Acute Mesenteric Ischaemia—<Emphasis Type="Italic">An Indian Perspective</Emphasis>

In Western countries, acute mesenteric ischaemia is commonly due to arterial occlusion and occurs in patients who are usually in their seventh decade. A venous cause for intestinal gangrene has been reported in only about 10 %. We examined whether this was so in India and compared the clinical features of patients with mesenteric arterial and venous ischaemia and relate these to their ultimate prognosis. We studied retrospectively, the records of all patients admitted or referred to the department with a diagnosis of acute mesenteric ischaemia between January 1997 and October 2012, noting their demographic details and mode of presentation, the results of preoperative imaging and blood investigations, the extent of bowel ischaemia, and the length of bowel that was resected at operation and their outcome. There were 117 patients, 85 males and 32 females whose median age was 53 years. Mesenteric venous thrombosis was seen in 56 patients (48 %) and mesenteric arterial occlusion in 61 (52 %). Forty six patients died (39 %); 15 with venous occlusion (27 %) and 31 with arterial occlusion (51 %). Compared to patients with arterial occlusion, the patients with venous obstruction were younger, had a longer duration of symptoms, were less frequently hypotensive at presentation, had higher platelet counts, had a shorter length of bowel resected, had fewer colonic resections and had a lower mortality. Other predictors of mortality on multivariate analysis were a longer duration of symptoms, lower serum albumin and higher creatinine levels at presentation and a shorter length of residual bowel. In India, acute mesenteric ischaemia in tertiary care centres is due to venous thrombosis in almost half of the patients who are at least a decade younger than those in the West. Significant predictors of mortality include low serum albumin and raised creatinine levels, a shorter residual bowel length and an arterial cause for mesenteric ischaemia.     

Systematic review of survival after acute mesenteric ischaemia according to disease aetiology

BACKGROUND: Differentiation of acute mesenteric ischaemia on the basis of aetiology is of great importance because of variation in disease progression, response to treatment and outcome. The aim of this study was to analyse the published data on survival following acute mesenteric ischaemia over the past four decades in relation to disease aetiology and mode of treatment. METHOD: A systematic review of the available literature from 1966 to 2002 was performed. RESULTS: Quantitative analysis of data derived from 45 observational studies containing 3692 patients with acute mesenteric ischaemia showed that the prognosis after acute mesenteric venous thrombosis is better than that following acute arterial mesenteric ischaemia; the prognosis after mesenteric arterial embolism is better than that after arterial thrombosis or non-occlusive ischaemia; the mortality rate following surgical treatment of arterial embolism and venous thrombosis (54.1 and 32.1 per cent respectively) is less than that after surgery for arterial thrombosis and non-occlusive ischaemia (77.4 and 72.7 per cent respectively); and the overall survival after acute mesenteric ischaemia has improved over the past four decades. CONCLUSION: There are large differences in prognosis after acute mesenteric ischaemia depending on aetiology. Surgical treatment of arterial embolism has improved outcome whereas the mortality rate following surgery for arterial thrombosis and non-occlusive ischaemia remains poor.     

急性肠系膜缺血性疾病的诊断与治疗

目的总结急性肠系膜缺血性疾病的早期诊治经验。方法回顾性分析1988—2005年间诊治的35例急性肠系膜缺血性疾病病人的临床资料。发生在肠系膜动脉30例，肠系膜静脉5例。主要临床表现为急性腹痛（94％）；51％的病人有血清酶谱异常。结果全部病例均通过手术得以证实。4例行肠系膜上动脉置管溶栓，15例行Fogarty导管取栓术，16例行肠管切除。总病死率为23％，肠管坏死病例病死率为50％，多例病人术后出现再灌注损伤。结论动态观察血清酶谱变化有助于该类疾病的早期诊断，对术后再灌注损伤要高度重视。     

Acute thrombo-embolic occlusion of the superior mesenteric artery: a prospective study in a well defined population.

OBJECTIVES: to characterize the clinical presentation of patients with acute thrombo-embolic occlusion of the superior mesenteric artery (SMA). DESIGN: prospective study. MATERIALS: twenty-four consecutive patients admitted to Blekinge County Hospital, Karlskrona, Sweden, with acute thrombo-embolic occlusion of the SMA, over a three-year period from April 1999 through March 2002. METHODS: clinical data were registered prospectively. Incidence, diagnostic procedures and factors associated with survival were analysed. RESULTS: the diagnosis was verified at operation in 20, and at autopsy in 4 patients. The incidence was 5.3 per 100 000 inhabitants per year. Among the 20 patients with embolic disease, atrial fibrillation was present in 95%, synchronous embolic events in 30% and warfarin treatment in 10%. D-dimer was elevated on admission in 13/13. Four patients were diagnosed at first consultation. Fifteen underwent curative revascularisation (6) or bowel resection only (9). Five were alive at one-year follow-up, of whom one had short bowel syndrome. Length of bowel ischaemia predicted institutional (p = 0.004) and one-year mortality (p = 0.005). CONCLUSIONS: the incidence was higher than expected. Embolic occlusions predominated. Old age, atrial fibrillation, severe abdominal pain and synchronous embolus suggest the diagnosis of acute bowel ischaemia. Length of bowel ischaemia predicted outcome.     

Acute mesenteric ischaemia.

The experience of acute mesenteric ischaemia at St Vincent's Hospital, Melbourne, has been reviewed over 17 years. The mortality remains appallingly high. This applies particularly to those patients who had thrombosis of the superior mesenteric artery, amongst whom the mortality in this series was 97%. The mortality was slightly less in the group suffering from embolic occlusion of the superior mesenteric artery (66%), and in those suffering from thrombosis of the superior mesenteric vein (60%). A mortality of 66% was also found in patients suffering from non-occlusive gut ischaemia. Delay in diagnosis accounted for this high mortality. Early diagnosis is all-important, and this depends on the performance of mesenteric angiography in any patient suspected of having mesenteric ischaemia. Appropriate surgery may then be carried out in the occlusive group and supportive treatment, including intraarterial papaverine infusion, given to those with non-occlusive ischaemia. There is a pressing need for simple non-invasive tests to segregate those patients suffering from acute mesenteric ischaemia from those whose acute abdomen is due to some other cause.     

Surgical intervention for acute intestinal ischemia: experience in a community teaching hospital

The aim of this study was to evaluate the current management of acute mesenteric ischemia secondary to thrombotic or embolic occlusion of visceral vessels in a community teaching hospital. Between October 1997 and July 2000, a review of all hospital discharges revealed 83 patients with a discharge diagnosis of "acute vascular insufficiency-intestine." Among these 83 patients, 22 cases of acute mesenteric ischemia were confirmed. Management of these 22 patients was divided into 2 groups for analysis. In Group A, 14 patients were aggressively treated with visceral angiography (n=10), visceral artery bypass (n=8), visceral embolectomy (n=4), and bowel resection (n=7). In 8 of 14 of these patients, surgical intervention occurred in less than 24 hours from presentation. In Group B, 8 patients were managed with supportive care because of advanced age (mean age = 86 +/- 7 years), comorbid conditions, or patient and family preference. Postoperative morbidity in Group A consisted of cardiac events (n=3), pulmonary insufficiency (n=5), and prolonged gastrointestinal tract dysfunction (n=3). Twelve of 14 patients in Group A survived and were discharged, whereas only 2 of 8 patients in Group B survived and were discharged from the hospital. Although the literature suggests that there can be a significant delay in the diagnosis and treatment of acute mesenteric ischemia, the early recognition and aggressive treatment of acute mesenteric ischemia resulted in a good survival rate. Supportive management of very elderly and debilitated patients needs to be considered on a case-by-case basis. Although the outlook for such patients is dismal, survivors are possible as demonstrated by this series.     

Antegrade aortomesenteric revascularisation originating from the supracoeliac aortic segment--a promising surgical option in chronic ischaemia of the visceral arteries

INTRODUCTION: Ischaemia of the visceral arteries is considered to be an extraordinary challenge in the interdisciplinary therapeutic management. AIM AND METHOD: Using a case series of patients with chronic ischaemia of the visceral arteries, our diagnostic and therapeutic experience was analysed with regard to postoperative quality of life (increase of body weight, frequency in daily diarrhoea), perioperative morbidity and hospital mortality in dependence on the type of surgical reconstruction of the visceral arteries. RESULTS: During a time period of 2 years, 3 patients (male/female=1:2; mean age, 61.7 years) underwent surgical interventions on the visceral arteries from a total of 1118 vascular interventions (main indication revealed by colonoscopy and pathohistology of mucosal biopsy: ischaemic colitis). In all cases, symptomatology was affected by abdominal angina. Duplex sonography, angiography, and multislice CT scan revealed the combination of an occlusion of the coeliac trunk and of the superior mesenteric artery by atherosclerosis in 2 cases. In the remaining case, there was an isolated occlusion at the origin of the superior mesenteric artery. For revascularisation, the aortomesenteric reconstruction was subdivided according to the: i) target vessel: -combination of revascularised common hepatic artery and superior mesenteric artery (n=1) with an autologous Y-vein bypass ("reversed technique"), -exclusive revascularisation of the superior mesenteric artery (n=2)-prosthetic bypass; ii) origin of the bypass: -from the supracoeliac aortic segment (antegrade) n=3 (primarily in patients 1 and 3; as a redo operation in patient 2); -from the infrarenal segment (retrograde) n=1 (initial surgical intervention in patient 2) using an autologous venous bypass. In all cases, a significant improvement of the quality of life was observed as indicated by an increase of body weight (n=3; +no further abdominal angina) and primary wound healing in all 3 cases (hospital mortality, 0). CONCLUSION: Chronic ischaemia of the visceral arteries is characterised by an increasing incidence and a stealthy onset and requires an interdisciplinary approach to find the correct diagnosis using all available diagnostic procedures including sufficient periodic follow-up investigations. We favour the antegrade aortomesenteric revascularisation from the supracoeliac aortic segment as a promising surgical option in chronic ischaemia of visceral arteries.     

Comparison of superficial femoral vein and saphenous vein as conduits for mesenteric arterial bypass

PURPOSE: Gangrenous bowel, intraabdominal sepsis, and previous failed mesenteric bypass are indications for use of an autogenous conduit for mesenteric arterial reconstruction. Saphenous vein (SV) is often used as the autogenous conduit of choice, but it may be prone to graft stenosis or occlusion. Recent experience with superficial femoral vein (SFV) suggests that it is an excellent alternative conduit for major arterial reconstruction. The purpose of this study was to compare the outcomes of SV and SFV for mesenteric arterial bypass. METHODS: During a 7-year period, 26 patients underwent 43 mesenteric arterial bypass procedures with autogenous conduit. SV was used for 23 bypasses (53%), and SFV was used for 20 bypasses (47%). Indications for revascularization included chronic mesenteric ischemia (n = 15; 58%), acute mesenteric ischemia (n = 9; 35%), and mycotic aneurysm of the paravisceral aorta (n = 2; 7%). Three patients (11%) underwent revascularization with SV grafts and two patients (8%) with SFV grafts after previous failed mesenteric bypass. RESULTS: The 30-day mortality rate was 15%. Three deaths occurred after SV bypass for acute mesenteric ischemia, and one death occurred after a SFV bypass for a ruptured paravisceral mycotic aneurysm. Twenty-two surviving patients were followed for a mean of 31 +/- 6 months. Three of 11 patients (27%) who survived after SV bypass had recurrent mesenteric ischemia develop (acute, n = 1; chronic, n = 2) from graft thrombosis at a mean interval of 32 +/- 22 months after surgery. No patient had recurrent symptoms develop after SFV bypass. One of the three patients with SV graft failure died of acute mesenteric ischemia, and the other two patients underwent successful bypass with SFV. Symptomatic graft failure was significantly more likely to occur in patients receiving SV grafts compared with SFV grafts (P <.05). CONCLUSION: SFV yields acceptable clinical outcomes for mesenteric arterial bypass compared with SV. SFV is a viable alternative to SV when autogenous conduit is indicated for mesenteric arterial reconstruction.     

Management and classification of type II congenital portosystemic shunts

Background

Congenital portosystemic shunts (PSS) with preserved intrahepatic portal flow (type II) present with a range of clinical signs. The indications for and benefits of repair of PSS remain incompletely understood. A more comprehensive classification may also benefit comparative analyses from different institutions.

Methods

All children treated at our institution for type II congenital PSS from 1999 through 2009 were reviewed for presentation, treatment, and outcome.

Results

Ten children (7 boys) with type II PSS were identified at a median age of 5.5 years. Hyperammonemia with varying degrees of neurocognitive dysfunction occurred in 80%. The shunt arose from a branch of the portal vein (type IIa; n = 2), from the main portal vein (type IIb; n = 7), or from a splenic or mesenteric vein (type IIc; n = 1). Management included operative ligation (n = 6), endovascular occlusion (n = 3), or a combined approach (n = 1). Shunt occlusion was successful in all cases. Serum ammonia decreased from 130 ± 115 μmol/L preoperatively to 31 ± 15 μmol/L postoperatively (P = .03). Additional benefits included resolution of neurocognitive dysfunction (n = 3), liver nodules (n = 1), and vaginal bleeding (n = 1).

Conclusion

Correction of type II PSS relieves a wide array of symptoms. Surgery is indicated for patients with clinically significant shunting. A refined classification system will permit future comparison of patients with similar physiology.     

Microtibial embolectomy.

BACKGROUND: microtibial embolectomy is an important technique in cases of limb threatening acute arterial occlusion affecting native crural and pedal vessels. It is particularly useful when thrombolysis is contraindicated or ineffective as in "trash foot". METHODS: in order to evaluate the efficacy of this technique, a retrospective case note review was carried out for patients undergoing microtibial embolectomy from 1990 to 1999. Data collected included the causes and degree of ischaemia, additional procedures required, vessel patency, limb salvage and complications encountered. RESULTS: twenty-two limbs underwent exploration of the crural/pedal vessels with ankle level arteriotomies under local anaesthetic in 12 cases, general anaesthetic in nine and epidural in one. The causes of ischaemia were cardiac emboli (8), "trash foot" (7), emboli from aortic and popliteal aneurysms (3) and thrombotic occlusion of crural vessels (4). The vessel patency rate was 69% and limb salvage rate 62% (13/21) up to 5-years follow-up. Six of the seven cases with "trash foot" were salvaged while one required an amputation at 3-months post-operatively. The 30-day mortality was 22% (5/22). CONCLUSIONS: microtibial embolectomy is effective in acute occlusion of the crural/pedal arteries including cases of "trash foot", offering limb salvage to a worthwhile proportion of cases.     

Mesenteric ischaemia

Acute mesenteric ischaemic (AMI) is a life-threatening vascular condition from which outcomes are poor. It results from acute thrombosis or embolization of one or more mesenteric arteries. Chronic mesenteric ischaemia (CMI) is a clinical syndrome of abdominal pain after eating related to stenosis or occlusion of one or more mesenteric vessels associated with other cardiovascular disease. Mesenteric ischaemia can also result from hypoperfusion, non-occlusive mesenteric ischaemia (NOMI), or mesenteric vein thrombosis (MVT).This article looks at the epidemiology, diagnosis, and management of mesenteric ischaemia. It recognizes the need for resuscitation and time-critical resection of non-viable bowel and revascularization in the acute setting. Improving outcomes necessitates a multidisciplinary approach involving emergency medicine, diagnostic radiology, general surgery, vascular surgery, interventional radiology, anaesthetic, and critical care specialists.     

Revascularization of the superior mesenteric artery after acute thromboembolic occlusion

BACKGROUND: The outcome and prognostic factors after revascularization of acute thromboembolic occlusion of the superior mesenteric artery (SMA) are poorly documented. METHODS: Sixty patients with acute thromboembolic occlusion of the SMA had revascularization procedures at 21 hospitals from 1987 to 1998. They were registered prospectively in the Swedish Vascular Registry. Patient files were analysed retrospectively. RESULTS: The median age of the patients was 76 years; 73 per cent suffered from cardiac disease and 23 per cent had previous vascular surgery. Onset of symptoms was classified as sudden (30 per cent), acute (33 per cent) or insidious (37 per cent). The occlusions were thought to be either embolic (67 per cent) or thrombotic (33 per cent). The diagnosis was suspected on first examination in 32 per cent of patients, a group whose median time to operation was shorter (P = 0.01). Fifty-eight patients had an exploratory laparotomy and subsequent revascularization, and two were treated with thrombolysis alone. Second-look laparotomy was performed in 41, and third look in eight patients; 19 required an additional bowel resection. The overall mortality rates were 43, 52, 60 and 67 per cent at 30 days, discharge, 1 and 5 years, respectively. No patient was dependent on intravenous nutrition after 1 year. Previous vascular surgery resulted in a higher institutional mortality rate (79 per cent; P = 0.02). Patients who had a sudden onset of symptoms outside hospital had a better outcome (mortality rate 27 per cent; P = 0.02). CONCLUSION: Many non-diagnostic radiological examinations were performed and a routine second-look is warranted. The results suggest that attempts at revascularization procedures for acute mesenteric ischaemia may improve the outcome.     

Traumatic and postoperative ischemic liver necrosis: causes, risk factors and treatment

BACKGROUND: To study the cause and outcome of ischemic liver necrosis and suggest treatment of these patients. METHODS: Retrospective study of 13 patients with ischemic liver necrosis treated at our departments from 1990 until 1997. RESULTS: Ischemic liver necrosis was caused by general hypoxia (n = 1) or acute arterial occlusion (n = 12) of the celiac and superior mesenteric artery (SMA, n = 3), proper hepatic artery (PHA, n = 1), right hepatic artery (RHA, n = 2), left hepatic artery (LHA, n = 2) and intrahepatic vessels (n = 4). Six of the cases were related to surgical procedures, 5 of these (38%) were unintended arterial injuries after biliary surgery. Ten patients (77%) had risk factors contributing to the development of liver necrosis: septicemia (n = 4), jaundice and septicemia (n = 2), shock and hypoxia (n = 3) and alcoholic cirrhosis (n = 1). Five patients (38%) needed resection of the liver necrosis due to infected necrosis. Three patients (23%) died; two of these had celiac/SMA occlusion. One died due to complete gastrointestinal ischemia and severe lactacidosis, two died of multiorgan failure after bile leakage and septicemia. CONCLUSION: Ischemic liver necrosis is mainly caused by arterial occlusion due to arteriosclerosis, arterial transection during biliary surgery or blunt liver trauma, and seldom occurs without additional risk factors. 50% of the patients develop infected necrosis and need liver resection. Patients with sterile necrosis may recover without surgical procedures of the liver. The mortality in patients with central (celiac/SMA) and peripheral (CHA, PHA, RHA, LHA, intrahepatic branches) occlusions was 67% (2/3) and 11% (1/9), respectively.     

Pharmacologic interventions in acute mesenteric ischemia: improved survival with intravenous glucagon, methylprednisolone, and prostacyclin

An experimental model of acute mesenteric ischemia following 85 minutes of superior mesenteric artery (SMA) occlusion in male Wistar rats was used in this investigation. Untreated control animals had a 48-hour survival rate of 38% (n = 26), whereas sham laparotomy resulted in a 100% 48-hour survival rate (n = 10). Study groups received intravenous infusions of normal saline solution (16.6 ml/kg/hr; n = 26) or similar volumes of normal saline solution with the addition of glucagon (1.6 micrograms/kg/min; n = 26), dopamine (3.2 micrograms/kg/min; n = 26), or prostacyclin (PGI2) (10.7 ng/kg/min; n = 26). Infusions were begun 15 minutes after initiating 85 minutes of SMA occlusion and were continued for a total of 90 minutes. Glucagon increased the 48-hour survival rate to 85%, significantly greater than both control survival (p less than 0.001) and normal saline solution group survival rates (p less than 0.025). Neither normal saline solution alone nor dopamine significantly increased the 48-hour survival rate, which was 54% in both groups. The PGI2 group survival rate, 65% at 48 hours, was significantly greater than the control rate (p less than 0.05), was not statistically different from the normal saline solution group survival rate, and was 20% less than the glucagon group survival rate, the latter difference approaching statistical significance (p = 0.10). Methylprednisolone (40 mg/kg; n = 26) administered as an intravenous bolus 15 minutes after initiating SMA occlusion significantly increased the 48-hour survival rate to 73% (p less than 0.01), whereas neither intravenous heparin (150 U/kg; n = 26) nor superoxide dismutase (11,900 U/kg; n = 26) were beneficial. Glucagon, methylprednisolone, and PGI2 improved the survival rate in this model of acute mesenteric ischemia.     

Juxtarenal aortic occlusion.

The authors' experience with 113 aortic occlusions in 103 patients during a 26-year period (1965 to 1991) is reviewed. The authors found three distinct patterns of presentation: group I (n = 26) presented with acute aortic occlusion, group II (n = 66) presented with chronic aortic occlusion, and group III (n = 21) presented with complete occlusion of an aortic graft. Perioperative mortality rates were 31%, 9%, and 4.7% for each respective group and achieved statistical significance when comparing group I with group II (p = 0.009) and group I with group III (p = 0.015). Group I presented with profound metabolic insults due to acute ischemia and fared poorly. Group II presented with chronic claudication and did well long-term. Group III presented with acute ischemia but did well because of established collateral circulation. The treatment and expected outcome of aortic occlusion depends on the cause.     

Acute Occlusive Mesenteric Ischemia: Surgical Management and Outcomes

Acute mesenteric ischemia secondary to arterial occlusion (AMI) remains a highly lethal condition. To examine recent trends in management and associated outcomes, we examined our institutional experience over a recent 10-year period. All patients treated for AMI between January 1990 and January 2000 were identified (76 patients, 77 cases) and their medical records examined. At presentation, 64% demonstrated peritonitis and 30% exhibited hypotension. The interval from symptom onset to treatment exceeded 24 h in 63% of cases. Etiology was mesenteric thrombosis in 44 patients (58%) and embolism in 32 patients (42%). Thirty-five patients (46%) had prior conditions placing them at high risk for the development of AMI including chronic mesenteric ischemia (n = 26) and inadequately anticoagulated chronic atrial fibrillation (n = 9). Surgical management consisted of exploration alone in 16 patients, bowel resection alone in 18 patients, and revascularization in 43 patients, including 28 who required concomitant bowel resection. Overall, intestinal necrosis was present in 81% of cases. Perioperative mortality was 62% and long-term parenteral nutrition (TPN) was required in 31% of survivors. Peritonitis (odds ratio [OR] 9.4, 95% confidence interval [CI] 1.6, 54.0; p = 0.012 and bowel necrosis (OR 10.4, CI 1.9, 56.3; p = 0.007) at presentation were independent predictors of death or survival dependent upon TPN. We conclude that AMI remains a highly lethal condition due in large part to advanced presentation and inadequate recognition and treatment of patients at high risk.     

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

IntroductionAcute mesenteric ischaemia may occur due to mesenteric arterial embolus, thrombosis, non-occlusive mesenteric ischaemia or venous thrombosis resulting in ischaemia of the bowel wall.Presentation of caseA 41 year old woman presented with worsening abdominal pain, decreased appetite, nausea and vomiting. Examination revealed right lower quadrant tenderness. Investigations revealed elevation of her inflammatory markers. At laparotomy two separate segments of ischaemic but potentially viable small bowel were identified secondary to mesenteric venous thrombosis. Bowel salvage was attempted with the use of intravenous unfractionated heparin and this was confirmed following a second look laparotomy.DiscussionDespite a normal platelet count at presentation a diagnosis of JAK-2 positive essential thrombocythaemia was made thus explaining the acquired prothrombotic state underlying the venous thrombosis. The selective use of intravenous unfractionated heparin and second look laparotomy may provide a means for bowel preservation in these cases.ConclusionThis case highlights the potential of bowel salvage can be achieved following an episode of acute mesenteric ischaemia with the use of intravenous unfractionated heparin and selective second look laparotomy and the importance of considering underlying myeloproliferative disease in such cases even in the absence of a thrombocytosis at presentation.     

The early diagnosis of acute occlusive mesenteric ischaemia: experimental results and clinical applications.

The diagnosis of acute superior mesenteric artery occlusion in the dog has been achieved in every case by isotope scanning of the abdomen using technetium-labelled red cells or technetium-labelled human serum albumin. The white cell count is also significantly elevated, but the changes in the levels of the enzymes CPK, LDH, AST and serum amylase are not specific for actue mesenteric ischaemia. In the human the presence of a normal gut circulation can be demonstrated by isotope scanning provided that the patient is not severely shocked. The presence of a normal gut circulation as shown on the scintigram conclusively eliminates the possibility of acute main trunk occlusion of the superior mesenteric artery. This should be of help in differentiating acute occulusive mesenteric ischaemia from other causes of the acute abdomen. Abdominal scintiscanning is complementary to angiography, which still remains the most precise means of diagnosing acute mesenteric ischaemia. Although the abdominal scintigram is more limited in its application and is not as accurate as angiography, it is quicker to perform, non-invasive, and entirely safe. Abdominal scintiscanning is an excellent screening test to be used in patients suspected of suffering from acute occlusive mesenteric ischaemia.     

Venous mesenteric infarction: a particular entity

Ninety-eight patients with documented mesenteric infarction during a 19-year period were reviewed. In 13 patients infarction was due to a mesenteric venous thrombosis (MVT). Patients with MVT distinguished themselves from those having another aetiology by: (1) longer history of pain before admission (median 8 days, P less than 0.0001); (2) typical appearance of the bowel at laparotomy (10/13); (3) a localized segment of ischaemic jejunum or ileum of less than 120 cm in length (12/13) allowing better operability at the first laparotomy (P = 0.006). In hospital the mortality was lower for venous mesenteric infarction (5/13, 38 per cent) than for mesenteric infarction of other aetiologies (70/85, 82 per cent) (P = 0.002). Patients with primary venous mesenteric infarction showed a better survival rate (one death in eight patients) than patients with associated diseases such as liver cirrhosis, sepsis or previous operation who had a poor prognosis with a mortality comparable to other aetiologies of acute bowel ischaemia (four deaths in five patients). Since the high recurrence rate of this disease in the early postoperative period was due to residual venous thrombosis and to a hypercoagulable state, a wide bowel resection is recommended followed by early and long-term anticoagulation. Thrombectomy is probably inefficient since it removes only centrally located thrombi and leaves peripheral occlusion, which is responsible for the recurrence.     

Prediction of the delayed complications of intestinal and mesenteric injuries following experimental blunt abdominal trauma

Injuries to the intestine and mesentery are often found in patients undergoing laparotomy for blunt abdominal trauma. Although treatment of perforations is relatively straightforward, the same is not true for contusions. Few guidelines exist at present to aid the surgeon in deciding which injuries require resection in order to avoid the complications of delayed perforation and late stricture formation. The natural history of these non-perforating intestinal and mesenteric injuries has been examined in an experimental model to identify possible criteria on which future management can be based. In the immediate postinjury period peristalsis and local mesenteric pulsation were absent in the majority of injuries which went on to full recovery and these observations are thus of little predictive value in predicting outcome. The initial size of contusion (length of contusion along longitudinal axis of bowel) relative to bowel wall circumference (BWC) was related to complications as follows: contusion less than BWC (n = 47)--one complication; contusion greater than BWC (n = 8)--three complications (P = 0.02). Similarly, six mesenteric injuries which produced an initial ischaemia (assessed by fluorescein) less than twice the BWC did not result in any complications, compared with four complications which occurred in ten cases when the initial ischaemia was greater than twice the BWC. These results go some way towards providing a better understanding of these injuries and in turn may help the emergency surgeon in deciding which injuries require resection.