Intestinal ischemia: current treatment concepts

Optimizing Outcomes for Acute Mesenteric Ischemia in the Context of Hypogammaglobulinemia: A Detailed Analysis of Surgical and Medical Strategies

Acute mesenteric ischemia is a critical condition marked by a sudden loss of blood supply to the intestines, often leading to rapid tissue necrosis and severe clinical outcomes if untreated. In the context of hypogammaglobulinemia, an immunodeficiency characterized by decreased levels of immunoglobulins, this vascular emergency becomes even more daunting. Hypogammaglobulinemia can impair the immune system's response to both infection and ischemic injury, intensifying the severity of intestinal damage. This report describes the case of a 52-year-old female with hypogammaglobulinemia who presented with severe abdominal pain. Surgical exploration revealed 100 cm of necrotic small bowel extending from 150 cm distal to the ligament of Treitz to within 10 cm of the ileocecal valve. The necrotic section was surgically removed, and primary anastomosis was performed. This instance highlights the significant impact of immunodeficiency on the progression and management of acute mesenteric ischemia, demonstrating the critical need for early intervention and tailored management strategies, especially in immunocompromised patients, to prevent severe outcomes. The case illuminates the importance of recognizing immunodeficiency as a complicating factor in acute gastrointestinal emergencies, stressing the necessity for prompt and effective medical and surgical interventions to improve prognosis and patient outcomes in complex clinical scenarios.

Prognostic Factors for Mortality in Acute Mesenteric Ischemia

Postoperative mortality in patients undergoing surgical and/or interventional treatment for acute mesenteric ischemia (AMI) has remained an unsolved problem in recent decades. Here, we investigated clinical predictors of postoperative mortality in a large European cohort of patients undergoing treatment for AMI. In total, 179 patients who underwent surgical and/or interventional treatment for AMI between 2009 and 2021 at our institution were included in this analysis. Associations between postoperative mortality and various clinical variables were assessed using univariate and multivariable binary logistic regression analysis. Most of the patients were diagnosed with arterial ischemia (AI; n = 104), while venous ischemia (VI; n = 21) and non-occlusive mesenteric ischemia (NOMI; n = 54) were present in a subset of patients. Overall inhouse mortality was 55.9% (100/179). Multivariable analyses identified leukocytes (HR = 1.08; p = 0.008), lactate (HR = 1.25; p = 0.01), bilirubin (HR = 2.05; p = 0.045), creatinine (HR = 1.48; p = 0.039), etiology (AI, VI or NOMI; p = 0.038) and portomesenteric vein gas (PMVG; HR = 23.02; p = 0.012) as independent predictors of postoperative mortality. In a subanalysis excluding patients with fatal prognosis at the first surgical exploration (n = 24), leukocytes (HR = 1.09; p = 0.004), lactate (HR = 1.27; p = 0.003), etiology (AI, VI or NOMI; p = 0.006), PMVG (HR = 17.02; p = 0.018) and intraoperative FFP transfusion (HR = 4.4; p = 0.025) were determined as independent predictors of postoperative mortality. Further, the risk of fatal outcome changed disproportionally with increased preoperative lactate values. The clinical outcome of patients with AMI was determined using a combination of pre- and intraoperative clinical and radiological characteristics. Serum lactate appears to be of major clinical importance as the risk of fatal outcome increases significantly with higher lactate values.

Clinical characteristics and outcome of patients with acute mesenteric ischemia: a retrospective cohort analysis

BACKGROUND

Acute mesenteric ischemia (AMI) is an uncommon, but life-threatening clinical entity due to late diagnosis resulting in irreversible ischemic bowel necrosis. The most common causes of AMI are the embolic occlusion and the acute thrombosis of the mesenteric circulation. Typical treatment is composed of an early revascularization of the mesenteric circulation followed by abdominal surgery for resection of nonviable intestine and restoration of the intestinal continuity, but the mortality rates remain high.

METHODS

A retrospective cohort analysis was conducted, aiming to evaluate clinical characteristics, performed surgical procedures and outcomes of patients with acute mesenteric ischemia who underwent emergency abdominal surgery at a high volume surgical center in Germany.

RESULTS

Overall, 53 patients were identified with the intraoperatively proven diagnosis of AMI. Overall hospital mortality was with 62% comparable to the literature. Nineteen patients presented with an intraoperatively verified complete and non-reversible intestinal infarction without any angiographic or surgical option for a revascularization of the mesenteric circulation or an option for intestinal resection. From the rest of the patients, 14 underwent intestinal resection of the ischemic area without restoration of intestinal continuity; the other 20 underwent resection with a primary anastomosis to restore intestinal continuity. The mortality rate of these patients with curative-intended surgery remained high (41% of patients died). Pre- and postoperative hyperlactatemia were associated with lower survival of these patients.

CONCLUSION

AMI remains a life-threatening abdominal emergency. Therapeutic approaches are highly depended on acting surgeon's decision, being affected by subjectively rated bowel viability and physical condition of the affected patient. Only selected patients with good bowel viability appear to be suitable for receiving primary anastomosis. The results clearly indicate the need for further research to develop therapeutic approaches for a better management of AMI and to improve outcome of affected patients.

Intraoperative quality assessment of tissue perfusion with indocyanine green (ICG) in a porcine model of mesenteric ischemia

Background

Mesenteric ischemia is a severe and potentially lethal event. Assessment of intestine perfusion is eminently depending on the skills, and the experience of the surgeon. Thus, the therapy is biased by the right evaluation. Aim of this study is to determine the applicability, and the usefulness of fluorescent-imaging (FI) with indocyanine green (ICG) in a porcine model of mesenteric ischemia. Second end-point is the verification of a visual and quantitative assessment tool of the intestinal perfusion.

Methods

In 18 pigs (54,2 ±2,9kg) an occlusion of a side-branch of the mesenteric artery was performed for 3 (group I, n = 7), 6 (group II, n = 7), and 10 hours (group III, n = 4). After reperfusion a 60 minutes observation period was carried out. 3 regions of interest were defined: ischemic bowel (D1), transitional zone (D2), and non-ischemic bowel (D3). ICG-FI was performed during baseline (T0), occlusion (T1), reperfusion (T2) and after an observation period of 60 minutes (T4).

Results

All experiments could be finished successfully. ICG-FI was assessed using assessment of background-subtracted peak fluorescence intensity (BSFI), slope of fluorescence intensity (SFI), and a baseline adjusted ratio of both parameters. ICG-FI confirmed loss of perfusion in D1, decreased perfusion in D2, and increased perfusion in D3. After reperfusion ICG-FI increased in group 2 due to a severe tissue damage resulting in a capillary leakage. In group I ICG-FI was equal to baseline values indicating the totally reversible loss of perfusion.

Conclusion

Using ICG-FI to estimate intestine perfusion after different durations of ischemia is viable using a porcine model of mesenteric ischemia. Even small differences in perfusion can be reliably determined by ICG-FI. Thus, ICG-FI is an encouraging method to evaluate intestine perfusion intraoperatively.

Interdisciplinary Management of Visceral Artery Aneurysms and Visceral Artery Pseudoaneurysms

The paper presents the results of treating 14 patients, namely eight patients with visceral artery aneurysms and six patients with visceral artery pseudoaneurysms. In 64.3% of the patients, the initial diagnosis was made based on the ultrasound examination. All the patients (100%) underwent CT angiography, while angiography was performed in 71.4% of the cases. Five (35.7%) patients with visceral artery pseudoaneurysms were emergently hospitalized; among them, the signs of bleeding were observed in 2 patients. In 9 patients, pathology was detected during tests for other conditions. Five (35.7%) patients underwent endovascular treatment, while 9 (64.3%) patients received surgical treatment. Endovascular interventions and open surgery demonstrated a nil mortality rate. After endovascular treatment, stent thrombosis was found in 1 patient. In the case of surgical treatment, visceral artery aneurysm was observed in 1 patient who underwent the resection of superior mesenteric artery pseudoaneurysm. Conclusions. The choice of the method of treating visceral artery aneurysms and visceral artery pseudoaneurysms depends on the location, size, anatomic features of the visceral arteries and the clinical course of the disease. Both endovascular and surgical treatment demonstrate good postoperative outcomes. Visceral ischemia is one of the most serious complications in the postoperative period, which can complicate both the diagnosis and the choice of treatment tactics.

Approaches for designing and discovering purinergic drugs for gastrointestinal diseases

INTRODUCTION

Purines finely modulate physiological motor, secretory, and sensory functions in the gastrointestinal tract. Their activity is mediated by the purinergic signaling machinery, including receptors and enzymes regulating their synthesis, release, and degradation. Several gastrointestinal dysfunctions are characterized by alterations affecting the purinergic system.

AREAS COVERED

The authors provide an overview on the purinergic receptor signaling machinery, the molecules and proteins involved, and a summary of medicinal chemistry efforts aimed at developing novel compounds able to modulate the activity of each player involved in this machinery. The involvement of purinergic signaling in gastrointestinal motor, secretory, and sensory functions and dysfunctions, and the potential therapeutic applications of purinergic signaling modulators, are then described.

EXPERT OPINION

A number of preclinical and clinical studies demonstrate that the pharmacological manipulation of purinergic signaling represents a viable way to counteract several gastrointestinal diseases. At present, the paucity of purinergic therapies is related to the lack of receptor-subtype-specific agonists and antagonists that are effective in vivo. In this regard, the development of novel therapeutic strategies should be focused to include tools able to control the P1 and P2 receptor expression as well as modulators of the breakdown or transport of purines.

Improved mortality in treatment of patients with endovascular interventions for chronic mesenteric ischemia

OBJECTIVE

Chronic mesenteric ischemia (CMI) continues to be a devastating diagnosis. There is a national trend toward increased use of endovascular procedures with improved survival for the treatment of these patients. Our aim was to evaluate whether this trend has changed CMI patients' length of hospitalization and health care cost.

METHODS

We identified all patients admitted for CMI from the National Inpatient Sample (NIS) from 2000 to 2014. Our primary end points included length of hospital stay (LOS) and cost of hospitalization (COH). Our secondary end points included mortality assessment of the CMI hospitalization.

RESULTS

There were 15,475 patients admitted for CMI. The mean age of patients was 71 years, and 4022 (26.0%) were male. There were 10,920 (70.6%) patients treated endovascularly (ENDO) and 4555 (29.4%) patients treated in an open fashion (OPEN). Although a higher proportion of patients in the ENDO (43.3%) group vs OPEN (33.1%) had a Charlson Comorbidity Index score of ≥2 (P < .0001), they had a lower mortality rate (2.4% vs 8.7%; P < .0001), lower mean LOS (6.3 vs 14.0 days; P < .0001), and lower COH ($21,686 vs $42,974; P < .0001). After adjusting for clinical and hospital factors, OPEN continued to demonstrate higher mortality than ENDO (odds ratio, 7.2; 95% confidence interval, 4.9-10.6; P < .0001), longer LOS (mean, +9.7 days; P < .0001), and higher COH (mean, +$25,834; P < .0001).

CONCLUSIONS

The rate of ENDO continues to rise nationally in the treatment of CMI patients. After adjusting for clinical and hospital factors, patients in the ENDO group tend to have lower in-hospital mortality of 2.4% and lower LOS by 10 days, and they incur a cost saving of >$25,000 compared with patients in the OPEN group. ENDO should be considered first line of therapy for patients with CMI.

Selection and Determination of Treatment for the Spontaneous Isolated Dissection of the Superior Mesenteric Artery

Objective: This study aimed to clarify the selection and determination of appropriate treatment for acute symptomatic spontaneous isolated dissection of the superior mesenteric artery (SIDSMA). Methods: Data from 10 consecutive patients, who were diagnosed with symptomatic SIDSMA using computed tomography angiography and were managed in our hospital from January 2010 to October 2015, were retrospectively collected and analyzed. Results: There were nine males and one female; mean patient age was 50.3 (range, 35-64) years. All patients experienced acute abdominal pain, and three patients experienced concomitant vomiting. Only one patient exhibited symptoms of suspected peritonitis and intestinal ischemia. Three patients showed improved abdominal pain before admission to our hospital. One patient experienced severe abdominal pain that could not be managed using morphine; he underwent right external iliac to superior mesenteric artery bypass with a great saphenous vein graft. No patient presented with intestinal necrosis. All patients survived, and no patient developed complications during the follow-up period of up to 42 (24.5±16.5) months. Conclusion: Conservative management appears to be the most feasible treatment for SIDSMA. However, open surgery can be performed in patients presenting with any symptoms of intestinal ischemia.

Outcome of primary percutaneous stent-revascularization in patients with atherosclerotic acute mesenteric ischemia

Background Patients with acute mesenteric ischemia (AMI) often exhibit severe co-morbidities and significant surgical risks, leading to high perioperative morbidity. Purpose To investigate the feasibility of primary percutaneous stent-revascularization (PPSR) in atherosclerotic AMI and its impact on patients' outcome. Material and Methods Retrospective analysis of 19 consecutive patients (7 women, 12 men; median age, 69 years) with AMI caused by atherosclerotic, non-embolic stenoses/occlusions of the splanchnic arteries and PPSR. Alternative minimally invasive techniques were excluded. Clinical characteristics including the Charlson Comorbidity Index adjusted by age (CCIa) and symptom duration, technical and clinical success of PPSR, clinical course, 30-day mortality, and follow-up were evaluated and compared to literature data for surgical approaches. Technical success was defined as residual stenosis of <30% in diameter. Clinical success was defined as resolution of symptoms of AMI and/or normalization of serum lactate after sole PPSR. Results The majority of patients presented with severe co-morbidities (CCIa >4 in 17 of 19 patients, 89%). Median symptom duration was 50 h. Technical and clinical success rates of PPSR were 95% (21 of 22 arteries) and 53% (10 of 19 patients). Seven patients underwent subsequent laparotomy with bowel resection in four cases. Thirty-day mortality was 42% (8 of 19 patients). Conclusion In our study population of patients with atherosclerotic AMI, severe co-morbidities, prolonged acute symptoms, and significant perioperative risks PPSR of splanchnic stenoses were technically feasible and the clinical outcome was acceptable.

Bladder Pneumatosis From a Catastrophic Vascular Event

Air within the bladder wall, or bladder pneumatosis, is a very rare finding typically resulting from an infectious etiology, as in emphysematous cystitis (EC). However, there have been reports of bladder pneumatosis occurring without clear infectious origins. We present a case of a female patient found to have concurrent bladder and ileal pneumatosis secondary to a catastrophic vascular event. Prompt recognition of non-infectious etiologies of bladder pneumatosis is essential as this distinction may dramatically alter clinical decision-making.

Mesenteric Ischemia

Acute mesenteric ischemia (AMI) is a rare disease that most commonly affects the elderly. The vague symptoms often lead to delayed diagnosis and consequent high mortality. Physical exam and laboratory findings lack the sensitivity and specificity to exclude AMI, but computed tomography angiography can rapidly and accurately confirm the diagnosis. Survival improves with prompt restoration of perfusion and resection of nonviable bowel. Advances in imaging, operative techniques, and critical care have led to a steady decline in overall mortality; however, long-term survival is limited because of the comorbidities in this patient group.

Long-term prognosis and a prediction model for acute bowel ischaemia following cardiac surgery

OBJECTIVES

Bowel ischaemia following cardiac surgery is associated with a high postoperative mortality. No scoring system exists as yet to predict this complication following surgery. In addition, the long-term survival is not known. We sought to evaluate in-hospital outcomes and long-term outcomes in bowel ischaemia following cardiac surgery. We also sought to devise a simple risk prediction model for this catastrophic entity.

METHODS

This was a retrospective study of data entered prospectively into our cardiac surgical database between July 1999 and May 2014. We compared the short- and long-term outcomes of patients who developed bowel ischaemia following cardiac surgery with those who did not develop bowel ischaemia using propensity-matched analysis. We developed a prediction model for bowel ischaemia from logistic regression.

RESULTS

In total, 13 853 patients underwent cardiac surgery. Of these, 85 had confirmed bowel ischaemia following surgery. The in-hospital mortality rate for those with bowel ischaemia was 60%, while in those without bowel ischaemia, the mortality rate was 3% (P < 0.0001). In those bowel ischaemia patients who had a laparotomy for corrective surgery, the in-hospital mortality was significantly less compared with those who did not have a laparotomy (39.2 vs 91.2%, P < 0.0001). The long-term survival for bowel ischaemia at 2, 6 and 10 years was 35% (±5), 31% (±5) and 26% (+/6), respectively. Multivariable analysis revealed that advanced age at surgery, peripheral vascular disease, intra-aortic balloon pump usage, NYHA IV and postoperative atrial fibrillation were the significant (P < 0.005) determinants of developing postoperative bowel ischaemia. We developed a model to predict bowel ischaemia and validated it within our population (c-index = 0.781).

CONCLUSIONS

We have shown that whilst bowel ischaemia carries a higher short-term mortality, the long-term mortality is not significantly greater for those few who survive to discharge. We have developed a simple prediction model to identify those at high risk of developing bowel ischaemia following cardiac surgery in order to optimize perioperative strategies in future.

The effectiveness of gastric tonometry in the diagnosis of acute mesenteric ischemia in cases where a contrast-enhanced computed tomography cannot be obtained

OBJECTIVE

The aim of the study was to evaluate the effectiveness of gastric tonometry in the diagnosis of acute mesenteric ischemia in cases where a contrast-enhanced computed tomography cannot be obtained.

MATERIAL AND METHODS

The gastric pH (pHi) and gastric CO2 (gpCO2) were measured with gastric tonometry catheter, preoperatively and postoperatively at 24 hours, in patients with suspicion of acute mesenteric ischemia. Simultaneous evaluation of blood gases and blood lactate levels were performed. Patients were divided into two groups after surgery. Group 1 included patients with mesenteric ischemia, and Group 2 consisted of patients without mesenteric ischemia.

RESULTS

Forty-two patients (26 males, 16 females) were evaluated. The mean age was 61.4±13.3 years. There was no significant difference between the groups in terms of demographic factors and co-morbid diseases. There were no significant differences between groups in terms of pHi and gpCO2 levels (7.24±0.2 and -3±12.0 in Group 1, 7.18±0.06 and -3±1.9 in Group 2, respectively), intra-abdominal pressure, lactate levels, and survival. Among all the study parameters, only arterial pH had statistical significance in the diagnosis of acute mesenteric ischemia (7.23±0.21 versus 7.35±0.07 for Groups 1 and 2, respectively,) (p<0.05).

CONCLUSION

Gastric tonometry is not a useful method in the early diagnosis of acute mesenteric ischemia.

The effect of melatonin on bacterial translocation following ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion

BACKGROUND

Acute mesenteric ischemia is a life-threatening vascular emergency resulting in tissue destruction due to ischemia-reperfusion injury. Melatonin, the primary hormone of the pineal gland, is a powerful scavenger of reactive oxygen species (ROS), including the hydroxyl and peroxyl radicals, as well as singlet oxygen, and nitric oxide. In this study, we aimed to investigate whether melatonin prevents harmful effects of superior mesenteric ischemia-reperfusion on intestinal tissues in rats.

METHODS

Rats were randomly divided into three groups, each having 10 animals. In group I, the superior mesenteric artery (SMA) was isolated but not occluded. In group II and group III, the SMA was occluded immediately distal to the aorta for 60 minutes. After that, the clamp was removed and the reperfusion period began. In group III, 30 minutes before the start of reperfusion, 10 mg/kg melatonin was administered intraperitonally. All animals were sacrified 24 hours after reperfusion. Tissue samples were collected to evaluate the I/R-induced intestinal injury and bacterial translocation (BT).

RESULTS

There was a statistically significant increase in myeloperoxidase activity, malondialdehyde levels and in the incidence of bacterial translocation in group II, along with a decrease in glutathione levels. These investigated parameters were found to be normalized in melatonin treated animals (group III).

CONCLUSION

We conclude that melatonin prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion.

Serum value of procalcitonin as a marker of intestinal damages: type, extension, and prognosis

BACKGROUND

Ischemic and necrotic damages are complications of digestive diseases and require emergency management. Nevertheless, the decision to surgically manage could be delayed because of no sufficiently preoperative accurate marker of ischemia diagnosis, extension, and prognosis.

METHODS

The aim of this study was to assess the predictive value of serum procalcitonin (PCT) levels for diagnosing intestinal necrotic damages, their extension, and their prognosis in patients with ischemic disease including ischemic colitis and mesenteric infarction by a gray zone approach. Between January 2007 to June 2014, 128 patients with ischemic colitis and mesenteric infarction (codes K55.0 and K51.9) were operated, for whom data on PCT were available. We perform a retrospective, multicenter review of their medical records. Patients were divided into subgroups: ischemia (ID group) versus necrosis (ND group); the extension [focal (FD) vs. extended (ED)] and the vital status [deceased (D) vs. alive (A)].

RESULTS

PCT levels were higher in the ND (n = 94; p = 0.009); ED (n = 100; p = 0.02); and D (n = 70; p = 0.0003) groups. With a gray zone approach, the predictive thresholds were (i) for necrosis 2.473 ng/mL, (ii) for extension 3.884 ng/mL, and (iii) for mortality 7.87 ng/mL.

CONCLUSION

In our population, PCT could be used as a marker of necrosis; especially in case of extended damages and reflects the patient's prognosis.

Procalcitonin and intestinal ischemia: A review of the literature

Intestinal ischemia is common after emergency gastrointestinal or cardiovascular surgery. At present, there are no diagnostic tools for the early diagnosis of intestinal ischemia. In the last decade, procalcitonin (PCT) has been suggested as a marker of this condition. Here, we review the use of PCT as a diagnostic tool for intestinal ischemia. Two reviewers independently searched the PubMed and EMBASE databases for articles on intestinal ischemia and PCT. They then considered (1) the criteria applicable to preclinical and clinical data; and (2) PCT’s predictive value in the diagnosis of intestinal ischemia. Article quality was rated according to the STAndards for Reporting of Diagnostic accuracy. Between 1993 and 2014, seven studies (including two preclinical studies and five clinical studies) dealt with the use of PCT to diagnose intestinal ischemia. Procalcitonin’s sensitivity, specificity, positive predictive value and negative predictive value ranged between 72% and 100%; 68% and 91%; 27% and 90% and 81% and 100%, respectively. The area under the receiver operating characteristic curve ranged from 0.77 to 0.92. In view of the preclinical and clinical data, we consider that PCT can be used in daily practice as a tool for diagnosing intestinal ischemia.

Emphysematous cystitis due to recurrent Clostridium difficile infection

A 78-year-old woman with long-standing obstipation presented herself to the hospital with diarrhoea and progressive abdominal cramping since 2 days. Acute abdomen developed and an emergency exploratory laparotomy was indicated, which showed no signs of bowel ischaemia. After admission to the internal ward, stool Clostridium difficile PCR was tested positive. Hence the diagnosis of pseudomembranous colitis became apparent. Abdominal imaging demonstrated multiple gas foci in the wall of the bladder and extensive pseudomembranous colitis. The patient was initially treated with oral vancomycin and secondarily with metronidazole for recurrent C. difficile infection. Resolution of diarrhoea and abdominal cramping was noted on 6-week follow-up visit.

D-dimer as an early marker of severity in patients with acute superior mesenteric venous thrombosis

No early serum marker of disease severity contributes to the treatment decision-making process of acute superior mesenteric venous thrombosis (ASMVT). This study aims to assess the value of serum D-dimer level in the first 3 days after admission as a severity marker of ASMVT patients. From May 2010 to June 2014, 50 consecutive patients of ASMVT were enrolled in this observational study. The serum D-dimer level was measured on a daily basis during the first 3 days after admission as well as other laboratory-testing parameters, clinical score, and outcome variables recorded during the same period. The maximum and mean D-dimer values were analyzed and compared with other potential markers for prediction of multiple-organ dysfunction syndrome (MODS) and short-bowel syndrome (SBS). The correlation of D-dimer level with other potential severity markers and inflammation parameters were also studied. Both maximum and mean D-dimer level during the first 3 days of admission were significantly higher in patients with several clinical variables such as death within 30 days, bowel resection, sepsis, abdominal compartment syndrome, MODS, and SBS. In addition, serum D-dimer level showed precise prediction for MODS and SBS, greater than L-lactate and intestinal-type fatty acid-binding protein (I-FABP). The D-dimer level was correlated well with L-lactate, I-FABP, and APACHE II score on the first 3 days of admission. Poor correlation of D-dimer level and inflammation parameters, white blood cell count, and C-reactive protein level, was detected. D-dimer level could be an effective, early, and specific serum marker indicating the clinical evolution and outcome of ASMVT.

The length of necrosis and renal insufficiency predict the outcome of acute mesenteric ischemia

BACKGROUND

Acute mesenteric ischemia (AMI) is a potentially life-threatening condition because of its diagnostic difficulty, operative challenges, and comorbidities a patient may have. The aim of this study was to identify factors associated with adverse outcomes in patients with AMI.

METHODS

The hospital records and clinical data of all patients with AMI were reviewed for a recent 4-year period. Clinical outcomes and factors influencing mortality were analyzed.

RESULTS

Included in the study were 104 patients (46 females and 58 males) with an overall mean age of 66 ± 13.4 years. The cause of AMI was arterial pathology in 74 (71%) patients, venous thrombosis in 15 (14%) patients, and nonocclusive ischemia in 12 (12%) patients. Abdominal pain was the most common presenting symptom (97% of patients). The 30-day mortality rate was 66%. Univariate analysis showed that mortality was associated with renal insufficiency (p = 0.004), an age greater than 70 years (p = 0.02), the presence of comorbidities (p = 0.001), a leukocyte count greater than 18,000/mL (p = 0.04), and small bowel necrosis of more than 100 cm (p < 0.0001). Logistic regression analysis showed that independent predictors of mortality were small bowel necrosis of more than 100 cm (p = 0.002) and a serum creatinine level greater than 2 mg/dL (p = 0.04).

CONCLUSION

The length of the necrosis and renal insufficiency are the primary factors that result in a poor outcome in AMI patients. Prompt diagnostic evaluation and early therapeutic interventions may help to prevent the development of these fatal predictors.

Investigating viability of intestine using spectroscopy: a pilot study

BACKGROUND

The differentiation of "viable" from "nonviable" bowel remains a challenge in the treatment of acute mesenteric ischemia. In this study, diffuse reflectance spectroscopy (DRS) was used to investigate the viability of bowel tissue after ischemia and reperfusion in an animal model in vivo and in real time.

METHODS

A total of 25 females Sprague-Dawley rats were divided into five groups based on different bowel ischemia times. In each study group for four of them, the superior mesenteric artery was occluded using a vascular clamp for a different period (i.e., 30, 45, 60, and 90 min; n = 5 for each group). Intestinal reperfusion was accomplished by releasing the clamps after the given occlusion period for each group. Spectra were acquired by gently touching the optical fiber probe to the bowel tissue before the induce ischemia, at the end of the induced ischemia, and after the reperfusion. The data acquired before the ischemia were used as a control group. Without occluding the superior mesenteric artery, the spectra were acquired on the bowel with the same time intervals of the experiments were used as a sham group (n = 5). Subsequently, the same bowel segments were sent for histopathologic examination.

RESULTS

Based on the correlation between the spectra acquired from the bowel segments and the results from the histopathologic investigation, DRS is able to differentiate the histopathologic grading that appears when the Chiu/Park score ≥5 (i.e., high-level ischemic injury) than Chiu/Park score <5. Eight out of nine low-level ischemic injury tissue samples were correctly defined using the spectroscopic classification system. All eleven high-level ischemic injury tissues that were histopathologically assigned grade 5 and above were correctly defined using the spectroscopic classification system in the ischemia-reperfusion groups.

CONCLUSIONS

DRS could potentially be used intraoperatively for the assessment of bowel viability in real time. These preliminary findings suggest that DRS has the potential to reduce unnecessary resection of viable tissue or insufficient resection of nonviable tissues may reduce the mortality and morbidity rates of intestinal ischemia-reperfusion as acute mesenteric ischemia.

Gradual colonic impaction of a chicken bone associated with inflammatory pseudotumor formation and nonocclusive colon ischemia

Foreign body (FB) ingestion is a common clinical problem and most FBs pass through the gastrointestinal tract without the need for intervention. A wide spectrum of clinical presentations may be possible and these can be either acute or chronic. We present a case of an 83-year-old woman featuring insidious abdominal discomfort who was hospitalized in our institution due to worsening symptoms. She underwent contrast-enhanced computed tomography (CT) evaluation which showed the presence of a significant parietal thickening of the transverse and descending colon, a mesenteric loose tissue imbibition, venous engorgement, and no filling defect of visceral arteries, suggesting a condition of nonocclusive colon ischemia. A hyperdense FB was identified in the sigma and was associated with a small pseudotumoral mass. The patient underwent surgical exploration which confirmed the hypoperfusional state of the colon, showing the presence of a chicken bone perforating the sigma and lying in the context of a pseudotumoral mass. Our experience shows how contrast-enhanced CT is feasible and can be strongly recommended as a first-line imaging tool on suspicion of colon ischemia and also how it can easily identify the underlying cause, in our case a FB sealed perforation of the sigma with pseudotumoral mass formation.

MiR-874 promotes intestinal barrier dysfunction through targeting AQP3 following intestinal ischemic injury

Intestinal ischemic injury is a significant clinical problem arising from diseases or as a complication of abdominal surgery. Our previous study showed aquaporin 3 is involved in intestinal barrier impairment. Here, we revealed that intestinal ischemia induced a time-dependent increase of miR-874 expression and a time-dependent decrease of AQP3 expression, and the level of miR-874 expression was inversely related to AQP3 protein expression. In addition, miR-874 promoted the paracellular permeability in vitro through targeting 3'UTR of AQP3. Two of the tight junction proteins, Occludin and Claudin-1, were found to be involved in miR-874-induced intestinal barrier dysfunction.

Acute extensive ischemic enteritis in a young man diagnosed with wireless capsule endoscopy: a case report

Ischemic enteritis is caused by either the interruption or significant reduction of arterial inflow to the small intestine. Risk factors are old age, diabetes mellitus and cardiovascular disease. It is very rare in young patients. We experienced a 21-year-old man with recurrent acute ischemic enteritis who was diagnosed with capsule endoscopy. He had previously taken medications for pulmonary hypertension and obstruction of both carotid arteries, and about 20 months earlier, he had been admitted due to hematochezia. Two sessions of angiography did not reveal the cause of hematochezia. At that time, capsule endoscopy showed mucosal edema and erythema in the terminal ileum, suggesting healed ischemic enteritis. The patient was admitted again due to hematochezia. Abdominal computed tomography showed focal celiac trunk stenosis and diffuse wall thickening of the small intestine, suggesting ischemic enteritis. Capsule endoscopy showed multiple active ulcers and severe hemorrhage with exudate, extending from the proximal jejunum to the terminal ileum. Using capsule endoscopy, the patient was diagnosed with acute extensive ischemic enteritis. Because endoscopic images of ischemic enteritis have rarely been reported, we report a case of a 21-year-old man who was diagnosed acute extensive ischemic enteritis with capsule endoscopy.

Computed tomography findings of pneumatosis and portomesenteric venous gas in acute bowel ischemia

AIM: To use more representative sample size to evaluate whether computed tomography (CT) scan evidence of the concomitant presence of pneumatosis and portomesenteric venous gas is a predictor of transmural bowel necrosis.

METHODS: Data from 208 patients who were referred for a diagnosis of bowel ischemia were retrospectively reviewed. Only patients who underwent a surgical intervention following a diagnosis of bowel ischemia who also had a post-operative histological confirmation of such a diagnosis were included. Patients were split into two groups according to the presence of histological evidence of transmural bowel ischemia (case group) or partial bowel ischemia (control group). CT images were reviewed for findings of ischemia, including mural thickening, pneumatosis, bowel distension, portomesenteric venous gas and arterial or venous thrombi.

RESULTS: A total of 248 subjects who underwent surgery for bowel ischemia were identified. Among the 208 subjects enrolled in our study, transmural bowel necrosis was identified in 121 subjects (case group), and partial bowel necrosis was identified in 87 subjects (control group). Based on CT findings, including mural thickening, bowel distension, pneumatosis, pneumatosis plus portomesenteric venous gas and presence of thrombi or emboli, there were no significant differences between the case and control groups. The concomitant presence of pneumatosis and porto-mesenteric venous gas showed an odds ratio of 1.95 (95%CI: 0.491-7.775, P = 0.342) for the presence of transmural necrosis. The presence of pneumatosis plus porto-mesenteric venous gas exhibited good specificity (83%) but low sensitivity (17%) in the identification of transmural bowel infarction. Accordingly, the positive and negative predictive values were 60% and 17%, respectively.

CONCLUSION: Although pneumatosis plus porto-mesenteric venous gas is associated with bowel ischemia, we have demonstrated that their co-occurrence cannot be used as diagnostic signs of transmural necrosis.

Arterial embolism

Surgical and intensive care patients are at a heightened risk for arterial embolization due to pre-existing conditions such as age, hypercoagulability, cardiac abnormalities and atherosclerotic disease. Most arterial emboli are clots that originate in the heart and travel to distant vascular beds where they cause arterial occlusion, ischemia, and potentially infarction. Other emboli form on the surface of eroded arterial plaque or within its lipid core. Thromboemboli are large clots that dislodge from the surface of athesclerotic lesions and occlude distal arteries causing immediate ischemia. Atheroemboli, which originate from fracturing the lipid core tend to cause a process of organ dysfunction and systemic inflammation, termed cholesterol embolization syndrome. The presentation of arterial emboli depends on the arterial bed that is affected. The most common manifestations are strokes and acute lower limb ischemia. Less frequently, emboli target the upper extremities, mesenteric or renal arteries. Treatment involves rapid diagnosis, which may be aided by precise imaging studies and restoration of blood flow. The type of emboli, duration of presentation, and organ system affected determines the treatment course. Long-term therapy includes supportive medical care, identification of the source of embolism and prevention of additional emboli. Patients who experienced arterial embolism as a result of clots formed in the heart should be anticoagulated. Arterial emboli from atherosclerotic disease of the aorta or other large arteries should prompt treatment to reduce the risk for atherosclerotic progression, such as anti-platelet therapy and the use of statin drugs. The use of anticoagulation and surgical intervention to reduce the risk of arterial embolization from atherosclerotic lesions is still being studied.

The role of purinergic pathways in the pathophysiology of gut diseases: pharmacological modulation and potential therapeutic applications

Gut homeostasis results from complex neuro-immune interactions aimed at triggering stereotypical and specific programs of coordinated mucosal secretion and powerful motor propulsion. A prominent role in the regulation of this highly integrated network, comprising a variety of immune/inflammatory cells and the enteric nervous system, is played by purinergic mediators. The cells of the digestive tract are literally plunged into a "biological sea" of functionally active nucleotides and nucleosides, which carry out the critical task of driving regulatory interventions on cellular functions through the activation of P1 and P2 receptors. Intensive research efforts are being made to achieve an integrated view of the purinergic system, since it is emerging that the various components of purinergic pathways (i.e., enzymes, transporters, mediators and receptors) are mutually linked entities, deputed to finely modulating the magnitude and the duration of purinergic signaling, and that alterations occurring in this balanced network could be intimately involved in the pathophysiology of several gut disorders. This review article intends to provide a critical appraisal of current knowledge on the purinergic system role in the regulation of gastrointestinal functions, considering these pathways as a whole integrated network, which is capable of finely controlling the levels of bioactive nucleotides and nucleosides in the biophase of their respective receptors. Special attention is paid to the mechanisms through which alterations in the various compartments of the purinergic system could contribute to the pathophysiology of gut disorders, and to the possibility of counteracting such dysfunctions by means of pharmacological interventions on purinergic molecular targets.

Successful percutaneous aspiration thrombectomy for acute mesenteric ischemia in a patient with atrial fibrillation despite optimal anticoagulation therapy

This report describes a case of acute mesenteric ischemia due to acute superior mesenteric artery (SMA) thromboembolism in a patient with chronic atrial fibrillation despite optimal anticoagulation therapy. The patient underwent SMA angiography and endovascular revascularization for acute mesenteric ischemia. We initially tried endovascular thrombolytic therapy for the thromboembolism of SMA, but it did not achieve complete revascularization. Therefore, we performed a percutaneous aspiration thrombectomy, which led to complete revascularization and successful treatment of acute mesenteric ischemia without any additional procedures.

Risk factors effecting mortality in acute mesenteric ischemia and mortality rates: a single center experience

The objective of this study is to discuss the effective factors on morbidity and mortality in patients who were operated on for acute mesenteric ischemia. Between 2006 and 2011, 95 patients, who underwent emergent surgery for acute mesenteric ischemia, were analyzed retrospectively. The study group consisted of 56 men (58.9%) and 39 women (41.1%), with an average age of 68.4 ± 14.4 years. Elapsed time between the onset of the symptoms and the surgical operation was less than 24 hours in 47 (49.5%) cases, and more than 24 hours in 48 cases (50.5%) (P < 0.001). Although all of the patients had intestinal necroses, colon involvement was seen in 38 patients, and mortality was higher in this group of patients (P < 0.001). Mortality rate was 42.1%. This was higher in older patients, those with increased leukocyte levels, increased elapsed time to laparotomy, and when the colon was involved.

Critical role of interleukin-17A in murine intestinal ischemia-reperfusion injury

Intestinal ischemia-reperfusion (I/R) injury causes severe illness frequently complicated by remote multiorgan dysfunction and sepsis. Recent studies implicated interleukin-17A (IL-17A) in regulating inflammation, autoimmunity, and I/R injury. Here, we determined whether IL-17A is critical for generation of intestinal I/R injury and subsequent liver and kidney injury. Mice subjected to 30 min of superior mesenteric artery ischemia not only developed severe small intestinal injury (necrosis, apoptosis, and neutrophil infiltration) but also developed significant renal and hepatic injury. We detected large increases in IL-17A in the small intestine, liver, and plasma. IL-17A is critical for generating these injuries, since genetic deletion of IL-17A- or IL-17A-neutralizing antibody treatment markedly protected against intestinal I/R injury and subsequent liver and kidney dysfunction. Intestinal I/R caused greater increases in portal plasma and small intestine IL-17A, suggesting an intestinal source for IL-17A generation. We also observed that intestinal I/R caused rapid small intestinal Paneth cell degranulation and induced murine α-defensin cryptdin-1 expression. Furthermore, genetic or pharmacological depletion of Paneth cells significantly attenuated the intestinal I/R injury as well as hepatic and renal dysfunction. Finally, Paneth cell depletion significantly decreased small intestinal, hepatic, and plasma IL-17A levels after intestinal I/R. Taken together, we propose that Paneth cell-derived IL-17A may play a critical role in intestinal I/R injury as well as extraintestinal organ dysfunction.

Stress-induced intestinal necrosis resulting from severe trauma of an earthquake

AIM: To investigate the possible reasons and suggest therapeutic plan of stress-induced intestinal necrosis resulting from the severe trauma.

METHODS: Three patients in our study were trapped inside collapsed structures for 22, 21 and 37 h, respectively. The patients underwent 3-4 operations after sustaining their injuries. Mechanical ventilation, intermittent hemodialysis and other treatments were also provided. The patients showed signs of peritoneal irritation on postoperative days 10-38. Small intestinal necrosis was confirmed by emergency laparotomy, and for each patient, part of the small bowel was removed.

RESULTS: Two patients who all performed 3 operations died of respiratory complications on the first and second postoperative days respectively. The third patient who performed 4 operations was discharged and made a full recovery. Three patients had the following common characteristics: (1) Multiple severe trauma events with no direct penetrating gastrointestinal injury; (2) Multiple surgeries with impaired renal function and intermittent hemodialysis treatment; (3) Progressive abdominal pain and tenderness, and peritoneal irritation was present on post-traumatic days 10-38; (4) Abdominal operations confirmed segment ulcer, necrosis of the small intestine, hyperplasia and stiffness of the intestinal wall; and (5) Pathological examinations suggested submucosal hemorrhage, necrosis, fibrosis and hyalinization of the vascular wall. Pathological examinations of all 3 patients suggested intestinal necrosis with fistulas.

CONCLUSION: Intestinal necrosis is strongly asso-ciated with stress from trauma and post-traumatic complications; timely exploratory laparotomy maybe an effective method for preventing and treating stress-induced intestinal necrosis.

Preservation of small bowel with the selective use of heparin and second look laparotomy in acute mesenteric ischaemia: A case report

INTRODUCTION

Acute mesenteric ischaemia may occur due to mesenteric arterial embolus, thrombosis, non-occlusive mesenteric ischaemia or venous thrombosis resulting in ischaemia of the bowel wall.

PRESENTATION OF CASE

A 41year old woman presented with worsening abdominal pain, decreased appetite, nausea and vomiting. Examination revealed right lower quadrant tenderness. Investigations revealed elevation of her inflammatory markers. At laparotomy two separate segments of ischaemic but potentially viable small bowel were identified secondary to mesenteric venous thrombosis. Bowel salvage was attempted with the use of intravenous unfractionated heparin and this was confirmed following a second look laparotomy.

DISCUSSION

Despite a normal platelet count at presentation a diagnosis of JAK-2 positive essential thrombocythaemia was made thus explaining the acquired prothrombotic state underlying the venous thrombosis. The selective use of intravenous unfractionated heparin and second look laparotomy may provide a means for bowel preservation in these cases.

CONCLUSION

This case highlights the potential of bowel salvage can be achieved following an episode of acute mesenteric ischaemia with the use of intravenous unfractionated heparin and selective second look laparotomy and the importance of considering underlying myeloproliferative disease in such cases even in the absence of a thrombocytosis at presentation.

[Acute mesenteric ischemia]

Acute mesenteric ischemia (AMI) is a rare cause of acute abdomen. Coupled with a high patient age, non-specific clinical symptoms and a significant co-morbidity the disease is still associated with a significant mortality of 60-85%. With a combination of preexisting cardiac arrhythmia and sudden abdominal pain AMI should always first be ruled out. Contrast-enhanced computed tomography (CT) scanning has replaced angiography as the first diagnostic step, largely because both intravascular and intra-abdominal pathologies can be diagnosed. In the case of an acute abdomen or lack of immediate access to diagnostic tools, rapid surgical exploration should be preferred. Surgical therapy includes embolectomy and resection of ischemic bowel segments. There should be a wide indication for second-look surgery. The most important prognostic factor and the only factor that can be influenced by the surgeon is the time interval between onset of symptoms and surgery. Therefore angiography or laparotomy should be performed as early as possible in cases of suspected AMI.

Superior mesenteric arterial branch occlusion causing partial jejunal ischemia: a case report

Introduction

Ischemic bowel disease comprises both mesenteric ischemia and colonic ischemia. Mesenteric ischemia can be divided into acute and chronic ischemia. These are two separate entities, each with their specific clinical presentation and diagnostic and therapeutic modalities. However, diagnosis may be difficult due to the vague symptomatology and subtle signs.

Case presentation

We report the case of a 68-year-old Caucasian woman who presented with abdominal discomfort, anorexia, melena and fever. A physical examination revealed left lower quadrant tenderness and an irregular pulse. Computed tomography of her abdomen as well as computed tomography enterography, enteroscopy, angiography and small bowel enteroclysis demonstrated an ischemic jejunal segment caused by occlusion of a branch of the superior mesenteric artery. The ischemic segment was resected and an end-to-end anastomosis was performed. The diagnosis of segmental small bowel ischemia was confirmed by histopathological study.

Conclusion

Mesenteric ischemia is a pathology well-known by surgeons, gastroenterologists and radiologists. Acute and chronic mesenteric ischemia are two separate entities with their own specific clinical presentation, radiological signs and therapeutic modalities. We present the case of a patient with symptoms and signs of chronic mesenteric ischemia despite an acute etiology. To the best of our knowledge, this is the first report presenting a case of acute mesenteric ischemia with segmental superior mesenteric artery occlusion.

Acute mesenteric ischaemia and unexpected death

Acute mesenteric ischaemia is a vascular emergency that arises when blood flow to the intestine is compromised leading to tissue necrosis. It is primarily a condition of the elderly associated with significant morbidity and mortality. Causes include arterial thromboembolism, venous thrombosis and splanchnic vasoconstriction (so-called nonocclusive mesenteric ischaemia). Reperfusion injury and breakdown of the intestinal mucosal barrier lead to metabolic derangements, sepsis and death from multiorgan failure. The diagnosis may be difficult to make clinically and numbers of cases are increasing due to ageing of the population. The clinical and pathological features are reviewed with discussion of predisposing conditions. Careful dissection of the mesenteric vasculature is required at autopsy with appropriate histologic sampling and documentation of associated comorbidities. Other organs need to be checked for thrombi and the possibility of testing for inherited thombophilias should be considered. Toxicological evaluation, particularly in younger individuals, may reveal evidence of cocaine use. On occasion no obstructive lesions will be demonstrated, however the confounding effects of post-mortem autolytic and putrefactive changes may mean that nonocclusive mesenteric ischaemia may be difficult to diagnose.

Case Report: Recognizing Pneumatosis Intestinalis: A Case of Bowel Ischemia Presenting as Renal Colic

The clinical diagnosis of bowel ischemia is often difficult and the diagnosis can easily be missed unless there is a high index of clinical and radiological suspicion. Bowel ischemia and or infarction must be considered in the differential diagnosis in the older patient with pre-existing coronary artery or generalized vascular disease, cardiac failure, or arrhythmias especially atrial fibrillation and hypertension. An elderly patient with caecal infarction is presented who was initially diagnosed and treated for renal colic.

[Effect of ischemic postconditioning on oxidative stress and structural tissue changes in intestinal warm ischemic and autotransplantation models]

INTRODUCTION/AIM

Our study investigated the effect of ischemic postconditioning (IPO) in intestinal warm ischemia/reperfusion (I/R) and autotransplantation models.

MATERIALS AND METHODS

Warm ischemia was performed by occlusion of superior mesenteric artery for 1, 3 and 6 hours in white domestic pigs (n = 15). Prior to 3 hours reperfusion the intestine was postconditioned by 3 cycles of 30-seconds ischemia and 30-seconds reperfusion (IPO protocol). In the cold ischemia group (n = 15) the bowel was preserved in University of Wisconsin solution for 1, 3, and 6 hours. Prior to 3 hours reperfusion IPO protocol was applied, too. Tissue samples were collected after laparotomy (control) and at the end of the reperfusion periods. As far as oxidative stress markers, malondialdehyde and reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity were determined. Tissue damage was evaluated by qualitative (Park-classification) and quantitative (Scion Image) methods.

RESULTS

As regards oxidative stress parameters, lipidperoxidation decreased and the protective effect of endogenous antioxidants (GSH, SOD) retained significantly by IPO procedure at the end of reperfusion. Tissue injury correlated significantly by the duration of warm ischemia and cold preservation. Quantitative analysis demonstrated that IPO ameliorated tissue injury in each group (p < 0.05).

CONCLUSION

IPO significantly attenuated intestinal oxidative stress and morphological damages in warm and cold I/R models.

Celiacomesenteric trunk: a variation that must be known before aortic surgery

The celiac trunk and the mesenteric arteries may present variations with different clinical significance. A celiacomesenteric trunk was discovered in a patient with mesenteric ischemia and a history of aortic bypass without inferior mesenteric artery reimplantation. Despite thrombectomies and digestive resections, the patient died. Anatomic variations like celiacomesenteric trunk must be known before aortic surgery.