Vascular imaging of the mesenteric vasculature

Hyperspectral imaging combined with blood oxygen saturation for in vivo analysis of small intestinal necrosis tissue

Acute mesenteric ischemia (AMI) is a clinically significant vascular and gastrointestinal condition, which is closely related to the blood supply of the small intestine. Unfortunately, it is still challenging to properly discriminate small intestinal tissues with different degrees of ischemia. In this study, hyperspectral imaging (HSI) was used to construct pseudo-color images of oxygen saturation about small intestinal tissues and to discriminate different degrees of ischemia. First, several small intestine tissue models of New Zealand white rabbits were prepared and collected their hyperspectral data. Then, a set of isosbestic points were used to linearly transform the measurement data twice to match the reference spectra of oxyhemoglobin and deoxyhemoglobin, respectively. The oxygen saturation was measured at the characteristic peak band of oxyhemoglobin (560 nm). Ultimately, using the oxygenated hemoglobin reflectance spectrum as the benchmark, we obtained the relative amount of median oxygen saturation in normal tissues was 70.0 %, the IQR was 10.1 %, the relative amount of median oxygen saturation in ischemic tissues was 49.6 %, and the IQR was 14.6 %. The results demonstrate that HSI combined with the oxygen saturation computation method can efficiently differentiate between normal and ischemic regions of the small intestinal tissues. This technique provides a powerful support for internist to discriminate small bowel tissues with different degrees of ischemia, and also provides a new way of thinking for the diagnosis of AMI.

Acute management of mesenteric emergencies: Tailoring the solution to the problem

Acute mesenteric ischemia (AMI) constitutes a life-threatening problem that can result in death, multiorgan failure, and severe nutritional disability. Although AMI is a rare cause of acute abdominal emergencies, ranging between 1 and 2 individuals per 10,000, the morbidity and mortality rates are high. Arterial embolic etiology composes nearly one-half of AMIs, with a sudden onset of severe abdominal pain considered the most common symptom. Arterial thrombosis is the second most common cause of AMI, which presents similarly to arterial embolic AMI, although often more severe due to anatomic differences. Veno-occlusive causes of AMI are the third most common and are associated with an insidious onset of vague abdominal pain. Each patient is unique, and the treatment plan should be tailored to their individual needs. This may include considering the patient's age, comorbidities, and overall health, as well as their preferences and personal circumstances. A multidisciplinary approach involving specialists from different fields, such as surgeons, interventional radiologists, and intensivists, is recommended for the best possible outcome. Potential challenges in tailoring an optimal treatment plan for AMI may include delayed diagnosis, limited availability of specialized care, or patient factors that make some interventions less feasible. Addressing these challenges requires a proactive and collaborative approach, with regular review and adjustment of the treatment plan as needed to ensure the best possible outcome for each patient.

Mesenteric venous thrombosis

Mesenteric vein thrombosis (MVT) is a rare condition that can present acutely, subacutely, or chronically. MVT can be isolated or within a splanchnic thrombosis (spleno-porto-mesenteric). Symptomatic cases usually present as nonspecific abdominal pain, with or without signs of intestinal ischemia, and the diagnosis is usually made by imaging test (abdominal CT or MRI) in patients with high clinical suspicion. An early clinical-surgical approach is recommended to screen those patients with warning signs and who benefit from an exploratory laparotomy in addition to anticoagulant treatment, which is the cornerstone of medical treatment. MVT is usually associated with prothrombotic states, with hematological disorders (myeloproliferative syndromes and/or JAK2 gene mutations) being of special clinical relevance. On the other hand, the 5-year survival rate is 70-82% and early overall 30-day mortality from MVT can reach 20-32%.

[Gas in superior mesenteric artery and celiac axis as a rare CT-sign of extensive bowel necrosis]

The authors report endovascular treatment of acute thromboembolic occlusion of superior mesenteric artery in a 75-year-old patient whose postoperative period was complicated by massive reperfusion and translocation syndrome. Contrast-enhanced CT in 12 hours after successful thrombectomy from superior mesenteric artery revealed CT signs of irreversible bowel lesion, i.e. gas in hepatic veins, intestinal wall and mesenteric veins, bowel wall thinning. In addition, CT revealed extremely rare sign of severe acute mesenteric ischemia (gas in superior mesenteric artery and celiac axis). We found no description of gas in celiac axis following acute mesenteric ischemia in available literature.

Endovascular management of portal vein obstruction in hepatobiliary cancer patients

BACKGROUND AND OBJECTIVES

The purpose of this article is to describe the procedural safety, technical success, and clinical success of endovascular management of portal and mesenteric venous obstruction in patients with hepatobiliary neoplasms.

METHODS

Institutional Review Board (IRB)-approved HIPAA compliant retrospective review of 21 consecutive patients with hepatobiliary malignancies who underwent endovascular portal vein recanalization and stent placement between January 2012 and March 2020. Clinical diagnoses were pancreatic cancer (n = 19), colon cancer metastatic to the liver (n = 1), and cholangiocarcinoma (n = 1). Presenting signs and symptoms included: ascites, abdominal pain, abnormal liver function tests, diarrhea, and gastrointestinal bleeding. Stent patency and patient survival are presented with Kaplan-Meier method.

RESULTS

The technical success rate was 100%. A transhepatic approach was used in 20 cases (95.2%); trans-splenic access in one. Primary stent patency was 95.2%, 84%, and 68% at 1, 3, and 6 months, respectively. All stent occlusions were caused by tumor progression. A total of 80% of patients reported symptomatic improvement. Patient survival at 10 months was 40%. The early death rate was 4.76%. There were no bleeding complications from the percutaneous tracts.

CONCLUSION

Endovascular recanalization with stent placement is safe with high technical and clinical success.

Chronic mesenteric ischemia: Clinical practice guidelines from the Society for Vascular Surgery

BACKGROUND

Chronic mesenteric ischemia (CMI) results from the inability to achieve adequate postprandial intestinal blood flow, usually from atherosclerotic occlusive disease at the origins of the mesenteric vessels. Patients typically present with postprandial pain, food fear, and weight loss, although they can present with acute mesenteric ischemia and bowel infarction. The diagnosis requires a combination of the appropriate clinical symptoms and significant mesenteric artery occlusive disease, although it is often delayed given the spectrum of gastrointestinal disorders associated with abdominal pain and weight loss. The treatment goals include relieving the presenting symptoms, preventing progression to acute mesenteric ischemia, and improving overall quality of life. These practice guidelines were developed to provide the best possible evidence for the diagnosis and treatment of patients with CMI from atherosclerosis.

METHODS

The Society for Vascular Surgery established a committee composed of vascular surgeons and individuals experienced with evidence-based reviews. The committee focused on six specific areas, including the diagnostic evaluation, indications for treatment, choice of treatment, perioperative evaluation, endovascular/open revascularization, and surveillance/remediation. A formal systematic review was performed by the evidence team to identify the optimal technique for revascularization. Specific practice recommendations were developed using the Grading of Recommendations Assessment, Development, and Evaluation system based on review of literature, the strength of the data, and consensus.

RESULTS

Patients with symptoms consistent with CMI should undergo an expedited workup, including a computed tomography arteriogram, to exclude other potential causes. The diagnosis is supported by significant arterial occlusive disease in the mesenteric vessels, particularly the superior mesenteric artery. Treatment requires revascularization with the primary target being the superior mesenteric artery. Endovascular revascularization with a balloon-expandable covered intraluminal stent is the recommended initial treatment with open repair reserved for select younger patients and those who are not endovascular candidates. Long-term follow-up and surveillance are recommended after revascularization and for asymptomatic patients with severe mesenteric occlusive disease. Patient with recurrent symptoms after revascularization owing to recurrent stenoses should be treated with an endovascular-first approach, similar to the de novo lesion.

CONCLUSIONS

These practice guidelines were developed based on the best available evidence. They should help to optimize the care of patients with CMI. Multiple areas for future research were identified.

European guidelines on chronic mesenteric ischaemia - joint United European Gastroenterology, European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Gastrointestinal and Abdominal Radiology, Netherlands Association of Hepatogastroenterologists, Hellenic Society of Gastroenterology, Cardiovascular and Interventional Radiological Society of Europe, and Dutch Mesenteric Ischemia Study group clinical guidelines on the diagnosis and treatment of patients with chronic mesenteric ischaemia

Chronic mesenteric ischaemia is a severe and incapacitating disease, causing complaints of post-prandial pain, fear of eating and weight loss. Even though chronic mesenteric ischaemia may progress to acute mesenteric ischaemia, chronic mesenteric ischaemia remains an underappreciated and undertreated disease entity. Probable explanations are the lack of knowledge and awareness among physicians and the lack of a gold standard diagnostic test. The underappreciation of this disease results in diagnostic delays, underdiagnosis and undertreating of patients with chronic mesenteric ischaemia, potentially resulting in fatal acute mesenteric ischaemia. This guideline provides a comprehensive overview and repository of the current evidence and multidisciplinary expert agreement on pertinent issues regarding diagnosis and treatment, and provides guidance in the multidisciplinary field of chronic mesenteric ischaemia.

Triple-phased mesenteric CT angiography using a test bolus technique for evaluation of the mesenteric vasculature and small intestinal wall contrast enhancement in dogs

Computed tomography angiography is widely used for the assessment of various mesenteric vascular and bowel diseases in humans. However, there are only few studies that describe CT angiography application to mesenteric vessels in dogs. In this prospective, experimental, exploratory study, the mesenteric vasculature and enhancement pattern of the intestinal wall were evaluated on triple-phase CT angiography, and improvement of the visibility of vasculature was assessed on multiplanar reformation, maximum intensity projection, and volume rendering technique. After test bolus scanning at the level of the cranial mesenteric artery arising from the aorta, mesenteric CT angiography was performed in 10 healthy, male, Beagle dogs. Scan delay was set based on time-to-attenuation curves, drawn by placing the regions of interest over the aorta, intestinal wall, and cranial mesenteric vein. Visualization and enhancement of mesenteric arteries and veins were evaluated with multiplanar reformation, maximum intensity projection, and volume rendering techniques. The degree of intestinal wall enhancement was assessed on the transverse images in precontrast, arterial, intestinal, and venous phases. Pure arterial images were obtained in the arterial phase. Venous phase images allowed good portal vascular mapping. All CT angiography images were of high quality, allowing for excellent visualization of the anatomy of mesenteric vasculature including the small branches, particularly on maximum intensity projection and volume rendering technique. Distinct contrast enhancement of the intestinal wall was observed in both intestinal and venous phases. Findings indicated that this technique is feasible for the evaluation of mesenteric circulation in dogs.

Clinical management of chronic mesenteric ischemia

This

This Dutch Mesenteric Ischemia Study group consists of: Ron Balm, Academic Medical Center, Amsterdam Gert Jan de Borst, University Medical Center Utrecht, Utrecht Juliette T Blauw, Medisch Spectrum Twente, Enschede Marco J Bruno, Erasmus MC University Medical Center, Rotterdam Olaf J Bakker, St Antonius Hospital, Nieuwegein Louisa JD van Dijk, Erasmus MC University Medical Center, Rotterdam Hessel CJL Buscher, Gelre Hospitals, Apeldoorn Bram Fioole, Maasstad Hospital, Rotterdam Robert H Geelkerken, Medisch Spectrum Twente, Enschede Jaap F Hamming, Leiden University Medical Center, Leiden Jihan Harki, Erasmus MC University Medical Center, Rotterdam Daniel AF van den Heuvel, St Antonius Hospital, Nieuwegein Eline S van Hattum, University Medical Center Utrecht, Utrecht Jan Willem Hinnen, Jeroen Bosch Hospital, ‘s-Hertogenbosch Jeroen J Kolkman, Medisch Spectrum Twente, Enschede Maarten J van der Laan, University Medical Center Groningen, Groningen Kaatje Lenaerts, Maastricht University Medical Center, Maastricht Adriaan Moelker, Erasmus MC University Medical Center, Rotterdam Desirée van Noord, Franciscus Gasthuis & Vlietland, Rotterdam Maikel P Peppelenbosch, Erasmus MC University Medical Center, Rotterdam André S van Petersen, Bernhoven Hospital, Uden Pepijn Rijnja, Medisch Spectrum Twente, Enschede Peter J van der Schaar, St Antonius Hospital, Nieuwegein Luke G Terlouw, Erasmus MC University Medical Center, Rotterdam Hence JM Verhagen, Erasmus MC University Medical Center, Rotterdam Jean Paul PM de Vries, University Medical Center Groningen, Groningen Dammis Vroegindeweij, Maasstad Hospital, Rotterdam

review provides an overview on the clinical management of chronic mesenteric ischemia (CMI). CMI is defined as insufficient blood supply to the gastrointestinal tract, most often caused by atherosclerotic stenosis of one or more mesenteric arteries. Patients classically present with postprandial abdominal pain and weight loss. However, patients may present with, atypically, symptoms such as abdominal discomfort, nausea, vomiting, diarrhea or constipation. Early consideration and diagnosis of CMI is important to timely treat, to improve quality of life and to prevent acute-on-chronic mesenteric ischemia. The diagnosis of CMI is based on the triad of clinical symptoms, radiological evaluation of the mesenteric vasculature and if available, functional assessment of mucosal ischemia. Multidisciplinary consensus on the diagnosis of CMI is of paramount importance to adequately select patients for treatment. Patients with a consensus diagnosis of single-vessel or multi-vessel atherosclerotic CMI are preferably treated with endovascular revascularization.

Collaterals management during pancreatoduodenectomy in patients with celiac axis stenosis: A systematic review of the literature

BACKGROUND/OBJECTIVES

Celiac axis stenosis (CAS) represents an uncommon and typically innocuous condition. However, when a pancreatic resection is required, a high risk for upper abdominal organs ischemia is observed. In presence of collaterals, such a risk is minimized if their preservation is realized. The aim of the present study is to systematically review the literature with the intent to address the routine management of collateral arteries in the case of CAS patients requiring pancreatoduodenectomy.

METHODS

A systematic search was done in accordance with the PRISMA guidelines, using "celiac axis stenosis" AND "pancreatoduodenectomy" as MeSH terms. Seventy-four articles were initially screened: eventually, 30 articles were identified (n = 87).

RESULTS

The main cause of CAS was median arcuate ligament (MAL) (n = 31; 35.6%), followed by atherosclerosis (n = 20; 23.0%). CAS was occasionally discovered during the Whipple procedure in 15 (17.2%) cases. Typically, MAL was divided during surgery (n = 24/31; 77.4%). In the great majority of cases (n = 83; 95.4%), vascular abnormalities involved the pancreatoduodenal arteries (i.e., dilatation, arcade, channels, aneurysms). Collateral arteries were typically preserved, being divided or reconstructed in only 14 (16.1%) cases, respectively. Severe ischemic complications were reported in six (6.9%) patients, 20.0% of whom were reported in patients with preoperatively unknown CAS (p-value 0.06).

CONCLUSIONS

A correct pre-operative evaluation of anatomical conditions as well as a correct surgical planning represent the paramount targets in CAS patients with arterial collaterals. Vascular flow must be always safeguarded preserving/reconstructing the collaterals or resolving the CAS, with the final intent to avoid dreadful intra- and post-operative complications.