Bladder calculi are an uncommon cause of illness in most Western countries, but they result in specific symptoms and are a significant source of discomfort. This article discusses the diagnosis and current management techniques for vesical calculus disease. For excellent patient education resources, visit eMedicine's Kidneys and Urinary System Center and Procedures Center. Also, see eMedicine's patient education articles Cystoscopy, Intravenous Pyelogram, and Blood in the Urine.
History of the Procedure: Bladder stones have been treated both medically and surgically for many centuries. The oldest bladder stone discovered dates back to 4800 BC and was found by archeologists in Egypt around the turn of the 20th century. The first literary references to bladder stones date back to a time as early as, or earlier than, the time of Hippocrates. More than 23 centuries ago, Hippocrates warned that, “To cut through the bladder is lethal,” and part of the Hippocratic oath includes, ”I will not cut for stone, even for the patients in whom the disease is manifest; I will leave this operation to be performed by practitioners.” His admonition to young physicians was to leave this highly risky and complicated procedure to the purveyors (ie, the lithotomists) of what could only be described as an art.
Famous historical figures who developed vesical calculi include King Leopold I of Belgium, Napoleon Bonaparte, Emperor Napoleon III, Peter the Great, Louis XIV, George IV, Oliver Cromwell, Benjamin Franklin, the philosopher Bacon, the scientist Newton, the physicians Harvey and Boerhaave, and the anatomist Scarpa.
Operations to remove bladder stones via the perineum were performed by Hindus, Greeks, Romans, and Arabs. Ammonius (200 BC), Celsus (first century), and the Hindu surgeon Susruta were among the first to write about perineal lithotomy as a treatment of bladder calculi. They wrote excellent and sometimes detailed descriptions of the surgery, including preoperative and postoperative care and management. In the 1500s, Pierre Franco introduced suprapubic lithotomy. Frère Jacques Beaulieu developed the lateral approach to perineal vesicolithotomy in the late 1600s. An itinerant lithotomist with little anatomic understanding but impeccable character, Beaulieu performed the often lethal procedure in France through the early 1700s. He is remembered by the urologic community as the subject of an old French nursery rhyme, although some have suggested that it was really written as a satirical mockery of the Jacobinic monks whose order was popular in France at the time.
In an attempt to avoid incisions, another form of surgical treatment, transurethral lithotrity, became more common in the early 1800s. This technological advancement was made with the introduction of the fenestrated lithotrite, which allowed stones to be grasped and crushed so their fragments could be evacuated from the bladder via glass or metal suction bottles. Sir Philip Crampton was the first to introduce this concept in Dublin (circa 1834). However, litholapaxy was not firmly established until Henry J. Bigelow, the famous professor of surgery at Harvard, performed (1876) and popularized (1878) the procedure. The mechanical crushing of stones remained popular through the 1960s and 1970s, although it was fraught with complications when performed by inexperienced urologists. In the 1950s, endoscopic electrohydraulic lithotripsy (EHL) was first carried out in the Soviet Union. Over the next 4 decades, multiple other modalities have been developed and allow safe transurethral or percutaneous stone ablation.
Problem: Vesical calculi refer to the presence of stones or calcified materials in the bladder (or bladder substitute that functions as a urinary reservoir). These stones are usually associated with urinary stasis, but they can form in healthy individuals without evidence of anatomic defects, strictures, infections, or foreign bodies. The presence of upper urinary tract calculi is not necessarily a predisposition to the formation of bladder stones.
Frequency: The incidence of primary bladder calculi in the United States and Western Europe has been steadily and significantly declining since the 19th century because of improved diet, nutrition, and infection control. In these countries, vesical calculi affect adults, with a steadily declining frequency in children. In the Western hemisphere, vesical calculi primarily affect men who are usually older than 50 years and have associated bladder outlet obstruction. However, bladder calculi remain common in countries and areas such as Thailand, Burma, Indonesia, the Middle East, North Africa, and, in general, in developing and less-developed countries. In these populations, it remains a disease that affects children. Among children, the disease is far more common in boys than in girls.
A symposium on idiopathic urinary bladder stone disease was published in 1977 (Van Reen). Unfortunately, no definitive worldwide data accurately reflect the frequency of bladder calculi. This mostly is because of poor hospital records in developing regions of the world. Despite the presence of several studies in countries with a high incidence of the disease, no complete uniformity in the reporting of data exists.
Etiology: Bladder outlet obstruction remains the most common cause of bladder calculi in adults. The elevation of the bladder neck and high postvoid residual cause urinary stasis, which, despite gravitational forces, cannot overcome the intravesical prostate and prostatic urethral pressure. Crystals are formed in this static urine; therefore, larger calculi develop.
Also, patients who have static urine and develop urinary infections have a higher tendency to form bladder calculi. In a study of patients with spinal cord injuries (newly acquired neurogenic bladders) who were monitored for more than 8 years, 36% developed bladder calculi. Bladder inflammation secondary to external beam radiation or schistosomiasis also can predispose the patient to vesical calculi.
Another etiologic factor of bladder stones is foreign bodies in the bladder that act as a nidus for stone formation. These are subclassified into iatrogenic and noniatrogenic bodies. The first group includes suture material, shattered Foley catheter balloons, egg shell calcifications that form on a catheter balloon, staples, ureteral stents, migrating contraceptive devices, and prostatic urethral stents. Noniatrogenic causes include objects placed into the bladder by the patients for recreational and various other reasons.
Metabolic abnormalities are not a significant cause of stone formation in patients with urinary diversions. In this group of patients, the stones are primarily composed of calcium and struvite.
In general, if an otherwise healthy person in the United States or Europe is found to have a bladder stone, a complete urological evaluation must be undertaken to find a cause for urinary stasis. Examples include benign prostatic hypertrophy, urethral stricture, neurogenic bladder, and bladder neck contracture. In females, examples include an incontinence repair that is too tight, cystoceles, and bladder diverticula.
Pathophysiology: In general, most vesical calculi are formed within the bladder, but some may initially have formed within the kidneys and subsequently passed into the bladder where additional deposition of crystals may cause the stone to grow. However, most renal stones that are small enough to pass through the ureters are small enough to pass through the urethra. In older men with a stone composition of uric acid, the stone is most likely formed in the bladder. If the stone is calcium oxalate, then the kidney is the usual site of initial formation.
The most common type of stone in adults is composed of uric acid (>50%). In the pediatric population, most bladder calculi are found in endemic areas and are composed mainly of ammonium acid urate, calcium oxalate, or an impure mixture of ammonium acid urate and calcium oxalate with calcium phosphate. The common link between these endemic areas relates to feeding infants human breast milk and polished rice. These foods are low in phosphorus, which ultimately leads to high ammonia excretion. These children also usually have a high intake of oxalate-rich vegetables (increased crystalluria) and animal protein (low dietary citrate).
Vesical calculi may be single or multiple, especially in the presence of bladder diverticula. Vesical calculi can be small or large enough to occupy the entire bladder. They span the spectrum from being soft to extremely hard and from having smooth-faceted surfaces to jagged spiculated surfaces (termed ”jack” stones for their resemblance to the metal objects in the children's game Jacks [see Image 5]). In general, most are mobile within the bladder, although fixed stones occasionally can be present when formed on a suture, on the intravesical portion of a papillary tumor or polyp, or on retained stents.
In regions where vesical lithiasis is endemic among children, a pattern appears to exist.
Clinical: Patients with vesical calculi may be completely asymptomatic. More commonly, however, patients report suprapubic pain, dysuria, intermittency, terminal gross hematuria, frequency, hesitancy, and nocturia. Another common symptom is sudden termination of voiding with some degree of associated pain, which may be referred to the tip of the penis, scrotum, perineum, back, or hip. The discomfort may be dull or sharp and often is aggravated by sudden movements and exercise. Assuming a supine, prone, or head-down position may alleviate the pain that was initiated by the stone impacting the bladder neck. Parents of children with vesical calculi may notice priapism and occasional enuresis.
Common physical examination findings include suprapubic fullness and, occasionally, a palpable distended bladder if the patient is in acute urinary retention. Associated findings include cystoceles in women, high postvoid residuals, and neurological deficits in people with a neurogenic bladder.
Signs of vesical calculi include microscopic or gross hematuria, pyuria, bacteriuria, crystalluria, and urine cultures demonstrating urea-splitting organisms.
Historically, bladder calculi were diagnosed by transurethral passage of van Buren sounds. The contact of the van Buren sounds with the stones causes transmission of a clicking noise or vibration that confirms the presence of the stone. This maneuver is rarely employed today. Now, physicians obtain an abdominopelvic plain radiograph, which can be used to easily identify radiopaque stones. However, adult calculi, which are composed predominantly of uric acid, may be radiolucent and, unless coated with calcium, are more difficult to visualize on plain radiographs. Cystoscopy, noncontrast CT scan, and sonography are common methods used to confirm the presence of bladder calculi.
Indications for surgery to remove bladder calculi include failure of medical management, recurrent infections, acute urinary retention, suprapubic pain, and significant gross hematuria. In addition to treating the stone, also investigate and correct the etiology of the underlying cause of stone formation (eg, bladder outlet obstruction, infections, foreign body, diet).
Relevant Anatomy: In men, the main anatomical problem that leads to vesical obstruction is prostatic enlargement. The prostate forms a ringlike growth around the vesical neck, and, when hypertrophic, it can significantly impede the flow of urine. Stasis that occurs because of this blockage is responsible for the deposition of layer upon layer of new stone material.
In women, voiding dysfunction and urinary stasis can occur but are less commonly associated with calculi. Any foreign body that cannot escape the bladder is calcified and eventually forms a stone.
Contraindications: In general, most vesical calculi procedures are performed via the endoscopic route. However, when the stone is too large or hard or when the patient's urethra is too small (pediatric), using the open or percutaneous suprapubic surgical approach is preferable.
Relative contraindications to EHL include small capacity bladder, possibly pregnancy, and the presence of cardiac pacing/defibrillation devices.
Contraindications to percutaneous lithotripsy include prior lower abdominal surgery, prior pelvic surgery, and small capacity noncompliant bladders.
Pregnancy is a relative contraindication to the use of some forms of lithotripsy (eg, electrohydraulic shock-wave lithotripsy [ESWL]), EHL, mechanical lithotrite), but the benefits of eliminating a source of infection, retention, or pain with other modalities (eg, holmium laser, lithoclast) may outweigh the risk of intervention.
Otherwise, the usual contraindications to any type of surgery apply here as well.
Medical therapy: The only potentially effective medical treatment for bladder calculi is urinary alkalinization for the dissolution of uric acid stones. Stone dissolution may be possible if the urinary pH is greater than or equal to 6.5. Potassium citrate (Polycitra K, Urocit K) at 60 mEq/d is the treatment of choice. However, overly aggressive alkalization may lead to calcium phosphate deposits on the stone surface, making further medical therapy ineffective.
Other agents for stone dissolution, such as Suby G or M solution, rarely are employed. Renacidin can be used to dissolve phosphate or struvite calculi, but treatment is slow and invasive because it must be used in conjunction with indwelling irrigating catheters.
Surgical therapy: “Cutting for the stone” is a phrase that has been used since the time of Hippocrates. Historically, stones were removed via the high operation, using a suprapubic incision, or the low operation, using a perineal incision. In the absence of antibiotic therapy and adequate hemostatic techniques, both operations were associated with a high morbidity and mortality rate. Civiale performed the first documented blind transurethral lithotripsy in 1822. Even with the introduction of the cystoscope in 1877, the risk of bladder injury was always present. The predominant technique in the 1800s and early 1900s was to fill the bladder with 150 cc of fluid, grasp the stone with the lithotrite, rotate it to free the engaged stone from the mucosa, and crush the stone manually. This was repeated until the fragments were small enough to suction out of the bladder with an Ellik evacuator. Common complications included mucosal injury, bladder wall perforation, sepsis, and hemorrhage.
Currently, 3 different surgical approaches to this problem exist. Unlike renal and most ureteral calculi, ESWL has shown little efficacy in most centers.
The first approach in adults is transurethral cystolitholapaxy. After cystoscopy is performed to visualize the stone, an energy source is used to fragment it, and the fragments are removed through the cystoscope. The energy sources are mechanical (ie, lithoclast [pneumatic jack hammer]), ultrasonic, electrohydraulic (ie, EHL [spark-induced pressure wave]), and laser. The pulsed-dye or other wavelength-specific light sources (eg, holmium) fracture the stone by direct absorption, vaporization, water absorption, and pressure wave generation.
The second approach in adults (and primary approach in the pediatric population) is percutaneous suprapubic cystolitholapaxy. The percutaneous route allows the use of shorter- and larger-diameter endoscopic equipment (usually with an ultrasonic lithotriptor), which allows rapid fragmentation and evacuation of the calculi. Often, a combined transurethral and percutaneous approach can be used to aid in stone stabilization and easier irrigation of the stone debris. The authors favor the combined approach with the use of the ultrasonic lithotriptor or the pneumatic lithoclast. The EHL unit has been associated with a higher incidence of bladder mucosal injury. The holmium laser also is effective but generally is slower, even when utilizing the 1000-micron fiber.
If indicated at the completion of lithotripsy, transurethral resection of the prostate (TURP) or transurethral incision of the prostate (TUIP) can be accomplished easily and safely. Completing the stone ablation prior to these interventions is advisable because hemorrhage and excess fluid absorption are potential complications when performed in the reverse order.
The third approach, open suprapubic cystostomy to remove the stone(s) intact can be employed with larger and harder stones and when open prostatectomy and/or bladder diverticulectomy are indicated. Open prostatectomy is generally indicated when the prostate volume exceeds 80-100 g. The advantages of suprapubic cystolithotomy include rapidity, easy removal of several calculi at one time, removal of calculi that are adherent to bladder mucosa, and the ability to remove large stones that are too hard or dense to fragment expeditiously via transurethral or percutaneous techniques. The major disadvantages are postoperative pain, longer hospital stay, and longer bladder catheterization times.
Preoperative details: After diagnosis and treatment planning have been completed, the usual preoperative evaluation, including urine culture and sensitivity, CBC, comprehensive metabolic panel (ie, serum chemistries), coagulation studies, chest radiograph, and ECG, is completed. Beginning appropriate antibiotic therapy to treat any diagnosed infection before the stone ablation is important.
Intraoperative details: The most commonly used contemporary treatment for bladder calculi is transurethral cystolitholapaxy. This can be performed using rigid or flexible cystoscopes; larger-caliber, rigid, continuous-flow scopes provide better visualization.
A cystoscope with a camera to provide video imaging is used to identify the stone under direct vision. If previous gross hematuria was noted, careful removal of all clots is necessary to ensure identification of all stone material. Fully assess the bladder mucosa and bladder neck. Lithotripsy is carried out, and the small remnant fragments are removed with one of several commercially available evacuators. Once inspection reveals no residual fragments in the bladder or any diverticula, attention can be paid to the bladder outlet or diverticula for further management of obstruction.
For TUIP and TURP, the irrigant is changed to 3% sorbitol, and the operation is completed in the usual fashion. If the bladder is not obstructed but a diverticulum needs to be addressed, sterile water or sorbitol can be used for diverticular fulguration and incision of the diverticular neck. While generally safe if performed expeditiously, reports have indicated that combined operations are associated with significantly increased complication rates (ie, 20-30%). A catheter generally is left in place overnight if TURP or TUIP have been performed or until the anesthetic has worn off. Incision of a diverticular neck may require that a catheter be left for a few days to protect against urinary extravasation.
Energy sources used to fragment the stone vary. A commonly used type of energy source is EHL. Other sources include the pulse-dye laser, the holmium laser, ultrasound, and the lithoclast (pneumatic jackhammer). The EHL probe was first introduced in 1959; since then, it has been widely used with excellent results. The EHL probe (5-9F) can be inserted through the working port of the cystoscope and advanced 1 cm beyond the lens. The probe must remain at least 1 cm away from the bladder mucosa to prevent injury and perforation of the bladder. The probe is then positioned 1-2 mm away from the stone, and fragmentation is initiated under direct vision to avoid bladder injury.
Pinning the stone against the bladder wall may reduce the duration of the procedure, but take care not to involve the ureteral orifices. Fragmentation of the stone is initiated by cracking the outer shell until the stone is reduced to a size suitable for evacuation. A manual suction evacuator (eg, Microvasive, Ellik) commonly is used to remove the fragments, although grasping forceps also can be used. Frequent drainage of the bladder or low-pressure continuous irrigation during the procedure is important to prevent bladder rupture. The success rate of EHL is 92-100% for stone sizes of 3-6 cm. Relative contraindications to EHL include small capacity bladder, possibly pregnancy, and the presence of cardiac pacing/defibrillation devices.
The lithoclast and laser (holmium) lithotriptors are used for calculi in all locations throughout the urinary tract, and they have largely supplanted the EHL unit when available. Ultrasonic lithotripsy also is commonly used for renal and bladder calculi.
Percutaneous lithotripsy has become the treatment of choice for the pediatric population because it avoids potential injury to the small-caliber urethra while providing a less invasive approach than open surgery. Access is obtained in a fashion similar to renal access. A rigid nephroscope, graspers, the ultrasonic lithotriptor, and suction are used for rapid stone fragmentation and evacuation. Contraindications include prior lower abdominal surgery, prior pelvic surgery, and small capacity noncompliant bladders.
Postoperative details: The usual postoperative course includes a short duration of catheterization, until the effects of anesthesia abate. The antibiotic coverage is continued according to preoperative findings and discontinued after the appropriate length of treatment (eg, usually 5-7 d for an active preoperative infection). Hospitalization is not necessary unless secondary procedures have been performed or the open surgical approach was used. Curtail use of anticoagulants until any hematuria has resolved.
Follow-up care: Typical follow-up is in 3-4 weeks with a KUB or bladder ultrasound study to document clearing of all the fragments. Thereafter, metabolic evaluation may be pursued as indicated and periodic KUB urography (approximately 6- to 12-mo intervals) is warranted.
Recommended follow-up for stone ablation is a KUB or bladder sonography to ensure that all the calculi and fragments were evacuated. A metabolic stone profile analysis is in order for patients with uric acid stones, concurrent upper tract calculi, a strong family history of stone disease, calculi without obstruction, and recurrent calculi.
Transurethral litholapaxy is, by far, the most common general modality of treating bladder calculi, and it has been associated with relatively few minor complications. Common complications include urinary infection (11%), fever (9%), bladder perforation (2%), hyponatremia (2%), and hemorrhage (1%). Fever and urinary tract infection are clinical diagnoses with elevated temperature, dysuria, elevated WBC count, and positive findings on urinalysis and cultures. Treatment involves intravenous antibiotics and good bladder drainage. Gross hematuria is not uncommon and, when present, usually is self-limiting. In severe cases, 3-way catheter irrigation and blood transfusions may be necessary. Bladder perforation is usually diagnosed intraoperatively when irrigating solution suddenly does not return during the procedure. Intraoperative cystogram is used to confirm the diagnosis.
Extraperitoneal perforation is managed with a Foley catheter, while intraperitoneal perforation usually requires retrieval of extravasated stone debris, open surgical repair of the bladder wall, and placement of a Foley catheter. The catheter is left for 5-7 days, and, prior to removal of the catheter, a cystogram may be performed to assure that no leakage exists.
Hyponatremia can be a consequence of cystolitholapaxy in combination with a TURP. Low serum sodium levels with mental status changes and lethargy confirm the diagnosis. The treatment involves administration of IV furosemide, use of isotonic sodium chloride solution or other iso-osmotic IV fluids postoperatively, and, occasionally, acute use of 3% hypertonic sodium chloride solution if the patient is symptomatic and not otherwise responding. Symptoms generally develop as the serum sodium level falls below 125 mg/dL.
Transurethral cystolitholapaxy has excellent results in treating bladder calculi. In a series of several hundred patients with calculi in the range of 0.5-7 cm, success rates varied from 92-99%. With the use of EHL, the time required to fragment and suction stones was 26 minutes, on average. As mentioned previously, patients who were treated with open surgery had lower recurrence rates than patients in the other major groups of treatment.
The incidence of bladder stones in children is slowly declining, even in endemic areas. This is mostly due to improved nutrition, better prenatal and postnatal care, and improved awareness of the problem in the endemic areas. This disease probably will continue to affect a decreasing number of children and largely become a disease of adults in the 21st century.