GI Endoscopy

GI endoscopy allows direct visual examination of the GI tract luminal surface and tissue biopsy. This review article summarized the indications, optimal instrumentation for greatest diagnostic utility, limitations, and correlations between clinical and histopathology findings for GI endoscopy. The procedure is useful for detecting morphologic or infiltrative disease; however, it is not helpful for diagnosing functional disorders and some chronic enteropathies.

GI endoscopy should always be accompanied by tissue biopsy and histopathologic evaluation. Although it varies by location in the GI tract, ≈6 adequate samples should be obtained from each region. Care should be taken to preserve tissue architecture and thus improve the pathologist’s ability to make a definitive diagnosis.

The decision to perform endoscopic biopsy vs surgical biopsy depends on the clinical situation, including the most likely differential diagnoses and patient stability. Similarly, the decision to perform upper vs lower GI assessment or both is based on relevant clinical signs. Careful specimen handling, avoidance and recognition of routine tissue artifacts, and consideration of tissue fixative options to facilitate special testing optimize the diagnostic utility of endoscopic biopsy.

Because there can be disagreement among pathologists—and there are no standards for histopathologic assessment of GI inflammation—the authors concluded that it remains difficult to correlate histopathology from GI endoscopic biopsy with clinical disease activity.

It is important to take into account individual patient indications when considering endoscopic exploration and biopsy. GI endoscopy and biopsy collection are valuable diagnostic tools and are less invasive than open surgical biopsy. However, the procedures can only sample mucosa and are limited to regions accessible with a scope. Although histopathologic evaluation may be considered the gold standard in many cases, lack of uniform criteria for assessment of GI inflammation may limit utility. Ultimately, a collaborative approach between endoscopist and pathologist is important to glean feedback regarding samples and inform clinical decisionmaking for each patient.—Jason Bleedorn, DVM, MS, DACVS