Multimodality Diagnosis of Mesenteric Ischemia

Summary

This article presents a multimodal approach that aims to overcome the limitations of traditional methods in detecting mesenteric ischemia and preventing bowel necrosis. The presented technique offers a promising solution by combining state-of-the-art ultrasonography with cutting-edge near-infrared light technologies.

Abstract

Early diagnosis of mesenteric ischemia remains challenging because mesenteric ischemia presents with no key symptoms or physical findings, and no laboratory data specifically indicates intestinal tissue ischemic status before necrosis develops. While computed tomography is the standard for diagnostic imaging, there are several limitations: (1) repeated assessments are associated with increased radiation exposure and risk of renal damage; (2) the computed tomography findings can be misleading because necrosis occasionally occurs despite opacified mesenteric arteries; and (3) computed tomography is not necessarily available within the golden time of salvaging the intestines for those patients in the operating room or at a place far from the hospital. This article describes a challenge to overcome such limitations using ultrasonography and near-infrared light, including clinical studies. The former is capable of providing not only morphologic and kinetic information of the intestines but also perfusion of the mesenteric vessels in real-time without transferring the patient or exposing them to radiation. Transesophageal echocardiography enables precise assessment of mesenteric perfusion in the OR, ER, or ICU. Representative findings of mesenteric ischemia in seven aortic dissection cases are presented. Near-infrared imaging with indocyanine green helps visualize the perfusion of vessels and intestinal tissues although this application requires laparotomy. Findings in two cases (aortic aneurysm) are shown. Near-infrared spectroscopy demonstrates oxygen debt in the intestinal tissue as digital data and can be a candidate for early detection of mesenteric ischemia without laparotomy. The accuracy of these assessments has been confirmed by intraoperative inspections and postoperative course (prognosis).

Introduction

Acute mesenteric ischemia can be life-threatening unless diagnosed and treated without delay^1,2; however, early diagnosis followed by restoration of perfusion before progressing to bowel necrosis, preferably within 4 h, remains challenging for several reasons: (1) mesenteric ischemia is caused via multiple mechanisms and associated with several diseases managed by different specialties; (2) there are no symptoms, signs, or laboratory data specific for mesenteric ischemia; and (3) computed tomography (CT), the gold standard for diagnostic imaging, is misleading because ischemia can be present despite a....

Protocol

A clinical investigation of ICG imaging was performed under approval by the Ethics Committee of Kochi Medical School with informed consent from every patient. A total of 25 patients were included, who underwent reconstructive surgery using free jejunal graft following resection of cancer of the pharynx or cervical esophagus between 2011 and 2016. Regarding the US, the video records obtained in clinical practice between 2000 and 2018 have been reviewed. Ethical approval was waived on this, according to the institutional ethical review committee.

1. Transesophageal echocardiography (TEE)

NOTE: TEE, w....

Results

TEE
There were two types of findings: (1) "branch type" with a true compressed lumen in the SMA by an expanded false lumen without blood flow, and (2) "aortic type" with the intimal flap at the orifice of the SMA and lack of blood flow in the SMA (Figure 5A). The representative TEE findings of three cases with bowel necrosis caused by acute aortic dissection are shown. In one case of the former type, the true lumen in the SMA were severely compressed (<.......

Discussion

Mesenteric ischemia remains an unsolved problem beyond the clinical field. To solve such a common problem, similar pathology in other organs may be helpful to take a hint. The concept of "ischemic cascade" was proposed for acute myocardial infarction³², and regional wall motion abnormalities (hypokinesis, akinesis, and dyskinesis) located at the early stage of the cascade have been used as an indicator of myocardial infarction instead of coronary blood flow, which cannot be assessed noninv.......

Materials

Name	Company	Catalog Number	Comments
HyperEye Medical System	Mizuho Ikakogyo Co., Ltd.		ICG imaging system used in Figure 3
Indocyanine green	Daiichi Sankyo Co., Ltd.		ICG used for ICG imaging in Figure 3
TEE system	Philips Electronics	iE33	TEE system used in Figure 5
TOS-96, TOS-OR	TOSTEC Co.		NIRS system used in Figure 4
Ultrasonographic system	Hitachi, Co.	EUB-555, EUP-ES322	echo system used in Figure 1
Ultrasonographic system	Aloka Co.	SSD 5500	echo system used in Figure 2
Vscan	GE Healthcare Co.		Palm-sized echo used in Figure 2