Renoalimentary Fistula - Causes, Symptoms, Treatment, and Prognosis

Introduction:

In 460 BC, Hippocrates is credited with reporting the first case of reno-alimentary fistula. Reno-alimentary fistulae became more widespread in the mid-nineteenth century and were primarily caused by renal tuberculosis (TB). Pyelonephritis caused by infection with other organisms was a distant second cause. Infectious causes of reno-alimentary fistula have decreased with advances in antitubercular and antibiotic therapy, except for pyelonephritis in combination with kidney stone disease. As a result, between 1950 and 1980, reno-alimentary fistulae became substantially less common, with cancer being the most common cause. Reno-alimentary fistulae, particularly iatrogenic reno-alimentary fistula, have become more common since the introduction of minimally invasive kidney surgery. Despite the rise, this type of occurrence of the reno-alimentary fistula is still uncommon and rare.

What Is Renoalimentary Fistula?

Renoalimentary fistulas are abnormal connections between the gastrointestinal tract and kidneys that affect any part of the gastrointestinal system with an improper link to the kidney. Reno-alimentary fistulas account for less than one percent of all fistulas between the urinary and gastrointestinal systems. Long-standing fistulas are caused by neglected instances of renal calculi, which can lead to infection and fistulation (formation of abnormal connections) in the alimentary canal. A pyelo duodenal fistula can develop when a foreign item lodges in the duodenum, triggering an inflammatory response that posteriorly affects the duodenum and surrounding renal pelvis.

What Are the Causes of Reno-alimentary Fistula?

There are different causes of the reno-alimentary fistulas. Some of them are:

• Most reno-alimentary fistulae are iatrogenic (physician induced or due to a particular treatment), resulting from percutaneous nephrostomy tube placement.

• Penetrating and blunt trauma.

• Malignancies (particularly colon, renal, and transitional cell cancer).

• Foreign body ingestion.

• Renal tuberculosis.

• Inflammatory processes are occasionally implicated in reno-alimentary fistulae.

• Percutaneous radiofrequency ablation (ablation is the process of removing or destroying something from an object through vaporization, chipping, erosive processes, or other methods) and laparoscopic cryoablation have been linked to reno-alimentary fistulas.

• Inflammatory bowel disease.

• Peptic ulcer disease.

• Reno-alimentary fistulae caused by radiofrequency ablation or cryoablation were identified on standard follow-up imaging and were usually asymptomatic.

What Are the Problems Associated With Reno-Alimentary Fistula?

Diarrhea, urinary tract infections, and electrolyte imbalances can develop from urine drainage into the gastrointestinal tract, gastrointestinal tract contents into the urinary tract, or both.

What Are the Symptoms of Reno-Alimentary Fistula?

A patient with a reno-alimentary fistula might manifest a different variety of symptoms which are:

• Patients may have isolated stomach, flank pain, and a fever.

• Watery diarrhea may be present in many cases.

• Fecaluria: Passage of feces in urine.

• Hematuria: Blood in the urine.

• Pneumaturia: Passage of gas in urine.

• Biliuria: Excretion of bile salts in urine.

• Dysuria: Difficulty while urinating and painful urination.

• Recurrent urinary tract infection (UTI).

• Patients with bloody diarrhea, pallor, and weariness have been reported, particularly in the presence of concomitant cancer.

• Fever and leukocytosis are common signs of sepsis (extreme response to infection).

What Is the Treatment for Reno-Alimentary Fistula?

The treatment of reno-alimentary fistula depends on the cause and the related symptoms. Therefore, managing symptoms is of prime importance in treating reno-alimentary fistula. The standard treatment options are:

• Antibiotic Therapy: Antibiotics are used to help treat concurrent infections. Usually, antibiotics are administered intravenously to control the disease.

• Surgery: Surgery is still the only way to definitive treatment modality for reno-alimentary fistulas. The etiology of the fistulae mainly determines surgical treatment and the intestinal segment affected. The types of surgeries performed include:

  • Resection of the intestinal segment.

  • Resection of the fistula tract.

  • Reanastomosis is a surgical procedure involving reuniting or making a new connection of a divided vessel between two structures.

  • A nephrectomy, rather than attempting to repair the urinary tract component of the fistula, may be more effective if renal function is adversely impacted.

• In some situations, successful percutaneous fulguration of the fistula tract in which a percutaneous nephrostomy tube is placed into the renal pelvis for urinary diversion under local anesthesia has been documented in some cases in the reno-alimentary fistula.

• Conservative therapies have been beneficial in rare cases of reno-alimentary fistula after radiofrequency ablation or cryoablation in malignancies.

Treatment Considerations and Contraindications:

• Patients with cancer-related reno-alimentary fistulas may not heal, leading to further consequences like systemic sepsis, severe electrolyte imbalances, and even death. Therefore, a significant component of success is the ability to resect the tumor at the fistula location.

• The chances of successful treatment are significantly reduced if the patient is malnourished. Therefore, the treatment should be postponed until the patient's nutritional status improves.

• If the patient has a gastric or small-intestinal fistula, they may require bowel rest and parenteral nourishment to achieve treatment goals.

What Is the Prognosis for Reno-Alimentary Fistula?

• The treatment outcome of a patient with a reno-alimentary fistula is mainly determined by the cause and duration of the fistula and the patient's overall health condition.

• If the fistula is caused by xanthogranulomatous pyelonephritis, the prognosis depends on early detection and treatment of the pyelonephritis.

• When a tumor is connected with malignancy (cancer), the tumor grade and stage are the most critical criteria in determining prognosis.

What Are the Complications of Renal-Alimentary Fistula?

The surgery complications include:

• Anastomotic bowel collapse.

• Bowel or urinary tract obstruction.

• Abscess recurrence.

• Infection.

• Sepsis can even lead to death.

The following measures can minimize the complications:

• Complete removal of the fistula and an abscess cavity, necrotic tissue, inflammatory mass, tumor, stones, or foreign things.

• Preoperative antibiotic therapy.

• Both the intestinal and urine components should be closed without tension.

• Careful irrigation of surgical sites.

• Adequate dietary assistance.

What Are the Follow-up Procedures?

For patients with renal-alimentary fistulae caused by tumors, appropriate radiographic and laboratory follow-up examinations are undertaken as dictated by the histology and stage of malignancy. In addition, three to six months following surgery, an intravenous pyelography or similar functional evaluation for fistulas caused by other benign reasons should be conducted to establish stable kidney function and appropriate kidney outflow.

Conclusion:

Renocolic connections are the most prevalent type of reno-alimentary fistula, followed by reno duodenal connections, accounting for fewer than one percent of all fistulous linkages between the urine and gastrointestinal (GI) tracts. The most prevalent cause of these fistulas is complicated pyonephrosis. Patients often appear with abdominal discomfort, fever, voiding difficulties, leukocytosis, and pyuria. Diagnosis is accomplished by pyelography, and treatment consists of radical nephrectomy and primary fistula closure or resection of the affected intestine.