Nephroptosis: A “disparaged” condition revisited

REVIEW

NEPHROPTOSIS: A “DISPARAGED” CONDITION REVISITED DAVID M. HOENIG, ASHOK K. HEMAL, ARIEH L. SHALHAV,

N

ephropexy to correct symptoms attributed to the ptotic kidney has been a controversial issue since its inception in 1881.1 Anatomically, nephroptosis has been defined as descent of the kidney of more than two vertebral bodies or caudal renal displacement greater than 5 cm when the patient moves from a supine to an upright position.2– 4 During the ensuing century, an estimated 170 different surgical techniques to accomplish fixation of the kidney to a position high within the retroperitoneum have been described.5 The premise of the most successful treatments has been suture fixation of the kidney or perinephric tissue to the body wall and the subsequent development of adhesions. The success of surgical fixation has provided the basis for the development of new, less invasive, surgical techniques: tissue adhesives,6,7 percutaneous fixation,8 –10 and laparoscopic fixation.11–17 Nephropexy was the among the more common urologic procedures being performed at the beginning of the 20th century. However, it rapidly became clear that the vast majority of patients with nephroptosis were asymptomatic and required no therapy. In addition, in patients with chronic abdominal and flank discomfort, the failure of nephropexy to resolve the symptoms in many patients pointed to the need to make a more accurate diagnosis before surgical therapy. As such, nephropexy fell into disfavor. By the mid to late 1900s, the procedure had all but disappeared from urologic practice. Intravenous urography with the symptomatic patient in the supine and upright positions with documentation of renal descent, delayed excretion, and hydronephrosis has been advocated as the best indication for surgical intervention.18 In recent years, however, improvements in radiologic imaging have allowed the urologist to more accuFrom the Albert Einstein College of Medicine, Bronx, New York and Washington University School of Medicine, St. Louis, Missouri Reprint requests: David M. Hoenig, M.D., Department of Urology, Albert Einstein College of Medicine, Montefiore Medical Center, 1500 Blondell Avenue, First Floor, Bronx, NY 10469 Submitted: October 26, 1998, accepted (with revisions): May 27, 1999

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© 1999, ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED

AND

RALPH V. CLAYMAN

rately identify patients with symptoms secondary to nephroptosis. Both diuretic renography18 and renal resistive indexes19 have been used to correlate symptoms with functional obstruction and/or impairment of renal blood flow. With diuretic renography or Doppler duplex sonography performed in both the supine and upright positions, changes in the degree of renal uptake, decreased excretion of radiotracer, or marked increase in renal resistive indexes can be used to objectively identify patients with truly pathologic nephroptosis. We review the history of nephroptosis and nephropexy, current diagnostic modalities, and corrective therapies. HISTORY According to Narath20 and others,2 the diagnostic entity of the “mobile kidney” was first described by Franciscus de Pedemontanus in the 13th century. During the next centuries, numerous investigators have contributed to the characterization of nephroptosis and its treatment. In 1864, Dietl21 meticulously described the symptoms of nephroptosis: episodes of acute abdominal pain and vomiting when the patient is upright, which are relieved when the patient assumes the recumbent or kneechest position (Dietl’s crisis). Nephrectomy was advocated as treatment for nephroptosis in the 1870s, but, although successful at relieving the symptoms of nephroptosis, high morbidity and mortality rates led to its rapid abandonment. Concurrently, various procedures to fix the kidney in a high retroperitoneal location were explored, many of which were unsuccessful or overly morbid. Successful surgical fixation of a mobile kidney was first described by Hahn1 in 1881, who fixed the perirenal fat to the lumbar incision and packed the wound with carbolic gauze. The very next year, 1882, Bassini introduced the concept of placing sutures through the renal capsule. This approach is the one most commonly used today. With advances in anesthetic techniques and given the technical simplicity of nephropexy surgery, by the beginning of the 20th century, nephropexy had become the most common uroUROLOGY 54: 590 –596, 1999

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EPIDEMIOLOGY AND SYMPTOMATOLOGY

FIGURE 1. (A) Demonstration of flaps created from renal capsule, used to suspend the kidney from the 12th rib. (B) Demonstration of a “skewered” kidney, created by flaps of renal capsule sutured over the 12th rib. (From Murphy LJT, The History of Urology, 1972. Courtesy of Charles C Thomas, Publisher, Ltd., Springfield, Illinois.)

logic operation performed and was frequently performed “prophylactically” during unrelated abdominal operations. Edebohls,22 Deming,23 and Burford3 all devised unique modifications of Hahn’s initial approach of supporting the ptotic kidney with sutures; each investigator reported high success rates and relatively minimal morbidity. Deming23 described the use of sutures through Gerota’s fascia to the quadratus lumborum to create a “shelf” to limit the degree of descent of the kidney. Alternative methods included direct fixation by stripping the renal capsule, use of gauzes and drainage catheters to promote the production of renal capsular adhesions, capsular “flaps” to skewer the kidney beneath its capsule onto the 12th rib (Fig. 1), and direct suturing of the renal capsule to the muscles of the retroperitoneum. During the 20th century, direct fixation of the renal capsule to the retroperitoneal muscles became the standard repair. Success rates in many reported studies suggested cure rates in nearly 100% of patients, although these series were poorly controlled, included only short-term follow-up, and lacked any analogue method to accurately define subjective improvement. In contrast, a carefully documented study by Braasch et al.24 at the Mayo Clinic reported that only 50% of patients treated with nephropexy achieved successful relief of symptoms. The conclusions of their report stressed conservative management as first-line therapy, reserving surgical therapy only for those patients with objective obstruction documented by upright intravenous urography. Their report marked the beginning of the “abandonment” of nephropexy. UROLOGY 54 (4), 1999

Historically, most patients with nephroptosis are lean young adults, with a female preponderance (approximately 5 to 10:1); the right kidney is involved in 70% of cases. However, one must be cautious, as it has been observed that renal mobility, consistent with the diagnosis of nephroptosis, is present in approximately 20% of normal female intravenous urograms.20,24,25 The primary presenting symptom is flank, low abdominal or groin pain. A syndrome of multiple symptoms (“Dietl’s crisis”) characterized by Dietl included intermittent, severe colicky pain, nausea, tachycardia, oliguria, proteinuria, and/or hematuria.21,26 The pain can be acutely relieved by upward manual reduction of the kidney into the renal fossa with the patient in the supine position or by the patient assuming a knee-chest or supine position with the head down and feet elevated. The etiology of the pain and other symptoms of Dietl’s crisis has been theorized to include acute hydronephrosis due to ureteral kinking, stimulation of visceral nerves due to traction on the renal hilum by the “fallen” ptotic kidney, and/or ischemia due to narrowing of the renal artery when the kidney descends. Among these “causes,” acute obstruction has been the most readily identifiable cause of symptoms, on the basis of supine and upright intravenous urograms. Interestingly, among patients with fibromuscular dysplasia of the renal artery, ipsilateral nephroptosis has been reported in as many as 64%.27 The relationship between nephroptosis and fibromuscular dysplasia is unclear, but it has been postulated that intermittent stretching of the renal artery may play a role in the development of fibromuscular dysplasia in some patients. DIAGNOSIS AND PATIENT SELECTION A history of flank or loin pain relieved by lying down is the most common symptom among patients with pathologic nephroptosis. The full range of symptoms of Dietl’s crisis may be present and should prompt a directed physical examination and radiologic studies. Physical examination, especially with the patient in the upright position, typically allows palpation of a mobile mass in the retroperitoneum or lower abdomen, as most patients with this condition have a very low body mass index. Indeed, patients may initially seek medical attention because of an abdominal mass they have “discovered” while upright. Reduction of such a mobile mass into the normal position with relief of symptoms is highly suggestive of the diagnosis. Indeed, misdiagnosis of nephroptosis has led to a variety of nonbeneficial surgical procedures: ex591

FIGURE 2. (A) A supine intravenous urogram shows the kidney in proper position with the renal pelvis opposite the L3 vertebral body and no hydronephrosis. (B) Upright film reveals marked descent and malrotation of the kidney with subsequent development of hydronephrosis.

ploratory laparotomy, diagnostic laparoscopy, appendectomy, and ipsilateral oophorectomy. Intravenous urography has been the primary diagnostic tool for the assessment of nephroptosis. It needs to be performed in both the supine and erect positions: duplication of symptoms after the administration of a diuretic with the patient upright assists in confirming the diagnosis (Fig. 2). Retrograde ureteropyelography in both supine and head-up positions has also been used to demonstrate obstructive changes in the ureter, renal pelvis, and calyces due to ureteral kinking with position change; this is coupled with the normalization of the collecting system with return of the patient to the supine position.12 However, the invasiveness of this study, plus the accuracy of both intravenous urography and diuretic renography, have led to the infrequent use of diagnostic retrograde ureteropyelography in these patients. Erect and supine diuretic renography, with its ability to document renal obstruction by radiotracer excretion, decreased renal perfusion, and/or changes in the degree of renal function, has been used to help identify patients with func592

tional nephroptosis (Fig. 3).13 It has been recommended as the most definitive study.13 More recently, Doppler ultrasonography has been used to diagnose clinically significant nephroptosis. Ultrasonography can be used to confirm a mobile, ptotic kidney and can demonstrate hydronephrosis with position change. Also, the renal resistive index has recently been reported to increase with position change in patients with nephroptosis.19 However, despite these encouraging early data, diuretic renography currently remains the standard. TREATMENT OPTIONS Among patients with “symptomatic” nephroptosis, accompanying neurotic or hypochondriac behavior was often noted.28 For this reason, empiric and intuitive treatments were often recommended as first-line therapy for nephroptosis before resorting to a surgical procedure. Reassurance, weight gain (for lean patients), gastrointestinal medications, abdominal wall strengthening exercises, abdominal wall binders and corsets, frequent rests in the supine position, and even behavioral or occuUROLOGY 54 (4), 1999

FIGURE 3. (A) Upright diuretic renogram reveals marked descent of the right kidney with the appearance of an obstructive pattern. (B) The ptotic right kidney became markedly hydronephrotic 25 to 30 minutes after intravenous injection of furosemide.

pational changes were all considered primary forms of conservative treatment.12,28 The most effective nonoperative treatments primarily involve extracorporeal support of the ptotic kidney using an abdominal binder or corset. Use of a cushion in the region below the kidney in combination with an abdominal binder to prevent downward renal migration was described by Dietl in his 1864 treatise on nephroptosis.26 Binders for this condition were in common use throughout the early 1900s (Fig. 4). Open surgical correction, as mentioned earlier, was characterized by the development of numerous surgical techniques for fixation of the kidney in a high retroperitoneal position. The Bassini nephropexy, involving suturing of the renal capsule to the quadratus lumborum, has become the most commonly used open surgical technique for nephropexy, as the various “sling” procedures have been largely abandoned. During the past 20 years, however, attempts to minimize the morbidity of open nephropexy have led to the application of endourologic techniques to stabilize the kidney in a high retroperitoneal position. Among these treatments, percutaneous fixation has been described by several investigators.8 –10,29 In one technique, a percutaneous nephrostomy tube is placed in an antegrade or retrograde fashion. The nephrostomy tube remains in place for 1 to 3 weeks, with the idea that adhesion formation around the tube will result in renal fixation after the nephrostomy tube is reUROLOGY 54 (4), 1999

moved. More recently, percutaneous nephropexy with a circle nephrostomy tube has been described: the exit points of the nephrostomy tube were placed above and just below the 12th rib.10 The circle nephrostomy tube was left in place for 2 to 3 weeks, resulting in a successful nephropexy in 88%.10 At Washington University, we have recently had success with this approach in 2 patients.29 Further studies with both single-point and two-point fixation procedures (Fig. 5), including extended objective and subjective follow-up, are needed to accurately determine the long-term effectiveness of this least invasive approach. Closely duplicating the open nephropexy technique, yet offering lower morbidity, is laparoscopic nephropexy. Initially described by Urban et al.,11 laparoscopic nephropexy has now been reported in several series (Fig. 6).12–17 Excellent success rates in small numbers of patients characterize these reports (Figs. 7 and 8). Transperitoneal and retroperitoneal approaches have been described, and, as with the open approach, myriad methods have been used, including absorbable mesh, fixation staples/sutures placed through Gerota’s fascia, and sutures through the renal capsule. Several reports on the use of tissue adhesives for accomplishing nephropexy have also been published.6,7 Butylcyanocryalate is applied to the posterior capsule of the kidney at open renal exploration to cause adherence of the kidney to the psoas and quadratus lumborum muscles. In one study, a 593

FIGURE 4. Corset used to correct nephroptosis. (From Murphy LJT, The History of Urology, 1972. Courtesy of Charles C Thomas, Publisher, Ltd., Springfield, Illinois.)

FIGURE 6. Laparoscopic nephropexy by way of a transperitoneal route. The renal capsule has been sutured vertically to the psoas muscle with interrupted sutures and horizontally to the posterior coronary ligament of the liver.

FIGURE 5. A “circle” nephrostomy tube has been placed. It enters the kidney above the 12th rib and exits the kidney below the 12th rib, suspending the kidney from the 12th rib.

single suture was used at the lower pole, and the remainder of the nephropexy was accomplished by use of the adhesive.7 Patients were maintained on bed rest for 4 to 14 days after surgery. Of note, patients uniformly suffered from fever postoperatively for a mean of 2 days; this was attributed to the tissue adhesive.6 The success rate has been reasonable: 75%, with follow-up ranging from 2 to 10 years. Although this use of tissue adhesive in the United States has not been approved by the Food and Drug Administration, further studies may be of particular value in providing a method to reduce or eliminate the need for the challenging suturing techniques required for laparoscopic nephropexy. CONCLUSIONS Nephroptosis is a common anatomic finding that only rarely results in significant symptoms. Recent advances in radiologic imaging have enhanced di594

FIGURE 7. Upright intravenous urogram 4 months after laparoscopic nephropexy of the patient depicted in Figure 2. The kidney remains in a normal position.

agnostic accuracy, thereby reinstating nephropexy as an acceptable procedure in those few patients with well-documented, “functional” nephroptosis (Fig. 8). UROLOGY 54 (4), 1999

ND PE and CT scan US, IVU, renal scan ND ND 20.9 ND 1/0 22/1 0/3 0/1 1/22 3 1 23 Cohen et al.17 Das et al.14 Fornara et al.30

KEY: M/F ⫽ male/female; BMI ⫽ body mass index; nl ⫽ normal; IVU ⫽ intravenous urogram; QL ⫽ quadratus lumborum; ND ⫽ not determined; PE ⫽ physical examination; CT ⫽ computed tomography; US ⫽ ultrasound.

ND ND 13 100 100 100 100 100 100 (21/21 available for follow-up)

11 Range 1.5–10.5 100 100 100 100

Sutures to QL muscle Polyglactin sling plus tissue-adhesive Sutures to QL muscle Sutures to psoas muscle Sutures to psoas or QL muscle IVU, renal scan IVU, renal scan 20.4 ND 6/0 10/0 0/6 0/10 6 10

Investigator

Elashry et al.12 Hubner et al.13

Mean Follow-up (mo) Sex (M/F)

Right/Left

Mean BMI (nl <28.0)

Method of Diagnosis

Method of Fixation

Subjective Success (%)

Objective Success (%)

UROLOGY 54 (4), 1999

Patients (n)

Surgical management of nephroptosis by nephropexy in the well-selected patient may be attempted through open, percutaneous, or laparoscopic means. The open surgical approach described by Bassini has withstood the test of time and provides a durable success. In contrast, percutaneous nephropexy, with either one- or two-point fixation, represents the least invasive surgical option. However, reports on this approach are few and lack long-term data. Laparoscopic nephropexy has been demonstrated by numerous investigators to be a highly effective and minimally invasive technique to fix the kidney in a high retroperitoneal position. However, with this technique, as with the percutaneous approach, the series remain small and follow-up has not been reported beyond 1 year (Table I). Longer follow-up and more extensive experience are needed to determine the safety and effectiveness of less invasive therapy for nephroptosis. In this regard, it is important for current and future investigators to obtain preoperative and postoperative objective studies: pain analogue scales, validated quality-of-life questionnaires, and supine/ erect radiographic studies. Only then can appropriate forms of therapy be determined.

TABLE I. Laparoscopic nephropexy: review of published reports

FIGURE 8. Decision-tree for evaluation and treatment of “functional” nephroptosis.

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16. Partin AW, Adams JB, Moore RG, et al: Complete robotassisted laparoscopic urologic surgery: a preliminary report. J Am Coll Surg 181: 552–557, 1995. 17. Cohen TD, Eubanks S, and Preminger GM: Laparoscopic nephropexy. J Urol 155(suppl): 299, 1996. 18. Nakada SY, McDougall EM, and Clayman MD: Renal surgery, in Smith’s Textbook of Endourology. St. Louis, Quality Medical Publishing, 1996, vol 2, pp 945–947. 19. Frauscher F, Janetschek G, Smekal V, et al: Renal resistive index (RI)—a new diagnostic parameter for the assessment of nephroptosis. J Urol 157(suppl): 125–129, 1997. 20. Narath PA: Nephroptosis. Urol Int 12: 164 –171, 1961. 21. Dietl J: Nerki wedrujace ich uwiezuienie. Przgl Lek (Krakow) 3: 225–248, 1864. 22. Edebohls GM: Movable kidney: with a report of twelve cases treated by nephrorrhaphy. Am J Med Sci 105: 247–253, 417– 425, 1893. 23. Deming CL: Nephroptosis: causes, relation to other viscera, and correction by a new operation. JAMA 95: 251–257, 1930. 24. Braasch WF, Greene LF, and Goyanna R: Renal nephroptosis and its treatment. JAMA 138: 399 – 401, 1948. 25. Kaufman JJ, Hanafee W, and Maxwell MH: Upright renal arteriography in the study of renal hypertension. JAMA 187: 977–981, 1966. 26. Dietl J: Wanderende Nieren und deren Einklemmung. Wien Med Wschr 14: 563– 605, 1864. 27. de Zeeuw DD, Donker AJM, Burema J, et al: Nephroptosis and hypertension. Lancet 1: 213–215, 1977. 28. Schreiner G: Miscellaneous renal disorders, in CecilLoeb Textbook of Medicine. Philadelphia, WB Saunders, 1967, p 833. 29. Hoenig DM, Hemal AK, Shalhav AL, et al: Percutaneous nephrostolithotomy, endopyelotomy, and nephropexy in a single sitting. J Urol 160: 826 – 827, 1998. 30. Fornara P, Doehn C, and Jocham D: Laparoscopic nephropexy: 3 year experience. J Urol 158: 1679 –1683, 1997.

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