From the Guidelines
The diagnosis of a pleuro-peritoneal fistula is primarily based on clinical presentation and confirmed by imaging studies, with CT peritoneography being the most reliable method, as evidenced by recent studies 1. The clinical presentation of a pleuro-peritoneal fistula typically includes dyspnea, particularly after peritoneal dialysis fluid instillation, recurrent pleural effusions, or unexplained dialysate loss in peritoneal dialysis patients. Some key diagnostic methods include:
- CT peritoneography, which involves injecting contrast material into the peritoneal cavity followed by CT scanning to visualize contrast movement into the pleural space
- Peritoneal scintigraphy using technetium-99m labeled albumin or sulfur colloid to detect radiotracer migration from the peritoneal to pleural cavity
- Thoracentesis with pleural fluid analysis showing high glucose concentration, similar to dialysate, in dialysis patients
- Methylene blue testing, where the dye is instilled into the peritoneal cavity and subsequently detected in pleural fluid
- Video-assisted thoracoscopy for direct visualization of the defect in challenging cases, as mentioned in the study by CHEN et al. 1. The pathophysiology involves a congenital or acquired diaphragmatic defect allowing communication between the peritoneal and pleural spaces, commonly associated with peritoneal dialysis, abdominal trauma, surgery, or malignancy, highlighting the importance of a thorough diagnostic approach to guide treatment decisions, such as those outlined in the European Respiratory Journal study 1.
From the Research
Diagnosing Pleuro-Peritoneal Fistula
The diagnosis of pleuro-peritoneal fistula (PPF) can be challenging, but various imaging modalities and biochemical analyses can aid in its detection.
- Pleuro-peritoneal fistula is a known complication in patients receiving continuous ambulatory peritoneal dialysis (CAPD) with an incidence of approximately 2% 2.
- Imaging signs in clinical practice are often subtle and indirect, and multimodality imaging can offer important adjunctive information when a diagnosis is only suggested with the first imaging study 3.
- A peritoneal scintigraphy with 99m Tc can confirm the diagnosis of pleuroperitoneal fistula, as seen in a case of an 81-year-old woman with a history of peritoneal dialysis presenting with recurrent pleural effusion 4.
Imaging Modalities
Different imaging modalities have their advantages in diagnosing pleuro-peritoneal fistula and other types of fistulas.
- CT fistulography and MRI have different advantages in the diagnosis of perianal fistulas, with MRI being more successful in defining fistula classification and detecting the locations of internal openings 5.
- CT imaging with fistulography can help the surgeon by providing detailed information about the fistula, including its location, direction, and associated ramifications or abscesses 6.
- Video-assisted thoracoscopic surgery (VATS) has been shown to be an effective and safe means of treating patients with PPF, with concomitant mechanical and talc pleurodesis having additional benefit in preventing recurrence 2.
Biochemical Analysis
Biochemical analysis of pleural fluid can also aid in the diagnosis of pleuro-peritoneal fistula.
- Pleural fluid analysis typically shows a transudate with elevated glucose concentration 4.
- The presence of elevated glucose concentration in the pleural fluid can be indicative of a pleuro-peritoneal fistula, especially in patients with a history of peritoneal dialysis.