rates of TURP were noted in Japan (70%) and France (69%).

Etiology

BPH is thought to be caused by aging and by long-term testosterone and dihydrotestosterone (DHT) production, although their precise roles are not completely clear. Histopathologic evidence of BPH is present in approximately 8% of men in their fourth decade and in 90% of men by their ninth decade. Loss of testosterone early in life prevents the development of BPH. The similarities in presentation, pathological examination findings, and symptoms of BPH among identical twins suggest a hereditary influence.

Once BPH has developed, it tends to progress. Cross-sectional studies based on cadaver autopsies or consecutive patients seen in urology clinics suggest that the growth rate decreases with age. In patients aged 31-50 years, the prostate doubling time averages 4.5 years. In men aged 51-70 years, the prostatic doubling time is approximately 10 years, while in men older than 70 years, the doubling time increases to more than 100 years. Note that these findings may only reflect a selection bias in the sample group.

A 5-year longitudinal study by Rhodes and colleagues of 631 community men aged 40-79 years from Olmsted County, Minnesota demonstrated an average annual prostate growth rate of 1.6%. This remained essentially constant regardless of age, although men with larger prostates tended to have higher growth rates.

The average prostate weighs approximately 20 grams by the third decade and remains relatively constant in size and weight unless BPH develops. The typical patient with BPH has a prostate that averages 33 grams. Only 4% of the male population ever develops prostates of 100 grams or more. (The largest recorded prostatectomy specimen weighed 820 grams. This prostate was removed by open suprapubic prostatectomy. Unfortunately, the patient ultimately died of hemorrhage.)

Symptoms of BPH tend to progress slowly over time in most individuals, with an average annual increase of 0.14-0.44 points per year in the American Urological Association (AUA) symptom score index for men aged 60 years and older. Once BPH has begun, the prostate grows an average of 0.6 mL in volume annually, with a mean decrease in average urinary peak flow rate of 0.2 mL per second each year. Men older than 70 years and those with a baseline peak flow rate less than 10 mL/s tend to have a more rapid and dramatic decline in their peak flow rates over time.

DHT has an affinity for prostate cell androgen receptors that is 5 times greater than that of testosterone. The levels of 5-alpha reductase are increased in the stromal tissue of men with BPH compared to controls. This and other data indicate that DHT is much more important in the development of prostatic hypertrophy than testosterone. The success of 5-alpha reductase blockers, such as finasteride (Proscar) and dutasteride (Avodart), in reducing prostatic size and relieving symptoms seems to confirm this, although it does not explain the relative lack of symptom relief in those with smaller prostate glands treated with these agents.

Pathophysiology

When a bladder is trying to empty through a blocked outlet from an obstructing prostate gland, the increased workload produces several changes to the bladder muscle. Initial changes include increased instability and irritability, which progress to decompensation with permanent loss of detrusor contractile ability. In patients with BPH, the intravesical pressure required to open the bladder neck is increased. The bladder is initially able to produce a higher transitory voiding pressure when required, but loses muscle tone over time.

Evidence also indicates that obstruction causes partial denervation of the bladder smooth muscle, which results in further bladder irritability and involuntary detrusor contractions. Fortunately, most of these hyperactive symptoms resolve over time with removal of the prostatic obstruction or with a response to appropriate medications. The detrusor becomes less able to maintain a constant voiding pressure over time, which leads to early termination of voiding, intermittency of the urinary stream, and higher residual urine volume. This is accompanied by a loss of bladder compliance.

Overall bladder mass increases because of detrusor muscle hypertrophy, but collagen deposition is also increased, which eventually contributes to decompensation, urinary retention, and permanent loss of detrusor contractile ability.

A fact that has been known for many years is that prostate size alone is not a reliable or accurate predictor of the presence or degree of urinary outlet obstruction. The failure of several purely obstructive therapies, such as prostatic balloon dilatation, and the obvious success of alpha-adrenergic blockers eventually led to the description of BPH as having both a dynamic (neurogenic) and an obstructive (mechanical) component.

Alpha-adrenergic receptors are present and functional in the stromal smooth muscle of the prostate and especially at the bladder neck. Many studies have documented the success of various alpha-adrenergic blockers in relieving symptoms of BPH. Evidence from the Medical Therapy of Prostate Symptoms Trial indicates that combination therapy with both an alpha-blocker and a 5-alpha reductase inhibitor can delay the progression of symptoms and is more effective over time than either medication alone for reducing symptom scores and improving peak urinary flow rates.

Presentation

Classic symptoms of BPH include a slow, intermittent, or weak urinary stream; the sensation of incomplete bladder emptying; double voiding (the need to void within a few seconds or minutes of urinating); postvoid dribbling; urinary frequency; and nocturia. Patients may also present with acute or chronic urinary retention, urinary tract infections, gross hematuria, renal insufficiency, bladder pain, a palpable abdominal mass, or overflow incontinence.

Upon physical examination, the bladder may be palpable during the abdominal examination and the prostate may be enlarged during the digital rectal examination. Symptoms are not necessarily proportional to the size of the prostate on digital rectal examination or transrectal ultrasound findings.

Indications

According to the Agency for Health Care Policy and Research guidelines for the diagnosis and treatment of BPH and the recommendations of the Second International Consultation on Benign Prostatic Hypertrophy, the absolute indications for primary surgical management of BPH are as follows:

• Refractory urinary retention
• Recurrent urinary tract infections due to prostatic hypertrophy
• Recurrent gross hematuria
• Renal insufficiency secondary to bladder outlet obstruction
• Bladder calculi
• Permanently damaged or weakened bladders
• Large bladder diverticula that do not empty well secondary to an enlarged prostate

Most men who present for surgical correction of their urinary outlet obstruction are those in whom medical therapy or alternative procedures have failed or are inappropriate for some reason. In general, patients with moderate-to-severe lower urinary tract obstructive symptoms (AUA symptom score >8) who have not responded to alpha-adrenergic blockers and/or 5-alpha reductase inhibitors are also candidates for surgical intervention.

A study by Blanchard and associates showed that patients in whom alpha-blocker therapy is ineffective or those in whom it has failed tend to have poorer outcomes after TURP compared to men who proceed directly to a transurethral resection. This is presumably from preoperative bladder damage and other risk factors that affect voiding rather than the size of the prostate. The operating time and weight of resected tissue has been documented as the same between the two groups; therefore, prostatic size alone does not account for the difference in outcomes.

Generally, TURP is indicated in patients with persistent, progressive, or bothersome symptoms of urinary obstruction due to prostatic hypertrophy that are refractory to medical therapy. While this is the most common indication, 70% of men undergoing the procedure have multiple indications. Patients with prostates larger than 45 grams, who present with acute urinary retention or who require operating times in excess of 90 minutes, are at increased risk of postoperative complications.

Surgical treatment of BPH is also indicated in cases of renal failure or insufficiency secondary to prostatic obstruction. Catheter drainage is usually recommended in such cases until the renal failure resolves. As many as 10% of men with BPH present with some degree of renal insufficiency.

The only absolute indication for an open prostatectomy over a TURP is the need for an additional open procedure on the bladder that must be performed at the same time as the prostatectomy. Such indications include open surgical resection of a large bladder diverticulum or removal of a bladder stone that cannot be easily fragmented by intracorporeal lithotripsy.

A relative indication for the selection of an open prostate surgery over a TURP is generally based on prostatic volume and the ability of the surgeon to complete the TURP in less than 90 minutes of actual operating time (although <60 min is considered optimal). In general, open prostatectomy can be justified in a patient with a prostate of 45 grams or larger, but this is totally dependent on the skill and experience of the endoscopic urological surgeon. Most experienced urologists use a prostatic volume of 60-100 grams as the upper limit amenable to endoscopic removal, but, for some highly skilled resectionists, a 200-g prostate can be safely treated with TURP in less than 90 minutes.

Relevant Anatomy

The prostate is divided into zones. The peripheral zone is the largest and encompasses approximately 75% of the total prostate glandular tissue in men without BPH. Most prostate cancers originate in the peripheral zone. It is located posteriorly and extends laterally on either side of the urethra.

The central zone is smaller and extends primarily around the ejaculatory ducts. It differs from the peripheral zone primarily in cytologic details and architecture.

The transition zone is usually the smallest, consisting of two separate lobes on either side of the urethra. The transition zone occupies only 5% of the prostate volume in men younger than 30 years. This is the zone thought to be the origin of BPH. It usually involves a small grouping of ductal tissue near the central portion of the prostatic urethra near the internal sphincter. As the transition zone expands, it can comprise 95% of the prostate volume, compressing the other zones. Intraoperatively, the two enlarged lobes of the transition zone can be seen obstructing the prostatic urethra on either side. Thus, the term lateral lobes is often used intraoperatively to distinguish this tissue from any hyperplastic periurethral gland tissue.

The periurethral glands are less commonly involved with BPH but, when enlarged, can form what is termed a median lobe, which appears as a teardrop-shaped midline structure at the posterior bladder neck. This can ball-valve into the urethra, creating severe obstructive voiding symptoms. Any significant intravesical extension of prostatic tissue can act as a valve when the detrusor pressure increases and presses this tissue against the bladder neck or across the outlet to the urethra, creating a functional obstruction (see Image 9).

The transition zone and periurethral region were called the central gland or inner gland, while the peripheral and central zone were called the outer gland in some earlier jargon. This language should be avoided because it is vague and creates confusion with the standard anatomical label of the central zone.

Prostatic calculi occur between the transition zone and the compressed peripheral zone. In fact, calculi can be used as a marker for this border. They are generally composed of calcium phosphate and are not considered clinically significant. Chemical analysis is unnecessary. If a channel is opened during surgery that allows these calculi to be expressed, they often flow out by themselves if the opening is large enough. They can be milked out by using the end of the cutting loop without current to gently press around the opening where the prostatic stones are seen and can be pushed into the opened prostatic fossa. They can be rinsed into the bladder and evacuated with the rest of the resected prostatic chips.

Prostatic calculi are formed from calcification of the corpora amylacea and precipitation of prostatic secretions. While they may arise spontaneously, they also may be formed in response to an inflammatory reaction or as a consequence of another pathological process that produces acinar obstruction. Some practitioners believe that calcifications that form in response to bacterial prostatitis may harbor bacteria that periodically flourish, causing recurrent prostatitis. Proponents of this theory advocate TURP to liberalize these calcifications as a treatment for recurrent prostatitis.

The prostate is thinnest and most narrow anteriorly (the 12-o'clock position when viewed through a cystoscope). Care should be taken when operating in this area to avoid perforating the prostatic capsule, especially if this portion of the prostate is resected early in the operation. Abundant venous blood vessels are located in the area just anterior to the prostatic capsule, which can cause significant bleeding that cannot be easily controlled if the vessels are damaged during resection.

The external sphincter muscle tends to be slightly tilted, with the most proximal portion located anteriorly, opposite the verumontanum. The external sphincter can be identified cystoscopically by its wrinkling and constricting action as the resectoscope is withdrawn. Upon reinsertion, the superficial mucosa in front of the telescope tends to bunch up. This is because the external sphincter muscle is imbedded within the urogenital diaphragm, which is relatively fixed in position, while the prostate has some limited mobility.

The single most important anatomical landmark in transurethral prostate surgery is the verumontanum (see Image 10). It is a midline structure located on the floor of the distal prostatic urethra just proximal to the external sphincter muscle. It appears as a small, rounded hump that is best seen when withdrawing the telescope through the prostate while visualizing the prostatic floor at the 6-o'clock position.

The orifices to the ejaculatory ducts emerge in the verumontanum (see Image 11). Its importance lies with its position immediately proximal to the external sphincter muscle (see Image 12). This allows it to be used as the distal landmark for prostate resection. The precise distance between the verumontanum and the external sphincter demonstrates some slight individual variation and should be verified visually before starting the resection and periodically during the surgery.

The proximity of the ureteral orifices to the cephalad margin of the hypertrophied prostate varies, particularly in patients with an enlarged median lobe. This distance should be frequently assessed throughout surgery.

The vascular anatomy of the prostate was accurately described in detail by Rubin Flocks in 1937. The blood supply of the prostate comes primarily from branches of the inferior vesical artery, which is a branch of the internal iliac artery (see Image 13). When the inferior vesical artery reaches the prostate just at the vesicoprostatic border, it branches into 2 groups of arteries (see Image 14). One penetrating group passes directly into the prostate toward the interior of the bladder neck. Upon reaching the prostatic interior near the urethra, most of these branches turn distally and parallel the prostatic urethra, while others supply the median lobe.

Vessels that parallel the prostatic urethra supply most of the blood to the hypertrophied lateral lobes. The second large group of arteries follows the exterior of the prostatic capsule posterolaterally, periodically giving rise to perforating vessels, and supplies the area around the verumontanum.

Contraindications

Although TURP is the standard of care for the management of BPH, it is an elective procedure that is not recommended for some patients. Most contraindications are relative, based on the comorbidities of the patient and his ability to withstand the surgical procedure and anesthesia. Some relative contraindications include unstable cardiopulmonary status and a history of uncorrectable bleeding disorders. Patients with a recent myocardial infarction or coronary artery stent placement should not have elective TURP surgery for a least 1 month because of the increased risk of cardiovascular events and other complications. A reasonable minimum delay of 3 months is suggested, but waiting at least 6 months after any significant myocardial event is optimal before performing an elective TURP.

Patients with myasthenia gravis, multiple sclerosis, or Parkinson disease in whom the external sphincter is dysfunctional and/or the bladder is severely hypertonic should not have a TURP because intractable incontinence invariably would result. Patients who have had major pelvic fractures that involved damage to the external urinary sphincter also should not undergo a TURP for similar reasons. Loss of the internal urinary sphincter from the TURP makes these patients totally dependent on their external sphincter muscle function for continence. Should the external sphincter be damaged, injured, or dysfunctional, they will have substantial problems with incontinence.

Patients who have recently completed definitive radiation therapy for prostate cancer are not candidates for TURP because of the unacceptably high rate of urinary incontinence reported. If a TURP is absolutely necessary, it should be delayed at least 6 months after definitive radiation therapy. Alternatives to TURP in such a situation include drainage with a Foley or suprapubic catheter, intermittent self-catheterization, and various other less-invasive prostatic surgical procedures. Patients with prostate cancer who are considering brachytherapy (radioactive seed implantation) or cryotherapy as part of their definitive treatment should not undergo a TURP because the resected tissue would be necessary for optimal needle, probe, and seed placement. The patient is also at increased risk for incontinence.

An active urinary tract infection is another contraindication for TURP surgery. Usually, the surgery can be rescheduled following a course of appropriate antibiotics.

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