Response to ‘Re. Computed Tomography Imaging Features and Classification of Isolated Dissection of the Superior Mesenteric Artery’

Abstract

Isolated superior mesenteric artery dissection (SMAD) is a pleiomorphic disease. A systematic approach requires adequate classification. The purpose of classification is to organize patients into groups, which should be clinically informative in order to assist medical decision making. Four classification systems, which were all devised based on the imaging appearance of the SMAD, have been proposed over recent years; 1e4 however, no consensus has emerged regarding which classification system should be used. Sakamoto et al. 1 categorized SMAD into four types. However, they did not consider the type of total thrombotic occlusion of the SMA. Yun et al. 2 categorized SMAD into three types, but they did not consider thrombosed false lumen with ulcer-like projection. Zerbib et al. 3 categorized SMAD into six types. However, SMAD with retrograde propagation of the false lumen to the SMA ostium wasn't addressed. Luan and Li 4 categorized SMAD into four types, but they did not consider the true and the false lumen itself, such as the shape, the thrombosed false lumen, and stenosis of the true lumen. The main anatomic and physio-pathologic features of SMADs are the location, extent of the false lumen, and the distinction between thrombosed or not false and true lumen. All four classification systems take into account some of these anatomic features. However, they are all incomplete. What we need is a simple system that allows exhaustive description of all anatomic types of SMADs and meets both the capabilities of modern imaging techniques and the demands of an ever-growing treatment armamentarium.

The Classification and Management Strategy of Spontaneous Isolated Superior Mesenteric Artery Dissection

“…However, it does not consider features of the true and false lumen such as shape, whether the false lumen is thrombosed, and the stenosis of the true lumen. Therefore, Luan and Li 12) suggested that their classification scheme can well describe SISMAD when combined with Yun's classification scheme. 8) For example, when a dissection is limited to the curved part of the SMA with a visible false lumen but without a visible re-entry site, it can be described as a type B-IIa, and when the dissection extends to the distal trunk of the SMA with thrombosed false lumen and occluded true lumen, it can be described as a type C-III.…”