Small Vascular Structures Research Articles

High-resolution imaging of human atherosclerotic carotid plaques with micro18F-FDG PET scanning exploring plaque vulnerability

AimsFDG-PET can be used to identify vulnerable plaques in atherosclerotic disease. Clinical FDG-PET camera systems are restricted in terms of resolution for the visualization of detailed inflammation patterns in smaller vascular structures. The aim of the study is to evaluate the possible added value of a high-resolution microPET system in excised carotid plaques using FDG. Methods and ResultsIn this study, 17 patients with planned carotid endarterectomy were included. Excised plaques were incubated in FDG and subsequently imaged with microPET. Macrophage presence in plaques was evaluated semi-quantitatively by immunohistochemistry. Plaque calcification was assessed additionally with CT and correlated to FDG uptake. Finally, FDG uptake and macrophage infiltration were compared with patient symptomatology. Heterogeneous distributions and variable intensities of FDG uptake were found within the plaques. A positive correlation between the distribution of macrophages and the FDG uptake (r = 0.68, P < .01) was found. A negative correlation was found between areas of calcifications and FDG uptake (r = −0.84, P < .001). Ratio FDGmax values as well as degree of CD68 accumulation were significantly higher in CVA patients compared with TIA or amaurosis fugax patients (P < .05) and CVA patients compared with asymptomatic patients (P < .05). ConclusionThis ex vivo study demonstrates that excised carotid plaques can be visualized in detail using FDG microPET. Enhancement of clinical PET/CT resolution for similar imaging results in patients is needed.

Flat-detector computed tomography with intravenous contrast material application in experimental aneurysms: Comparison with multislice CT and conventional angiography

Despite limited soft tissue resolution flat-detector computed tomography (FD-CT) provides substantial superior spatial resolution in comparison with multislice computed tomography (MS-CT). This may add value in the visualization of small vascular structures if intravenous contrast application leads to substantial opacification and visibility of intracranial vessels or aneurysms. To evaluate the feasibility of visualization of vascular structures by FD-CT angiography (FD-CTA) after intravenous contrast injection compared with MS-CTA and intra-arterial digital subtracted angiography (IADSA) in an animal model. Aneurysms were created in the right common carotid artery in six New Zealand White Rabbits using the elastase technique. Imaging was performed using FD-CTA, MS-CTA (injection of 1 ml/kg body weight) and IADSA. Anonymized volume rendering reconstruction (VRT), maximum intensity projection (MIP), and multiplanar reconstruction (MPR) images were reconstructed and evaluated by two experienced reviewers for aneurysm geometry and vascular structure anatomy using standard tools of a dedicated workstation. Aneurysms could be successfully created in all animals. Measurements of aneurysm geometry (aneurysm height, width, neck width) and vascular structures (brachiocephalic trunk, carotid artery diameter and plane) were nearly identical in all three modalities. Intra- and inter-observer correlations of the different parameters showed high r values between 0.83 and 0.99. Our results show the feasibility of FD-CTA in comparison with MS-CTA and IADSA in an animal model. Despite limited soft tissue resolution, opacification of vascular structures with sufficient contrast to the surrounding structures was possible in all animals. Vascular structures appeared better delineated in FD-CTA than in MS-CTA, probably due to the superior spatial resolution.

Epithelioid Hemangiosarcomas of the Bovine Urinary Bladder: A Histologic, Immunohistochemical, and Ultrastructural Examination of Four Tumors

Epithelioid hemangiosarcoma is a specific variant of hemangiosarcoma that has recently been recognized in domestic animals. These malignant vascular neoplasms histologically resemble, and may be mistaken for, carcinomas. Four epithelioid hemangiosarcomas in the urinary bladders of 4 cows with severe enzootic hematuria are described in the current study. Grossly, the vesicular mucosa of the urinary bladder of each cow contained a single red elevated nodule. Histologically, each neoplasm was composed of short strands, cords, or nests of epithelioid, round, or slightly spindle-shaped endothelial cells that formed small vascular structures. Neoplastic cells were immunohistochemically positive for factor VIII-related antigen and vimentin, and were negative for cytokeratin and desmin. Ultrastructurally, the neoplastic cells often contained cytoplasmic intermediate filaments, a prominent granular endoplasmic reticulum, a Golgi complex, mitochondria, marked pinocytotic activity, and rare Weibel-Palade bodies. These neoplasms were diagnosed as epithelioid hemangiosarcomas based on their histologic, immunohistochemical, and ultrastructural features. The present report widens the spectrum of mesenchymal tumors of the bovine urinary bladder and aids in the characterization of these vascular neoplasms.

High‐contrast in vivo visualization of microvessels using novel FeCo/GC magnetic nanocrystals

FeCo-graphitic carbon shell nanocrystals are a novel MRI contrast agent with unprecedented high per-metal-atom-basis relaxivity (r(1) = 97 mM(-1) sec(-1), r(2) = 400 mM(-1) sec(-1)) and multifunctional capabilities. While the conventional gadolinium-based contrast-enhanced angiographic magnetic MRI has proven useful for diagnosis of vascular diseases, its short circulation time and relatively low sensitivity render high-resolution MRI of morphologically small vascular structures such as those involved in collateral, arteriogenic, and angiogenic vessel formation challenging. Here, by combining FeCo-graphitic carbon shell nanocrystals with high-resolution MRI technique, we demonstrate that such microvessels down to approximately 100 mum can be monitored in high contrast and noninvasively using a conventional 1.5-T clinical MRI system, achieving a diagnostic imaging standard approximating that of the more invasive X-ray angiography. Preliminary in vitro and in vivo toxicity study results also show no sign of toxicity.

First‐pass and steady‐state magnetic resonance angiography of the thoracic vasculature using gadofosveset trisodium

To compare a high-resolution, ECG-gated, motion-compensated, steady-state magnetic resonance angiography (SS-MRA) of the thoracic vasculature to standard first-pass MRA (FP-MRA) using a blood-pool contrast agent (gadofosveset trisodium). In all, 25 patients >or=18 years with congenital or acquired disease of the thoracic vasculature, who underwent both FP-MRA and SS-MRA, were retrospectively identified. Diameters of left superior pulmonary vein (LSPV), left pulmonary artery (LPA), and aortic arch (AA) were measured. Image quality for LSPV, LPA, AA, coronary ostia, and coronary sinus were assessed. Vessel sharpness of LPA and LSPV and contrast ratio (CR) of LSPV, LPA, and AA were calculated. SS-MRA yielded significantly higher image quality for all vessels, and significantly higher vessel sharpness for LSPV and LPA compared to the FP-MRA. SS-MRA revealed lower intra- and interobserver variability for vessel diameters compared with the FP-MRA. The FP-MRA showed higher CR compared to the SS-MRA. Motion-compensated high-resolution SS-MRA of the thoracic vasculature using gadofosveset trisodium offers superior image quality compared to standard FP-MRA. Although SS-MRA delivers no dynamic information it may prove specifically helpful as an add-on to FP-MRA for imaging of small vascular structures.

MRI and contrast enhanced MR angiography in a patient with right aortic arch and aberrant left subclavian artery

IntroductionCongenital malformations of the aortic arch are animportant group of pediatric pathologies. Depending on thetype of the vascular anomaly, patients may be completelyasymptomatic not requiring any therapy or may manifestwith hazardous or even life threatening situations such asrecurrent pneumonia, respiratory distress or apnea [1]. Dueto the complexity of pathologic anatomy, the clinicalsymptoms and the resulting therapeutic consequences thesemalformations require detailed diagnostic imaging.MRI is nowadays considered the imaging modality ofchoice for the work-up of vascular malformations in thepediatric age group. The application of Cine SSFP (steadystate free precession) sequences and flow sensitive phase-contrast sequences allow for depiction of vascular struc-tures and qualitative as well as quantitative assessment ofblood flow. In addition, contrast enhanced magnetic reso-nance angiography (CE-MRA) provides high-resolutionthree-dimensional (3D) datasets providing excellent imagesof even small vascular structures based on maximumintensity projection (MIP), volume rendering technique(VRT), and multiplanar reconstructions (MPR). Recentstudies have shown that CE-MRA in the pediatric agegroup may clarify uncertain diagnoses in one-third of thepatients and reveal additional unsuspected pathologicstructures in another third of cases [2, 3]. Furthermore, CE-MRA has been shown to be superior to echocardiographyfor evaluation of the pulmonary vasculature in pediatricpatients [3], [4].The value of unenhanced MRI and CE-MRA in imagingof vascular anomalies in pediatric subjects is highlighted inthis case of a congenital malformation of the aortic archwith aberrant left subclavian artery.CaseA 14-year old male patient presented with dysphagia,globus, and temporary malaise without vomiting. Physicalexamination of the patient was normal and there were nosigns of dyspnea, dizziness, or chest pain. ECG and bloodanalysis did not reveal any abnormality. A frontal viewX-ray examination of the chest demonstrated a right-sidedaortic arch (Fig. 1). Barium esophagography, performedfor further evaluation of dysphagia, revealed a right-sidedand posterior compression of the proximal esophagus at thelevel of the aortic arch (Fig. 2). The echocardiographicexamination showed regular intracardiac structures andfunction; there was a right aortic arch with origin of the leftand right carotid artery as the first two supra-aortic vessels.Based on these findings the patient was referred for MRIexamination.MRI was performed on a 1.5 T Siemens MagnetomSonata system (Siemens Medical Systems, Erlangen,Germany) using a phased-array body coil. The unenhancedMRI sequences utilized comprised T2w HASTE sequenceand retrospectively ECG-gated Cine SSFP sequences. Con-trast enhanced magnetic resonance angiography (CE-MRA)

Both Protein Kinase A and Exchange Protein Activated by cAMP Coordinate Adhesion of Human Vascular Endothelial Cells

cAMP regulates integrin-dependent adhesions of vascular endothelial cells (VECs) to extracellular matrix proteins, their vascular endothelial cadherin-dependent intercellular adhesions, and their proliferation and migration in response to growth and chemotactic factors. Previously, we reported that cAMP-elevating agents differentially inhibited migration of human VECs isolated from large vascular structures (macro-VECs, human aortic endothelial cells [HAECs]) or small vascular structures (micro-VECs, human microvascular endothelial cells [HMVECs]) and that cAMP hydrolysis by phosphodiesterase (PDE)3 and PDE4 enzymes was important in coordinating this difference. Here we report that 2 cAMP-effector enzymes, namely protein kinase (PK)A and exchange protein activated by cAMP (EPAC), each regulate extracellular matrix protein-based adhesions of both macro- and micro-VECs. Of interest and potential therapeutic importance, we report that although specific pharmacological activation of EPAC markedly stimulated adhesion of micro-VECs to extracellular matrix proteins when PKA was inhibited, this treatment only modestly promoted adhesion of macro-VECs. Consistent with an important role for cAMP PDEs in this difference, PDE3 or PDE4 inhibitors promoted EPAC-dependent adhesions in micro-VECs when PKA was inhibited but not in macro-VECs. At a molecular level, we identify multiple, nonoverlapping, PKA- or EPAC-based signaling protein complexes in both macro- and micro-VECs and demonstrate that each of these complexes contains either PDE3B or PDE4D but not both of these PDEs. Taken together, our data support the concept that adhesion of macro- and micro-VECs is differentially regulated by cAMP and that these differences are coordinated through selective actions of cAMP at multiple nonoverlapping signaling complexes that contain PKA or EPAC and distinct PDE variants.

Juvenile and Adult Congenital Heart Disease: Time-resolved 3D Contrast-enhanced MR Angiography

To assess the incremental diagnostic value of time-resolved three-dimensional (3D) magnetic resonance (MR) angiography over single-phase 3D MR angiography and cine MR imaging in juvenile and adult patients with congenital heart disease (CHD). The study was HIPAA compliant and was approved by the institutional review board. Written informed consent was obtained from each patient. Eighty-one consecutive patients (46 male and 35 female patients; mean age, 31.1 years +/- 13.5 [standard deviation]) with CHD were examined with a 1.5-T MR imaging unit. The imaging protocol comprised time-resolved MR angiography (repetition time msec/echo time msec, 2.01/0.81) after injection of 0.03 mmol gadodiamide per kilogram of body weight at 4 mL/sec and single-phase high-spatial-resolution MR angiography (2.87/0.97) after injection of 0.15 mmol/kg gadodiamide at 1.5 mL/sec. After review of the time-resolved and conventional MR angiographic data sets, each of two independent observers listed the additional clinical information gained from time-resolved MR angiographic data. A Wilcoxon signed rank test was used to test for statistical differences between the image quality ratings of the two observers. Time-resolved and single-phase high-spatial-resolution MR angiography yielded diagnostic image data in all patients. Observers 1 and 2 found functional information in time-resolved MR angiographic series in 52 and 51 patients, respectively, that was not seen at high-spatial-resolution MR angiography. Intra- and extracardiac shunts, respectively, were exclusively depicted by time-resolved MR angiography for observer 1 in 18 and two patients and for observer 2 in 15 and two patients. However, both observers reported higher confidence in the assessment of such smaller vascular structures as supraaortic vessels (in 12 patients for observer 1 and 11 patients for observer 2) and major aortopulmonary collateral arteries (in eight patients for observer 1 and 10 patients for observer 2) at high-spatial-resolution MR angiography. No significant difference was evident in image quality scoring between the two observers (P = .32 for time-resolved and P = .47 for conventional MR angiography). Compared with conventional MR angiography, time-resolved MR angiography yields clinically relevant information in a substantial number of patients; hence, the two techniques should be regarded as complementary.

Vascular reconstruction and complications in living donor liver transplantation in infants weighing less than 6 kilograms: The Kyoto experience

Smaller-size infants undergoing living-donor liver transplantation (LDLT) are at increased risks of vascular complications because of their smaller vascular structures in addition to vascular pedicles of insufficient length for reconstruction. Out of 585 child patients transplanted between June 1990 and March 2005, 64 (10%) weighing less than 6 kg underwent 65 LDLTs. Median age and weight were 6.9 months (range: 1-16 months) and 5 kg (range: 2.8-5.9 kg), respectively. Forty-five lateral segment, 12 monosegment, and 8 reduced monosegment grafts were adopted, and median graft-to-recipient weight ratio was 4.4% (range: 2.3-9.7). Outflow obstruction occurred in only 1 patient (1.5%). Portal vein complication occurred in 9 (14%) including 5 with portal vein thrombosis. Hepatic artery thrombosis (HAT) occurred in 5 (7.7%). Patient and graft survivals were 73% and 72% at 1 yr, and 69% and 68% at 5 yr after LDLT, respectively. Thirteen of 22 grafts (58%) lost during the follow-up period occurred within the first 3 months posttransplantation. Overall graft survival in patients with and without portal vein complication was 67% and 65%, respectively (P = 0.54). Overall graft survival in patients with and without HAT was 40% and 67%, respectively. HAT significantly affected graft survival (P = 0.04). In conclusion, our surgical technique for smaller-size recipients resulted in an acceptable rate of vascular complications. Overcoming early posttransplantation complications will further improve outcomes in infantile LDLT.

Trattamento endovascolare prechirurgico con colle acriliche

We describe a female neonate with clinical features of neonatal suffering who underwent trans-fontanelle ultrasound scan. Ultrasound disclosed a hyperchoic expanding lesion, confirmed by subsequent MR scan which revealed large vascular structures and signs of bleeding within the lesion. Angiography was problematic given the weight of the neonate, the small vascular structures and the choice of angiographic materials. Three large vessels feeding the lesion were detected. Embolization was undertaken using acrylic glue to obtain rapid devascularization with a straightforward technique and minimum use of contrast medium and fluids in general.

Fístula arteriovenosa radial oscilante

Summary Introduction Spontaneously appearing arteriovenous fistulae are an infrequent pathological condition. Case report We report the case of a 44-year-old male, employed as a builder, with no history of traumatic injury, who presented a pulsating tumour in his left wrist. A Doppler ultrasound study revealed the existence of an arteriovenous fistula in the radial artery. A later arteriographic study was found to be normal and the patient's clinical features then disappeared. Three weeks later they reappeared and a new study using Doppler ultrasound revealed the existence of an arteriovenous fistula. Another exploration using arteriography and phlebography were performed and both were found to be normal; the symptoms again disappeared after these procedures had been carried out. A Doppler ultrasound recording was conducted, the results of which were normal. Three weeks later the tumour again reappeared and a Doppler ultrasound study confirmed the previous diagnoses. Computerized tomographic angiography suggested the existence of an arteriovenous fistula. The patient was submitted to surgery and a venous plexus could be seen around the radial artery, which was very dilated with arterialized walls, and this was excised during the operation. The anatomicopathological study revealed the existence of small and medium calibre vascular structures with an arterial morphology.

Stromal progenitor cells present within liposuction and reduction abdominoplasty fat for autologous transfer to aged skin.

Autologous fat is used for direct transfer to locally replace fat, as well as for use intradermally in the treatment of rhytids in aged skin. To determine if the components of the autologous fat could be separated to produce a better agent for the treatment of rhytids. Liposuction material from four patients and fat from abdominoplasty from five patients was processed by homogenization and centrifugation to separate mature lipocytes from other stromal cell populations in its associated extracellular matrix, and then to separate this from the blood and cellular debris. The cellular layer was evaluated histologically and with the immunohistochemical antibodies for CD34, SM-actin, S-100 protein, MIB-1, Bcl-2, and factor XIIIa. The cellular layer showed spindle cells, some small vascular structures, a small amount of mature fat, and extracellular matrix. CD34 showed diffuse staining of most spindle and endothelial cells in all sections, factor XIIIa showed only focal staining of spindle and dendritic cells, and Bcl-2 showed light to moderate staining in scattered cells within the cellular component. S-100 protein, SM-actin, and MIB-1 were negative. Processed liposuction and abdominoplasty processed fat may be ideal for the treatment of wrinkles in aged skin because it contains progenitor stromal cells that are known to be present within the fat and which may be concentrated by processing methods.

Immunolocalisation of vascular endothelial growth factor (VEGF) in human neonatal growth plate cartilage.

Angiogenesis is essential for the replacement of cartilage by bone during growth and repair. In order to obtain a better understanding of the mechanisms regulating vascular invasion at sites of endochondral ossification we have investigated the expression of the endothelial cell-specific mitogen, vascular endothelial growth factor (VEGF), by chondrocytes in human neonatal growth plates. VEGF was absent from chondrocytes in the resting zone and only weakly expressed by occasional chondrocytes in the proliferating region. In the hypertrophic zone the number of chondrocytes stained and the intensity of staining for VEGF increased with chondrocyte hypertrophy, maximum expression of VEGF being observed in chondrocytes in the lower hypertrophic and mineralised regions of the cartilage. These observations provide the first demonstration of the presence of VEGF in situ in developing human bone and are consistent with in vitro observations demonstrating the upregulation of proangiogenic growth factor production with increasing chondrocyte hypertrophy. The presence of numerous small blood vessels and vascular structures in the subchondral region where VEGF expression was maximal indicates that VEGF produced by hypertrophic chondrocytes may play a key role in the regulation of vascular invasion of the growth plate.

Small Red Nodule on the Leg of a Young Woman

REPORT OF A CASE A 24-year-old white woman presented with a slowly enlarging nodule on her left calf. The lesion was of 6 months' duration and was generally asymptomatic with only occasional mild pruritus and slight tenderness. There was no history of trauma. The physical examination revealed a firm red nod- ule (diameter, 0.6 cm), with a slightly irregular contour (Figure 1). A biopsy specimen was obtained (Figure 2andFigure 3). What is your diagnosis? Figure 1 . Figure 2 . Figure 3 . Small Red Nodule on the Leg of a Young Woma n DIAGNOSIS: Microvenular hemangioma. HISTOLOGIC FINDINGS The microscopic examination revealed a superficial and middermal haphazard infiltrate of collapsed small vascular structures extending between collagen bundles. These vessels showed irregular branching and consisted mostly of plump endothelial cells. Focally, some of the vessels had more visible lumens, giving a sinusoidal appearance. Significant atypia and mitotic figures were not observed.

Expression of the platelet‐derived growth factor β receptor during organogenesis and tissue differentiation in the mouse embryo

In this study we used in situ hybridization to localize expression of the platelet-derived growth factor beta (PDGF beta) receptor mRNA during organogenesis in the mouse embryo (E 9.5-16.5). Expression was first seen in periaortic mesenchyme (E 9.5-10.5). Later (E 12.5-E 16.5), the receptor was expressed in the mesenchymal component of many developing tissues and organs, particularly derivatives of the primitive gut. The expression was exceptionally high in mesenchyme directly supporting an epithelium, typical of many developing organs such as the trachea and intestine. However, as the mesenchyme differentiated into smooth muscle, PDGF beta receptor mRNA was no longer detected. The expression of the PDGF beta receptor mRNA in mesenchymal components of developing organs, along with its absence in epithelial tissues, indicates that it may play a role in mesenchymal-epithelial interactions during organ development. Somewhat unexpectedly, the PDGF beta receptor was highly expressed in the endothelium of small blood vessels and vascular structures such as the hyaloid plexus and choroid plexus. In large blood vessels, PDGF beta receptor mRNA was found in the mesenchyme surrounding the endothelium. This suggests that the PDGF beta receptor is involved in growth and development of blood vessels.

Quantitative assessment of human fetal renal blood flow

Our purpose was to longitudinally quantify human fetal renal blood flow. Twenty-two normal fetuses underwent a color-pulsed Doppler evaluation of the renal artery. The Doppler waveforms were digitized to assess the velocity-time integral. The size of the vessel was determined during systole with color high-resolution two-dimensional ultrasonography. Renal blood flow was estimated by multiplying the time-velocity integral (i.e., area under the curve) by the area of the renal artery. The combined cardiac output was calculated by adding right and left inflow Doppler-derived volumes. Renal artery size, peak flow velocity, time-velocity integral, and renal blood flow significantly increased with advancing gestational age. The resistivity indexes, such as the systolic/diastolic ratio or the Pourcelot index of the fetal renal artery, did not significantly change with advancing gestational age. The pulsatility index, however, was correlated with gestational age. The percentage of the combined cardiac output to the fetal kidney remained constant throughout gestation. Color pulsed Doppler can be used to visualize small and deep vascular structures in the human fetus. Renal blood flow increased with advancing gestational age. This increase seems to be related to the increase in the combined cardiac output.

Successful transesophageal echocardiography in an unsedated critically ill patient with superior laryngeal nerve blocks

mediastinal mass and compression of the superior vena cava. Tissue density studies performed at the time of CAT scanning further characterized the mass. Supraclavicular node biopsy was diagnostic of poorly differentiated carcinoma. The patient failed to respond to medical therapy and died 7 days later. Postmortem examination was refused. To our knowledge, this is the first report demonstrating the utility of transesophageal echocardiography in delineating compression of the superior vena cava by a mediastinal mass. Although transthoracic two-dimensional echocardiography has been useful in differentiating large vascular abnormalities such as aortic aneurysms from nonvascular mediastinal masses, this technique would appear limited in delineating small vascular structures such as the superior vena cava, particularly in patients requiring ventilatory support. In addition, the advent of color flow-guided, pulsed Doppler echocardiographic interrogation of potentially abnormal vascular flow greatly aids in the assessment of hemodynamically significant compression of the superior vena cava. The role of transesophageal echocardiography in tissue characterization of mediastinal masses has yet to be explored, but may prove to be beneficial.7 Recent advances that may broaden the utility of transesophageal echocardiography in the evaluation of mediastinal masses include the development of biplane and wide-field transesophageal echocardiographic probes.6p gAlthough preliminary, this case study suggests a role for two-dimensional and Doppler transesophageal echocardiography in the assessment of mediastinal masses that potentially compromise vascular flow.

Pulmonary vasculature: high-resolution MR imaging. Work in progress.

High-resolution magnetic resonance (MR) imaging of the lung has the potential to depict not only small pulmonary vascular structures but also pulmonary blood flow. Five healthy volunteers were examined to assess the effects of (a) the use of two 5-inch surface coils located on the anterior and posterior chest walls, with a 24-cm field of view and a matrix of 256 X 256; (b) spin-echo acquisition with electrocardiographic (ECG) gating during systole or diastole; and (c) gradient recalled acquisition in a steady state (GRASS) with breath holding. These techniques yielded images showing small peripheral pulmonary vascular structures. Most subsegmental vessels and sixth- and seventh-order branches could be traced, especially near the coils. GRASS images obtained with dual surface coils and breath holding depicted fifth- and sixth-order branches. Preliminary results indicated that small pulmonary vessels can be imaged with MR with a combination of high-resolution techniques and ECG gating in diastole. The sensitivity and reproducibility of these techniques in demonstrating pulmonary vasculature warrant further investigation.

Abdominal Gunshot Wounds

From July 1983 through December 1987, 300 consecutive patients with penetrating gunshot wounds of the abdomen causing visceral or vascular injuries were treated. Resuscitative thoracotomy was required in 20 patients (6.6%), and only two survived. The most commonly injured organs were the small bowel (60%), colon (41.6%), liver (29.3%), vascular structures (24.6%), stomach (17.3%), and kidney (17.0%). The overall survival rate for the series was 88.3%; however, if only the 226 patients without vascular injuries are considered, the survival rate was 97.3%. In the 35 patients who died, the blood pressure on admission was 51 mmHg, 18 required a resuscitative thoracotomy, four visceral or vascular injuries were present, and the median blood replacement was 18 units. The cause of death was perioperative shock in 30 patients (85.7%), whereas five patients (14.3%) died of sepsis and multiple organ failure. The most common postoperative complication in survivors and patients who died later in the study was an intra-abdominal abscess (3.0%). Rapid conservative operative techniques for civilian gunshot wounds leads to few postoperative complications and an excellent survival rate, especially if vascular injuries are not present.

Normal anatomy and pathologic changes of the small bowel mesentery: US appearance.

The ultrasonographic (US) appearance of the normal small bowel mesenteric leaves was evaluated in two in vitro studies and in 30 patients. Such structures had an elongated shape, echogenic surfaces, and small vessels in their center and could be recognized in 28 of the 30 patients. They did not show active movements, and at their distal end, the small bowel loops could be seen and peristalsis detected. Doppler signals were obtained from the small vascular structures in their center in three additional cases. On the basis of these anatomic findings, pathologic changes such as lymphoma, desmoid tumor, metastatic lesions, dilated vessels, and edema could be detected in 15 patients. When examining with US patients with diseases prone to involve the mesentery, careful attention should be given to this structure, since useful information about the abdominal spread of the disease can be obtained.