Intestinal ischemia

A Miraculous Save: Gangrenous Bowel and Meckle's Diverticulum With Acute Superior Mesenteric Artery Thrombosis

The superior mesenteric artery (SMA) is vital for parts of the small intestine and ascending colon. Thrombosis of this major artery is a severe and potentially fatal condition involving the occlusion of the arterial vascular supply, causing ischemia predisposing to gangrene. Meckel's diverticulum is a congenital outpouching in the lower part of the small intestine. The condition of gangrenous meckels diverticulum is, therefore, even more limited. This study presents a unique case of a 45-year-old male with coexisting features of SMA thrombus with acute small bowel intestinal obstruction. During the study, the patient was found to have sickle cell anemia with an AS pattern, which may have predisposed the formation of a thrombus. The patient underwent sequential management of active thrombus by thrombolysis first, followed by resection anastomosis for gangrenous bowel. With precise monitoring and therapeutic care, the patient made a remarkable recovery. The condition possesses a high mortality rate. Prompt recognition and timely intervention in this case are of utmost significance.

Isquemia intestinal por trombosis mesentérica en paciente geriátrico, resuelta por intervencionismo. Reporte de caso

Mesenteric thrombosis represents a vascular urgency caused by the abrupt interruption of blood flow, whether arterial or venous; clinical presentation can be nonspecific, which can represent a diagnostic challenge. According to its vascular etiology, a different therapeutic approach is required. If there is clinical suspicion or signs of peritonitis, the imaging diagnosis can support to identify the presented pathology. On this occasion, there is a clinical case of an 84-year-old http://doi.org/10.22201/fm.24484865e.2020.63.2.04 | Vol. 63, n.o 2, Marzo-Abril 2020 25 patient who goes to the emergency department for generalized abdominal pain, which led to a diagnostic imaging study, to confirm this finding. Key words: Intestinal ischemia; atherosclerosis; Mesenteric thrombosis; catheterization

Heat Shock Protein 70 Messenger RNA in Rat Leukocytes Elevates After Severe Intestinal Ischemia-Reperfusion

BACKGROUND

Heat shock protein 70 (HSP70) confers protection against heat shock, oxidative stress, infection, and inflammation in many cell types. A recent study reported that the induction of HSP70 was associated with morphologic protection against ischemia-reperfusion injury (IRI) in the rat small intestine. This study investigated the dynamics of HSP70 in leukocytes during intestinal IRI in a rat model.

MATERIALS AND METHODS

Serial blood samples were collected at 60-minute intervals up to 240 min from male Wistar rats (n = 15). The rats were divided into three groups of five each: the control group, the nonlethal IRI group, and the lethal IRI group. Rats belonging to the control group underwent a sham operation, and laparotomy was performed on rats in the lethal and nonlethal IRI groups. The nonlethal group experienced a 30-minute clamping of the superior mesenteric artery, and the lethal group experienced a 75-minute clamping of the superior mesenteric artery. The expression of HSP70 messenger RNA (mRNA) in leukocytes was measured by real-time quantitative polymerase chain reaction. Mixed-effects modeling of repeated measures was used to carry out the statistical analysis. The Bonferroni correction was applied to multiple comparisons. A P value < 0.0167 was considered to indicate statistical significance.

RESULTS

The expression of HSP70 mRNA in leukocytes increased 60 min after reperfusion in both IRI groups, and it was 12.8 times higher in the lethal group and 3.6 times higher in the nonlethal group compared with the control group. The expression of mRNA in the lethal group was significantly increased compared with the nonlethal group and the control group at 120 and 180 min after reperfusion. At 120 min after reperfusion, the expression of HSP70 mRNA was 6.1 times higher in the lethal group than in the nonlethal group (P = 0.0075) and 17.7 times higher than in the control group (P = 0.0011). At 180 min after reperfusion, the expression of HSP70 mRNA was 6.8 times higher in the lethal group than in the nonlethal group (P = 0.0007) and 4.3 times higher than in the control group (P = 0.0032). Although the expression of HSP70 mRNA in the nonlethal group was elevated in the early stages of reperfusion, there was no difference between the nonlethal group and the control group (P = 0.0212 at 60 min).

CONCLUSIONS

The expression of HSP70 mRNA in leukocytes may be a clinically useful indicator for evaluating pathologic conditions in intestinal IRI.

Survival from a 75% TBSA thermal injury complicated by bowel ischemia presenting with pneumatosis intestinalis

Thermal injury is associated with an increased risk of abdominal complications such as ischemia, infarction and pneumatosis intestinalis (PI). PI is characterized by gas in the intestinal wall and, when diagnosed it can signify the presence of a life-threatening condition. We present a case of a patient who survived 75% total body surface area burns complicated by ischemic bowel that initially presented as extensive PI. This patient was emergently taken to the operating room and underwent a subtotal colectomy and small bowel resection for ischemic bowel. Prompt diagnosis and successful management of the underlying condition ultimately contributed to the patient’s survival. The presence of peritonitis or abdominal distension, portomesenteric venous gas and lactic acidosis should prompt immediate surgical intervention in the post-burn period.

Intestinal histopathological changes in a porcine model of pneumoperitoneum-induced intra-abdominal hypertension

BACKGROUND

Low splanchnic perfusion is an immediate effect of pneumoperitoneum-induced intra-abdominal hypertension (IAH). Anatomical structure results in the intestinal mucosa being the area most sensitive to hypoperfusion. The relationship between intestinal injury and clinical parameters of tissue perfusion [abdominal perfusion pressure (APP), gastric intramucosal pH (pH_i) and lactic acid (Lc)] has not been previously studied. This study aimed to monitorize intestinal pathogenesis through sequential ileal biopsies and to measure APP, pH_i, and Lc levels at different pneumoperitoneum-induced intra-abdominal pressures (20, 30, and 40 mmHg) to evaluate the potential relationships between them.

MATERIALS AND METHODS

Fifty pigs were divided into four groups; a control group (C) and three experimental groups with different pneumoperitoneum-induced levels [20 mmHg (G20), 30 mmHg (G30), and 40 mmHg (G40)], that were maintained for 3 and 5 h. APP, pH_i, and Lc were measured and ileal biopsies taken laparoscopically every 30 min. The mucosal damage was graded using the standardized Park's Score and animals were classified as injured (I+) or uninjured (I-).

RESULTS

Different histopathological lesions were observed in groups G20, G30, and G40 but no damage observed in group C. A 33.3% of animals in G20 and G30 were I+ after 3 h, while 93.3% were injured in G40. After 5 h, histopathological lesions were no longer seen in some animals in G20 and only 10% were I+. Conversely, in G30 I+ pigs increased to 80% while those in G40 remained at 93.3% I+. The I+ animals had significantly lower APP and pH_i than those I-. Lc was the clinical parameter that showed the earliest differences, with significantly higher figures in I+ animals.

CONCLUSIONS

The evolution of intestinal injuries from pneumoperitoneum-induced IAH depends on the degree of IAP. These damages may be associated with decreases in APP and pH_i, and increases in Lc.

Thrombectomy Devices in the Treatment of Acute Mesenteric Ischemia: Initial Single-Center Experience

BACKGROUND

To report our preliminary experience with endovascular revascularization of patients with acute mesenteric ischemia (AMI), using thrombectomy devices.

METHODS

It is a retrospective analysis of patients admitted to our hospital due to AMI and who were subjected to concomitant or exclusive endovascular treatment, from January 2011 to January 2016. Patients were admitted at the emergency department, underwent imaging investigation, and were referred to the endovascular specialist. Endovascular treatment was performed through left brachial artery access and selective catheterization and thrombectomy with a 6F Rotarex Debulking Device (Straub Medical, Wangs, Switzerland). Laparotomy was performed based on clinical and radiologic sings and at the discretion of the surgeon. Demographic, clinical/periprocedural, postoperative, complication, and adjunct intervention data were reviewed. Technical success was defined as recanalization of the Riolan's arcade on angiographic control.

RESULTS

Twenty patients (mean age: 69.8 ± 11.3 years) underwent endovascular revascularization for AMI using thrombectomy devices, during the period of the study. Abdominal pain was the most common complain on admission (65%), with ileus (35%), sepsis (25%), and myocardial infarction as the main clinical referral presentation at admission. Fifteen patients (75%) had suggestive computer tomography (CT) signs of AMI on admission. Endovascular revascularization was successfully performed in all patients through the left brachial artery with a mean procedural time of 28 ± 17 min. Superior mesenteric artery (SMA) was the main vessel involved in 75% on a solely basis. The majority of the SMA occlusions were in the periosteal (30%) and proximal to middle colic artery offspring (35%). Primary use of thrombectomy devices was performed in all patients, associated with balloon angioplasty (7/20; 50%), stent deployment (5/20; 25%), intraoperative selective thrombolysis (4/20; 20%) and catheter-assisted aspiration in 10% (2/20) of patients. Average time between admission and computed tomography angiography was 1.5 ± 0.5 hr, between admission and angiographic procedure was 2.5 ± 1 hr, and between admission and surgery was 9 ± 5 hr. Following recanalization, 14 patients (70%) underwent open surgery. Laparotomy with intestinal resection (enterectomy, colectomy) and transit deviation was the most common procedure. Complications directly related to the endovascular procedure occurred in 2 patients, represented by self-limited small perforations. Overall 30-day mortality was 40% (n = 8). During the period of this study, no patient died as a result of complications related to the use of rotational thrombectomy.

CONCLUSIONS

Endovascular treatment of the AMI with the use of thrombectomy devices proved to be technically feasible and reasonably fast procedure. Early diagnosis and adequate treatment remains the cornerstone of the treatment. Early surgical evaluation and close integration between surgical and endovascular specialists are crucial to faster treatment and consequently lower extensive surgical resections and mortality. Further studies are necessary on this field to confirm these findings.

Clinical Mimics: An Emergency Medicine-Focused Review of Influenza Mimics

BACKGROUND

Influenza viruses are a significant cause of morbidity and mortality in the United States. Given the wide range of symptoms, emergency physicians must maintain a broad differential diagnosis in the evaluation and treatment of patients presenting with influenza-like illnesses.

OBJECTIVE

This review addresses objective and subjective symptoms commonly associated with influenza and discusses important mimics of influenza viruses, while offering a practical approach to their clinical evaluation and treatment.

DISCUSSION

Influenza-like symptoms are common in the emergency department (ED), and influenza accounts for > 200,000 hospitalizations annually. The three predominant types are A, B, and C, and these viruses are commonly transmitted through aerosolized viral particles with a wide range of symptoms. The most reliable means of identifying influenza in the ED is rapid antigen detection, although consideration of local prevalence is required. High-risk populations include children younger than 4 years, adults older than 50 years, adults with immunosuppression or chronic comorbidities, pregnancy, obesity, residents of long-term care facilities, and several others. The Centers for Disease Control and Prevention recommends treatment with neuraminidase inhibitors in these populations. However, up to 70% of patients with these symptoms may have a mimic. These mimics include infectious and noninfectious sources. The emergency physician must be aware of life-threatening mimics and assess for these conditions while beginning resuscitation and treatment.

CONCLUSIONS

The wide range of symptoms associated with influenza overlap with several life-threatening conditions. Emergency physicians must be able to rapidly identify patients at risk for complications and those who require immediate resuscitation.

Successful selective arterial thrombolysis in patient with acute abdominal thromboembolism

The paper reports successful thrombolysis conducted in 64 years old woman admitted to the clinic with clinical and angiographic data for acute surgical abdomen caused by acute tromboembolia of arteria mesenterica superior (AMS). The therapeutic approach required to undertake lifesaving decision on i.e. surgical vs. invasive treatment in conditions of emergency. Finally, it was decided to undertake invasive treatment with successful restoration of blood flow in the related artery. The patient was discharged from the clinic with considerable clinical improvement on the fifth day of her stay. The case report includes discussion on issues relating the consequence of the diagnostic and interventional procedures in such patients, opportunities for conducting emergency thrombolysis in acute embolia of AMS and preventive measures in patients with high tromboembolic risk.

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.

Ischemic colitis: spectrum of CT findings, sites of involvement and severity

To summarize the frequency of findings on IV contrast, enhanced computer tomography (CT) in 335 patients with pathologically proven ischemic colitis (IC) determine the most frequent locations and patterns of involvement and establish the correlation of these findings with the severity of IC. 231 patients were excluded for not having a concomitant CT or for having underlying comorbidities. 104 cases were analyzed. Scans were evaluated for abnormal wall enhancement (AE), bowel wall thickening (BWT), bowel dilatation (DIL), mesenteric fat stranding (FS), venous engorgement (VE), pericolonic free fluid (FF), and pneumatosis (PN) and portomesenteric venous gas. Segmental versus pancolonic involvement was noted. Severity was determined by histopathology criteria. Data obtained are as follows: female to male incidence, 69 % (70) vs. 31 % (34); average age, 64.5; and positive CT, 102/104 (98.1 %). The most frequent findings include FS (88 %), BWT (88 %), and AE (82 %) regardless of severity of involvement. Statistically significant increased risk ratio and likelihood of severe ischemia for PN, DIL, and FF individually. BWT, DIL, FS, FF, VE, and PN together have a probability for severe IC of 91.8 %. A correlation between fewer findings and milder IC was found (R (2) = 0.6771). The most frequently involved segments: descending (64 %) and sigmoid colon (54 %). Splenic flexure (SF) was infrequently involved (n = 8, 7.84 %). Females had two times higher incidence of IC. The most frequent CT findings in IC are FS, BWT, and AE regardless of the severity. PN is suggestive of severe IC. Segmental involvement is the predominant pattern. The distal colon is more frequently involved. SF contrary to the conventional literature is not disproportionately involved in IC.

Hyperamylasaemia and ischaemic colitis

INTRODUCTION

Ischaemic colitis is a differential diagnosis to be considered in patients who have a high cardiovascular risk. Presentation of severe ischaemia is usually that of an acute abdomen with passage of fresh blood per rectum, and hyperamylasaemia.

PRESENTATION OF CASE

A 66-year-old gentleman was admitted to A&E with a short history of central abdominal pain, nausea, vomiting and fresh bleeding per rectum. A diagnosis of ischaemic colitis was made by the computed tomography (CT) scan findings of colonic thickening and pneumatosis, in addition to colonoscopy demonstrating sloughy mucosa and ulceration. Symptoms did not resolve with conservative management, therefore laparotomy + Hartmann's procedure was performed. Histology showed extensive areas of both partial and full thickness ischaemia with stricture.

DISCUSSION

Amylase is an indicator of intra-abdominal inflammatory processes. Hyperamylasaemia (normal <100 U/l) is most frequently associated with pancreatitis; however, causation is not exclusive and other differentials including bowel ischaemia must be considered, although amylase is not a specific marker for ischaemic colitis. It is important to distinguish between ischaemic and ulcerative colitis.

CONCLUSION

Intestinal ischaemia is a serious acute abdominal pathology that is associated with hyperamylasaemia, and frequently requires prompt surgical intervention to prevent subsequent mortality.

Berberine Reduces Rat Intestinal Tight Junction Injury Induced by Ischemia–Reperfusion Associated with the Suppression of Inducible Nitric Oxide Synthesis

Berberine (BBR) has been shown to attenuate the deleterious effects of ischemia/reperfusion (I/R) injury in the brain. We evaluated the effects of BBR on intestinal tight junction (TJ) changes during mesenteric I/R. I/R was induced in rats by the occlusion of the superior mesenteric artery and reperfusion. The rats were randomized into four groups: control, BBR, I/R, and I/R + BBR. Intestinal permeability was determined by the lactulose/mannitol test. The ileum and colon were harvested to assess mucosal injury and inducible nitric oxide synthase activity. The TJ ultrastructure was studied by transmission electron microscopy. The expressions and locations of the TJ proteins, occludin and ZO-1, in the epithelium were investigated by immunofluorescence microscopy. We also used Western blot analysis to detect the distribution of TJ proteins in lipid raft fractions. Our results suggest that I/R-induced intestinal TJ dysfunction can be improved by BBR, thereby demonstrating the therapeutic potential of BBR for intestinal I/R.

Non-occlusive mesenteric ischemia and the role of cilostazol in its management

Bowel ischemia is a rare and potential life-threatening disorder. The reason for its rarity is the difficulty in its diagnosis. Vague and nonspecific clinical findings and limitations of diagnostic and treatment options make this disease a significant challenge. We hereby report two cases of non-occlusive mesenteric ischemia and the use of cilostazol in the successful management of such cases.

Pneumatosis intestinalis in patients with severe thermal injury

Severe thermal injury is associated with pronounced changes in intestinal physiology, which may cause ischemia, infarction, and pneumatosis intestinalis (PI). PI is a pathologic condition defined as infiltration of gas into the gastrointestinal tract wall. Historically, PI prompted urgent surgery, yet some surgeons "watch and wait" to avoid the risks of a negative laparotomy. The authors reviewed experience with PI at a single burn center. They retrospectively identified burn center intensive care unit patients with radiographic or pathologic evidence of PI. Data included demographics, injury severity score, TBSA burned, operative findings, length of stay, and mortality. From January 2003 through August 2009, 1129 patients were admitted to the authors' burn center intensive care unit. Fifteen had PI. Twelve had radiographic evidence of PI, and 10 had PI associated with intestinal infarction. Nonsurvivors had lower base deficits (P = .02), higher lactate levels (P = .05), and required vasopressor support (P = .02) within 24 hours of developing PI. Massive intestinal infarction (P = .004) and open abdomens (P = .004) were more common among nonsurvivors. PI can be identified by radiologic or pathologic findings. The authors' experience with PI among patients with burn injury revealed a high mortality rate. Because of the association of bowel ischemia with PI, exploratory laparotomy should be strongly considered in patients with burn injury with radiographic evidence of PI.

Domain V peptides inhibit beta2-glycoprotein I-mediated mesenteric ischemia/reperfusion-induced tissue damage and inflammation

Reperfusion of ischemic tissue induces significant tissue damage in multiple conditions, including myocardial infarctions, stroke, and transplantation. Although not as common, the mortality rate of mesenteric ischemia/reperfusion (IR) remains >70%. Although complement and naturally occurring Abs are known to mediate significant damage during IR, the target Ags are intracellular molecules. We investigated the role of the serum protein, β2-glycoprotein I as an initiating Ag for Ab recognition and β2-glycoprotein I (β2-GPI) peptides as a therapeutic for mesenteric IR. The time course of β2-GPI binding to the tissue indicated binding and complement activation within 15 min postreperfusion. Treatment of wild-type mice with peptides corresponding to the lipid binding domain V of β2-GPI blocked intestinal injury and inflammation, including cellular influx and cytokine and eicosanoid production. The optimal therapeutic peptide (peptide 296) contained the lysine-rich region of domain V. In addition, damage and most inflammation were also blocked by peptide 305, which overlaps with peptide 296 but does not contain the lysine-rich, phospholipid-binding region. Importantly, peptide 296 retained efficacy after replacement of cysteine residues with serine. In addition, infusion of wild-type serum containing reduced levels of anti-β2-GPI Abs into Rag-1(-/-) mice prevented IR-induced intestinal damage and inflammation. Taken together, these data suggest that the serum protein β2-GPI initiates the IR-induced intestinal damage and inflammatory response and as such is a critical therapeutic target for IR-induced damage and inflammation.

Intestinal ischemia in the elderly

Mesenteric ischemia in the elderly is an uncommon but often fatal disorder for which the prognosis depends entirely on the speed and accuracy of the diagnosis. A high index of suspicion is required as the early signs and symptoms, at a time when ischemic changes are reversible, are typically nonspecific or absent. This article reviews the clinical spectrum of mesenteric ischemia in the elderly with particular emphasis on the varied presentations, evaluation, and management of ischemic disorders of the intestines.

Pathogenic natural antibodies recognizing annexin IV are required to develop intestinal ischemia-reperfusion injury

Intestinal ischemia-reperfusion (IR) injury is initiated when natural IgM Abs recognize neo-epitopes that are revealed on ischemic cells. The target molecules and mechanisms whereby these neo-epitopes become accessible to recognition are not well understood. Proposing that isolated intestinal epithelial cells (IEC) may carry IR-related neo-epitopes, we used in vitro IEC binding assays to screen hybridomas created from B cells of unmanipulated wild-type C57BL/6 mice. We identified a novel IgM mAb (mAb B4) that reacted with the surface of IEC by flow cytometric analysis and was alone capable of causing complement activation, neutrophil recruitment and intestinal injury in otherwise IR-resistant Rag1(-/-) mice. mAb B4 was found to specifically recognize mouse annexin IV. Preinjection of recombinant annexin IV blocked IR injury in wild-type C57BL/6 mice, demonstrating the requirement for recognition of this protein to develop IR injury in the context of a complex natural Ab repertoire. Humans were also found to exhibit IgM natural Abs that recognize annexin IV. These data in toto identify annexin IV as a key ischemia-related target Ag that is recognized by natural Abs in a pathologic process required in vivo to develop intestinal IR injury.

Tempol reduces bacterial translocation after ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion

PURPOSE

We investigated whether Tempol, a water-soluble antioxidant, prevents the harmful effects of superior mesenteric ischemia/reperfusion on intestinal tissues in rats.

METHODS

The rats were divided into three groups of 10. In group 1, the superior mesenteric artery (SMA) was isolated but not occluded, and in groups 2 and 3 the superior mesenteric artery was occluded for 60 min. After that, the clamp was removed and reperfusion began. In group 3, 5 min before the start of reperfusion, a bolus dose of 30 mg/kg Tempol was administered intravenously and continued at a dose of 30 mg/kg for 60 min. All animals were euthanized after 24 h and tissue samples were collected for analysis.

RESULTS

There was a significant increase in myeloperoxidase activity, malondialdehyde levels, and the incidence of bacterial translocation in group 2, with a decrease in glutathione levels. These parameters were found to be normalized in group 3. The intestinal mucosal injury score in group 2 was significantly higher than those in groups 1 and 3.

CONCLUSION

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

Imaging in intestinal ischemic disorders

Intestinal ischemia and infarction are a heterogeneous group of diseases that have as their unifying theme hypoxia of the small bowel or colon. The incidence of bowel ischemia and infarction is on the rise for several reasons: the aging of the population, the ability of intensive care units to salvage critically ill patients, and heightened clinical awareness of these disorders. Improvements in diagnostic imaging techniques have greatly contributed to the earlier diagnosis of intestinal ischemia, which can have a positive influence on patient outcomes. In this article, role of radiology in the detection, differential diagnosis, and management of patients who have intestinal ischemia and infarction is discussed.

Regulation of enteric functions by adenosine: pathophysiological and pharmacological implications

The wide distribution of ATP and adenosine receptors as well as enzymes for purine metabolism in different gut regions suggests a complex role for these mediators in the regulation of gastrointestinal functions. Studies in rodents have shown a significant involvement of adenosine in the control of intestinal secretion, motility and sensation, via activation of A1, A2A, A2B or A3 purinergic receptors, as well as the participation of ATP in the regulation of enteric functions, through the recruitment of P2X and P2Y receptors. Increasing interest is being focused on the involvement of ATP and adenosine in the pathophysiology of intestinal disorders, with particular regard for inflammatory bowel diseases (IBDs), intestinal ischemia, post-operative ileus and related dysfunctions, such as gut dysmotility, diarrhoea and abdominal discomfort/pain. Current knowledge suggests that adenosine contributes to the modulation of enteric immune and inflammatory responses, leading to anti-inflammatory actions. There is evidence supporting a role of adenosine in the alterations of enteric motor and secretory activity associated with bowel inflammation. In particular, several studies have highlighted the importance of adenosine in diarrhoea, since this nucleoside participates actively in the cross-talk between immune and epithelial cells in the presence of diarrhoeogenic stimuli. In addition, adenosine exerts complex regulatory actions on pain transmission at peripheral and spinal sites. The present review illustrates current information on the role played by adenosine in the regulation of enteric functions, under normal or pathological conditions, and discusses pharmacological interventions on adenosine pathways as novel therapeutic options for the management of gut disorders and related abdominal symptoms.

Mesenteric ischemia in the elderly

Intestinal ischemia is a relatively common disorder in the elderly and, if not treated promptly, still carries a high morbidity and mortality rate. High degree of clinical suspicion is of paramount importance in diagnosis, because there is no specific laboratory test available and physical examination findings may be subtle. Once the diagnosis is made, management relies on early resuscitation, identification, and treatment of the predisposing conditions, along with careful planning of the therapeutic invasive interventions, which altogether may help reduce the mortality and morbidity associated with this condition.

Transjugular intrahepatic portosystemic shunt, mechanical aspiration thrombectomy, and direct thrombolysis in the treatment of acute portal and superior mesenteric vein thrombosis

A patient was admitted because of severe abdominal pain, anorexia, and intestinal bleeding. Contrast-enhanced multidetector computed tomography demonstrated acute portal and superior mesenteric vein thrombosis (PSMVT). The patient was treated percutaneously with transjugular intrahepatic portosystemic shunt (TIPS), mechanical aspiration thrombectomy, and direct thrombolysis, and 1 week after the procedure, complete patency of the portal and superior mesenteric veins was demonstrated. TIPS, mechanical aspiration thrombectomy, and direct thrombolysis together are promising endovascular techniques for the treatment of symptomatic acute PSMVT.

Impact of etiologic factors and APACHE II and POSSUM scores in management and clinical outcome of acute intestinal ischemic disorders after surgical treatment

BACKGROUND

Acute intestinal ischemic disorder (AIID) is an uncommon vascular disease with high mortality. According to etiology, it can be categorized into three groups: arterial occlusive mesenteric ischemia (AOMI), mesenteric venous thrombosis (MVT), and nonocclusive mesenteric ischemia (NOMI). This study analyzes the effect of classification on surgical outcome.

PATIENTS AND METHODS

All AIID patients who underwent operative treatment at National Cheng Kung University Hospital between January 1989 and August 2003 were enrolled in this study. Preoperative information on these patients was compared to find predictors of outcome.

RESULTS

Data from 77 patients (49 men and 28 women, median age 70 years) were analyzed. The etiology was AOMI in 30 patients, MVT in 19 patients, and NOMI in 28 patients. Median age was younger in MVT (54 years) than in AOMI (70 years) or NOMI (72 years). In addition, MVT usually involved the jejunum (74%, versus 31% in AOMI and 46% in NOMI), whereas both AOMI and NOMI involved ileum and colon. The patients with AOMI had shorter duration of symptoms and higher ratio of underlying hypertension than those with MVT. The overall mortality rate was 53.2% (41/77). The day 1 and day 30 mortality were 0% and 10.5% in MVT, 16.7% and 30% in AOMI, and 42.9% and 67.9% in NOMI, respectively (P < 0.05). Both the etiology and the APACHE II scores were significant risk factors for day 30 and long-term mortality. The patients with NOMI had higher POSSUM physiologic scores than patients with MVT. The P-POSSUM regression equation can accurately predict mortality.

CONCLUSIONS

Patients with MVT had a more favorable prognosis, whereas those with NOMI had the worst outlook. The APACHE II and POSSUM scoring systems are useful in predicting the clinical outcome. Early diagnosis and classification of AIID patients are useful for aggressive treatment to improve the clinical outcome.

Ischemic colitis during pegylated interferon-alpha and ribavirin therapy for chronic hepatitis C

Rare cases of ischemic colitis associated with interferon-alpha (IFN-alpha) treatment for chronic hepatitis C (HCV) infection and metastatic cancer have been reported. The present study describes the first case of ischemic colitis attributable to pegylated IFN-alpha and ribavirin combination therapy in an HCV-infected patient after 34 weeks of treatment. The clinical presentation, endoscopic appearance and histopathology of the colon were consistent with ischemic colitis, and the patient's symptoms rapidly resolved with cessation of therapy. The association between the therapy and the pathogenesis of ischemic colitis is unclear, but immunoregulatory, vasospastic and procoagulant mechanisms have been proposed. Physicians should be aware of this complication, and should consider it in any HCV-infected patient taking pegylated IFN-alpha and ribavirin who develops abdominal discomfort and gastrointestinal bleeding.

Favorable response to subcutaneous administration of infliximab in rats with experimental colitis

AIM

To investigate the influence of infliximab (Remicade) on experimental colitis produced by 2,4,6,trinitrobenzene sulfonic acid (TNBS) in rats.

METHODS

Thirty-six Wistar rats were allocated into four groups (three groups of six animals each and a fourth of 12 animals). Six more healthy animals served as normal controls (Group 5). Group 1: colitis was induced by intracolonic installation of 25 mg of TNBS dissolved in 0.25 mL of 50% ethanol and infliximab was subcutaneously administered at a dose of 5 mg/kg BW; Group 2: colitis was induced and infliximab was subcutaneously administered at a dose of 10 mg/kg BW; Group 3: colitis was induced and infliximab was subcutaneously administered at a dose of 15 mg/kg BW; Group 4: colitis was induced without treatment with infliximab. Infliximab was administered on d 2-6. On the 7(th) d, all animals were killed. The colon was fixed in 10% buffered formalin and examined by light microscopy for the presence and activity of colitis and the extent of tissue damage. Tumor necrosis factor-alpha (TNF-alpha) and malondialdehyde (MDA) were also measured.

RESULTS

Significant differences concerning the presence of reparable lesions and the extent of bowel mucosa without active inflammation in all groups of animals treated with infliximab compared with controls were found. Significant reduction of the tissue levels of TNF-alpha in all groups of treated animals as compared with the untreated ones was found (0.47+/-0.44, 1.09+/-0.86, 0.43+/-0.31 vs 18.73+/-10.53 respectively). Significant reduction in the tissue levels of MDA was noticed in group 1 as compared to group 4, as well as between groups 2 and 4.

CONCLUSION

Subcutaneous administration of infliximab reduces the inflammatory activity as well as tissue TNF-alpha and MDA levels in chemical colitis in rats. Infliximab at a dose of 5 mg/kg BW achieves better histological results and produces higher reduction of the levels of TNF-alpha than at a dose of 10 mg/kg BW. Infliximab at a dose of 5 mg/kg BW produces higher reduction of tissue MDA levels than at a dose of 15 mg/kg BW.

Intraoperative determination of intestinal viability: a comparison with transserosal pulse oximetry and histopathological examination

BACKGROUND

In this study, we aimed to measure the O2 saturation of ischemic intestinal segments and the relationship between these measures and concomitant pathological gradings.

MATERIALS AND METHODS

We used 14 New Zealand White rabbits, anesthetized with a combination of 80 mg/kg (i.m.) Ketamine hydrochloride and 10 mg/kg Acepromazine (i.m.). The superior mesenteric artery (SMA) was explored, and O2 saturation was measured by pulse oximetry 5 cm proximal to the ileocecal valve at the 0th hour. At the same time a 0.5-cm full-thickness wedge biopsy was taken from the same region. Thereafter, the SMA was ligated and the abdomen was closed. All rabbits were undertaken relaparotomy at the 4th hour; O2 saturation was measured by pulse oximetry at 5 cm away from the region of the first biopsy and a 0.5-cm full-thickness wedge biopsy was taken. The abdomen was then closed. The same procedure was performed at the 8th and the 12th hour. Mucosal hemorrhage, transmural congestion, mucosal necrosis, and transmural necrosis were examined in the specimens.

RESULTS

Pathologically, transmural necrosis was concomitant with 64% O2 saturation (sensitivity: 100%; specificity: 86%). Mucosal necrosis was concomitant with 76% O2 saturation values (sensitivity: 100%; specificity: 75%). Transmural congestion was concomitant with 81% O2 saturation values (sensitivity: 89%; specificity: 58%). Mucosal hemorrhage was concomitant with 91% O2 saturation (sensitivity: 100%; specificity: 31%).

CONCLUSION

O2 saturation measures > 76% may indicate reversible changes as mucosal necrosis, transmural congestion, or mucosal hemorrhage, and O2 saturation measures < 64% may indicate permanent transmural necrosis. As a result, intraoperative evaluation of intestinal viability by pulse oximetry may give us an idea about the degree of pathological changes and subsequently might reduce the number of second-look operations.

Abdominal organ injury after cardiac surgery

Gastrointestinal complications occur in about 2.5% of patients undergoing cardiac surgery, are associated with a high mortality (about 33%), and account for nearly 15% (and perhaps increasing) of all postoperative deaths. The various complications and risk factors are reviewed. Splanchnic ischemia prior to, during, and especially postoperatively appears to be an important cause of these complications. In addition, splanchnic ischemia is hypothesized to be one cause of the systemic inflammatory response syndrome and multiorgan failure that may follow cardiac surgery. The physiology of splanchic perfusion and the effects of cardiac surgery, including cardiopulmonary bypass, on it are reviewed. Finally, possible methods to minimize splanchnic ischemia and reduce the incidence of abdominal complications are discussed.

Anti-phospholipid antibodies restore mesenteric ischemia/reperfusion-induced injury in complement receptor 2/complement receptor 1-deficient mice

Complement receptor 2-deficient (Cr2(-/-)) mice are resistant to mesenteric ischemia/reperfusion (I/R) injury because they lack a component of the natural Ab repertoire. Neither the nature of the Abs that are involved in I/R injury nor the composition of the target Ag, to which recognition is lacking in Cr2(-/-) mice, is known. Because anti-phospholipid Abs have been shown to mediate fetal growth retardation and loss when injected into pregnant mice, we performed experiments to determine whether anti-phospholipid Abs can also reconstitute I/R injury and, therefore, represent members of the injury-inducing repertoire that is missing in Cr2(-/-) mice. We demonstrate that both murine and human monoclonal and polyclonal Abs against negatively charged phospholipids can reconstitute mesenteric I/R-induced intestinal and lung tissue damage in Cr2(-/-) mice. In addition, Abs against beta2 glycoprotein I restore local and remote tissue damage in the Cr2(-/-) mice. Unlike Cr2(-/-) mice, reconstitution of I/R tissue damage in the injury-resistant Rag-1(-/-) mouse required the infusion of both anti-beta2-glycoprotein I and anti-phospholipid Ab. We conclude that anti-phospholipid Abs can bind to tissues subjected to I/R insult and mediate tissue damage.