Mesenteric stenosis, collaterals, and compensatory blood flow.

BACKGROUND: The mesenteric circulation has an extensive collateral network. Therefore, stenosis in one or more mesenteric arteries does not necessarily lead to symptoms. The objective of this study was to determine the effect of collateral flow on celiac artery (CA) and superior mesenteric artery (SMA) duplex parameters. METHODS: Between 1999 and 2007, a cohort of 228 patients analyzed for suspected chronic mesenteric syndrome was studied. Stenosis of the mesenteric vessels and collateral flow patterns were identified on angiography and categorized. The effect of stenosis in one mesenteric vessel and the presence of collaterals from the other unaffected vessel was examined in both the CA and SMA. RESULTS: Stenosis of the CA resulted in a significantly higher peak systolic velocity (PSV) and end-diastolic velocity in the normal SMA without stenosis. This was also found for the CA without stenosis in the presence of a stenosis of the SMA. An incremental effect of the severity of the CA stenosis was found with a mean SMA PSV of 158 cm/s when normal and 259 cm/s when occluded. The presence of collaterals had a clear effect on duplex parameters of the angiographically normal SMA. In the presence of collaterals and a 70% CA stenosis, the PSV in the normal SMA was significantly higher (P = .025). CONCLUSIONS: This study shows that stenosis in either the CA or SMA increases flow velocities in the other unaffected mesenteric artery. This increase was correlated with the presence of collaterals. Collaterals and stenoses in one of the mesenteric arteries may lead to mimicking or overgrading of stenosis in the other mesenteric artery.

Results of the Anaconda endovascular graft in abdominal aortic aneurysm with a severe angulated infrarenal neck.

OBJECTIVE: Proximal neck anatomy of an abdominal aortic aneurysm (AAA), especially a severe angulated neck of more than 60 degrees, predicts adverse outcome in endovascular aneurysm repair. In the present study, we evaluate the feasibility of the use of the Anaconda endovascular graft (Vascutec, Terumo, Inchinnan, Scotland) for treating infrarenal AAA with a severe angulated neck (>60 degrees) and report the midterm outcomes. METHODS: In total, nine Dutch hospitals participated in this prospective cohort study. From December 2005 to January 2011, a total of 36 AAA patients, 30 men and six women, were included. Mean and median follow-up were both 40 months. RESULTS: Mean infrarenal neck angulation was 82 degrees. Successful deployment was reached in 34 of 36 patients. Primary technical success was achieved in 30 of 36 patients (83%). There was no aneurysm-related death. Four-year primary clinical success was 69%. In the first year, eight clinical failures were reported including four leg occlusions which could be solved using standard procedures. After the first year, three patients with additional failures occurred; two of them were leg occlusions. Four patients needed conversion to open AAA exclusion. In six of 36 patients, one or more reinterventions were necessary. Three of them were performed for occlusion of one Anaconda leg and two were for occlusion of the body. CONCLUSIONS: The use of the Anaconda endovascular graft in AAA with a severe angulated infrarenal neck is feasible but has its side effects. Most clinical failures occur in the first year. Thereafter, few problems occur, and midterm results are acceptable. Summarizing the present experiences, we conclude that open AAA repair is still a preferable option in patients with challenging aortic neck anatomy and fit for open surgery.

The influence of respiration on criteria for transabdominal duplex examination of the splanchnic arteries in patients with suspected chronic splanchnic ischemia.

BACKGROUND: Duplex ultrasound imaging of the mesenteric vessels is often used as a first diagnostic tool to evaluate the mesenteric circulation in patients with unexplained chronic abdominal symptoms. Several studies on duplex criteria have been published; however, most studies are small and included not exclusively patients with symptoms suggestive of chronic mesenteric syndrome (CMS). This study evaluated the contribution of respiration-monitored duplex ultrasound imaging in the diagnosis of stenosis or occlusion of the mesenteric arteries in patients suspected of CMS and thereby improves the definition of the criteria for stenosis. METHODS: Between 1999 and 2007, 779 consecutive patients presented to our tertiary referral center for evaluation and treatment of CMS. Mesenteric artery duplex ultrasound imaging and angiography of the abdominal aorta and its branches were performed in 324 patients. Angiography was considered the gold standard for verifying the presence or absence of arterial pathology. Results from duplex imaging and angiography were compared to determine the optimal duplex criteria for stenosis. In addition, the contribution of expiration and inspiration on duplex imaging and angiography were established. RESULTS: Significantly higher peak systolic and end-diastolic velocities were found in the celiac artery (CA) and superior mesenteric artery (SMA) during expiration than during inspiration. Receiver operating characteristic curve analyses found respiration-dependent cutoff values for CA and SMA stenosis. The values corresponding with the highest accuracy (minimal false-negative and false-positive results) were determined. Peak systolic velocities cutoff points during expiration and inspiration were 280 and 272 cm/s, respectively, for the CA and 268 and 205 cm/s for the SMA. The end-diastolic velocity cutoff points during expiration and inspiration were 57 and 84 cm/s, respectively, for the CA and 101 and 52 cm/s for the SMA. Sensitivity for different duplex parameters in detecting mesenteric stenosis was 66% to 78% and specificity was 77% to 86%. CONCLUSIONS: This study proposes new criteria related to respiration for duplex ultrasound imaging of the mesenteric arteries in patients with symptoms suggestive of CMS. It emphasizes the importance of taking into account the effect of respiration on duplex parameters. The lower sensitivity and specificity in our study compared with other studies puts into perspective the position of duplex imaging in the work-up of patients with suspected CMS. Duplex results should be used as a guide, with a low threshold giving a higher negative predictive value and, consequently, a lower positive predictive value.

The cardiovascular risk profile of atherosclerotic gastrointestinal ischemia is different from other vascular beds.

BACKGROUND: The distribution of cardiovascular risk factors in patients with chronic gastrointestinal ischemia due to atherosclerosis of the splanchnic vessels (chronic splanchnic syndrome) is not well studied. The aim of this study was to determine the cardiovascular risk factor pattern in patients with chronic splanchnic syndrome. METHODS: From April 2003 to September 2007, atherosclerotic risk factors in consecutive patients with chronic splanchnic syndrome were compared prospectively with the general atherosclerotic risk profile in Western Europe and worldwide risk profile of coronary heart disease, peripheral artery disease, and cerebral vascular disease. RESULTS: Of 376 analyzed patients, 97 were diagnosed with chronic splanchnic syndrome. Data from 90 patients were available for analysis (7 were excluded because of incomplete data). Mean age was 63 years (range 28-86 years), and 74% were female. Fifty-nine percent of the patients had atherosclerotic disease in other vascular beds. Smoking was reported in 57%, and increased bodyweight in 21%. Hypercholesterolemia was present in 53%, hypertension in 62%, and diabetes in 21%. CONCLUSIONS: The atherosclerotic risk profile in patients with chronic splanchnic syndrome differed from other atherosclerotic diseases with a female preponderance, lower incidence of obesity/increased bodyweight, diabetes, hypertension, and hypercholesterolemia. Reduced caloric intake, related to the postprandial pain, may explain the observed differences.

Abdominal symptoms during physical exercise and the role of gastrointestinal ischaemia: a study in 12 symptomatic athletes.

BACKGROUND: Gastrointestinal (GI) symptoms during exercise may be caused by GI ischaemia. The authors report their experience with the diagnostic protocol and management of athletes with symptomatic exercise-induced GI ischaemia. The value of prolonged exercise tonometry in the diagnostic protocol of these patients was evaluated. METHODS: Patients referred for GI symptoms during physical exercise underwent a standardised diagnostic protocol, including prolonged exercise tonometry. Indicators of GI ischaemia, as measured by tonometry, were related to the presence of symptoms during the exercise test (S+ and S- tests) and exercise intensity. RESULTS: 12 athletes were specifically referred for GI symptoms during exercise (five males and seven females; median age 29 years (range 15-46 years)). Type of sport was cycling, long-distance running and triathlon. Median duration of symptoms was 32 months (range 7-240 months). Splanchnic artery stenosis was found in one athlete. GI ischaemia was found in six athletes during submaximal exercise. All athletes had gastric and jejunal ischaemia during maximum intensity exercise. No significant difference was found in gastric and jejunal Pco(2) or gradients between S+ and S- tests during any phase of the exercise protocol. In S+ tests, but not in S- tests, a significant correlation between lactate and gastric gradient was found. In S+ tests, the regression coefficients of gradients were higher than those in S- tests. Treatment advice aimed at limiting GI ischaemia were successful in reducing complaints in the majority of the athletes. CONCLUSION: GI ischaemia was present in all athletes during maximum intensity exercise and in 50% during submaximal exercise. Athletes with GI symptoms had higher gastric gradients per mmol/l increase in lactate, suggesting an increased susceptibility for the development of ischaemia during exercise. Treatment advice aimed at limiting GI ischaemia helped the majority of the referred athletes to reduce their complaints. Our results suggest an important role for GI ischaemia in the pathophysiology of their complaints.

[Endarterectomy more favourable than stenting in symptomatic significant carotid stenosis: higher risk of ischaemic stroke or death following stenting]. / Endarteriëctomie gunstiger dan stent bij symptomatische carotisstenose: hoger risico op CVA of overlijden na stentplaatsing.

Carotid endarterectomy (CEA) has proven its value in the treatment of patients with recent significant carotid artery stenosis. Percutaneous transluminal angioplasty with carotid artery stenting ('stenting' in short) is an alternative to CEA. The results of stenting and CEA in patients with symptomatic significant carotid artery stenosis were evaluated in 9 prospective randomized controlled trials and 11 meta-analyses. Almost all of these trials failed to show superiority of stenting to CEA. According to the 4 largest and most recent studies in this field the risk of a stroke or death within 30 days after the intervention is considerably higher following stenting than following CEA. In the long run the results of stenting and CEA seem to be comparable. CEA remains the gold standard in treatment of significant carotid artery stenosis, in particular in patients older than 70.

Open or percutaneous revascularization for chronic splanchnic syndrome.

BACKGROUND: Treatment of chronic splanchnic syndrome remains controversial. In the past 10 years, endovascular repair (ER) has replaced open repair (OR) to some extent. This evidence summary reviews the available evidence for ER or OR of chronic splanchnic syndrome. METHODS: A systematic literature search of MEDLINE database was performed to identify all studies that evaluated treatment of chronic splanchnic syndrome between 1988 and 2009. RESULTS: The best available evidence consists of prospectively accumulated but retrospectively analyzed data with a high risk for confounding. Only a few of these studies incorporated functional tests to assess splanchnic ischemia before or after treatment. ER has the advantage of low short-term morbidity but the disadvantage of decreased long-term primary patency compared with OR. ER and OR have similar rates of secondary patency, although the reintervention rate after ER is higher. CONCLUSION: ER appears to be preferential in the treatment of elderly patients and in patients with comorbidity, severe cachexia, or hostile abdomen. Long-term results after OR are excellent. OR can still be proposed as the preferred option for relatively young and fit patients.

Retroperitoneal endoscopic release in the management of celiac artery compression syndrome.

INTRODUCTION: Celiac artery compression syndrome (CACS) can be treated successfully by division of the median arcuate ligament and celiac plexus fibers. The standard technique is the open approach by an upper midline or left subcostal incision. Only six single cases in which a laparoscopic transabdominal approach for CACS was used have been reported. We prospectively evaluated the feasibility of the endoscopic retroperitoneal approach for treatment of CACS. METHODS: All patients with symptoms suggestive of CACS were evaluated using splanchnic duplex ultrasound scanning, gastric exercise tonometry (GET), and multiplane selective splanchnic angiography. The criteria for treatment were chronic abdominal symptoms, respiratory-dependent CA stenosis, and abnormal GET result. The release was performed by a retroperitoneal endoscopic approach. Anatomic success of the procedure was confirmed by angiography. RESULTS: The endoscopic retroperitoneal approach was used to treat 46 patients with CACS. One patient (2%) required conversion to an open procedure due to suprarenal artery bleeding. Release was ended prematurely in one patient due to a pneumothorax resulting in loss of working space. A postoperative pneumothorax developed in two patients, of which one needed treatment. No other complications were observed. Postoperative angiography during inspiration and expiration showed normal vessel anatomy in 36 of 46 patients. Six of 10 patients with persisting intraluminal stenoses were treated endovascularly. Five of these were successful, which brings the primary-assisted anatomic patency for the total group to 89% (41 of 46 patients). Three patients are being observed, and endovascular treatment remains an option in case of insufficient improvement. On median follow-up of 20 months (range, 2-42 months) 41 patients were free of symptoms or showed significant improvement. CONCLUSIONS: The endoscopic retroperitoneal approach for the release of the CA in CACS, with additional endovascular treatment of persistent stenosis, is feasible and effective. Short-term results were comparable with the open procedure.

Diagnosis and management of splanchnic ischemia.

Splanchnic or gastrointestinal ischemia is rare and randomized studies are absent. This review focuses on new developments in clinical presentation, diagnostic approaches, and treatments. Splanchnic ischemia can be caused by occlusions of arteries or veins and by physiological vasoconstriction during low-flow states. The prevalence of significant splanchnic arterial stenoses is high, but it remains mostly asymptomatic due to abundant collateral circulation. This is known as chronic splanchnic disease (CSD). Chronic splanchnic syndrome (CSS) occurs when ischemic symptoms develop. Ischemic symptoms are characterized by postprandial pain, fear of eating and weight loss. CSS is diagnosed by a test for actual ischemia. Recently, gastro-intestinal tonometry has been validated as a diagnostic test to detect splanchnic ischemia and to guide treatment. In single-vessel CSD, the complication rate is very low, but some patients have ischemic complaints, and can be treated successfully. In multi-vessel stenoses, the complication rate is considerable, while most have CSS and treatment should be strongly considered. CT and MR-based angiographic reconstruction techniques have emerged as alternatives for digital subtraction angiography for imaging of splanchnic vessels. Duplex ultrasound is still the first choice for screening purposes. The strengths and weaknesses of each modality will be discussed. CSS may be treated by minimally invasive endoscopic treatment of the celiac axis compression syndrome, endovascular antegrade stenting, or laparotomy-assisted retrograde endovascular recanalization and stenting. The treatment plan is highly individualized and is mainly based on precise vessel anatomy, body weight, co-morbidity and severity of ischemia.

Jejunal tonometry for the diagnosis of gastrointestinal ischemia. Feasibility, normal values and comparison of jejunal with gastric tonometry exercise testing.

BACKGROUND AND AIM: In most patients with chronic splanchnic syndrome the celiac artery is involved, enabling the use of gastric exercise tonometry as a diagnostic function test. In this study, we investigated the feasibility of combining gastric and jejunal exercise tonometry and determined the normal values. We investigated the potential diagnostic value of combining gastric with jejunal exercise tonometry. MATERIALS AND METHOD: Between 1998 and 2000, combined gastric and jejunal exercise tonometry tests were performed in a healthy volunteer and in patients suspected of chronic gastrointestinal ischemia. Using automated air tonometry, gastric (PgCO2) and jejunal PCO2 (PjCO2) were measured before, during and after 10-min of exercise. Luminal-arterial PCO2 gradients (DeltagPCO2 respectively DeltajPCO2) were calculated. In the patient cohort, final diagnosis of chronic ischemia was made by our institutional multidisciplinary working group on gastrointestinal ischemia. RESULTS: Jejunal tonometry was possible in 25 of 27 participants. The healthy volunteer was tested twice, yielding a total of 26 combined tests. Mean normal basal PjCO2 was 0.9 kPa higher than PgCO2. The calculated upper threshold (mean+2SD) of normal DeltajPCO2 was 1.4 kPa. In five of eight patients with chronic gastrointestinal ischemia gastric exercise tonometry was abnormal, in one, both gastric and jejunal tonometry were abnormal, in two only jejunal exercise tonometry was abnormal. CONCLUSION: Combined gastric and jejunal exercise tonometry is a feasible procedure that is relatively easy to perform. On the basis of this pilot study, jejunal tonometry seems to have a small additional value in the diagnosis of chronic gastrointestinal ischemia.

Twenty-four hour tonometry in patients suspected of chronic gastrointestinal ischemia.

BACKGROUND AND AIMS: Gastrointestinal tonometry is currently the only clinical diagnostic test that enables identification of symptomatic chronic gastrointestinal ischemia. Gastric exercise tonometry has proven its value for detection of ischemia in this patients group, but has its disadvantages. Earlier studies with postprandial tonometry gave unreliable results. In this study we challenged (again) the use of postprandial tonometry in patients suspected of gastrointestinal ischemia. METHODS: Patients suspected for chronic gastrointestinal ischemia had standard diagnostic work up, including gastric exercise tonometry and 24-h tonometry using standard meals. RESULTS: Thirty-three patients were enrolled in the study. Chronic gastrointestinal ischemia was diagnosed in 17 (52%) patients. The 24-h tonometry correctly predicted the presence of ischemia in 13/17 patients, and absence of ischemia in 15/16 patients. CONCLUSIONS: The use of 24-h tonometry after meals in patients suspected of gastrointestinal ischemia seems feasible, with promising accuracy for the detection of ischemia.

What is the best diagnostic approach for chronic gastrointestinal ischemia?

BACKGROUND: Chronic gastrointestinal ischemia is still a difficult diagnosis to establish. The diagnosis depends on a high degree of clinical suspicion as well as selective angiography. Duplex sonography may serve as a screening tool, providing information on splanchnic vessel patency and flow patterns. GET is a minimally invasive test that can be used for diagnosis in patients with chronic gastrointestinal ischemia, and can differentiate between symptomatic and asymptomatic splanchnic artery stenosis. In the present study, we compared four different diagnostic approaches. METHODS: Between 1997 and 2000, 84 patients were evaluated for suspected chronic gastrointestinal ischemia. All underwent splanchnic arterial angiography, duplex sonography, and GET. For the presence or absence of stenosis, angiography was used as the gold standard. For diagnosing ischemia, we relied on a panel decision. The diagnostic approaches studied were: (a) angiography, only in patients with classic abdominal angina; (b) screening with duplex sonography, angiography if sonography abnormal or unreliable; (c) screening with gastric tonometry and angiography if tonometry not normal; (d) both gastric tonometry exercise and duplex sonography, angiography if one of both screening tests not normal. RESULTS: In 28 patients, chronic gastrointestinal ischemia was diagnosed. Using clinical suspicion only, 16 patients (57%) would have been missed. Screening by duplex sonography or gastric tonometry only would have missed 4 or 6 patients, respectively. Screening with combined gastric tonometry and duplex sonography would not have missed patients with symptomatic ischemia, while 21% of angiographies would have been avoided. CONCLUSION: Screening by combined GET and duplex sonography has excellent diagnostic accuracy. Currently, this approach represents the best diagnostic workup strategy in patients with suspected chronic gastrointestinal ischemia.

Effect of various test meals on gastric and jejunal carbon dioxide: A study in healthy subjects.

OBJECTIVE: The normal pattern of carbon dioxide (CO2) levels in the human stomach and small bowel after meals is unknown. The intraluminal carbon dioxide level is a sensitive and early marker for organ mucosal ischemia. CO2 levels in both the stomach and small bowel are influenced by multiple factors other than adequacy of perfusion. Gastric acid production, salivary bicarbonate and CO2 produced or absorbed by meals are the disturbing variables. Prolonged gastric (and jejunal) tonometry after meals can be of additional value in the work-up of patients suspected of (chronic) gastrointestinal ischemia. The purpose of this study was to challenge these problems using in vitro tested meals and a rigid acid-suppression regimen in a group of healthy subjects. MATERIAL AND METHODS: Standard meals were tested in vitro on the ability to produce and buffer CO2. Meals with the least CO2 variations were subsequently used in healthy subjects. Tonometry of the stomach and jejunum was performed for 24 h, with optimal and controlled acid suppression. RESULTS: Ten subjects were enrolled in the study. Acid production was sufficiently suppressed. The gastric PCO2 baseline (fasting) was 6.5 (1.0), and significantly lower than the jejunum PCO2 baseline of 7.6 (0.9) kPa. The gastric baseline during the day was 6.9 (1.6), and significantly lower than the gastric baseline during the night of 8.0 (1.8), suggesting a diurnal variation of PCO2. Increases in PCO2 levels were seen in all subjects, after meals and between meals. CONCLUSIONS: Prolonged gastric and jejunal tonometry is feasible in humans. PCO2 levels were seen to peak after, but also in-between, most meals. The diurnal variation in PCO2 might reflect reversible gastric mucosal ischemia.

Gastric exercise tonometry: the key investigation in patients with suspected celiac artery compression syndrome.

INTRODUCTION: Controversy continues about the mere existence of the celiac artery compression syndrome. Earlier results of treatment of unselected patients groups showed varying, mostly disappointing, results. The recently introduced gastric exercise tonometry test is able to identify patients with actual gastrointestinal ischemia. We prospectively studied the use of gastric exercise tonometry as a key criterion for revascularization treatment in patients with otherwise unexplained abdominal complaints and significant stenosis of the celiac artery by compression of the arcuate ligament. METHODS: Patients were prospectively selected using abdominal artery angiography and gastric exercise tonometry. Patients with a significant compression of the celiac artery, typical abdominal complaints, and abnormal tonometry were considered for revascularization. RESULTS: Over a 7-year period, 43 patients with significant celiac artery compression were included in this study, and 30 patients were diagnosed as ischemic. Twenty-nine patients had revascularization, 22 (76 %) had a trunk release only. After a median follow-up of 39 months, 83% of patients were free of symptoms. The repeated tonometry after treatment improved in 100% of patients free of symptoms, compared with 25% in patients with persistent complaints after revascularization. CONCLUSIONS: The results of this study suggest that the celiac axis compression syndrome exists and that the actual ischemia can be detected by gastric exercise tonometry and treated safely, with success.

Clinical impact of gastric exercise tonometry on diagnosis and management of chronic gastrointestinal ischemia.

BACKGROUND & AIMS: Chronic gastrointestinal ischemia or chronic splanchnic syndrome is a difficult diagnosis. The use of a physiologic test, combined with clinical and anatomic data, should improve diagnostic accuracy. This study evaluates the diagnostic accuracy and clinical impact of gastric tonometry during exercise (GET) in a patient cohort suspected of chronic splanchnic syndrome. METHODS: From 1997 to 2000, 102 patients with chronic abdominal pain were analyzed. The workup included GET and selective biplane angiography. The diagnosis of gastrointestinal ischemia was based on consensus in a multidisciplinary working group and sustained on follow-up. RESULTS: Gastrointestinal ischemia was diagnosed in 38 patients. In 33 patients chronic splanchnic syndrome was found, with single vessel involvement in 20 (17 celiac artery, 3 mesenteric superior) and multivessel disease in 13. In 5 patients nonocclusive ischemia was found. By using receiver operator curve analysis, the difference between gastric and arterial partial pressure of carbon dioxide (PCO2 gradient) proved to be the best GET parameter. The criteria for diagnosing ischemia in GET were Pco2 gradient > 0.8 kPa and increase gastric PCO2, with base excess decrease <8 mmol/L during exercise. GET had 78% sensitivity and 92% specificity. Twenty-five patients underwent vascular treatment (19 operative, 6 stent/percutaneous transluminal angioplasty). After 4 years of follow-up 83% of patients were alive and free of symptoms. CONCLUSIONS: GET is an accurate diagnostic tool to show gastrointestinal ischemia. Including GET into clinical decision making enabled selecting patients with ischemia, who benefited from vascular and medical treatment. These benefits were sustained during 4-year follow-up. GET should be considered in the workup of patients with a suspected diagnosis, of gastrointestinal ischemia.