Nonocclusive mesenteric ischemia

Intraoperative indocyanine green fluorescence for precise resection of nonocclusive mesenteric ischemia: a case report and diagnostic considerations based on pathology findings

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI) is characterized by intestinal ischemia caused by spasms in the peripheral intestinal vessels without organic obstruction in the main mesenteric vessels. NOMI can be fatal in case of delayed diagnosis and treatment. Although the use of indocyanine green (ICG) fluorescence in assessing intestinal viability during NOMI surgery is well recognized, there is a paucity of reported cases using this technique. Herein, we present a case of NOMI that was successfully managed through accurate diagnosis and resection of the ischemic intestines guided by ICG fluorescence.

CASE PRESENTATION

An 81-year-old man presented with abdominal pain. Contrast-enhanced computed tomography revealed intrahepatic portal vein gas, superior mesenteric vein gas, and terminal ileal edema. Considering these findings, the patient was diagnosed with NOMI and emergency surgery was performed. Intestinal edema was observed 30 cm upstream of the terminal ileum without serosal discoloration. ICG fluorescence revealed areas of normal perfusion as well as mild and moderate hypoperfusion. The small bowel, including the hypoperfusion area, was resected. As no clinical signs of residual bowel ischemia were observed during the postoperative course, a second-look operation was deemed unnecessary. Intraoperative ICG fluorescence and histopathological findings indicated mucosal edema in the mildly hypoperfused area and mucosal necrosis in the moderately hypoperfused area.

CONCLUSIONS

This case highlights the use of intraoperative ICG fluorescence in the disease. ICG fluorescence is invaluable in assessing the extent of bowel ischemia and guiding precise resection. Thus, future efforts should focus on identifying accumulation of cases and quantification of ICG fluorescence intensity to further improve diagnostic performance.

Treatment outcomes in non-occlusive mesenteric ischemia and post-treatment return to social activities

PURPOSE

To investigate the treatment outcomes of patients with non-occlusive mesenteric ischemia (NOMI) at our institution, we focused on their post-treatment return to social activities.

METHODS

This study included patients with suspected NOMI who were referred to our department between 2011 and 2023. In-hospital mortality was also investigated as a prognostic factor. The Glasgow-Pittsburgh Outcome Categories (GPOC) score was used to evaluate the return to social activities. The relationship between in-hospital mortality and GPOC scores and patient background and treatment factors was examined.

RESULTS

Eighty-two patients were included in the study. Among them, 54 (65.9%) died during hospitalization. Only 9 patients (11%) returned to their social activities. In the multivariate analysis, non-surgical management was found to be the only independent factor for in-hospital mortality. Positive portal venous gas on computed tomography, no open abdomen, no pre-onset catecholamine administration, platelet count < 100,000/µL, lactate level < 5 mmol/L, APTT < 46 s, and Sequential Organ Failure Assessment score < 11 were factors significantly associated with an increased likelihood of return to social activities.

CONCLUSION

This is the first study to assess the post-treatment return to social activities among patients with NOMI. Our findings highlight the concerning reality that survivors may face prolonged dependence on medical care.

Preoperative risk factors for 90-day postoperative mortality outcome in patients with non-occlusive mesenteric ischemia

PURPOSE

The mortality rate for non-occlusive mesenteric ischemia remains high even after patients survive the acute postoperative period with tremendous treatment efforts, including emergency surgery, which is challenging. The aim of this study was to explore the preoperative risk factors for 90-day postoperative mortality in patients with non-occlusive mesenteric ischemia.

METHODS

This single-center, retrospective cohort study included patients diagnosed with non-occlusive mesenteric ischemia who underwent emergency surgery between August 2014 and January 2023. All patients were divided into survival-to-discharge and mortality outcome groups at the 90-day postoperative follow-up. Preoperative factors, including comorbidities, preoperative status of vital signs and consciousness, blood gas analysis, blood test results, and computed tomography, were compared between the two groups.

RESULTS

Twenty patients were eligible, and 90-day mortality was observed in 10 patients (50%). The mortality outcome group had significantly lower HCO3- (20.9 vs. 14.6, p = 0.006) and higher lactate (4.4 vs. 9.4, p = 0.023) levels than did the survival outcome group. The median postoperative time to death was 19 [2-69] days, and five patients (50%) died after postoperative day 30, mainly because hemodialysis was discontinued because of hemodynamic instability in patients requiring hemodialysis.

CONCLUSION

Low preoperative HCO3- and high lactate levels may be preoperative risk factors for 90-day postoperative mortality in patients with non-occlusive mesenteric ischemia. However, patients on hemodialysis die from discontinuing hemodialysis even after surviving the acute postoperative phase. Therefore, indications for emergency surgery in patients with risk factors for postoperative mortality should be carefully determined.

A Case of Nonocclusive Mesenteric Ischemia During Bioradiotherapy With Cetuximab

Nonocclusive mesenteric ischemia (NOMI) causes mesenteric ischemia and intestinal necrosis despite the absence of organic obstruction, such as thrombi and emboli in mesenteric blood vessels, and it has an extremely poor prognosis. We report a case of NOMI developed during bioradiotherapy (BRT) with cetuximab for cervical lymph node metastasis of tongue cancer. The patient was a 73-year-old man who underwent right radical neck dissection for neck lymph node metastasis after tongue cancer surgery. Postoperatively, the patient received BRT with cetuximab. On the 34th day after BRT, the patient had abdominal distension and a decreased level of consciousness. Contrast-enhanced computed tomography revealed mesenteric ischemia without thrombi and extensive intestinal emphysema. The patient was diagnosed with NOMI. Furthermore, he had septic shock and was treated with vasopressors and antibacterial agents; however, the condition of the patient did not improve, and he died on the same day.

Association between Postoperative Adjuvant Vasodilator Therapy and In-Hospital Mortality for Non-Occlusive Mesenteric Ischemia: A Nationwide Observational Study

BACKGROUND

Although several clinical guidelines recommend vasodilator therapy for non-occlusive mesenteric ischemia (NOMI) and immediate surgery when bowel necrosis is suspected, these recommendations are based on limited evidence.

METHODS

In this retrospective nationwide observational study, we used information from the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018 to identify patients with NOMI who underwent abdominal surgeries on the day of admission. We compared patients who received postoperative vasodilator therapy (vasodilator group) with those who did not (control group). Vasodilator therapy was defined as venous and/or arterial administration of papaverine and/or prostaglandin E1 within 2 days of admission. The primary outcome was in-hospital mortality. Secondary outcomes included the prevalence of additional abdominal surgery performed ≥3 days after admission and short bowel syndrome.

RESULTS

We identified 928 eligible patients (149 in the vasodilator group and 779 in the control group). One-to-four propensity score matching yielded 149 and 596 patients for the vasodilator and control groups, respectively. There was no significant difference in in-hospital mortality between the groups (control vs. vasodilator, 27.5% vs. 30.9%; risk difference, 3.4%; 95% confidence interval, -4.9 to 11.6; p=0.42) and no significant difference in the prevalences of abdominal surgery, bowel resection ≥3 days after admission, and short bowel syndrome.

CONCLUSIONS

Postoperative vasodilator use was not significantly associated with a reduction in in-hospital mortality or additional abdominal surgery performed ≥3 days after admission in surgically treated NOMI patients.

Late-onset non-obstructive mesenteric ischemia (NOMI) resulting from delayed absorption of overdosed antihypertensive drugs: An autopsy case report

Non-obstructive mesenteric ischemia (NOMI) is caused by reduced blood flow to the intestines without physical occlusion in the mesenteric artery. Previous reports show that drug overdose occasionally induces late-onset NOMI; however, in most cases, the reason for the delayed onset is unclear. Here, we present an autopsy case of late-onset NOMI that was induced by a drug overdose. An 80-year-old man was admitted to the intensive care unit because of severe hypotension after an overdose of antihypertensive drugs. He received vasopressor therapy and continuous hemodiafiltration dialysis; however, gastrointestinal decontamination was not performed. He began to recover but developed acute mesenteric ischemia on the evening of day 4 and died on day 5. Autopsy showed discontinuous submucosal bleeding from the duodenum to the colon; there was no thrombus in the mesenteric artery, which led to a diagnosis of NOMI. In the stomach, there was 250 mL of reddish-brown fluid with a muddy brown substance. Histologic examination revealed ischemic necrosis in the small intestine. Quantitative analysis of serum collected during hospitalization revealed that nifedipine and cilostazol levels had peaked on day 3 of hospitalization. The formulation of nifedipine was a controlled-release tablet, and the low water solubility of cilostazol may have caused the tablets to adhere and remain in the stomach. Therefore, the drugs had been released into the blood stream several days after hospitalization, leading to delayed-onset NOMI. In cases of overdose, it is crucial to consider the formulation and properties of the involved drugs when determining medical treatment.

Organ damage evaluation in a temperature-controlled circulatory arrest rat model

BACKGROUND

Deep hypothermic circulatory arrest (DHCA) is commonly used in adult aortic surgery and pediatric complex congenital heart disease, and is associated with pathophysiological changes and postoperative complications. Here, a temperature-controlled circulatory arrest model in rats was established to study the suitable temperature of circulatory arrest by investigating the damage to body organs under different temperatures.

METHODS

Thirty Sprague‒Dawley rats were randomly divided into 5 equal groups for DHCA experiments: I (15-20 °C), II (20-25 °C), III (25-30 °C), IV (normothermic cardiopulmonary bypass), and V (sham operation group). Blood gas analysis, homodynamic parameters, and intervals of cardiac recovery were measured at different time points in all groups. Morphological changes in intestinal tissue were observed under light and electron microscopes. Oxidative stress was measured by MPO activity, MDA, and SOD content. Tissue damage was confirmed by serum detection of ALT, AST, BUN, Cr, and LDH. To examine the inflammatory response, cytokines, including IL-1, IL-4, IL-10, IFN-γ, and TNF-α, were detected.

RESULTS

The extracorporeal circulation technique caused damage to the body; the degree of the damage caused by the circulatory arrest technique may be related to circulating temperature, with the least amount of damage occurring at 20-25 °C compared to 15-20 °C and 25-30 °C. Ischemia and hypoxia can cause intestinal tissue damage, which manifests primarily as a loss of the intestinal mucosal barrier. Ischemic intestinal damage caused by DHCA was not associated with inflammation.

CONCLUSION

The study provides new insights into the pathophysiologic mechanisms of DHCA.

Nonocclusive mesenteric ischemia during treatment for ketoacidosis associated with acute‐onset type 1 diabetes mellitus: A case report

This case report describes a patient with nonocclusive mesenteric ischemia that developed due to diabetic ketoacidosis. We believe that early diagnosis and intervention may improve the prognosis of nonocclusive mesenteric ischemia that has low vascular risk, with the major risk factor being dehydration due to diabetic ketoacidosis.

Non-occlusive mesenteric ischemia in reconstructive digestive tract surgery

OBJECTIVE

To analyze the mechanisms of non-occlusive mesenteric ischemia (NOMI) after digestive tract surgery.

MATERIAL AND METHODS

NOMI occurred in 10 (0.4%) patients after reconstructive digestive tract surgery between 2015 and 2021. There were 4 women and 6 men aged 29-92 years (67 [60; 71]). Patients differed from each other in the nature of baseline disease and surgical approach. All patients underwent standardized surgical interventions. There were no intraoperative complications.

RESULTS

Median of surgery time was 372.5 (246.25; 548.75) min, blood loss - 450 (200; 725) ml. These parameters conformed to the type of surgery. There were no specific clinical signs of NOMI. Lactic acidosis (>4 mmol/L) occurred in 7 patients after 1-3 postoperative days. In 6 patients, fulminant NOMI developed after 1-2 postoperative days with subsequent multiple organ failure syndrome and septic shock. All patients underwent emergency redo surgery. Multivisceral gastrointestinal necrosis occurred in 5 patients, gastric conduit necrosis - 3, colon necrosis - 1, gastric stump necrosis - 1 patient. Mortality rate was 80%. Two patients survived.

CONCLUSION

NOMI manifested as a septic shock in 60% of patients that was due to fulminant development of multivisceral necrosis after 1-2 postoperative days. Timely diagnosis of reversible NOMI in these cases was impossible. Extensive visceral necrosis in early postoperative period is probably associated with intraoperative critical ischemia of digestive organs.

Non-Occlusive Mesenteric Ischemia in Children With Diabetic Ketoacidosis: Case Report and Review of Literature

INTRODUCTION

Despite the use of technology, recurrent diabetic ketoacidosis (DKA) prevention remains an unmet need in children and adolescents with T1D and may be accompanied by life-threatening acute complications. We present a rare case of non-occlusive mesenteric ischemia (NOMI) with overt manifestation after DKA resolution and a discussion of recent literature addressing DKA-associated NOMI epidemiology and pathogenesis in children and adolescents.

CASE PRESENTATION

A 13-year-old female with previously diagnosed T1D, was admitted at our emergency department with hypovolemic shock, DKA, hyperosmolar state and acute kidney injury (AKI). Mildly progressive abdominal pain persisted after DKA correction and after repeated ultrasound evaluations ultimately suspect for intestinal perforation, an intraoperative diagnosis of NOMI was made.

CONCLUSION

The diagnosis of DKA-associated NOMI must be suspected in pediatric patients with DKA, persistent abdominal pain, and severe dehydration even after DKA resolution.

Vasodilator Therapy and Mortality in Nonocclusive Mesenteric Ischemia: A Nationwide Observational Study

OBJECTIVES

Previous studies have suggested that vasodilator therapy may be beneficial for patients with nonocclusive mesenteric ischemia. However, robust evidence supporting this contention is lacking. We examined the hypothesis that vasodilator therapy may be effective in patients diagnosed with nonocclusive mesenteric ischemia.

DESIGN

Retrospective cohort study.

SETTING

The Japanese Diagnosis Procedure Combination inpatient database.

PATIENTS

A total of 1,837 patients with nonocclusive mesenteric ischemia from July 2010 to March 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We compared patients who received vasodilator therapy (vasodilator group; n = 161) and those who did not (control group; n = 1,676) using one-to-four propensity score matching. Vasodilator therapy was defined as papaverine and/or prostaglandin E1 administered via venous and/or arterial routes within 2 days of admission. Only patients who did not receive abdominal surgery within 2 days of admission were analyzed. The main outcomes were in-hospital mortality and abdominal surgery performed greater than or equal to 3 days after admission. After propensity score matching, in-hospital mortality was significantly lower in the vasodilator group (risk difference, -11.6%; p = 0.005). The proportion of patients who received abdominal surgery at greater than or equal to 3 days after admission was also significantly lower in the vasodilator group (risk difference, -10.2%; p = 0.002).

CONCLUSIONS

Vasodilator therapy with papaverine and/or prostaglandin E1 is associated with lower in-hospital mortality and prevalence of abdominal surgery in patients with nonocclusive mesenteric ischemia.

A rare case of penetration related to ischemic duodenitis after ventricular assist device implantation for dilated cardiomyopathy

A 66-year-old man with a history of diabetes and dilated cardiomyopathy underwent the implantation of a ventricular assist device (VAD) at the age of 62. He suffered from epigastralgia for a month and then visited our hospital with complaints of severe epigastralgia and hematemesis. A physical examination revealed abdominal distension without rigidity. Laboratory data showed severe systemic inflammation, multiple organ failure, and disseminated intravascular coagulation. Computed tomography showed multifocal thickness of the gastroduodenal wall with surrounding panniculitis, gas in a portal vein and a perigastric vein. Emergency esophago-gastro duodenoscopy (EGD) demonstrated a large erosion in the antrum of the stomach, and penetration surrounded by circumferentially ischemic mucosa in the second and third portions of the duodenum. Based on informed consent, conservative therapy was performed, and his condition improved enabling the start of oral intake on the 37th hospital day. However, 7 days later, there was a relapse of epigastralgia after a meal. Gastrointestinal series and EGD revealed a 10-mm-long pinhole-like stricture at the site. After laparoscopic gastro-jejunal bypass surgery, he has remained in a good condition for 2 years. We demonstrated a rare case of penetration due to severe ischemic duodenitis 4 years after VAD implantation.

A case of non-occlusive mesenteric ischaemia caused by pelvic fracture due to fall trauma

BACKGROUND

Non-occlusive mesenteric ischaemia (NOMI) is a condition in which intestinal ischaemia arises due to spasms of peripheral blood vessels; however, there is no obstruction of the main arteries. Risk factors include hypertension, diabetes, and increasing age, but the traumatic injury triggering NOMI onset is rarely reported. We report a case of NOMI caused by a pelvic fracture due to a fall injury.

CASE PRESENTATION

A 77-year-old man was transported to the hospital due to a fall injury. CT revealed a pelvic fracture and a haematoma in the pelvic extraperitoneal space. The next day, the patient developed shock, and CT revealed an increase in haematoma size. Both internal iliac arteries were embolized by transcatheter arterial embolization (TAE). The next day's CT revealed intestinal necrosis of the ascending colon, and emergency surgery was planned. During surgery, necrosis was identified in the serosa of the ascending, transverse, and sigmoid colon. We performed subtotal excision from the ascending colon to the sigmoid colon. On postoperative day 10, melena was observed, and CT revealed partial thickening of the small intestine and a decrease in the contrast effect. Considering the post-total colectomy and general condition, we proceeded with conservative treatment. Over time, the patient developed liver and renal dysfunction and died 16 days after surgery.

CONCLUSIONS

We experienced a case of NOMI caused by bleeding from a pelvic fracture. It is important to keep in mind the risk of developing NOMI in traumatic bleeding to avoid missing this diagnosis.

Surgical Outcomes in Acute Mesenteric Ischemia: Has Anything Changed Over the Years?

BACKGROUND

Despite increases in knowledge and advances in the management of acute mesenteric ischemia syndrome (AMI), there have been no significant improvements in mortality in recent years. The objective of this study was to assess the changes in clinical characteristics and surgical outcomes in patients who underwent AMI over time.

METHODS

A total of 323 consecutive patients who underwent acute mesenteric ischemia at our institution between 1990 and 2015 were examined. The occurrence of significant changes over this 25-year period in demographic data, comorbidity, clinical characteristics, laboratory results, operative findings, etiology of the AMI, and operative mortality were evaluated. The evolution mortality rates for the studied period were analyzed using the additive logistic regression, and the significant effect was determined using the Akaike Information Criterion (AIC).

RESULTS

A significant increasing linear trend was observed in recent years in Charlson score values (p = 0.008), antiplatelet drug intake (p < 0.001), use of CT scan (p < 0.001), arterial thrombosis (p < 0.001), and intestinal resection (p = 0.047), while a decreasing linear trend was observed in digoxin intake (p < 0.001), angiography use (p = 0.004), and embolia (p < 0.001). The rest of the parameters did not present changes over time. Regarding the evolution of the adjusted surgical mortality, a significant decrease according the AIC criterion was observed.

CONCLUSIONS

In recent years, the characteristics of patients with AMI requiring surgery have changed. Changes in operative mortality have also been detected, showing a tendency toward a progressive and significant decrease.

A Retrospective Analysis of Nonocclusive Mesenteric Ischemia in Medical and Surgical ICU Patients: Clinical Data on Demography, Clinical Signs, and Survival

Background:

To analyze demography, clinical signs, and survival of intensive care patients diagnosed with nonocclusive mesenteric ischemia (NOMI) and to evaluate the effect of a local intra-arterial prostaglandin therapy.

Methods:

Retrospective observational study screening 455 intensive care patients with acute arterial mesenteric perfusion disorder in a tertiary care hospital within the past 8 years. Lastly, 32 patients with NOMI were enrolled, of which 11 received local intra-arterial prostaglandin therapy. The diagnosis of NOMI was based on the clinical presentation and established biphasic computed tomography criteria. Clinical and biochemical data were obtained 24 hours before, at the time, and 24 hours after diagnosis.

Results:

Patients were 60.5 (49.3-73) years old and had multiple comorbidities. Most of them were diagnosed with septic shock requiring high doses of norepinephrine (NE: 0.382 [0.249-0.627] μg/kg/min). The Sequential Organ Failure Assessment (SOFA) score was 18 (16-20). A decrease in oxygenation (Pao₂/Fio₂), pH, and bicarbonate and an increase in international normalized ratio, lactate, bilirubin, leucocyte count, and NE dose were early indicators of NOMI. Median SOFA score significantly increased in the last 24 hours before diagnosis of NOMI (16 vs 18, P < .0001). Overall, 28-day mortality was 75% (81% nonintervention vs 64% intervention cohort; P = .579). Median SOFA scores 24 hours after intervention increased by +5% in the nonintervention group and decreased by 5.5% in the intervention group (P = .0059).

Conclusions:

Our data suggest that NOMI is a detrimental disease associated with progressive organ failure and a high mortality. Local intra-arterial prostaglandin application might hold promise as a rescue treatment strategy. These data encourage future randomized controlled trials are desirable.

Protein-losing enteropathy secondary to nonocclusive mesenteric ischemia: A case report

RATIONALE

Nonocclusive mesenteric ischemia (NOMI) is a life-threatening disorder; prompt diagnosis is vital. Surgical treatment is often required, but some cases can be treated conservatively. We herein report an extremely rare case wherein protein-losing enteropathy (PLE) developed after conservative treatment of NOMI.

PATIENT CONCERNS

The patient was a 66-year-old man. He underwent laparoscopic super low anterior resection and temporary ileostomy for sigmoid colon cancer and rectum cancer. During the postoperative course, he developed ileus. Subsequently, he developed shock. On examination, the possibility of NOMI could not be denied, but intestinal necrosis was absent. Conservative treatment was initiated. His general condition improved, but the ileus persisted. Therefore, we performed a stoma closure. Ten days after stoma closure, he developed continuous unexplained diarrhea. The serum albumin and total protein levels were low. The symptoms improved after administration of an antidiarrheal drug, but the root cause was yet untreated.

DIAGNOSIS

The patient's alpha-1 antitrypsin clearance was increased. A CT scan revealed an enhanced hypertrophied wall of the short segment of the small intestine, and 99m Tc-labeled human serum albumin scintigraphy revealed protein leakage into the thickened wall of the small intestine. We arrived at a definitive diagnosis of PLE secondary to NOMI.

INTERVENTIONS

Partial resection of the affected small intestine was performed.

OUTCOMES

The patient recovered uneventfully and was discharged on the 30th postoperative day.

LESSONS

NOMI has a high mortality rate, often requiring intestinal resection immediately after onset. To our knowledge, there is no report of PLE developing after conservative treatment, as in our case. Further study of cases is necessary to determine the reversibility of the condition, which will influence the therapeutic plan. We herein present an extremely rare case of PLE after conservative treatment for NOMI. The possibility of PLE also needs to be considered when hypoalbuminemia occurs after conservative treatment of NOMI.

The Relationship between Intradialytic Hypotension and Hospitalized Mesenteric Ischemia: A Case-Control Study

BACKGROUND AND OBJECTIVES

Mesenteric ischemia is a rare but devastating condition caused by insufficient blood supply to meet the demands of intestinal metabolism. In patients with ESKD, it can be difficult to diagnose and has a >70% mortality rate. Patients on hemodialysis have a high prevalence of predisposing conditions for mesenteric ischemia, but the contribution of intradialytic hypotension, a potential modifiable risk factor, has not been well described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used data from the US Renal Data System to identify 626 patients on hemodialysis with a hospitalized mesenteric ischemia event (cases). We selected 2428 controls in up to a 1:4 ratio matched by age, sex, black race, incident dialysis year, diabetes mellitus, coronary artery disease, and peripheral artery disease. We used six different definitions of intradialytic hypotension on the basis of prior studies, and categorized patients as having had intradialytic hypotension if ≥30% of hemodialysis sessions in the 30 days before the event met the specified definition.

RESULTS

The proportion of patients with intradialytic hypotension varied depending on its definition: from 19% to 92% of cases and 11% to 94% of controls. Cases had a higher adjusted odds (1.82; 95% confidence interval, 1.47 to 2.26) of having had intradialytic hypotension in the preceding 30 days than controls when using nadir-based intradialytic hypotension definitions such as nadir systolic BP <90 mm Hg. To examine a potential dose-response association of intradialytic hypotension with hospitalized mesenteric ischemia, we categorized patients by the proportion of hemodialysis sessions having intradialytic hypotension, defined using the Nadir90 definition (0%, 1%-9%, 10%-29%, 30%-49%, and ≥50%), and found a direct association of proportion of intradialytic hypotension with hospitalized mesenteric ischemia (P-trend<0.001).

CONCLUSIONS

Patients with hospitalized mesenteric ischemia had significantly higher odds of having had intradialytic hypotension in the preceding 30 days than controls, as defined by nadir-based definitions.

Use of indocyanine green fluorescence imaging to determine the area of bowel resection in non-occlusive mesenteric ischemia: A case report

•

In cases of NOMI, it is difficult to determine the area of bowel resection.

•

Using ICG fluorescence imaging, we can evaluate ischemia of the intestine.

•

We adeptly resected the ischemic intestine in NOMI using ICG fluorescence imaging.

Introduction

Non-occlusive mesenteric ischemia (NOMI) is a type of acute intestinal ischemia, and its associated mortality is very high. In laparotomy of NOMI, we often have difficulty determining the area of bowel resection. We herein describe a case in which we detected the area of bowel resection using indocyanine green (ICG) fluorescence imaging.

Presentation of the case

An 89-year-old man diagnosed as having advanced gastric cancer underwent distal gastrectomy. On the night of postoperative day 4, he strongly complained of distention of the abdomen. The laboratory data indicated severe metabolic acidosis and dehydration. The abdominal computed tomography scan showed a dilated small bowel, but there were no specific signs suggestive of bowel necrosis. We suspected NOMI and decided to perform emergency laparotomy because we could not exclude the possibility of bowel necrosis. During the operation, we could not detect the necrotic bowel macroscopically. After injecting 2.5 mg of ICG, the ischemic area of the bowel became visible as a region with poor fluorescence emission using the Photodynamic Eye™ (Hamamatsu Photonics K.K.). We resected the ischemic bowel and performed anastomosis. We confirmed that he was alive at 4 months after the operation of NOMI.

Conclusion

Intraoperative ICG fluorescence imaging makes it possible to detect necrotic intestine that cannot be found with the naked eye. By using this method, planned reoperation to find any newly developed necrotic intestine might be unnecessary. Intraoperative ICG fluorescence imaging is useful for defining the area of ischemic bowel in a patient with NOMI.

Establishment of Predictive Models for Nonocclusive Mesenteric Ischemia Comparing 8,296 Control with 452 Study Patients

OBJECTIVE

The aim of this study was to develop clinical preoperative, intraoperative, and postoperative scores for early identification of patients who are at risk of nonocclusive mesenteric ischemia (NOMI).

DESIGN

A retrospective analysis.

SETTING

Single center.

PARTICIPANTS

From January 2008 to December 2014, all patients from the Department of Thoracic and Cardiovascular Surgery were included on the basis of the hospital database.

INTERVENTIONS

All mesenteric angiographically identified NOMI patients were compared with non-NOMI patients.

MEASUREMENTS AND MAIN RESULTS

The study population of 8,748 patients was randomized into a cohort for developing the scores (non-NOMI 4,214 and NOMI 235) and a cohort for control (non-NOMI 4,082 and NOMI 217). Risk factors were identified using forward and backward Wald test and were included in the predictive scores for the occurrence of NOMI. C statistic showed that the scores had a high discrimination for the prediction of NOMI preoperatively (C statistic 0.79; p < 0.001), intraoperatively (C statistic 0.68; p < 0.001), and postoperatively (C statistic 0.85; p < 0.001). A combination of the preoperative, intraoperative, and postoperative risk scores demonstrated the highest discrimination (C statistic 0.87; p < 0.001). The combined score included the following risk factors: renal insufficiency (preoperative); use of cardiopulmonary bypass and intra-aortic balloon pump support (intraoperative); and reexploration for bleeding, renal replacement therapy, and packed red blood cells ≥ 4 units (postoperative). The results were similar in the control group.

CONCLUSIONS

These scores could be useful to identify patients at risk for NOMI and promote a rapid diagnosis and therapy.

The Pathogenesis of Nonocclusive Mesenteric Ischemia: Implications for Research and Clinical Practice

Nonocclusive mesenteric ischemia (NOMI) is a condition that can encompass ischemia, inflammation, and infarction of the intestinal wall. In contrast to most patients with acute mesenteric ischemia, NOMI is distinguished by patent arteries and veins. The clinical presentation of NOMI is often insidious and nonspecific, resulting in a delayed diagnosis. Patients most at risk are those with severe acute and critical disease, including major surgery and trauma. Nonocclusive mesenteric ischemia is part of a spectrum, from mild, asymptomatic, and an unexpected finding on CT scanning, through to those exhibiting abdominal distension and peritonitis. Severe NOMI is associated with a significant mortality rate. This review of NOMI pathophysiology was conducted to document current concepts and evidence, to examine the implications for diagnosis and treatment, and to identify gaps in knowledge that might direct future research. The key pathologic mechanisms involved in the genesis of NOMI represent an exaggerated normal physiological response to maintain perfusion of vital organs at the expense of mesenteric perfusion. A supply-demand mismatch develops in the intestine due to the development of persistent mesenteric vasoconstriction resulting in reduced blood flow and oxygen delivery to the intestine, particularly to the vulnerable superficial mucosa. This mismatch can be exacerbated by raised intra-abdominal pressure, enteral nutrition, and the use of certain vasoactive drugs, ultimately resulting in the development of intestinal ischemia. Strategies for prevention, early detection, and treatment are urgently needed.

Risk factor analysis for nonocclusive mesenteric ischemia following cardiac surgery: A case-control study

Although rare, postcardiac surgery nonocclusive mesenteric ischemia (NOMI) is a life-threatening condition. Identifying the risk factors for NOMI during immediate postoperative period may help early detection and intervention, which leads to improved clinical outcomes. The objective of this study was to identify the clinical features and risk factors of NOMI for prognosis identification after cardiac surgery, focusing on immediate postoperative parameters.Among 9445 patients who underwent cardiac surgery over a span of 9 years, 40 NOMI cases (0.4%) requiring surgical interventions were reviewed. Suspected NOMI was diagnosed by sigmoidoscopy or computed tomography. To identify the risk factors, a control group (case: control = 1:3 ratio) was randomly selected and compared using logistic regression models.NOMI was diagnosed after a mean of 8.1 ± 9.6 days following cardiac surgery. Age (odds ratio: 1.16, 95% confidence interval: 1.08-1.25, P < .001), total vasoactive-inotropic score (VIS), and the maximal lactate level at postoperative day 0 (1.003, [1.001-1.005], P = .012), (1.23, [1.04-1.44], P = .011) were shown as risk factors. NOMI cases showed persistent hyperlactatemia without washout during the first 48 hours (P = .04). Thirty-four cases underwent exploratory laparotomy within a median of 10 (2-356) hours after the diagnosis, but only 17 patients (42.5%) survived. Compared with survivors, nonsurvivors showed higher total VIS at diagnosis, higher lactate levels during the first 24 hours postoperatively, and more frequently required extensive bowel resection (P < .05).Old age, postoperative high-dose vasoactive-inotropic use, and persistent high lactate level during the first 24 hours postsurgery were identified as risk factors for NOMI. Lactic acidosis and necrotic-bowel extent at surgical exploration were associated with poor survival.

Reperfusion in non-occlusive mesenteric ischaemia (NOMI): effectiveness of CT in an emergency setting

OBJECTIVE

To investigate the CT features of reperfusion (presence/absence) in non-occlusive mesenteric ischaemia (NOMI) and their prognostic value in an emergency setting.

METHODS

A revision was undertaken of imaging from 20 patients (16 males/4 females) with a dismissal summary of NOMI. All patients had previously undergone a minimum of one multidetector CT examination, and consequently underwent surgery (n = 8), autopsy (n = 2), angiography (n = 1) or endoscopy (n = 9). An evaluation of the CT scans was conducted to determine vessels, mesentery, bowel and peritoneal cavity features. The superior mesenteric artery (SMA) average diameter of NOMI cases were compared with 30 controlled cases. Kappa, Kolmogorov-Smirnov (K-S) and Fisher's exact tests were used for statistical analysis.

RESULTS

A mean SMA diameter significantly smaller than that of the controlled cases was found for patients with NOMI (K-S test: D = 0.75, p = 3.7 × 10-08). Fisher's exact tests showed a strong connection between the presence of reperfusion and mesenteric fat stranding (p = 0.026), bowel wall thickening (p = 3.2 × 10-05) and a high attenuation of the bowel wall on unenhanced CT images (p = 2.8 × 10-04). A reduction in mortality was significantly linked to the combination of normal mesenteric vessels and wall thickening (p = 0.034).

CONCLUSION

Analysis of not only vessels findings but also mesentery and bowel CT features will support the identification of NOMI with or without a reperfusion event in an emergency setting. A strong correlation between some CT features and lower mortality exists.

ADVANCES IN KNOWLEDGE

CT features of NOMI with or without reperfusion are demonstrated. Correctly assessing the presence of reperfusion in NOMI, may allow better management of these conditions in the emergency setting.

What We Can Learn from Cases of Synchronous Acute Mesenteric Obstruction and Nonocclusive Mesenteric Ischemia: How to Reduce the Acute Mesenteric Ischemia-Related Mortality Rate

Although the survival rate of patients with ischemic heart disease has recently increased, it remains unknown why the mortality rate of acute mesenteric ischemia (AMI) remains high. Here, we report a possible method of improving the survival rate of patients with AMI obtained through 2 cases of simultaneous acute mesenteric obstruction (AMO) and nonocclusive mesenteric ischemia (NOMI). Case 1 was a 74-year-old woman with atrial fibrillation, hypertension, and dyslipidemia as underlying diseases who developed NOMI immediately after undergoing SMA thrombolysis. Case 2 was a 69-year-old man with atrial fibrillation, hypertension, chronic heart failure, chronic renal failure, and old myocardial infarction who was diagnosed with SMA occlusion complicated by NOMI on the basis of abdominal angiography findings during the first visit. Cure was achieved by thrombolytic therapy, resection of the necrotic intestine, and continuous intra-arterial and/or intravenous injection of prostaglandin E1 (PGE1) in case 1 and by resection of the necrotic intestine and continuous intra-arterial and/or intravenous injection of PGE1 in case 2. AMO and NOMI have many background similarities (e.g., atherosclerosis, hypertension, and ischemic heart disease), making their coexistence very likely. However, no case of AMO plus NOMI has been reported until now. It is highly probable that concomitant NOMI is overlooked in cases of AMO. When managing AMO, NOMI should be considered as a complication, which may lower the patient's potential risk of developing NOMI and contribute to improved prognosis of both AMO and AMI.

Elevated endothelin-1 level is a risk factor for nonocclusive mesenteric ischemia

OBJECTIVE

Nonocclusive mesenteric ischemia may occur after cardiac surgery, commonly in conjunction with the use of cardiopulmonary bypass. Some evidence suggests that endothelin-1 serum levels are increased in patients with mesenteric ischemia, but the association of endothelin-1 and nonocclusive mesenteric ischemia has not been studied. The objective was to investigate whether elevated levels of endothelin-1 could be found in patients exhibiting nonocclusive mesenteric ischemia.

METHODS

In an observational cohort study, nonocclusive mesenteric ischemia developed in 78 of 865 patients undergoing elective cardiac surgery. Control patients were identified from the cohort through 1:1 propensity score matching. Preoperative and postoperative endothelin-1 serum levels were determined by means of enzyme-linked immunosorbent assay. Odds ratios (with 95% confidence interval) were calculated by logistic regression analyses to determine the risk of endothelin-1 for the development of nonocclusive mesenteric ischemia.

RESULTS

Patients with nonocclusive mesenteric ischemia had higher preoperative (11.3 vs 9.3 pg/mL; P = .001) and postoperative (15.7 vs 11.1 pg/mL, P < .001) levels of endothelin-1 than the controls. The probability of developing nonocclusive mesenteric ischemia increased with each picogram/milliliter endothelin-1 level preoperatively (odds ratio, 1.29; 95% confidence interval, 1.12-1.49) and each picogram/milliliter postoperatively (odds ratio, 2.04; 95% confidence interval, 1.54-2.72). Receiver operating characteristic analyses showed that elevated endothelin-1 serum levels had a high accuracy to predict nonocclusive mesenteric ischemia (optimal cutoff value of 14.5 pg/mL, area under the curve of 0.77, sensitivity 51%, and specificity 94%).

CONCLUSIONS

Endothelin-1 seems to predispose patients undergoing cardiac surgery to develop nonocclusive mesenteric ischemia. In addition, it may be a useful marker to identify patients at risk for nonocclusive mesenteric ischemia after cardiac surgery.

Isolated cecal necrosis: our surgical experience and a review of the literature

OBJECTIVE

Isolated cecal necrosis is a rare cause of ischemic colitis. Ischemic colitis is further divided into two groups: occlusive mesenteric ischemia and non-occlusive mesenteric ischemia. The aim of this study was to investigate the cause of isolated cecal necrosis.

MATERIAL AND METHODS

We operated on 3 male and 3 female patients with a mean age of 60.3±18.7 (38-85) years with a preliminary diagnosis of acute appendicitis between 2007 and 2012. Four of these patients were on hemodialysis, 1 patient had an aortofemoral bypass, and 1 patient had coronary artery disease with atrial fibrillation.

RESULTS

The diagnosis was made intraoperatively in all cases. Five patients died postoperatively. One patient survived.

CONCLUSION

In the case of right lower quadrant pain, the possibility of isolated cecal necrosis should be kept in mind, especially in patients on hemodialysis, elderly patients with diabetes, and heart disease; surgical strategies should be planned accordingly, and it should be understood that a high mortality rate will be inevitable.

Evaluating for acute mesenteric ischemia in critically ill patients: diagnostic peritoneal lavage is associated with reduced operative intervention and mortality

BACKGROUND

The diagnosis of acute mesenteric ischemia among intensive care unit (ICU) patients continues to be difficult and carries high mortality, and yet, it is essential that it be made expeditiously such that lifesaving operative intervention can be offered. A recent study suggested that computed tomography (CT) scan delays operative intervention. Thus, we hypothesized that diagnostic peritoneal lavage (DPL), a rapidly performed bedside procedure of established high sensitivity, is associated with reduced operative intervention, time to operative intervention, and mortality.

METHODS

We performed a single-institution, retrospective study of 120 patients admitted to an ICU at the University of Pittsburgh Medical Center's Presbyterian Hospital between January 1, 2002, and December 31, 2010, who were diagnosed with acute mesenteric ischemia. We defined a DPL of greater than 500 cells per cubic millimeter as diagnostic of intra-abdominal pathology. CT scan results were categorized as (1) diagnostic of mesenteric ischemia, (2) abnormal, or (3) normal. We performed multivariate logistic regression, adjusting for difference in case mix, to determine whether DPL is associated with the outcomes of mortality and operative intervention.

RESULTS

The cohort was severely ill, with a mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 21.7 (range, 0-48), and 51 patients (42.5%) died. The distribution of preoperative evaluation is as follows: CT, 67; DPL, 11; both modalities, 18; and no preoperative evaluation, 24. Those undergoing DPL were more severely ill, as evidenced by significantly higher APACHE II scores. By comparison with CT, DPL was associated with a reduced risk for operation intervention (adjusted odds ratio, 0.04; 95% confidence interval, 0.01-0.32; p = 0.002) and mortality (adjusted odds ratio, 0.09; 95% confidence interval, 0.01-0.62; p = 0.02).

CONCLUSION

DPL is associated with reduced operative intervention yet improved survival, when compared with patients evaluated with either CT or no diagnostic modality. These data support that, for critically ill ICU patients suspected of harboring intra-abdominal pathology such as acute mesenteric ischemia, DPL should be a mainstay in the preoperative diagnostic evaluation. Further investigation is needed, however, to better define the proper place and timing of DPL in evaluating the acute abdomen.

LEVEL OF EVIDENCE

Diagnostic study, level III; therapeutic/care management study, level IV.

Cangrelor: an emerging therapeutic option for patients with coronary artery disease

OBJECTIVES

To perform a systematic up-to-date review and critical discussion of potential clinical applications of cangrelor based on its pharmacologic properties and the main findings from randomized clinical studies.

METHODS

A database search (PubMed, CENTRAL and Google Scholar) by two independent investigators, including proceedings from scientific sessions of ACC, AHA, ESC, TCT and EuroPCR, from January 1998 through December 2013.

RESULTS

Cangrelor is a potent, intravenous, direct-acting P2Y12 antagonist with rapid onset and quickly reversible action. In contrast to ticagrelor, cangrelor's interaction with thienopiridines requires termination of cangrelor infusion before switching to clopidogrel or prasugrel. According to randomized trials, a cangrelor-clopidogrel combination is relatively safe and more effective than the standard clopidogrel regimen in both urgent and elective percutaneous coronary intervention (PCI) settings, with the advantage of this drug combination fully evident when the universal definition of myocardial infarction is applied. In contrast to available antiplatelet drugs with delayed onset and offset of action, its favorable properties make cangrelor a desirable agent for ad hoc elective PCI, high risk acute coronary syndromes treated with immediate coronary stenting and for bridging those surgery patients who require periprocedural P2Y12 inhibition. Current evidence on cangrelor therapy is limited by the lack of adequately powered studies assessing cangrelor co-administration either with prasugrel or ticagrelor, suboptimal design of some of the trials favoring cangrelor, potentially attenuated benefits with modern stent design, and finally, by the lack of survival advantage.

CONCLUSIONS

With its pharmacokinetic and pharmacodynamic advantages, allowing consistent and strong P2Y12 inhibition, and with its rapid onset and swift reversal of action devoid of need for an antidote, cangrelor might improve clinical outcomes in clopidogrel-treated patients by reducing ischemic events, while maintaining a favorable safety profile. However, further studies, addressing the safety and efficacy of cangrelor on top of novel oral P2Y12 inhibitors, are warranted.

[Acute mesenteric ischemia: analysis of cases over a ten-years period (2001-2010)]

Acute mesenteric ischemia is a rare disorder; it occurs on average of 0.4% of acute surgery cases. Its diagnosis is often difficult because of the poor symptoms, and mortality of the patients is still as high as 70-90%.

AIMS

The aims of the study were to assess the importance of time factor that may influence the outcome and to find out whether it is possible to decrease the high mortality rate in this disease.

METHOD

Among patients admitted to Saint Pantaleon Hospital in Hungary between January 2001 and December 2010, patients whose surgery or autopsy findings confirmed intestinal necrosis were analyzed. A total of 114 patients with acute mesenteric ischemia were included in the study.

RESULTS

55% of the patients had typical symptoms. 43.8% of the patients underwent surgery and among these patients the mortality rate was 70% despite surgical intervention. The survival rate was 72.3% when surgery was performed within less than 12 hours after the onset of symptoms, but only 20% of patients survived when surgery was delayed between 24 and 48 hours after the onset of symptoms.

CONCLUSION

With early diagnosis and intervention, patients with acute mesenteric ischemia may have a better a chance to survive.

Prevention and Treatment of Gastrointestinal Complications in Patients on Mechanical Ventilation

There exists a complex, dynamic interaction between mechanical ventilation and the splanchnic vasculature that contributes to a myriad of gastrointestinal tract complications that arise during critical illness. Positive pressure-induced splanchnic hypoperfusion appears to play a pivotal role in the pathogenesis of these complications, the most prevalent of which are stress-related mucosal damage, gastrointestinal hypomotility and diarrhea. Furthermore, characteristics of the splanchnic vasculature make the gastrointestinal tract vulnerable to adverse effects related to positive pressure ventilation. While most of these complications seen in mechanically ventilated patients are reflections of altered gastrointestinal physiology, some may be attributed to medical interventions instituted to treat critical illness. Since maintenance of normal hemodynamics cannot always be achieved, pharmacologic prophylactic therapy has become a mainstay in the prevention of gastrointestinal complications in the intensive care unit. Improved understanding of the systemic effects of mechanical ventilation and greater application of lung-protective ventilatory strategies may potentially minimize positive pressure-induced reductions in splanchnic perfusion, systemic cytokine release and, consequently, reduce the incidence of gastrointestinal complications associated with mechanical ventilation. Herein, we discuss the pathophysiology of gastrointestinal complications associated with mechanical ventilation, summarize the most prevalent complications and focus on preventive strategies and available treatment options for these complications. The most common causes of gastrointestinal hemorrhage in mechanically ventilated patients are bleeding from stress-related mucosal damage and erosive esophagitis. In general, histamine H(2) receptor antagonists and proton pump inhibitors prevent stress-related mucosal disease by raising the gastric fluid pH. Proton pump inhibitors tend to provide more consistent pH control than histamine H(2) receptor antagonists. There is no consensus on the drug of choice for stress ulcer prophylaxis with several meta-analyses providing conflicting results on the superiority of any medication. Prevention of erosive esophagitis include careful use of nasogastric tubes and institution of strategies that improve gastric emptying. Many mechanically ventilated patients have gastrointestinal hypomotility and diarrhea. Treatment options for gastrointestinal motility are limited, thus, preventive measures such as correction of electrolyte abnormalities and avoidance of medications that impair gastrointestinal motility are crucial. Treatment of diarrhea depends on the underlying cause. When associated with Clostridium difficile infection antibacterial therapy should be discontinued, if possible, and treatment with oral metronidazole should be initiated.More studies are warranted to better understand the systemic effects of mechanical ventilation on the gastrointestinal tract and to investigate the impact of lung protective ventilatory strategies on gastrointestinal complications.

Circulating intestinal fatty acid-binding protein as an early marker of intestinal necrosis after aortic surgery: a prospective observational cohort study

OBJECTIVE

This study evaluated the usefulness of plasma intestinal fatty-acid binding protein (IFABP) levels in the early identification of intestinal necrosis (IN) in patients undergoing different types of aortic surgery.

BACKGROUND

Intestinal compromise greatly contributes to postoperative adverse outcome. IN is the most detrimental form of intestinal compromise and is notoriously difficult to diagnose. IFABP is a small protein exclusively expressed by mature enterocytes and a promising marker of intestinal damage.

METHODS

Plasma IFABP concentrations were measured in blood samples taken perioperatively from 55 patients undergoing open thoracic or thoracoabdominal aneurysm repair [OR-TAA(A)], 25 patients undergoing conventional open abdominal aneurysm repair (OR-abdominal aortic aneurysm [AAA]), and 16 patients undergoing endovascular aneurysm repair (EVAR). Data were compared with perioperative changes in arterial pH and serum lactate levels.

RESULTS

IFABP levels increased in all patients undergoing OR-TAA(A) and OR-AAA reaching peak levels shortly after surgery; 281 ± 33 to 2,298 ± 490 pg/mL (P < 0.001) and 187 ± 31 to 641 ± 176 pg/mL (P < 0.05) respectively. IFABP levels were significantly higher in patients undergoing OR-TAA(A) (P < 0.001). IFABP levels in EVAR patients remained at baseline concentrations throughout the study. Four patients [2 OR-AAA, 2 OR-TAA(A)] developed fatal postoperative intestinal ischemia on day 2 or 3. High levels of plasma IFABP at the end of surgery had 100% sensitivity and 98.1% specificity for the identification of patients developing IN. In OR-AAA patients, arterial pH and lactate levels were of additional discriminating value. Complete discrimination between patients with and without IN using plasma IFABP could be made on the first postoperative day.

CONCLUSIONS

Analysis of plasma IFABP levels is of additional value to other current plasma markers in the diagnosis of IN, and it enables early identification of patients with IN after aortic surgery days before clinical diagnosis.

Intestinal ischemia

Ischemic changes of the abdominal organs are crucial since they develop slowly and are therefore often diagnosed at a late stage. Due to this general aspect, mortality from this disease could not be significantly reduced over the last decade. One of the main causes of these high mortality rates is the insufficient integration of the overall clinical picture into the diagnostic work-up. Acute mesenteric ischemia should be differentiated from chronic visceral ischemia. Acute intestinal ischemia is a vascular emergency with a mortality rate of 60-80%. The incidence of chronic visceral vascular disorders accounts for approximately 1-2% of all abdominal conditions and has to be differentiated from the acute form, since intestinal ischemia has a progressive nature and usually is related to general atherosclerotic disease. Therefore, this condition is associated with an increase of arteriosclerotic-related multimorbidity in an increasingly elderly population. Due to excellent collateralization, extensive chronic occlusion processes affecting the visceral arteries can be asymptomatically treated on a long-term basis.

[Diagnosis and management of acute mesenteric ischemia]

The prevalence of significant splanchnic arterial stenoses is increasing, but remains mostly asymptomatic due to abundant collateral circulation. Acute insufficiency of mesenteric arterial blood flow accounts for 60 to 70% of cases of mesenteric ischemia and results mostly from a superior mesenteric embolus. Despite major advances have been achieved in understanding the pathogenic mechanisms of bowel ischemia, its prognosis remains dismal with mortality rates about 60%. The diagnosis of acute mesenteric ischemia depends upon a high clinical suspicion, especially in patients with known risk factors. Rapid diagnosis is essential to prevent intestinal infarction. However, early signs and symptoms of mesenteric ischemia are non specific, and definitive diagnosis often requires radiologic examinations. Early and liberal implementation of angiography has been the major advance over the past 30 years which allowed increasing diagnostic accuracy of acute mesenteric ischemia. CT and MR-based angiographic techniques have emerged as alternatives less invasive and more accurate to analyse splanchnic vessels and evaluate bowel infarction. The goal of treatment of patients with acute mesenteric ischemia is to restore intestinal oxygenation as quickly as possible after initial management that includes rapid hemodynamic monitoring and support. Surgery should not be delayed in patients suspected of having intestinal necrosis.

A Wolf in Sheep's Clothing: A Case of Dilated Cardiomyopathy Presenting with Nonspecific Digestive Symptoms: Insights into Nonocclusive Mesenteric Ischemia

We report on a 32-year-old male patient who presented to the emergency room for abdominal pain associated with nausea and vomiting. The patient experienced these symptoms for the last 3 months and was taken in charge on an outpatient basis. Assessment in the emergency room showed hemodynamic collapse, there were no signs of acute surgical abdomen. Emergent cardiac echogram showed severely dilated hypokinetic cardiomyopathy. The diagnosis of acute heart failure associated with nonocclusive mesenteric ischemia was retained. A review of the pertinent literature is presented.

The Unusual Suspect: A Case of Non-occlusive Mesenteric Ischemia in a Patient With Cirrhosis

Acute mesenteric ischemia has a variety of etiologies. Non-occulusive mesenteric ischemia accounts for 20-30% of patients with acute mesenteric ischemia. We describe a case of non-occulusive jejunal ischemia leading to infarction that occurred in a patient with cirrhosis and no previous history of cardiovascular disease.

Effects of different peep levels on mesenteric leukocyte-endothelial interactions in rats during mechanical ventilation

INTRODUCTION

Mechanical ventilation with positive end expiratory pressure (PEEP) improves oxygenation and treats acute pulmonary failure. However, increased intrathoracic pressure may cause regional blood flow alterations that may contribute to mesenteric ischemia and gastrointestinal failure. We investigated the effects of different PEEP levels on mesenteric leukocyte-endothelial interactions.

METHODS

Forty-four male Wistar rats were initially anesthetized (Pentobarbital I.P. 50 mg/kg) and randomly assigned to one of the following groups: 1) NAIVE (only anesthesia; n=9), 2) PEEP 0 (PEEP of 0 cmH2O, n=13), 3) PEEP 5 (PEEP of 5 cmH2O, n=12), and 4) PEEP 10 (PEEP of 10 cmH2O, n=13). Positive end expiratory pressure groups were tracheostomized and mechanically ventilated with a tidal volume of 10 mL/kg, respiratory rate of 70 rpm, and inspired oxygen fraction of 1. Animals were maintained under isoflurane anesthesia. After two hours, laparotomy was performed, and leukocyte-endothelial interactions were evaluated by intravital microscopy.

RESULTS

No significant changes were observed in mean arterial blood pressure among groups during the study. Tracheal peak pressure was smaller in PEEP 5 compared with PEEP 0 and PEEP 10 groups (11, 15, and 16 cmH2O, respectively; p<0.05). After two hours of MV, there were no differences among NAIVE, PEEP 0 and PEEP 5 groups in the number of rollers (118+/-9,127+/-14 and 147+/-26 cells/10 minutes, respectively), adherent leukocytes (3+/-1,3+/-1 and 4+/-2 cells/100 microm venule length, respectively), and migrated leukocytes (2+/-1,2+/-1 and 2+/-1 cells/5,000 microm(2), respectively) at the mesentery. However, the PEEP 10 group exhibited an increase in the number of rolling, adherent and migrated leukocytes (188+/-15 cells / 10 min, 8+/-1 cells / 100 microm and 12+/-1 cells / 5,000 microm(2), respectively; p<0.05).

CONCLUSIONS

High intrathoracic pressure was harmful to mesenteric microcirculation in the experimental model of rats with normal lungs and stable systemic blood pressure, a finding that may have relevance for complications related to mechanical ventilation.

A novel approach for percutaneous treatment of massive nonocclusive mesenteric ischemia: tolazoline and glycerol trinitrate as effective local vasodilators

Nonocclusive mesenteric ischemia (NOMI) generally affects patients with low cardiac output, resulting in splanchnic hypoperfusion. It includes all forms of mesenteric ischemia without vessel occlusion and makes up between 20 and 30% of all cases of acute mesenteric ischemia. We present the case of a 84-year-old man with a history of total atrioventricular block developing NOMI. This was diagnosed by percutaneous selective catheter arteriography (PSCA), which demonstrated remarkable abrupt termination of the jejunal vasculature and multiple severe spasms of the colonic arteries. Control PSCA after local intraarterial vasodilator therapy (LIVT) with tolazoline and glycerol trinitrate documented an excellent therapeutic result with a completely unremarkable vasculature. Although LIVT was complicated by severe cardiovascular complications inclusive of cardiac arrest with the need of cardiopulmonary resuscitation, the patient fully recovered and was discharged after implantation of a cardiac pacemaker in good clinical condition 7 days later.

Mesenteric ischemia: still a deadly puzzle for the medical community

The main goal of this article is to update etiology, epidemiology, diagnosis, treatment and outcome of the various causes of mesenteric ischemia in order to elucidate its labyrinthine clinical riddle, by reviewing the current English medical literature. Mesenteric ischemia is a quite uncommon disorder, observed in the emergency department. It is a life-threatening vascular emergency that requires early diagnosis and intervention to restore mesenteric blood flow and to prevent bowel necrosis and patient death. Consequently, it is a vital diagnosis to make because of its high mortality rate and its thorny complications. The underlying causes vary, and the prognosis depends on the specific findings during clinical examination. Vague and nonspecific clinical findings and limitations of diagnostic studies make the diagnosis a significant challenge. The prognosis of acute mesenteric ischemia of any type is grave. The complications following this medical jigsaw puzzle are also severe. Patients in whom the diagnosis is missed until infarction occurs have a mortality rate of 90%. Even with good treatment, up to 50-80% of patients die. Survivors of extensive bowel resection face lifelong disability. Despite the progress in understanding the pathogenesis of mesenteric ischemia and the development of treatment modalities, the entity remains a diagnostic challenge for clinicians. Delay in diagnosis contributes to a high mortality rate. Early diagnosis and adequate treatment can improve the clinical outcome. Even if diagnostic modalities have improved since the first successful attempts to confront effectively this clinical entity, mesenteric ischemia still remains a lethal diagnostic enigma for the medical community.

Gastrointestinal disorders in elderly patients

Gastrointestinal disorders are common in elderly patients, and the clinical presentation, complications, and management may differ from those in younger patient. Most impairment occurs in the proximal and distal tract of the gastrointestinal system. Swallowing abnormalities with a wide span of symptoms and pelvic floor pathologies involving all the pelvic compartments are common. Acute abdomen, often from small bowel obstruction or mesenteric ischemia, can pose a diagnostic challenge, because a mild clinical presentation may hide serious visceral involvement. In this setting, the radiologist often is asked to suggest the appropriate management options and to guide the management.

Acute mesenteric ischemia after cardio-pulmonary bypass surgery

Acute mesenteric ischemia (AMI) is a highly-lethal surgical emergency. Several pathophysiologic events (arterial obstruction, venous thrombosis and diffuse vasospasm) lead to a sudden decrease in mesenteric blood flow. Ischemia/reperfusion syndrome of the intestine is responsible for systemic abnormalities, leading to multi-organ failure and death. Early diagnosis is difficult because the clinical presentation is subtle, and the biological and radiological diagnostic tools lack sensitivity and specificity. Therapeutic options vary from conservative resuscitation, medical treatment, endovascular techniques and surgical resection and revascularization. A high index of suspicion is required for diagnosis, and prompt treatment is the only hope of reducing the mortality rate. Studies are in progress to provide more accurate diagnostic tools for early diagnosis. AMI can complicate the post-operative course of patients following cardio-pulmonary bypass (CPB). Several factors contribute to the systemic hypo-perfusion state, which is the most frequent pathophysiologic event. In this particular setting, the clinical presentation of AMI can be misleading, while the laboratory and radiological diagnostic tests often produce inconclusive results. The management strategies are controversial, but early treatment is critical for saving lives. Based on the experience of our team, we consider prompt exploratory laparotomy, irrespective of the results of the diagnostic tests, is the only way to provide objective assessment and adequate treatment, leading to dramatic reduction in the mortality rate.

Computed tomographic imaging findings of bowel ischemia

LEARNING OBJECTIVES

Learning objectives of this paper are to review and to summarize the pathogenesis of bowel ischemia and to describe its clinical, pathological, and radiological manifestations.

BACKGROUND

Bowel ischemia is a common disorder produced by several causes, and it shows various clinical presentations connected with an high mortality. With the increase in average life expectancy, bowel ischemia represents one of the most threatening abdominal conditions in elderly patients. In the last decade, computed tomography has tremendously altered the diagnostic approach to bowel ischemia also influencing the therapeutic approach in the current practice.

IMAGING FINDINGS

Computed tomographic imaging findings include bowel wall thickening, portal venous gas, intramural pneumatosis, engorgement of mesenteric veins, loss or increase of bowel wall enhancement, and infarction of other abdominal organs.

CONCLUSIONS

Bowel ischemia shows a broad spectrum of radiological manifestations, and regardless of the primary causes, it produces similar radiological features. Bowel ischemia may simulate cancer or inflammatory conditions; so it is a mandatory tight integration between radiological and clinical signs.