Diagnostic Ability of Convex-Arrayed Endoscopic Ultrasonography for Major Vascular Invasion in Pancreatic Cancer

Abstract

Background/AimsThis study aimed to examine the diagnostic ability of endoscopic ultrasonography (EUS) for major vascular invasion in pancreatic cancer and to evaluate the relationship between EUS findings and pathological distance. MethodsIn total, 57 consecutive patients who underwent EUS for pancreatic cancer before surgery were retrospectively reviewed. EUS image findings were divided into four types according to the relationship between the tumor and major vessel (types 1 and 2: invasion, types 3 and 4: non-invasion). We also compared the EUS findings and pathologically measured distances between the tumors and evaluated vessels. ResultsThe sensitivity, specificity, and accuracy of EUS diagnosis for vascular invasion were 89%, 92%, and 91%, respectively, in the veins and 83%, 94%, and 93%, respectively, in the arteries. The pathologically evaluated distances of cases with type 2 EUS findings were significantly shorter than those of cases with type 3 EUS findings in both the major veins (median [interquartile range], 96 [0–742] µm vs. 2,833 [1,076–5,694] µm, p=0.012) and arteries (623 [0–854] µm vs. 3,097 [1,396–6,000] µm, p=0.0061). All cases with a distance of ≥1,000 µm between the tumors and main vessels were correctly diagnosed. ConclusionsTumors at a distance ≥1,000 µm from the main vessels were correctly diagnosed by EUS.

Endoscopic Ultrasonography for Vascular Invasion in Pancreatic Cancer

“…In the current issue, Fujii et al studied the diagnostic ability of EUS for major vascular invasion in pancreatic cancer, and evaluated the relationship between EUS findings and pathological distance [8]. The sensitivity, specificity, and accuracy of EUS diagnosis for vascular invasion were 89%, 92%, and 91% in the veins and 83%, 94%, and 93% in the arteries, respectively [8]. The values showed narrow improvement from previous studies, despite the development of EUS.…”

“…The values showed narrow improvement from previous studies, despite the development of EUS. In accordance with the relationship between tumors and major vessels, Fujii et al classified the EUS findings into four types: type 1, clear invasion, encasement of a vessel by a tumor; type 2, a tumor that makes contact with a vessel, with loss of the hyperechoic vessel layer; type 3, a tumor that makes contact with a vessel, without loss of the hyperechoic vessel layer; type 4, clear non-invasion, with space between a tumor and a vessel [8]. The vascular invasion defined by Fujii et al is far simpler than in previous studies [8].…”

“…In accordance with the relationship between tumors and major vessels, Fujii et al classified the EUS findings into four types: type 1, clear invasion, encasement of a vessel by a tumor; type 2, a tumor that makes contact with a vessel, with loss of the hyperechoic vessel layer; type 3, a tumor that makes contact with a vessel, without loss of the hyperechoic vessel layer; type 4, clear non-invasion, with space between a tumor and a vessel [8]. The vascular invasion defined by Fujii et al is far simpler than in previous studies [8]. According to Buchs et al, the findings of vascular invasion in EUS are as follows: (1) loss of the hyperechoic vessel wall/tumor interface; (2) direct visualization of tumor within the vessel lumen; (3) vascular encasement or occlusion; (4) nonvisualization of a major vessel in the presence of collaterals; (5) proximity of the tumor (<3 mm) to the vessel; (6) irregularity of the vascular wall [9].…”

“…According to Buchs et al, the findings of vascular invasion in EUS are as follows: (1) loss of the hyperechoic vessel wall/tumor interface; (2) direct visualization of tumor within the vessel lumen; (3) vascular encasement or occlusion; (4) nonvisualization of a major vessel in the presence of collaterals; (5) proximity of the tumor (<3 mm) to the vessel; (6) irregularity of the vascular wall [9]. Between these two definitions, the one by Fujii et al has the advantage of allowing the clinician to assess the vascular invasion more easily, but has the potential disadvantage of decreased accuracy [8]. For example, Fujii et al explained that no vessel invasion is expected when the distance between the main vessel and tumor is 1mm or greater by EUS, therefore, there may be more cases that meet the criteria for surgical tumor resection than already discovered [8].…”

“…Between these two definitions, the one by Fujii et al has the advantage of allowing the clinician to assess the vascular invasion more easily, but has the potential disadvantage of decreased accuracy [8]. For example, Fujii et al explained that no vessel invasion is expected when the distance between the main vessel and tumor is 1mm or greater by EUS, therefore, there may be more cases that meet the criteria for surgical tumor resection than already discovered [8]. However, this is a retrospective study involving only a few cases, thereby requiring careful interpretation.…”