Unchanged high mortality rates from acute occlusive intestinal ischemia: six year review

Acute abdominal pain in the older adult

Abdominal pain in older adults is a concerning symptom common to a variety of diagnoses with high morbidity and mortality. Organizing the differential into categories based on pathology (inflammatory, obstructive, vascular, or other causes) provides a framework for the history, physical, and diagnostic studies. An organized approach and treatment and considerations specific to the geriatric population are discussed.

High APACHE II score and long length of bowel resection impair the outcomes in patients with necrotic bowel induced hepatic portal venous gas

Background

Hepatic portal venous gas (HPVG) is a rare but potentially lethal condition, especially when it results from intestinal ischemia. Since the literatures regarding the prognostic factors of HPVG are still scarce, we aimed to investigate the risk factor of perioperative mortality in this study.

Methods

We analyzed data for patients with intestinal ischemia induced HPVG by chart review in our hospital between 2000 and 2007. Factors associated with perioperative mortality were specifically analyzed.

Results

There were 22 consecutive patients receiving definite bowel resection. 13 cases (59.1%) died after surgical intervention. When analyzing the mortality in patients after bowel resections, high Acute Physiology And Chronic health Evaluation (APACHE) II score (p < 0.01) and longer length of bowel resection (p = 0.047) were significantly associated with mortality in univariate analyses. The complication rate was 66.7% in alive patients after definite bowel resection.

Conclusions

Bowel resection was the only potential life-saving therapy for patients with mesenteric ischemia induced HPVG. High APACHE II score and severity of underlying necrotic bowel determined the results in patients after bowel resection.

A comparison of endovascular revascularization with traditional therapy for the treatment of acute mesenteric ischemia

OBJECTIVES

Few centers have adopted endovascular therapy for the treatment of acute mesenteric ischemia (AMI). We sought to evaluate the effect of endovascular therapy on outcomes for the treatment of AMI.

METHODS

A single-center, retrospective cohort review was performed on all consecutive patients with thrombotic or embolic AMI presenting between 1999 and 2008. Patients with mesenteric venous thrombosis, nonocclusive mesenteric ischemia, and ischemia associated with aortic dissection were excluded. Demographic factors, preoperative metabolic status, and etiology were compared. Primary clinical outcomes included endovascular technical success, operative complications, and in-hospital mortality.

RESULTS

Seventy consecutive patients were identified with AMI (mean age, 64 ± 13 years). Etiology of mesenteric ischemia was 65% thrombotic and 35% embolic occlusions. Endovascular revascularization was the preferred treatment (81%) vs operative therapy (19%). Successful endovascular treatment was achieved in 87%. Endovascular therapy required laparotomy in 69% vs traditional therapy in 100% (P < .05), with a median 52-cm necrotic bowel resected (interquartile range [IQR], 11-140 cm) vs 160 cm (IQR, 90-250 cm; P < .05), respectively. Acute renal failure and pulmonary failure occurred less frequently with endovascular therapy (27% vs 50%; P < .05 and 27% vs 64%; P < .05). Successful endovascular treatment resulted in a mortality rate of 36% compared with 50% (P < .05) with traditional therapy, whereas the mortality rate for endovascular failures was 50%. Endovascular therapy was associated with improved mortality in thrombotic AMI (odds ratio, 0.10; 95% confidence interval, 0.10-0.76; P < .05).

CONCLUSIONS

Endovascular therapy has altered the management of AMI, and there are measurable advantages to this approach. Using endovascular therapy as the primary modality for AMI reduces complications and improves outcomes.

Intestinal ischemia: current treatment concepts

PURPOSE

Mesenteric ischemia is a condition well-known among physicians treating patients with abdominal symptoms. Even so, mortality rates have not decreased significantly over the last decades. The purpose of this article is to review current treatment concepts of acute and chronic mesenteric ischemia.

RESULTS

Early diagnosis is one of the most important features that determine a patient's prognosis. Conventional angiography and multidetector computed tomography are therefore appropriate to quickly diagnose mesenteric ischemia, the latter being commonly more available. Once a patient presents with signs of peritonitis, instant laparotomy is indicated, and infarcted bowel segments need to be resected, followed by a second-look operation if necessary. If bowel necrosis is clinically not suspected, different approaches should be applied according to source and nature of mesenteric ischemia. Besides established surgical treatment concepts, more and more interventional procedures are developed and evaluated. However, superiority of these new techniques could only be shown for selected patient groups so far. In chronic mesenteric ischemia, interventional approaches seem to be an attractive alternative in patients who are in a condition too bad to undergo surgery. Patients with colonic ischemia are treated best in a conservative manner and by resolving the underlying cause, if identified.

CONCLUSION

Patients with acute mesenteric ischemia are still at highest risk for a fatal course of disease. New diagnostic and therapeutic developments have not been tested in larger studies yet, neither has any of these methods led to an increased survival in studies published so far. Taken together, mesenteric ischemia requires high awareness, earliest possible diagnosis, and treatment by an experienced interdisciplinary team of gastroenterologists, radiologists, and surgeons.

Endovascular and open surgery for acute occlusion of the superior mesenteric artery

BACKGROUND

Acute thromboembolic occlusion of the superior mesenteric artery (SMA) is associated with high mortality. Recent advances in diagnostics and surgical techniques may affect outcome.

METHODS

Through the Swedish Vascular Registry (Swedvasc), 121 open and 42 endovascular revascularizations of the SMA at 28 hospitals during 1999 to 2006 were identified. Patient medical records were retrieved, and survival was analyzed with multivariate Cox-regression analysis.

RESULTS

The number of revascularizations of the SMA increased over time with 41 operations in 2006, compared to 10 in 1999. Endovascular approach increased sixfold by 2006 as compared to 1999. The endovascular group had thrombotic occlusion (P < .001) and history of abdominal angina (P = .042) more often, the open group had atrial fibrillation more frequently (P = .031). All the patients in the endovascular group, but only 34% after open surgery, underwent completion control of the vascular reconstruction (P < .001). Bowel resection (P < .001) and short bowel syndrome (SBS; P = .009) occurred more frequently in the open group. SBS (hazard ratio [HR], 2.6; 95% confidence interval [CI], 1.3-5.0) and age (HR, 1.03/year; 95% CI, 1.00-1.06) were independently associated with increased long-term mortality. Thirty-day and 1-year mortality rates were 42% vs 28% (P = .03) and 58% vs 39% (P = .02), for open and endovascular surgery, respectively. Long-term survival after endovascular treatment was better than after open surgery (log-rank, P = .02).

CONCLUSION

The results after endovascular and open surgical revascularization of acute SMA occlusion were favorable, in particular among the endovascularly treated patients. Group differences need to be confirmed in a randomized trial.

Acute mesenteric ischemia: diagnostic approach and surgical treatment

Mortality related to acute mesenteric arterial occlusion remains very high. Patient survival is dependent on prompt recognition and revascularization before ischemia progresses to intestinal gangrene. Biphasic computed tomography angiography has surpassed angiography as the diagnostic test of choice due to its ability to define the arterial anatomy and to evaluate secondary signs of mesenteric ischemia. Unlike chronic mesenteric ischemia, the treatment of acute arterial mesenteric ischemia, either embolic or thrombotic, remains largely surgical. This is due to the emergent need for revascularization combined with a careful evaluation of the intestines. Endovascular techniques remain useful, however, and can save precious time in the treatment of these challenging patients if integrated into a treatment pathway combined with definitive surgical treatment. A new hybrid endovascular-surgical treatment for the treatment of acute mesenteric thrombosis is described.

Thromboembolism in atrial fibrillation

Thromboembolism is a severe complication in atrial fibrillation. This overview presents thromboembolic disease as a single entity, ranging from stroke through mesenteric ischemia to acute limb ischemia. The PubMed, Embase, and Cochrane databases were systematically searched for the terms "atrial fibrillation" and "thromboembolism" in reports published from January 1986 to September 2009. The information of 10 evidence-based practice guideline documents and 61 further sources was systematically extracted. In atrial fibrillation, the average annual stroke risk is increased by 2.3% (lethality 30%). The annual incidence of acute mesenteric ischemia is 0.14% (lethality 70%), and that of acute limb ischemia is 0.4% (lethality 16%). In total, approximately 80% of embolism-related deaths are from stroke and 20% from other systemic thromboembolism. The ischemic symptoms generally have an acute onset but may mimic other diseases, particularly in mesenteric ischemia. Early diagnosis and treatment can limit or even prevent tissue infarction. Guideline-recommended therapy with aspirin or warfarin reduces the thromboembolic risk. Suitable patients may optimize their warfarin therapy by self-monitoring of the international normalized ratio (INR). New oral and parenteral anticoagulants with more stable pharmacokinetics are being developed. In conclusion, atrial fibrillation predisposes to thromboembolism. If ischemic stroke or systemic thromboembolism occurs, early diagnosis and treatment can improve outcomes. The thromboembolic risks are reduced by guideline-adherent antithrombotic therapy with warfarin or aspirin. Future directions may include self-monitoring of the international normalized ratio and novel anticoagulants.

Anesthetic management of acute mesenteric ischemia in elderly patients

Ischemic insult to the splanchnic vasculature can jeopardize bowel viability and lead to devastating consequences, including bowel necrosis and gangrene. Although acute mesenteric ischemia (AMI) may occur at any age, the elderly are most commonly affected due to their higher incidence of underlying systemic pathology, most notably atherosclerotic cardiovascular disease. Treatment options include pharmacology-based actions, endovascular, and surgical interventions. AMI remains a life-threatening condition with a mortality rate of 60% to 80%, especially if intestinal infarction has occurred and surgical intervention becomes emergent. Early recognition and an aggressive therapeutic approach are essential if the usually poor outcome is to be improved. Anesthetic management is complex and must account for comorbid disease as well as the patient's presumptive acute deterioration. Blood pressure support typically involves careful, but often massive, fluid resuscitation and may also additionally require pharmacologic support.

TLR4-mediated Cox-2 expression increases intestinal ischemia/reperfusion-induced damage

Mesenteric IR induces significant inflammation and immune-mediated mucosal damage. TLR4 is a critical receptor in the induction of the inflammatory response and plays a role in intestinal homeostasis. To determine the role of TLR4 in IR-induced epithelial damage, we performed IR studies using TLR4(lps-def) and TLR4(lps-n) mice and analyzed mucosal damage and inflammation. We found that the absence of TLR4 or TLR4-induced signaling attenuated local mucosal damage with significantly decreased cytokine and eicosanoid secretion including PGE2 production. Similar results were seen in MyD88-/- mice. Wild-type mice treated with NS-398 (a Cox-2 inhibitor) not only decreased PGE2 production but also attenuated tissue damage. In contrast, PGE2 was not sufficient to induce damage in the TLR4(lps-def) mice. Together, these data indicate that TLR4 stimulation of Cox-2 activation of PGE2 production is necessary but not sufficient for intestinal IR-induced damage and inflammation.

Prognostic value of multidetector computed tomography in bowel infarction

PURPOSE

This study aimed to correlate computed tomography (CT) findings and outcomes in patients affected by bowel infarction.

MATERIALS AND METHODS

Twenty-seven patients with bowel infarction due to vascular obstruction were evaluated with multidetector CT (MDCT) to establish the prognostic value of CT findings and their correlation with the origin of the ischaemia. The chi-square test was used to analyse the results (p</=0.05).

RESULTS

MDCT images allowed recognition of the nature of ischaemia in all cases. In particular, arterial occlusion was found in 67% of patients and venous obstruction in 33%. The overall mortality rate was 63%. Outcome closely correlated with the kind of vascular obstruction, with a mortality rate of 89% in arterial forms and 11% in venous forms. Bowel-wall hyperdensity (2/9 venous occlusions), loss of wall enhancement (1/9 venous occlusions, 2/18 arterial occlusions) and wall thickening (8/9 venous obstructions, 2/18 arterial occlusions) were predictive of good outcome. Bowel-loop dilatation (4/9 venous occlusions, 13/18 arterial occlusions), intramural pneumatosis (1/9 venous occlusions, 17/18 arterial occlusions), mesenteric venous gas (2/9 venous occlusions, 11/18 arterial occlusions), portal venous gas (1/9 venous occlusions, 4/18 arterial occlusions), pneumoperitoneum (8/18 arterial occlusions) and pneumoretroperitoneum (1/18 arterial occlusions) were predictive of poor outcome. Ascites (6/9 venous occlusions, 12/18 arterial occlusions) did not add any prognostic information.

CONCLUSIONS

MDCT is able to detect the nature of bowel ischaemia and provide important prognostic information.

Acute mesenteric venous thrombosis: improved outcome with early diagnosis and prompt anticoagulation therapy

AIM

To analyze the clinical spectrum of acute mesenteric venous thrombosis (AMVT), to assess the factors affecting the outcome and to determine the optimal management of this disease.

METHODS

We retrospectively reviewed the case records of 20 patients with acute mesenteric venous thrombosis confirmed on CT imaging or on laparotomy over a 23 year period. Patients were divided into two groups according to the duration of symptoms: group I with symptoms for up to 3 days duration and group II with symptoms for more than 3 days.

RESULTS

The mean age was 50.55 year, with 15 male and five female patients. In all patients the diagnosis were confirmed on CT imaging preoperatively except two patients when the diagnosis was established on exploratory laparotomy in the period before 1998. There were six patients in group I and 14 in group II. Five patients underwent an operation and one received a non-operative treatment in group I. Three patients underwent laparotomy and 11 received non-operative treatment in group II (P-value 0.01, Fisher's exact test). There were three and one mortality in groups I (n=6) and II (n=14) respectively (P-value 0.061, Fisher's exact test). Most patients received preoperative therapeutic anticoagulation. Two patients in group II who underwent exploratory laparotomy, neither did receive preoperative anticoagulation. Both patients died in the postoperative period. Eighteen patients were investigated for thrombophilia. Eleven patients had one (n=6) or more (n=5) identifiable hypercoagulable state, these included protein S deficiency (n=1), both protein C and S deficiency (n=5), polycythemia (n=2), factor V Leiden deficiency (n=1) and malignancy (n=2). None had antithrombin III deficiency, hyperhomocystine urea and contraceptive pill intake. There were no statistical differences between thrombophilic and non-thrombophilic patients regarding duration of symptoms, indications for laparotomy and 30 days mortality rate.

CONCLUSIONS

Patients with AMVT of rapid onset (<3 days duration) had poor outcome and more patients required laparotomy because of extensive thrombosis leading to bowel gangrene and peritonitis. Early diagnosis with CT scanning, prompt treatment with anticoagulation in all patients, surgical treatment in cases of peritonitis or failure of medical treatment can contain the mortality rate in these patients.

Clinical symptoms of intestinal vascular disorders

Despite advances made in the diagnostic and therapeutic field, acute intestinal ischemia remains a highly lethal condition. This is related to the variability of symptoms and the absence of typical laboratory alterations in early stage.

Acute mesenteric ischemia after cardio-pulmonary bypass surgery

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