Cystic Diseases of the Kidney Treatment & Management

Updated: Mar 28, 2017
  • Author: Thomas Patrick Frye, DO; Chief Editor: Bradley Fields Schwartz, DO, FACS  more...
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Treatment

Medical Care

Effective means of prevention or modulation of disease have not yet been identified. Current treatment is aimed at symptom control. In general, therapy is reserved for pain, hypertension, infection, renal salt wasting, and nephrolithiasis.

Inherited cystic renal disease

Autosomal dominant polycystic kidney disease

Patients with autosomal dominant polycystic kidney disease (ADPKD) have decreased ability to concentrate urine and should be encouraged to drink 1-2 L of water daily.

Generally, a blood pressure of 130/80 mm Hg is considered the treatment goal for hypertension in this population. Moderate hypertension may be treated with sodium restriction (ie, < 100 mEq/d), exercise, and weight control. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are effective in controlling hypertension in ADPKD. However, ACE inhibitors have been associated with reversible renal failure in polycystic kidney disease. Calcium channel blockers also are effective in managing hypertension in ADPKD.

Hypertension appears to correlate with the size of the cyst, and aspiration of renal cysts results in a reduction of blood pressure. [47]

Prevention of infection with appropriate precautions is important, particularly in women. Avoid urinary tract instrumentation whenever possible.

Treatment of infection involving cystic kidneys requires a prolonged course of antibiotics. Most cyst walls are permeable to polar antibiotics, including cephalosporins, penicillin derivatives, and aminoglycosides. Occasionally, cysts are relatively impermeable to these agents and require parenteral lipophilic antibiotics, such as ciprofloxacin, erythromycin, chloramphenicol, or a tetracycline. Clinical evaluation findings, including sterile urine, lack of fever, and no renal pain on deep palpation, should guide the route and duration of antibiotic therapy.

Autosomal recessive polycystic kidney disease

Infants with autosomal recessive polycystic kidney disease (ARPKD) should be delivered at a facility with a neonatal intensive care unit of level IV. [48] The newborn should be provided supportive therapy while the degree of pulmonary insufficiency and the etiology is reviewed.

Pulmonary hypoplasia is common and is responsible for 30-40% of mortality. [49] Pulmonary insufficiency can be treated with-high frequency ventilation. Pulmonary hypertension can be reversed with inhaled nitric oxide.

Dialysis may be required for renal failure. In one case series, neonates with ESRD before 28 days of age had 1-year survival of 52% and 5-year survival of 48% with peritoneal dialysis. [50]

With less severe childhood disease, edema often is a problem and is managed with sodium restriction and loop diuretics. Hypertension is controlled with salt restriction and antihypertensives, with particular emphasis on the use of ACE inhibitors and ARBs.

The ESCAPE trial (Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke) demonstrated that maintaining a mean arterial blood pressure below the 50th percentile for age, height, and sex in children with stage 2-4 chronic kidney disease can increase the length of time before patients progress to ESRD. [51] Currently, there are no specific guidelines for an ideal target blood pressure. [32]

Hypersplenism and associated thrombocytopenia should not be treated with splenectomy. Limitation from contact sports is recommended. Cholangitis secondary to hypersplenism should be treated with a prolonged course of intravenous antibiotics.

Juvenile nephronophthisis (JNPHP) and medullary cystic kidney disease

In patients with severe salt wasting, salt supplementation may improve renal function and slow renal demise. ESRD necessitates dialysis or renal transplantation.

Acquired cystic renal disease

In acquired renal cystic disease (ARCD), mild bleeding episodes may be managed with bed rest and analgesics.

In medullary sponge kidney (MSK), encourage patients with nephrolithiasis to produce 2 L of urine daily. Patients with hypercalciuria may benefit from oral thiazide diuretics. Patients may develop urinary tract infections and should be taught preventative measures.

In patients with simple cysts, a cyst infection usually requires a combination of antimicrobial and surgical management. Pathogens encountered most frequently in infected simple cysts include Enterobacteriaceae, staphylococci, and Proteus species.

Investigational therapy

Research has identified biochemical targets that may allow disease-modifying therapy for renal cystic disease, and several agents have been tested in randomized clinical trials. Results with mammalian target of rapamycin (mTOR) inhibitors were disappointing: In adults with ADPKD and early chronic kidney disease, 18 months of treatment with sirolimus did not halt polycystic kidney growth. [52] Studies of somatostatin analogues (octreotide, lanreotide, pasireotide) have yielded more encouraging results, and additional drugs are being tested. [53]

Vasopressin receptor activation results in increased levels of cyclic adenosine monophosphate (cAMP), and cAMP has been shown to be cystogenic. This provides the rationale for vasopressin receptor blockade. Tolvaptan is a vasopressin receptor antagonist with high affinity in humans. In a 3-year phase III clinical trial in patients with ADPKD, tolvaptan slowed the increase in total kidney volume and the decline in kidney function, compared with placebo, but was associated with a higher discontinuation rate, owing to adverse events. [54]

New candidate drugs are currently being investigated in the preclinical phase. Promising therapies include metformin, rosiglitazone, calcimimetics (R-568), and roscovitine, all of which have shown efficacy in animal models. Metformin and rosiglitazone both have mTOR-inhibiting effects but act on additional pathways. R-568 combats defective Ca2+ intracellular regulation, which favors proliferation, and has been shown to decrease renal fibrosis and late stage cystic volume but has no effect on overall cystic burden. Roscovitine is a cyclin-dependent kinase inhibitor that initiates cell cycle arrest and inhibits cystic disease in mouse models. [55, 56]

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Surgical Care

Surgical indications in renal cystic disease vary with the underlying disorder.

Multicystic dysplastic kidney (MCDK)

Previously, the involved kidney in patients with MCDK was routinely removed to prevent the subsequent development of symptoms. Currently, however, surgical excision is indicated only if the dysplastic kidney interferes with respiratory or digestive function or if significant hypertension has developed. Additionally, cyst rupture, which can occur spontaneously or secondary to trauma, may require emergent surgical intervention.

Inherited cystic renal disease

In autosomal dominant polycystic kidney disease (ADPKD), significant chronic pain may result from expansion of renal cysts. Needle aspiration is usually the first-line approach to symptomatic cysts.

Initial resolution and then return of symptoms with reaccumulation of cyst fluid increases the chance that a laparoscopic cyst decortication will eliminate the patient's pain. [57] However, for the management of severe pain, hypertension, hematuria, or infection, surgical excision may be preferred.

Complex cysts can be explored laparoscopically and treated appropriately based on intraoperative frozen sections. Laparoscopic techniques have been used with good results. Studies have reported good outcomes of laparoscopic cyst decortication using a retroperitoneal approach especially for posterior or lower pole lesions. [58, 59]

Percutaneous endocystolysis is another technique described for treatment of symptomatic cysts. The technique involves obtaining percutaneous access, dilating the tract, and then introducing a resectoscope with rollerball electrode to cauterize the internal surface of the cyst. A 13-year experience with this technique reported clinical improvement in 100% of the patients with minimal complications. [60]

Nephrectomy may be performed simultaneously with renal transplantation to create space for the transplanted kidney and to relieve symptoms associated with the native polycystic kidney. The timing of performing the nephrectomy in the transplant patient has been debated. Data suggest that open ipsilateral nephrectomy at the time of transplantation with staged contralateral native nephrectomy has fewer perioperative complications than performing a laparoscopic bilateral nephrectomy. [61] In extreme cases of liver enlargement, severe pain and wasting may result. Partial hepatectomy may alleviate these symptoms.

In autosomal recessive polycystic kidney disease patients with severe portal hypertension, sclerotherapy or portosystemic shunt placement may be necessary to control bleeding. Splenectomy may be indicated for splenomegaly with significant complications. Patients with ESRD can be treated successfully with kidney transplantation. In combination with peritoneal dialysis, kidney transplantation in one series was associated with a 5-year survival of 83%. [50]

In juvenile nephronophthisis (JNPHP) and medullary cystic kidney disease (MCKD), if transplantation is considered, selecting an older or unrelated donor is advisable to minimize the risk of the transplanted kidney also being affected with these diseases.

Acquired cystic renal disease

In acquired renal cystic disease, persistent or severe hemorrhage may necessitate nephrectomy or renal embolization. If a 3-cm renal mass suggestive of renal cell carcinoma (RCC) is noted, a partial or radical nephrectomy is indicated.

Simple renal cysts rarely require surgical management to relieve pain or obstruction. Treatment options include the following:

  • Aspiration

  • Sclerosis

  • Open resection

  • Endoscopic marsupialization and fulguration

  • Percutaneous resection

  • Laparoscopic resection

A randomized trial by Agarwal et al that compared percutaneous sclerotherapy versus laparoscopic unroofing for symptomatic renal cysts determined that both procedures were safe and had equal efficacy. These investigators also concluded that cyst aspiration with sclerotherapy was associated with lower morbidity and shorter hospital stay. [62]

Bosniak category III and IV renal cysts require surgical exploration. Approximately 50% of Bosniak category III cystic renal lesions are malignant. Management depends on the appearance of the lesion and varies from exploration and biopsy to nephrectomy. The current standard approach is open exploration with anticipated partial nephrectomy. However, as the experience with laparoscopic exploration and nephrectomy grows, this technique may prove equally reasonable.

Cystic clear cell renal cell carcinoma

Whether the patient has known pathologically diagnosed malignancy from biopsy or suspected malignancy based on Bosniak classification, a urologist can anticipate good surgical outcomes after resection. In a study of laparoscopic nephrectomy for cystic clear cell RCC, all patients treated were alive after 5 years and no patient had extrarenal disease at the time of surgery. These data suggest that patients with cystic RCC should expect to be cured after surgical resection, and furthermore should undergo nephron-sparing surgery when possible. [63]

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