Transcatheter arterial embolization in abdominal blunt trauma with active mesenteric bleeding: case series and review of literature.

PURPOSE: To evaluate the safety and effectiveness of transcatheter arterial embolization (TAE) in treating traumatic mesenteric injuries with active bleeding, to report the outcome in a case series, and to compare the results with the existing data. METHODS: All consecutive patients with active mesenteric bleeding due to blunt abdominal trauma referred to a level-one Trauma Center and treated by TAE were included; the related demographic and medical data were retrospectively reported. A literature review was conducted; all reported cases were collected and analysed together with our case series. A univariate analysis of risk factors for TAE failure, bowel necrosis, complication and length of stay was performed. RESULTS: Four consecutive patients were included. Technical success was 100%. One patient developed colon ischemia after the procedure and underwent surgical treatment; another presented transient mild renal failure and late respiratory failure. No 30-day mortality was reported. These results are consistent with those reported in literature. The analysis of our cases together with case collected from literature resulted in a case series of 25 patients. Univariate analysis showed colon as site of bleeding as a significant risk factor for bowel necrosis and older age as a significant risk factor for longer length of stay. TAE failure was not significantly associated neither with a higher complication rate nor with a higher length of stay. CONCLUSION: TAE is a safe and effective procedure to control mesenteric bleeding, thus should be considered, in selected cases and in appropriate setting, as an alternative to emergency surgery.

Portopulmonary Hypertension: A Complex Case Derived from Multiple Penetrating Trauma-Induced Mesenteric Arteriovenous Fistulae.

Portopulmonary hypertension (PoPH) is a well-recognized complication of portal hypertension. This study reports a case of PoPH that was secondarily caused by post-traumatic mesenteric arteriovenous fistula. A 38-year-old man with a history of knife stabbing wounds in the abdomen in 2003 was admitted to the hospital with exertional shortness of breath and a mechanic murmur over the umbilical region. Computed tomography indicated signs of PoPH and mesenteric arteriovenous fistula. Percutaneous catheter-directed embolization was first performed but failed. Subsequently, the patient was successfully treated with fistula resection and partial enterectomy. The patient had been postoperatively followed regularly, and chief symptoms had been alleviated significantly and pulmonary pressure had successfully decreased to normal range. We believe that this is the first case of PoPH caused by mesenteric arteriovenous fistula.

Multi-detector CT of blunt mesenteric injuries: usefulness of imaging findings for predicting surgically significant bowel injuries.

PURPOSE: The objective of this study is to determine which imaging features of blunt mesenteric injuries best predict the presence of a bowel injury requiring surgical correction. METHODS: The radiology archives at a Level 1 trauma center were searched over a 5-year period to identify patients with mesenteric injuries seen on admission 64 slice MDCT. Two emergency radiologists, blinded to clinical and surgical outcomes, retrospectively recorded mesenteric injury size, the presence/absence of active mesenteric bleeding, bowel wall thickening, adjacent interloop free fluid, extraluminal gas, mesenteric vessel termination, mesenteric vessel "beading", focal bowel wall defect, and bowel wall perfusion abnormality. Based on all of the imaging findings, the radiologists were asked to determine if they thought the patient had a surgical bowel injury. RESULTS: One hundred twenty-six patients with mesenteric injuries were identified. Eighteen patients underwent laparotomy confirming the presence of bowel injury in 15. The remaining patients were successfully managed non-operatively. There was no statistically significant difference in size of mesenteric injury for surgical vs. non-surgical bowel injuries. Active bleeding, adjacent interloop free fluid, and bowel wall perfusion defects were strong predictors of the presence of a surgically significant bowel injury (p < 0.001, 0.002, and 0.020, respectively). The overall accuracy, sensitivity, specificity, PPV, and NPV of 64-MDCT were 73.8%, 80%, 73.0%, 28.6%, and 96.4%, respectively. CONCLUSIONS: Mesenteric active bleeding, adjacent interloop free fluid and bowel wall perfusion defects are associated with surgically significant bowel injuries. The diagnosis of surgical bowel injuries remains challenging despite 64-slice MDCT technology.

MDCT of acute conditions affecting the mesenteric vasculature.

Acute conditions affecting the mesenteric vessels can cause abdominal pain and result in significant morbidity and mortality if not diagnosed and treated quickly. As bowel viability depends on patency of the mesenteric vessels, prompt diagnosis is essential. Helical multidetector computed tomography (MDCT) provides a rapid, widely available, non-invasive method to promptly evaluate the mesenteric arteries, veins, and abdominopelvic viscera. Given the value of MDCT in diagnosing vascular disease, it is important the radiologist understand technical and imaging findings of mesenteric vascular injury. Therefore, successful diagnosis hinges on familiarity with MDCT angiography and the extended capabilities of volume rendering and multiplanar reformation. In this review, we illustrate and describe key MDCT findings of congenital, inflammatory, traumatic, infectious, and thromboembolic conditions affecting the mesenteric vasculature in adult patients.

Hydrogen sulfide as endothelium-derived hyperpolarizing factor sulfhydrates potassium channels.

RATIONALE: Nitric oxide, the classic endothelium-derived relaxing factor (EDRF), acts through cyclic GMP and calcium without notably affecting membrane potential. A major component of EDRF activity derives from hyperpolarization and is termed endothelium-derived hyperpolarizing factor (EDHF). Hydrogen sulfide (H(2)S) is a prominent EDRF, since mice lacking its biosynthetic enzyme, cystathionine γ-lyase (CSE), display pronounced hypertension with deficient vasorelaxant responses to acetylcholine. OBJECTIVE: The purpose of this study was to determine if H(2)S is a major physiological EDHF. METHODS AND RESULTS: We now show that H(2)S is a major EDHF because in blood vessels of CSE-deleted mice, hyperpolarization is virtually abolished. H(2)S acts by covalently modifying (sulfhydrating) the ATP-sensitive potassium channel, as mutating the site of sulfhydration prevents H(2)S-elicited hyperpolarization. The endothelial intermediate conductance (IK(Ca)) and small conductance (SK(Ca)) potassium channels mediate in part the effects of H(2)S, as selective IK(Ca) and SK(Ca) channel inhibitors, charybdotoxin and apamin, inhibit glibenclamide-insensitive, H(2)S-induced vasorelaxation. CONCLUSIONS: H(2)S is a major EDHF that causes vascular endothelial and smooth muscle cell hyperpolarization and vasorelaxation by activating the ATP-sensitive, intermediate conductance and small conductance potassium channels through cysteine S-sulfhydration. Because EDHF activity is a principal determinant of vasorelaxation in numerous vascular beds, drugs influencing H(2)S biosynthesis offer therapeutic potential.

Radiofrequency ablation of the pancreas with and without intraluminal duodenal cooling in a porcine model.

OBJECTIVE: To determine the short-term outcome of radiofrequency ablation (RFA) of pancreatic tissue near the duodenum and portomesenteric vessels (PMV) in a porcine model with and without intraluminal duodenal cooling. BACKGROUND: RFA has been proposed as a new treatment strategy in patients with unresectable locally advanced pancreatic cancer. RFA may cause thermal damage to the duodenum and vascular structures, but these risks and potential protective measures have never been systematically addressed. Intraluminal duodenal cooling during RFA could prevent thermal damage to the duodenum. METHODS: RFA was performed in 11 pigs during laparotomy with a bipolar probe of 30 mm active length at a power of 30 W until a total energy of 15 kJ was administered. The RFA probe was inserted in the pancreas at 5 or 15 mm from the duodenum, PMV, and in the pancreatic tail. RFA near the duodenum was performed with and without intraluminal duodenal cooling using 100 mL/min saline of 5°C. Histopathologic assessment was performed. RESULTS: The maximum RFA-induced temperature was 92°C. RFA with one single probe induced adequate ablation lesions with a diameter of 20 mm over a length of 30 mm. Without duodenal cooling, RFA induced duodenal thermal damage, whereas with duodenal cooling, no damage was observed. RFA at 15 mm from the PMV resulted in minimal superficial focal vascular damage, without thrombosis or hemorrhage. CONCLUSIONS: RFA provides adequate ablation zones in the pancreas of the porcine. Thermal damage to the duodenum can be prevented by intraluminal duodenal cooling without loss of ablation effectivity.

Management of intraoperative hemorrhage during NOTES: a prospective, randomized comparison.

BACKGROUND: The optimal strategy to manage intraoperative hemorrhage during NOTES is unknown. A randomized comparison of three instruments for hemorrhage control was performed [prototype endoscopic bipolar hemostasis forceps (BELA) vs. prototype endoscopic clip (E-CLIP) applier versus laparoscopic clip (L-CLIP) applier]. METHODS: A hybrid transvaginal NOTES model in swine was used, with hemorrhage induced in either the gastroepiploic (GE) arteriovenous bundle (vessel diameter ~3 mm) or in distal mesenteric vessels (vessel diameter ~1-2 mm). Hemostasis was attempted three times per vessel using each instrument in a randomized order. Full laparoscopic salvage was performed if hemorrhage persisted beyond 10 min. Outcomes included primary success rate (PS), primary hemostasis time (PHT), number of device applications (DA), and overall hemostasis time (OHT, including salvage). RESULTS: Seventy hemostasis attempts were made in 12 swine. PS was 42-67 % for the GE vessels, with no difference between instruments. PHT and OHT also were similar between instruments, with the BELA and L-CLIP having a higher number of DA. PS was (80-100 %) in mesenteric vessels, with the BELA and L-CLIP resulting in a shorter mean PHT compared with the E-CLIP. CONCLUSIONS: All three instruments had similar effectiveness in achieving primary hemostasis during hybrid NOTES. Management of small vessel bleeding (1-2 mm) in a porcine model is effective using all three instruments but may be most efficient with the BELA or L-CLIP. Large vessel bleeding (≥3 mm) may be best managed by adding laparoscopic ports for assistance while maintaining a low threshold for conversion to full laparoscopy.

Mesenteric artery complications during angioplasty and stent placement for atherosclerotic chronic mesenteric ischemia.

OBJECTIVE: The purpose of this study was to describe the incidence, management, and outcomes of mesenteric artery complications (MACs) during angioplasty and stent placement (MAS) for chronic mesenteric ischemia (CMI). METHODS: We retrospectively reviewed the clinical data of 156 patients treated with 173 MAS for CMI (1998-2010). MACs were defined as procedure-related mesenteric artery dissection, stent dislodgement, embolization, thrombosis, or perforation. End points were procedure-related morbidity and death. RESULTS: There were 113 women and 43 men (mean age, 73 ± 14 years). Eleven patients (7%) developed 14 MACs, including distal mesenteric embolization in six, branch perforation in three, dissection in two, stent dislodgement in two, and stent thrombosis in one. Five patients required adjunctive endovascular procedures, including in two patients each, catheter-directed thrombolysis or aspiration, retrieval of dislodged stents, and placement of additional stents for dissection. Five patients (45%) required conversion to open repair: two required evacuation of mesenteric hematoma, two required mesenteric revascularization, and one required bowel resection. There were four early deaths (2.5%) due to mesenteric embolization or myocardial infarction in two patients each. Patients with MACs had higher rates of mortality (18% vs 1.5%) and morbidity (64% vs 19%; P <.05) and a longer hospital length of stay (6.3 ± 4.2 vs 1.6 ± 1.2 days) than those without MACs. Periprocedural use of antiplatelet therapy was associated with lower risk of distal embolization or vessel thrombosis (odds ratio, 0.2; 95% confidence interval, 0.06-0.90). Patients treated by a large-profile system had a trend toward more MACs (odds ratio, 1.8; 95% confidence interval, 0.7-26.5; P = .07). CONCLUSIONS: MACs occurred in 7% of patients who underwent MAS for CMI and resulted in higher mortality, morbidity, and longer hospital length of stay. Use of antiplatelet therapy reduced the risk of distal embolization or vessel thrombosis. There was a trend toward more MACs in patients who underwent interventions performed with a large-profile system.

Plasma fibronectin depletion enhances platelet aggregation and thrombus formation in mice lacking fibrinogen and von Willebrand factor.

We previously showed that platelet aggregation and thrombus formation occurred in mice lacking both fibrinogen (Fg) and von Willebrand factor (VWF) and that plasma fibronectin (pFn) promoted thrombus growth and stability in injured arterioles in wild-type mice. To examine whether pFn is required for Fg/VWF-independent thrombosis, we generated Fg/VWF/conditional pFn triple-deficient (TKO; Cre(+), Fn(flox/flox), Fg/VWF(-/-)) mice and littermate control (Cre(-), Fn(flox/flox), Fg/VWF(-/-)) mice. Surprisingly, TKO platelet aggregation was not abolished, but instead was enhanced in both heparinized platelet-rich plasma and gel-filtered platelets. This enhancement was diminished when TKO platelets were aggregated in pFn-positive control platelet-poor plasma (PPP), whereas aggregation was enhanced when control platelets were aggregated in pFn-depleted TKO PPP. The TKO platelet aggregation can be completely inhibited by our newly developed mouse anti-mouse beta(3) integrin antibodies but was not affected by anti-mouse GPIbalpha antibodies. Enhanced platelet aggregation was also observed when heparinized TKO blood was perfused in collagen-coated perfusion chambers. Using intravital microscopy, we further showed that thrombogenesis in TKO mice was enhanced in both FeCl(3)-injured mesenteric arterioles and laser-injured cremaster arterioles. Our data indicate that pFn is not essential for Fg/VWF-independent thrombosis and that soluble pFn is probably an important inhibitory factor for platelet aggregation.

Transcatheter arterial embolization is effective for mesenteric arterial hemorrhage in trauma.

A 58-year-old man was injured in a traffic accident and hemodynamically unstable on admission. An abdominal computed tomography (CT) with contrast enhancement was performed after fluid resuscitation. Fluid accumulated along the mesentery around the cecum. A pseudoaneurysm was found by angiography in the ileal branch. Transcatheter arterial embolization (TAE) was performed in the branch using microcoils. His hemodynamics stabilized after TAE. In a CT performed after 12 h, free air was suspected and an exploratory laparotomy was performed. No intestinal perforations were found and hemostasis was completed in the injured mesentery. No ischemic findings were obtained in the intestines. TAE is one of the treatments of choice for mesenteric hemorrhage.

P2Y12 regulates platelet adhesion/activation, thrombus growth, and thrombus stability in injured arteries.

The critical role for ADP in arterial thrombogenesis was established by the clinical success of P2Y12 antagonists, currently used at doses that block 40-50% of the P2Y12 on platelets. This study was designed to determine the role of P2Y12 in platelet thrombosis and how its complete absence affects the thrombotic process. P2Y12-null mice were generated by a gene-targeting strategy. Using an in vivo mesenteric artery injury model and real-time continuous analysis of the thrombotic process, we observed that the time for appearance of first thrombus was delayed and that only small, unstable thrombi formed in P2Y12-/- mice without reaching occlusive size, in the absence of aspirin. Platelet adhesion to vWF was impaired in P2Y12-/- platelets. While adhesion to fibrinogen and collagen appeared normal, the platelets in thrombi from P2Y12-/- mice on collagen were less dense and less activated than their WT counterparts. P2Y12-/- platelet activation was also reduced in response to ADP or a PAR-4-activating peptide. Thus, P2Y12 is involved in several key steps of thrombosis: platelet adhesion/activation, thrombus growth, and stability. The data suggest that more aggressive strategies of P2Y12 antagonism will be antithrombotic without the requirement of aspirin cotherapy and may provide benefits even to the aspirin-nonresponder population.

Traumatic mesenteric bleeding managed solely with transcatheter embolization.

We report a rare case of mesenteric bleeding following blunt abdominal trauma successfully treated solely with transcatheter arterial embolization (TAE) of the right colic marginal artery. A 56-year-old woman presented with mesenteric bleeding after being involved in a car accident. Computed tomography (CT) showed a large mesenteric hematoma and hemoperitoneum with no associated major injuries to other organs. There was a pseudoaneurysm with extravasation inside the hematoma. TAE was attempted to control bleeding during the preparation for surgical laparotomy. A superior mesenteric angiogram revealed a right colic marginal artery pseudoaneurysm. After successful TAE with microcoils, the affected colon perfusion was preserved via collateral circulation from the ileocolic artery. No ischemic gastrointestinal complications have occurred, and laparotomy has not been necessary during the 6 months after TAE. In isolated mesenteric injury cases, TAE may be a reasonable alternative to emergency laparotomy.

[Rare injury from blunt abdominal trauma in a child]. / Seltene Verletzung bei stumpfem Bauchtrauma im Kindesalter.

Presented in this work is a rare injury of a blunt abdominal trauma in a child. Besides a partial rupture of the kidney and a retro-/intraperitoneal haematoma, a further injury occurred from the accident: an initially clinically indetectable tear of the A. iliaca communis which was found intraoperatively and with systematic CT analysis. Traumatic blood vessel lesions of the abdominal aorta and in particular the iliac blood vessels are very rare in children. By such violent impact injuries, it is therefore vital to perform a clinical examination of the foot pulse, systematic analysis of radiology diagnostics, and intraoperative exploration. The growth phase should be considered for therapy of the blood vessels depending on the child's age group. As the long-term results of graft implants are practically unknown, if possible a primary suture or vein patch should be performed.

Non-occlusive mesenteric ischaemia: the prevalent cause of gastrointestinal infarction in patients with severe burn injuries.

BACKGROUND: Gastrointestinal complications occur frequently in intensive care patients with severe burns. Intestinal infarction and its deleterious consequences result in high mortality despite rapid surgical intervention. Our objective was to evaluate the aetiology of gastrointestinal infarction in intensive care patients with severe burns. STUDY DESIGN: We retrospectively evaluated all of the severe-burn victims at the burn unit of the Medical University of Vienna from 01/2002 to 06/2012 for whom a gastrointestinal infarction was diagnosed during their inpatient stay on computed-tomography, in the context of acute laparotomy, or upon autopsy by aetiology. RESULTS: After a severe thermal injury, 17 patients suffered a gastrointestinal infarction during their stay. In 82% of those patients, non-occlusive mesenteric ischaemia (NOMI) was identified as the cause of the gastrointestinal infarction. Patients with an embolic infarction tended to be older (78.0years embolism vs. 53.4 NOMI, mean, p<0.01), with a lower abbreviated burn severity index (8.7 embolism vs. 10.4 NOMI, mean, p<0.02) and a smaller total body surface area burned (20% embolism vs. 48% NOMI, mean, p<0.01) than those with a non-occlusive mesenterial ischaemia. No patients with an embolic infarction or any of the females in the entire gastrointestinal infarction group survived this event, resulting in a mortality rate of 100% for the embolic infarction group and female group. The decisive factor for surviving a NOMI was age (median age: male survivors 28years vs. nonsurvivors 66years (of this median, males=72years and females=60years), p<0.02). CONCLUSION: The results of our study clearly demonstrate that in severe-burn intensive care patients, non-occlusive mesenteric ischaemia is the most frequent cause of gastrointestinal infarction and that the decisive factor for survival is the patient's age.

Gastric outlet obstruction caused by traumatic pseudoaneurysm of superior mesenteric artery.

Traumatic pseudoaneurysms of the superior mesenteric artery (SMA) are extremely rare. We describe two cases of posttraumatic proximal SMA pseudoaneurysms with symptoms of gastric outlet obstruction. Repair was accomplished by aorta-SMA bypass with saphenous vein. Injuries to the proximal SMA are easily missed at laparotomy, especially if intestinal ischemia or hematomas are absent. Recognition and repair are stressed to avoid the complications associated with pseudoaneurysm formation.

Traumatic injury to the proximal superior mesenteric vessels.

Twenty-one patients were treated for 25 injuries to the proximal superior mesenteric vessels (eight, superior mesenteric artery; nine, superior mesenteric vein; four, superior mesenteric artery plus superior mesenteric vein). Mechanisms of injury were stab wounds (11 cases), motor vehicle accidents (9 cases), and iatrogenic (one case). Ten patients (48%) arrived at the emergency room in shock (two with no obtainable case blood pressure). Superior mesenteric artery repair was performed by lateral suture (seven cases), end-to-end anastomosis (three cases), autogenous vein graft (one case), and no repair (one case). All 13 venous injuries were repaired by lateral suture. Four patients (19%) died in the operating room secondary to acute blood loss and irreversible shock. There were no late deaths and no second-look operations. Further improvement in survival depends on rapid transportation from injury site to operating room.

Injuries to the visceral arteries.

Injuries of the major visceral arteries are among the more difficult to manage and rarely occur without serious associated injuries. Sixty-six patients are presented with injuries to the celiac, superior, and inferior mesenteric arteries. Fifty-three injuries resulted from gunshot wounds, nine from stab wounds, and four from blunt trauma. Operative management included vessel ligation in 11 patients, arteriorrhaphy in 43, resection and end-to-end anastomosis in six, Dacron graft interposition in four, and aortic reimplantation in two. Twenty-three patients died, 16 from failure to control hemorrhage. In two patients failure to restore adequate visceral circulation resulted in bowel ischemia and infarction. The successful management of patients with visceral arterial injuries is dependent upon rapid and adequate exposure followed by primary repair or revascularization utilizing available surgical techniques.