Intestinal (mesenteric) vasculopathy. I. Acute superior mesenteric arteriopathy and venopathy

Venous Congestive Ischemic Colitis After Sigmoid Colectomy: A Case Report

Venous congestion is a possible cause of ischemic colitis following colorectal surgery. As such, congestive ischemic colitis should be considered in such cases where the mesenteric artery is preserved. Herein, we describe the case of a 73-year-old man who presented to the hospital with a two-week history of difficult defecation and frequent mucous stools and was subsequently diagnosed with refractory ischemic enterocolitis due to venous congestion. The patient had undergone resection of the sigmoid colon cancer with preservation of the inferior mesenteric artery 11 months before presentation. Contrast-enhanced abdominal computed tomography revealed edematous wall thickening on the anal side of the anastomosis. A colonoscopy revealed a normal mucosa extending from the anastomosis to the descending colon; however, mucosal swelling, erythema, and erosion were observed on the rectal side of the anastomosis. Based on these findings, he was diagnosed with ischemic colitis. After two months of ineffective conservative treatment, the patient underwent surgery. Ischemic colitis was diagnosed as venous congestion based on the histopathological examination. Preservation of the mesenteric artery may result in ischemic colitis due to an imbalance between the arterial and venous blood flow. Chronic ischemic colitis due to venous congestion should be considered in cases of mesenteric artery preservation to reduce anastomotic leakage.

Colonoscopy-related colonic ischemia

Colonoscopy is a risk factor for colon ischemia. The colon is susceptible to ischemia due to its minor blood flow compared to other abdominal organs; the etiology of colon ischemia after colonoscopy is multifactorial. The causative mechanisms include splanchnic circulation impairment, bowel preparation, drugs used for sedation, bowel wall ischemia due to insufflation/barotrauma, and introduction of the endoscope. Gastroenterologists must be aware of this condition and its risk factors for risk minimization, early diagnosis, and proper treatment.

Ischemic bowel disease in 2021

Ischemic bowel disease (ISBODI) includes colon ischemia, acute mesenteric ischemia (AMI) and chronic mesenteric ischemia (CMI). Epidemiologically, colon ischemia is the most common type followed by AMI and CMI. There are various risk factors for the development of ISBODI. Abdominal pain is the common presenting symptom of each type. High clinical suspicion is essential in ordering appropriate tests. Imaging studies and colonoscopy with biopsy are the main diagnostic tests. Treatment varies from conservative measures to surgical resection and revascularization. Involvement of multidisciplinary team is essential in managing ISBODI. Although open surgery with revascularization plays an important role, recently there is an increasing interest in percutaneous endovascular treatment.

Acute Mesenteric Infarction: The Chameleon of Acute Abdomen Evaluating the Quality of the Diagnostic Parameters in Acute Mesenteric Ischemia

INTRODUCTION/OBJECTIVE

Acute mesenteric ischemia (AMI) is difficult to diagnose. Since the established parameters have low sensitivity and specificity, the aim of this study is to analyze the diagnostic quality of the established parameters of AMI.

METHODS

All patients that underwent emergency surgery due to suspected diagnosis of mesenteric ischemia at the University Medical Center Hamburg-Eppendorf between 2008 and 2014 were evaluated. Overall, 275 patients were enrolled and pre-, intra- and postoperative data were evaluated.

RESULTS

In 200 patients, a mesenteric ischemia was confirmed intraoperatively, and 75 patients had no ischemia. Comparing these groups, the rate of patients with pH < 7.2 (25 vs. 12%; p = 0.021) and elevated mean CRP level (175 ± 117 mg/L vs. 139 ± 104 mg/L; p = 0.019) was significantly higher in ischemic patients. There was no significant difference in the level of preoperative lactate. Concerning abdominal CT scan, a sensitivity and specificity of 61 and 68%, respectively, was found.

CONCLUSION

New diagnostic parameters are needed. So far, explorative laparotomy is the only reliable diagnostic method to detect mesenteric infarction.

Bowel obstruction complicated by ischemia: analysis of CT findings

PURPOSE

To analyze CT signs of bowel ischemia in patients with surgical bowel obstruction, and thereby improve CT diagnosis in this common clinical scenario. Surgical and histopathological findings were used as the reference standard.

METHODS

We retrospectively analyzed CT findings in patients brought to surgery for bowel obstruction over 13 years. Etiology of obstruction (adhesion, hernia, etc.) was recorded. Specific CT features of acute mesenteric ischemia (AMI) were analyzed, including bowel wall thickening, mucosal hypoenhancement, and others.

RESULTS

173 cases were eligible for analysis. 21% of cases were positive for bowel ischemia. Volvulus, internal hernia, and closed-loop obstructions showed ischemia rates of 60%, 43%, and 43%; ischemia rate in obstruction from simple adhesion was 21%. Patients with bowel obstruction related to malignancy were never ischemic. Sensitivities and specificities for CT features predicting ischemia were calculated, with wall thickening, hypoenhancement, and pneumatosis showing high specificity for ischemia (86%-100%).

CONCLUSION

Wall thickening, hypoenhancement, and pneumatosis are highly specific CT signs of ischemia in the setting of obstruction. None of the evaluated CT signs were found to be highly sensitive. Overall frequency of ischemia in surgical bowel obstruction is 21%, and 2-3 times that for complex obstructions (volvulus, closed loop, etc.). Obstructions related to malignancy virtually never become ischemic.

Contemporary Management of Acute Mesenteric Ischemia in the Endovascular Era

Objective:

Acute mesenteric ischemia is a rare disease entity associated with high morbidity and mortality. Disparate etiologies and nonspecific symptoms make the diagnosis challenging and often result in delayed diagnosis and intervention. Open laparotomy with mesenteric revascularization and resection of necrotic bowel has been considered the gold standard of care. With recent advances in percutaneous catheter-directed techniques, multiple retrospective studies have demonstrated the outcomes of endovascular therapy. Herein, we review the etiology, presentation, and diagnosis of acute mesenteric ischemia with contemporary outcomes associated with both open and endovascular treatments.

Methods:

The PubMed electronic database was queried in the English language using the search words mesenteric, acute ischemia, embolism, thromboembolism, thrombosis, revascularization, and endovascular in various combinations. Abstracts of the relevant titles were examined to confirm their relevance and the full articles then extracted. References from extracted articles were checked for any additional relevant articles. This systematic review encompassed literature for the past 5 years (between 2011 and 2016).

Results:

Early diagnosis and intervention improves acute mesenteric ischemia outcomes. Early restoration of mesenteric flow minimizes morbidity and mortality. In comparison to open laparotomy with mesenteric revascularization and resection of necrotic bowel, several retrospective studies using administrative data and single-center chart reviews demonstrate noninferior outcomes of an endovascular first approach in acute arterial mesenteric occlusion.

Conclusions:

For acute mesenteric arterial occlusive disease, both endovascular and open revascularization techniques are viable options. Although there is lack of level 1 evidence, single-center retrospective studies and administrative database studies demonstrated that an endovascular first approach may have improved outcomes in the immediate postoperative period. However, selection and other bias in these studies necessitate the need for definitive randomized prospective studies between endovascular and open mesenteric intervention. In contrast, mesenteric venous thrombosis may be treated with systemic anticoagulation without surgical revascularization. Catheter-directed thrombectomy and thrombolysis can be considered at the discretion of the clinician.

Mesenteric ischaemia: an overview of diagnostic and therapeutic best practice

Mesenteric ischaemia is relatively uncommon, but is an important diagnosis to remember as it can lead to significant morbidity and mortality. Improvements in clinical imaging technology have made rapid diagnosis and treatment possible, but this relies on awareness of the condition. This article summarizes current best practice in diagnosis and management of mesenteric ischaemia to guide the clinician.

Umbilical mesenchymal stromal cells provide intestinal protection through nitric oxide dependent pathways

BACKGROUND

Umbilical-derived mesenchymal stromal cells (USCs) have shown promise in the protection of ischemic organs. We hypothesized that USCs would improve mesenteric perfusion, preserve intestinal histological architecture, and limit inflammation by nitric oxide-dependent mechanisms following intestinal ischemia/reperfusion (IR) injury.

METHODS

Adult wild-type C57BL/6J (WT) and endothelial nitric oxide synthase knock out (eNOS KO) mice were used: (1) WT IR + vehicle, (2) WT IR + USC, (3) eNOS KO IR + vehicle, and (4) eNOS KO IR + USC. Mice were anesthetized, and a midline laparotomy was performed. The superior mesenteric artery was clamped with a nonoccluding clamp for 60-min. Following IR, mice were treated with an injection of 250 μL phosphate buffered saline or 2 × 10⁶ USCs suspended in 250-μL phosphate buffered saline solution. Mesenteric perfusion images were acquired using laser Doppler imaging. Perfusion was analyzed as a percentage of baseline. At 24 h, mice were euthanized, and intestines were harvested. Intestines were evaluated for injury, and data were analyzed using the Mann-Whitney or Kruskal-Wallis tests.

RESULTS

Intestinal mesenteric perfusion was significantly improved in WT mice treated with USC therapy compared with eNOS KOs. Intestinal histological architecture was preserved with USC therapy in WT mice. However, in eNOS KO mice, this benefit was abolished. Finally, the presence of several cytokines and growth factors were significantly improved in WT mice compared with eNOS KO mice treated with USCs.

CONCLUSIONS

The benefits of USC-mediated therapy following intestinal IR injury likely occur via nitric oxide-dependent pathways. Further studies are required to define the molecular mechanisms by which USCs activate endothelial nitric oxide synthase to bring about their protective effects.

A Systematic Review of the Clinical Presentation, Diagnosis, and Treatment of Small Bowel Obstruction

PURPOSE OF REVIEW

This study aimed to systematically review small bowel obstruction (SBO), focusing on recent changes in diagnosis/therapy.

RECENT FINDINGS

SBO incidence is about 350,000/annum in the USA. Etiologies include adhesions (65%), hernias (10%), neoplasms (5%), Crohn's disease (5%), and other (15%). Bowel dilatation occurs proximal to obstruction primarily from swallowed air and secondarily from intraluminal fluid accumulation. Dilatation increases mural tension, decreases mucosal perfusion, causes bacterial proliferation, and decreases mural tensile strength that increases bowel perforation risks. Classical clinical tetrad is abdominal pain, nausea and emesis, abdominal distention, and constipation-to-obstipation. Physical exam may reveal restlessness, acute illness, and signs of dehydration and sepsis, including tachycardia, pyrexia, dry mucous membranes, hypotension/orthostasis, abdominal distention, and hypoactive bowel sounds. Severe direct tenderness, involuntary guarding, abdominal rigidity, and rebound tenderness suggest advanced SBO, as do marked leukocytosis, neutrophilia, bandemia, and lactic acidosis. Differential diagnosis includes postoperative ileus, narcotic bowel, colonic pseudo-obstruction, mesenteric ischemia, and large bowel obstruction. Medical resuscitation includes intravenous hydration, correcting electrolyte abnormalities, intravenous antibiotics, nil per os, and nasoenteral suction. Abdominal CT with oral and intravenous gastrografin contrast is highly sensitive and specific in detecting/characterizing SBO. SBO usually resolves with medical therapy but requires surgery, preferentially by laparoscopy, for unremitting total obstruction, bowel perforation, severe ischemia, or clinical deterioration with medical therapy. Overall mortality is 10% but increases to 30% with bowel necrosis/perforation. Key point in SBO is early diagnosis, emphasizing abdominal CT; aggressive medical therapy including rehydration, antibiotics, and nil per os; and surgery for failed medical therapy.

Mesenteric ischemia

This article reviews the presentation, diagnosis, evaluation, and treatment of the various forms of mesenteric ischemia, including acute and chronic ischemia. In addition, nonocclusive mesenteric ischemia and median arcuate ligament compressive syndrome are covered. The goals are to provide a structured and evidence-based framework for the evaluation and management of patients with these intestinal ischemia syndromes. Special attention is given to avoiding typical pitfalls in the diagnostic and treatment pathways. Operative techniques are also briefly discussed, including an evidence-based review of newer endovascular techniques.

Ischemic bowel syndromes

Atherosclerotic vascular disease involving the mesenteric arteries occurs frequently in the elderly population. Although the prevalence of ischemic bowel disease is difficult to determine, acute mesenteric ischemia (AMI) has been reported to cause in 1 in 1000 hospital admissions, whereas chronic mesenteric ischemia (CMI) is estimated to affect 1 in 100,000 individuals. Mesenteric ischemia generally manifests in its chronic form as postprandial abdominal pain resulting in significant weight loss, and in its acute form as an abrupt development of abdominal pain, lower gastrointestinal bleeding, and subsequent intestinal necrosis. This article discusses the cause, clinical manifestations, diagnosis, and management of AMI and CMI.

Interatrial block - a novel risk factor for acute mesenteric ischemia

Interatrial block (IAB; P-wave duration ≥110 milliseconds) denotes a conduction delay between the two atria. IAB has been shown to have a strong correlation with atrial arrhythmias, left atrial enlargement, left atrial electromechanical dysfunction and cerebral thromboembolism. Our study sought to determine whether there was an increased incidence of IAB in patients with acute occlusive mesenteric ischemia. Medical records of patients admitted with a diagnosis of acute mesenteric ischemia (AMeI) from January 2009 to March 2011 were reviewed retrospectively. One hundred seventy-two out of 342 patients reviewed, qualified after excluding mechanical surgical obstruction, suspected non-occlusive mesenteric ischemia due to shock/hypoperfusion, and mesenteric venous thrombosis. Of 99 patients who were in normal sinus rhythm without prior history of atrial arrhythmia, 88 (88.9 %) had IAB. This was more than twice the average prevalence of IAB of two general hospital populations (41 % and 47 % as demonstrated by two previous studies). IAB may thus represent a novel risk factor for AMeI as it does for embolic stroke.

[A case of superior mesenteric venous thrombosis due to protein C deficiency in a patient with duodenal ulcer bleeding]

Mesenteric venous thrombosis is a clinically very rare disease, and may cause bowel infarction and gangrene. Difficulty in the diagnosis the disease due to its non-specific symptoms and low prevalence can cause a clinically fatal situation. Mesenteric venous thrombosis may be caused by both congenital and acquired factors, and protein C deficiency, which is a very rare genetic disorder, is one of many causes of mesenteric thrombosis. The authors experienced a case of mesenteric venous thrombosis caused by protein C deficiency in a patient with duodenal ulcer bleeding, so here we report a case together with literature review.

A rare cause of chronic mesenteric ischemia from fibromuscular dysplasia: a case report

Introduction

Chronic mesenteric ischemia is a condition that is classically associated with significant atherosclerosis of the abdominal arteries, causing postprandial abdominal pain out of proportion to physical examination. The abdominal pain is exacerbated after meals due to the shunting of blood away from the intestines to the stomach, causing relative ischemia. More than 95% of chronic mesenteric ischemia cases are due to atherosclerosis. We report the first known case of chronic mesenteric ischemia from fibromuscular dysplasia. To the best of our knowledge, this is also the first known case in the literature where postprandial abdominal pain was the presenting symptom of fibromuscular dysplasia.

Case presentation

A 44-year-old Caucasian woman with a history of hypertension and preeclampsia, who had taken oral contraceptive pills for 15 years, presented with an intractable, colicky abdominal pain of two weeks duration. This abdominal pain worsened with oral intake. It was also associated with diarrhea and vomiting. Physical examination revealed stage III hypertension out of proportion to her risk factors and diffuse abdominal pain without peritoneal signs. An abdominal computed tomography scan, completed in the emergency room, revealed nonspecific colitis. Laboratory work revealed leukocytosis with a left shift, an erythrocyte sedimentation rate of 79 and a C-reactive protein level of 100. She was started on intravenous flagyl and intravenous ciprofloxacin. However, all microbial cultures were negative including three cultures for clostridium difficile. Urine analysis revealed nephritic range proteinuria. The laboratory profile was within normal limits for perinuclear-anti-neutrophil cytoplasmic antibody, cytoplasmic-anti-neutrophil cytoplasmic antibody, anti-saccharomyces cerevisiae antibody, antinuclear antibody test, celiac profile, lactate, carbohydrate antigen-125 and thyroid stimulating hormone. A colonoscopy was completed, which revealed diffuse colonic lymphoid reactive hyperplasia. A small bowel series was negative for any inflammation. An indium scan, pan-computed tomography scan and transvaginal ultrasound were also negative. Magnetic resonance angiography of her abdomen revealed proximal superior mesenteric artery stenosis, which was confirmed by computed tomography angiogram findings of severe proximal and distal superior mesenteric artery stenosis, consistent with the appearance of fibromuscular dysplasia on angiography in the absence of vasculitis or atherosclerotic disease. The patient's superior mesenteric artery stenosis was subsequently angioplastied suboptimally and had to be stented with an Angioplus stent. One month after she was admitted, her abdominal pain and tolerance to oral feeds improved tremendously.

Conclusion

Fibromuscular dysplasia most commonly presents with renal artery stenosis, which rarely causes abdominal pain. This case illustrates how fibromuscular dysplasia can present as a rare cause of chronic mesenteric ischemia, similar to chronic mesenteric ischemia from atherosclerosis.

Left atrial appendage thrombus detected by intraoperative transesophageal echocardiography in a patient with acute small bowel infarction -A case report-

Acute mesenteric ischemia and infarction is an emergent situation associated with high mortality, commonly due to emboli or thrombosis of the mesenteric arteries. Embolism to the mesenteric arteries is most frequently due to a dislodged thrombus from the left atrium, left ventricle, or cardiac valves. We report a case of 70-year-old female patient with an acute small bowel infarction due to a mesenteric artery embolism dislodged from a left atrial appendage detected by intraoperative transesophageal echocardiography and followed by anticoagulation therapy.

The effects of sildenafil on the functional and structural changes of ileum induced by intestinal ischemia-reperfusion in rats

There is evidence demonstrating the protective effect of cGMP-specific phosphodiesterase type 5 (PDE5) inhibitors against ischemic injury in certain tissues. In this study, sildenafil, a potent inhibitor of PDE5, was tested for its beneficial effects in the prevention of disrupted ileal contractility and damage to tissue caused by intestinal ischemia-reperfusion in rats. Male Sprague-Dawley rats were divided into four groups: sham-operated; sham-operated with sildenafil pretreatment; ischemia-reperfusion with vehicle pretreatment; and ischemia-reperfusion with sildenafil pretreatment. The superior mesenteric artery was occluded for 45 min to induce ischemia. The clamp was then removed for a 60 min period of reperfusion. Sildenafil (1 mg/kg, i.v.) or saline was administered prior to the surgical procedure in the ischemia-reperfusion and sham-operated groups. Isometric contractions of the ileal segments in response to acetylcholine or electrical field stimulation (120 V, 2 ms pulse for 5 s, 1-20 Hz) were recorded. Additionally, levels of thiobarbituric acid reactive substances and myeloperoxidase activity were measured in addition to a histopathological examination of the ileal tissue. The contractions induced by both acetylcholine and electrical field stimulations were markedly inhibited after ischemia-reperfusion. Sildenafil pretreatment (1 mg/kg, i.v.) abolished the inhibition of responses to acetylcholine. The increased levels of thiobarbituric acid reactive substances and myeloperoxidase activity caused by ischemia-reperfusion were reversed to control levels with sildenafil pretreatment. Intestinal ischemia-reperfusion caused severe ischemic injury in rat ileum, which was prevented by sildenafil. These results suggest that sildenafil pretreatment has a protective effect against ileal dysfunction and damage induced by intestinal ischemia-reperfusion in the rat.

Endovascular treatment of arterial mesenteric ischaemia: a retrospective review

Mesenteric ischaemia is a condition that has traditionally been managed surgically. It poses a challenging diagnostic and therapeutic problem, particularly in the acute setting. We review a small series of eight patients managed with endovascular techniques for either acute or chronic mesenteric ischaemia at The Royal Melbourne Hospital, from 1997 to 2002. We describe our results and relate these to the recent published literature regarding endovascular and surgical management of mesenteric ischaemia. Our experience confirms the valuable contribution of angioplasty and stenting in chronic mesenteric ischaemia, which compares favourably with surgery with regards to complication rates and mortality. We suggest the need for further studies to compare the long-term efficacy of endovascular techniques compared with surgery in the management of chronic mesenteric ischaemia. Furthermore, we demonstrate a role for endovascular management in acute mesenteric ischaemia, in the appropriate clinical setting.

Colonic ischemia: an under-recognized cause of lower gastrointestinal bleeding

We described signs and symptoms of patients who present to an Emergency Department (ED) with intestinal ischemia and compare clinical course and outcomes of patients with mesenteric vs. colonic ischemia. We retrospectively reviewed charts of 100 patients discharged from our hospital with an ICD-9 code for mesenteric or intestinal ischemia. Compared to patients with mesenteric ischemia, those with colonic ischemia were older (61 vs. 77 years, respectively; p = 0.002), were more likely to present with gastrointestinal (GI) bleeding (11 vs. 90%, respectively; p < 0.001), but were less likely to report abdominal pain as their primary complaint (89% vs. 10%, respectively; p < 0.001) or to receive a correct ED diagnosis (75% vs. 9%, respectively; p < 0.001). Patients with colonic ischemia frequently presented with gross GI bleeding, and were often misdiagnosed in the ED. For timely treatment of a potentially serious condition, the diagnosis of intestinal ischemia should be considered in ED patients presenting with GI bleeding and appropriate risk factors.

Lansoprazole ameliorates intestinal mucosal damage induced by ischemia-reperfusion in rats

AIM: To investigate the protective effect of lansoprazole on ischemia and reperfusion (I/R)-induced rat intestinal mucosal injury in vivo.

METHODS: Intestinal damage was induced by clamping both the superior mesenteric artery and the celiac trunk for 30 min followed by reperfusion in male Sprague-Dawley rats. Lansoprazole was given to rats intraperitoneally 1 h before vascular clamping.

RESULTS: Both the intraluminal hemoglobin and protein levels, as indices of mucosal damage, significantly increased in I/R-groups comparion with those of sham-operation groups. These increases in intraluminal hemoglobin and protein levels were significantly inhibited by the treatment with lansoprazole at a dose of 1 mg/kg. Small intestine exposed to I/R resulted in mucosal inflammation that was characterized by significant increases in thiobarbituric acid-reactive substances (TBARS), tissue-associated myeloperoxidase activity (MPO), and mucosal content of rat cytokine-induced neutrophil chemoattractant-1 (CINC-1). These increases in TBARS, MPO activities and CINC-1 content in the intestinal mucosa after I/R were all inhibited by pretreatment with lansoprazole at a dose of 1 mg/kg. Furthermore, the CINC-1 mRNA expression was increased during intestinal I/R, and this increase in mRNA expression was inhibited by treatment with lansoprazole.

CONCLUSION: Lansoprazole inhibits lipid peroxidation and reduces development of intestinal mucosal inflammation induced by I/R in rats, suggesting that lansoprazole may have a therapeutic potential for I/R injury.

Angioplasty and stenting of the superior mesenteric artery in acute mesenteric ischaemia

Acute mesenteric ischaemia is a challenging diagnostic problem with a very high mortality. Traditionally, laparotomy is required for definitive management. We describe a successful case of angioplasty and stenting of the superior mesenteric artery in a surgically unfit patient. We recommend that stenting be considered only in situations where the diagnosis has been made prior to bowel infarction, and if the patient poses a poor operative risk.

Suppression of intestinal ischemia-reperfusion injury by a specific peroxisome proliferator-activated receptor-gamma ligand, pioglitazone, in rats

Neutrophil activation and tumor necrosis factor-alpha (TNF-alpha) induction play a critical role in ischemia-reperfusion-induced intestinal inflammation. Peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, has recently been implicated as a regulator of inflammatory responses. The aim of the present study was to determine whether pioglitazone, a specific PPAR-gamma ligand, can ameliorate reperfusion-induced intestinal injury in rats, and whether the agent can inhibit the increase in neutrophil accumulation associated with TNF-alpha expression. Intestinal damage was induced in male Sprague-Dawley rats by clamping the superior mesenteric artery for 30 min followed by reperfusion. Reperfusion after 30 min ischemia resulted in an increase in luminal protein concentrations with levels reaching a maximum after 60 min of reperfusion. In contrast, pretreatment with pioglitazone 2 h before ischemia inhibited the increase in luminal protein concentrations after 60 min reperfusion in a dose-dependent manner (1-30 mg/kg). The increase in tissue-associated myeloperoxidase activity, an index of neutrophil infiltration, after reperfusion was significantly inhibited by pretreatment with pioglitazone. Pioglitazone also inhibited increases in intestinal TNF-alpha protein and mRNA expression determined by ELISA and RT-PCR, respectively. In conclusion, activation of PPAR-gamma may represent a novel approach to the treatment of intestinal inflammation induced by ischemia-reperfusion.

Abdominal pain during pregnancy

Numerous medical, surgical, psychiatric, gynecologic, and obstetric disorders can cause abdominal pain during pregnancy. The patient history, physical examination, laboratory data, and radiologic findings usually provide the diagnosis. The pregnant woman has physiologic alterations that affect the clinical presentation, including atypical normative laboratory values. Abdominal ultrasound is generally the recommended radiologic imaging modality; roentgenograms are generally contraindicated during pregnancy because of radiation teratogenicity. Concerns about the fetus limit the pharmacotherapy. Maternal and fetal survival have recently increased in many life-threatening conditions, such as ectopic pregnancy, appendicitis, and eclampsia, because of improved diagnostic technology, better maternal and fetal monitoring, improved laparoscopic technology, and earlier therapy.

Radiologic diagnosis and treatment of gastrointestinal hemorrhage and ischemia

Major breakthroughs in catheter, guidewire, and other angiographic equipment currently allow interventional radiologists to diagnose massive life-threatening upper and lower GI hemorrhage and to stop the bleeding safely and effectively using superselective catheterization and microcoil embolization. Similarly, the interventional radiologist can treat acute intestinal ischemia safely and effectively with selective catheterization and papaverine administration and treat chronic mesenteric ischemia by percutaneous angioplasty and stent placement. A multidisciplinary approach, including the gastroenterologist, radiologist, and surgeon, is critical in managing GI bleeding and intestinal ischemia, particularly in patients at high risk or presenting as diagnostic dilemmas.

Role of induced nitric oxide in the initiation of the inflammatory response after postischemic injury

The aim of this study was to investigate the role of inducible nitric oxide (NO) synthase (iNOS) and NO on the modulation of the inflammatory response caused by splanchnic ischemia and reperfusion. A severe model of mesenteric ischemia and reperfusion was produced by subjecting mice to 45 min occlusion followed by reperfusion of the superior mesenteric artery and celiac trunk. In this experimental protocol, wild-type mice treated with GW274150 (5 mg/kg i.p.), a novel, potent, and selective inhibitor of iNOS activity, and mice lacking of the gene for iNOS (iNOS 'knock-out', iNOS-KO) exhibited no difference in the rate of mortality in comparison with wild-type control mice. In a second study, using a less severe model of mesenteric injury obtained by occlusion of the superior mesenteric artery only for 45 min, we evaluated the survival rate. Under these conditions, wild-type mice treated with GW274150 and iNOS-KO mice showed a significant difference in the rate of mortality in comparison with wild-type. Therefore, wild-type mice treated with GW274150 and iNOS-KO mice when compared with wild-type littermates showed a significant reduction of the mesenteric injury, upregulation of P-selectin and intercellular adhesion molecule-1, and neutrophil infiltration, as well as a significant inhibition of the degree of oxidative and nitrosative damage, indicated by malondialdehyde levels, formation of nitrotyrosine and poly(ADP-ribose)polymerase (PARP), respectively. Plasma levels of the proinflammatory cytokines tumour necrosis factor-alpha, interleukin (IL) 6, and IL-1beta were also significantly reduced in iNOS-KO mice in comparison with control wild-type mice. Wild-type mice treated with GW274150 and iNOS-KO mice were also found to have reduced activation of the transcriptional factor nuclear factor-kappaB in the ileum. These results suggest that the induction of iNOS and NO production are essential for the upregulation of the inflammatory response in splanchnic ischemia/reperfusion and participate in end organ damage under these conditions.

Isolated Superior Mesenteric Artery Vasculitis with Response to Glucocorticoids

This report describes a patient with abdominal pain at presentation, which on angiography was found to be caused by vasculitis limited to the superior mesenteric artery. He was treated with oral glucocorticoids after an initial 5-day course of pulse therapy and obtained excellent relief of symptoms. Steroids were tapered over 8 months. Repeat angiography revealed complete resolution of the vasculitis with a residual aneurysm of a branch of the left gastric artery, which was resected to avoid the risk of rupture. Histologic analysis revealed thickened intima with myxoid degeneration and no evidence of active vasculitis. Extensive laboratory and clinical investigations did not reveal an underlying connective tissue disorder to account for the gastrointestinal vasculitis. This report of an angiographically defined regional vasculitis involving the superior mesenteric artery with complete clinical as well as radiologic resolution on treatment with glucocorticoids alone emphasizes the need to differentiate between an isolated or regional vasculitis, which has an excellent prognosis, to avoid subjecting the patient to cytotoxic therapy with significant toxicities.

Mesenteric Vascular Disease

The clinical presentation of mesenteric ischemia depends on the site, grade, and cause of vascular obstruction; the degree of collateralization; and the stage of disease. Patients in the early stages of ischemia typically have abdominal pain out of context with an unimpressive abdominal examination. It is during this stage that medical and endovascular techniques can be most effective. After signs of peritonitis are present (signaling bowel infarction), surgical exploration and bowel resection are necessary. Chronic mesenteric ischemia induced by stenotic arteriosclerosis should be treated with percutaneous transluminal angioplasty and stenting (PTAS). Chronic mesenteric arterial occlusions are better handled with bypass surgery. Acute embolic or thrombotic ischemia is surgically treated after medical resuscitation. Endovascular techniques may be applicable in selected patients (usually in those with subacute symptoms), but thrombolytic therapy should be avoided if intestinal infarction is suspected. Non-occlusive mesenteric ischemia requires a rapid correction of the predisposing hypotension or sepsis followed by papaverine infusion into the superior mesenteric artery. Celiac artery compression syndrome requiring treatment is best treated with surgical release of the median arcuate ligament; PTAS should not be performed. Mesenteric venous occlusion should be treated with anticoagulation. Surgical exploration and bowel resection is necessary in patients presenting with acute signs and symptoms, reserving thrombolytic therapy for early, mildly symptomatic, thromboses in whom there is no contraindication to thrombolysis.

Absence of endogenous interleukin 10 enhances early stress response during post-ischaemic injury in mice intestine

BACKGROUND

Interleukin 10 (IL-10) exerts a wide spectrum of regulatory activities in immune and inflammatory responses.

AIMS

The aim of this study was to investigate the role of endogenous IL-10 on modulation of the early inflammatory response after splanchnic ischaemia and reperfusion.

METHODS

Intestinal damage was induced by clamping the superior mesenteric artery and the coeliac trunk for 45 minutes followed by reperfusion in IL-10 deficient mice (IL-10(-/-)) and wild-type controls.

RESULTS

IL-10(-/-) mice experienced a higher rate of mortality and more severe tissue injury compared with wild-type mice subjected to ischaemia and reperfusion. Splanchnic injury was characterised by massive epithelial haemorrhagic necrosis, upregulation of P-selectin and intercellular adhesion molecule 1, and neutrophil infiltration. The degree of oxidative and nitrosative damage was significantly higher in IL-10(-/-) mice than in wild-type littermates, as indicated by elevated malondialdehyde levels and formation of nitrotyrosine. Plasma levels of the proinflammatory cytokines tumour necrosis factor alpha and interleukin 6 were also greatly enhanced in comparison with wild-type mice. These events were preceded by increased immunostaining and activity of the stress regulated c-Jun NH(2) terminal kinase and activation of the transcription factor activator protein 1 in the cellular nuclei of damaged tissue.

CONCLUSIONS

These data demonstrate that endogenous IL-10 exerts an anti-inflammatory role during reperfusion injury, possibly by regulating early stress related genetic response, adhesion molecule expression, neutrophil recruitment, and subsequent cytokine and oxidant generation.

Acute intestinal ischaemia

The subsets of acute mesenteric ischaemia include mesenteric arterial occlusion (by embolus or thrombosis), mesenteric venous thrombosis and non-occlusive mesenteric ischaemia. Despite advances in pathophysiology, laboratory diagnosis and imaging techniques, acute mesenteric ischaemia is still associated with mortality rates of more than 60% and continues to be a challenging diagnostic problem. The key to a better outcome (and the main problem in clinical practice) is early diagnosis. Clinical presentation may be unspecific, but is often characterized by an initial discrepancy between severe subjective pain and relatively unspectacular findings on physical examination. Up to now, there are no simple and non-invasive diagnostic tests of sufficient sensitivity and specificity; thus, angiography remains the cornerstone of diagnosis and should be performed early in all patients in which mesenteric ischaemia is a realistic differential diagnosis. Treatment for obstructive mesenteric arterial syndromes and most patients with mesenteric venous thrombosis is surgical, whereas non-occlusive mesenteric ischaemia may be managed by pharmacological vasodilation.

Acute gastrointestinal bleeding in the intensive care unit. The gastroenterologist's perspective

Although SRES-associated hemorrhage previously constituted a significant cause of bleeding in the ICU, improvements in ICU management and the institution of prophylactic measures in high-risk patients have significantly reduced SRES-associated hemorrhage since the 1980s. Antacids, H2-receptor antagonists, and sucralfate have been shown to be effective in preventing clinically significant bleeding resulting from SRES, particularly when the intragastric pH is maintained at greater than 4. A selective approach should be adopted in SRES prophylaxis: Patients on mechanical ventilation, with coagulopathy, or with two of the other known risk factors should receive prophylaxis. Although the drug of choice depends to some extent on local preferences, an H2-receptor antagonist by continuous intravenous infusion may represent the best option. No pharmacologic therapy is of proven value once hemorrhage begins, but the current interventional techniques are effective in controlling hemorrhage. Gastrointestinal bleeding from NOMV has become less common with improvements in the hemodynamic monitoring of critically ill patients, but this disease must always be considered when lower gastrointestinal bleeding occurs in the context of relative hypoperfusion. For SRES and NOMV, treatment of the underlying disease or diseases is the optimal route to prevention.

Gastrointestinal bleeding associated with myocardial infarction

Gastrointestinal (GI) bleeding associated with myocardial infarcation (MI) often presents as a distinct syndrome that differs from either disease alone. MI is frequently overlooked in the setting of severe GI bleeding because the symptoms and signs of MI are frequently overshadowed by the severe bleeding. GI bleeding, particularly when massive, may precipitate MI from hypovolemia, hemodynamic compromise, and myocardial hypoperfusion. Esophagogastroduodenoscopy is safe in relatively clinically stable patients after MI and is indicated to evaluate significant upper GI bleeding.

Acute gastrointestinal bleeding in the intensive care unit. The intensivist's perspective

Gastrointestinal (GI) hemorrhage is a common and potentially lethal medical emergency that is a common cause for intensive care unit admission. The intensivist plays an important role as a member of the medical team managing the patient with GI bleeding who is at high risk because of severe bleeding, comorbidity, or the presence of endoscopic stigmata of recent hemorrhage. This article presents the intensivist's approach to GI hemorrhage in initial patient assessment, triage, resuscitation, specialist consultation, diagnostic evaluation, and medical therapy. This article focuses on types of GI bleeding of particular concern to the intensivist, including esophageal variceal bleeding, stress-related GI bleeding, and GI bleeding associated with myocardial infarcation.