Exposed Blood Vessels Research Articles

Aortic valve papillary fibroelastoma associated with acute cerebral infarction: a case report.

An 80-year-old woman with a history of congestive heart failure, atrial fibrillation, and hypertension was transferred to our institution with hematemesis. Her drug regimen included 2 mg warfarin potassium/day to prevent thromboembolic events. Transthoracic echocardiography (TTE) performed at 78 years of age revealed a mass attached to the noncoronary cusp and a cardiac tumor was suspected. The patient declined surgery and was meticulously followed up with periodic TTE. Upper gastroendoscopy revealed a gastric ulcer with an exposed blood vessel; anticoagulant therapy was ceased. On day 15 of admission, acute cerebral infarction occurred. Heparin sodium and warfarin potassium were administered rapidly, and her symptoms improved. TTE revealed no alteration of the mobile, string-like mass attached to the noncoronary cusp. Cardiac tumor was considered the cause of cerebral infarction, and the patient consented to surgical therapy. Pathological examination of the resected tumor suggested papillary fibroelastoma (PFE). Although no guidelines exist for PFE management, a mobile, cardiac tumor necessitates surgical resection to prevent thromboembolic events, even when small in size.

The use of a rigid disc to protect exposed structures in wounds treated with negative pressure wound therapy: Effects on wound bed pressure and microvascular blood flow

There are increasing reports of deaths and serious complications associated with the use of negative pressure wound therapy (NPWT). Bleeding may occur in patients when NPWT is applied to a wound with exposed blood vessels or vascular grafts, possibly due to mechanical deformation and hypoperfusion of the vessel walls. Recent evidence suggests that using a rigid barrier disc to protect underlying tissue can prevent this mechanical deformation. The aim of this study was to examine the effect of rigid discs on the tissue exposed to negative pressure with regard to tissue pressure and microvascular blood flow. Peripheral wounds were created on the backs of eight pigs. The pressure and microvascular blood flow in the wound bed were measured when NPWT was applied. The wound was filled with foam, and rigid discs of different designs were inserted between the wound bed and the foam. The discs were created with or without channels (to accommodate exposed sensitive structures such as blood vessels and nerves), perforations, or a porous dressing that covered the underside of the discs (to facilitate pressure transduction and fluid evacuation). When comparing the results for pressure transduction to the wound bed, no significant differences were found using different discs covered with dressing, whereas pressure transduction was lower with bare discs. Microvascular blood flow in the wound bed decreased by 49 ± 7% when NPWT was applied to control wounds. The reduction in blood flow was less in the presence of a protective disc (e.g., -6 ± 5% for a dressing-covered, perforated disc, p = 0.006). In conclusion, NPWT causes hypoperfusion of superficial tissue in the wound bed. The insertion of a rigid barrier counteracts this effect. The placement of a rigid disc over exposed blood vessels or nerves may protect these structures from rupture and damage.

Exposed blood vessels of more than 2 mm in diameter are a risk factor for rebleeding after endoscopic clipping hemostasis for hemorrhagic gastroduodenal ulcer

There are few clinical studies on the risk factors for rebleeding based on the endoscopic hemostatic procedure carried out, including ulcer characteristics such as exposed blood vessels. The present study aims to clarify the risk factors for rebleeding after endoscopic clipping hemostasis for hemorrhagic gastroduodenal ulcers. A retrospective study was carried out with data collected during the 10-year period from January 2000 to December 2009 for 312 consecutive patients with hemorrhagic gastroduodenal ulcer. Two hundred and ninety-three patients (216 men and 77 women; mean age, 67.0 ± 15.0 years) who underwent endoscopic clipping as the initial hemostatic treatment were analyzed. The risk factors for rebleeding were determined by comparing 271 patients who did not rebleed after initial treatment with 22 patients who developed rebleeding. The success rate of initial clipping hemostasis was 100%; however, rebleeding occurred in 7.5% (22/293) and a multivariate analysis identified exposed blood vessels of more than 2 mm in diameter as independent risk factors for rebleeding (P = 0.0124, odds ratio 6.25 [95% CI: 1.53-13.62]). Endoscopic clipping monotherapy is effective for hemorrhagic gastroduodenal ulcers; however, exposed blood vessels of more than 2 mm in diameter in the initial endoscopic procedure are a risk factor for rebleeding.

A Rigid Disc for Protection of Exposed Blood Vessels During Negative Pressure Wound Therapy

There are increasing reports of serious complications and deaths associated with negative pressure wound therapy (NPWT). Bleeding may occur when NPWT is applied to a wound with exposed blood vessels. Inserting a rigid disc in the wound may protect these structures. The authors examined the effects of rigid discs on wound bed tissue pressure and blood flow through a large blood vessel in the wound bed during NPWT. Wounds were created over the femoral artery in the groin of 8 pigs. Rigid discs were inserted. Wound bed pressures and arterial blood flow were measured during NPWT. Pressure transduction to the wound bed was similar for control wounds and wounds with discs. Blood flow through the femoral artery decreased in control wounds. When a disc was inserted, the blood flow was restored. NPWT causes hypoperfusion in the wound bed tissue, presumably as a result of mechanical deformation. The insertion of a rigid barrier alleviates this effect and restores blood flow.

Vacuum Assisted Wound Closures in Gynaecologic Surgery

Vacuum assisted closure and negative pressure (NP) dressings are innovative forms of wound management used in multiple fields of medicine, including surgery. We review here the current literature in this area relevant for the gynaecologist. Negative pressure dressings increase blood flow to the wound, decrease bacterial counts, decrease tension on wound edges, and increase the formation of granulation tissue. Until recently, use of NP dressings has been contraindicated in wounds that have been previously radiated or that have necrotic tissue, an infection, an open fistula, an underlying malignancy, or an exposed blood vessel. In this review, we discuss the use of negative pressure for the treatment of abdominal wounds, including those associated with dehiscence, fistula, and prior radiation. We also discuss the use of NP dressings in gynaecologic oncology, including the vulvar and perineal areas. Finally, we outline the basics of applying NP dressings, and discuss pressure settings, “foam counts,” debridement, and interface dressings to optimize the benefits of vacuum dressings. When used in the appropriate setting, NP dressing is a unique and important modality of treatment in gynaecology.

Rate of post-tonsillectomy hemorrhage after elective bipolar microcauterization of nonbleeding vessels

The objective of this paper is to describe an extended microscopic hemostasis technique involving cauterization of exposed blood vessels that were not actively bleeding in tonsillar fossa after bipolar tonsillectomy and to assess the rate of post-tonsillectomy hemorrhage with this technique in children who had bipolar tonsillectomy. The medical records of children who underwent microscopic bipolar tonsillectomy with extended hemostasis between June 2008 and January 2011 were reviewed. Relevant history and physical examination, diagnosis, and characteristics of postoperative hemorrhage were recorded; 994 children (531 males, 463 females), aged between 1 and 18 years (6 ± 3 years), underwent tonsillectomy; of the 994 patients, 11 (1.1%) developed post-tonsillectomy hemorrhage. No primary post-tonsillectomy hemorrhage occurred. The hemorrhage was seen 6-13 days after the surgery. One patient had bleeding after having trauma to the neck on postoperative day 13. Of the 11 patients with post-tonsillectomy bleeding, 3 had blood clot with no active bleeding and 8 exhibited active bleeding after removal of blood clot. Of the 994 patients, 8 (0.8%) needed intervention to control active bleeding. Compared to previous studies of bipolar tonsillectomy, extended microscopic hemostasis achieved by cauterization of tonsil fossa non-bleeding blood vessels appeared to reduce bleeding rate after bipolar cautery tonsillectomy. The present study did not include a control arm; further randomized controlled studies are needed to establish the definite effect of extended microscopic hemostasis technique on the rate of hemorrhage rates after tonsillectomy techniques.

A Long-Term Randomized Controlled Trial of a Novel Nanopowder Hemostatic Agent for Control of Severe Upper Gastrointestinal Bleeding in a Porcine Model

Endoscopic therapy of brisk upper GI bleeding remains challenging with the use of conventional endoscopic devices. A proprietary granular mineral blend (TC-325) for the management of high pressure arterial wounds has been proven to be effective for external wounds by the US Army in both Iraq and Afghanistan. Aim: To assess the efficacy and safety of a novel hemostatic nanomaterial in short and long term hemostasis in a survival GI bleeding animal model. Methods: 10 animals randomized into treatment and control group based on a sample size calculation from a pilot study. All animals underwent a sterile laparotomy with dissection of the gastroepiploic vessels. A 1cm gastrotomy was made through which the blood vessels were pushed into the gastric lumen. A gastric incision was then approximated in a standard manner along with the abdominal wall. All animals then received IV antibiotics and daily H2 blocker therapy. To create anticoagulation and worst case scenario, a bolus of heparin (mean of 150units/kg) was given with a target of achieving activated clotting time (ACT) levels 2X the ULN. Double channel endoscope was inserted into the gastric lumen and needle knife injury of the exposed blood vessels. A visual scale of bleeding was used: Grade1 oozing of blood, Grade 2 dripping of blood and Grade 3 pulsatile bleeding from site of injury. The treatment group received endoscopic guided application of nanopowder. A modified delivery catheter was used to deliver the active material. Times to hemostasis, mortality at 60 minutes, 24 hours, 48 hours and 7 days were noted. Necropsy was performed in all animals. Results: Creation of the active GI bleeding model by laparotomy with gastroepiploic vessel exposure was successful. A grade 3 injury and bleeding was achieved in all animals. None of the control group animals achieved hemostasis within the first hour compared to 100% in the treatment arm (mean 13.8 minutes, P<0.0079). Durable hemostasis was achieved with no evidence of rebleeding after 1 and 24 hours in 80% of the animals in the treatment group as compared to none in the control group (P<0.0098). Endoscopy at day seven revealed no evidence of active bleeding in all animals in the treatment group. None of the animals in the control could survive more than 6 hours because of ongoing bleeding. Necropsy revealed healed gastrotomy with no foreign body granuloma. Lung and brain assessment revealed no evidence of embolization in treatment animals. Conclusion: The endoscopic application of this novel granular mineral nanopowder is safe and highly effective in achieving hemostasis in anticoagulated severe GI bleeding animal model.

Line Scanning Flow Measurements

We are developing a new technique to measure flow of micron scale particles using laser scanning. This technique will also detect complex flow patterns, identify stationary particles and determine particle size. In this method, a laser beam is raster scanned over an area containing a flowing liquid. Particles in the liquid scatter the laser. Detailed information about the flow can be obtained from analyzing the fluctuations in this scattered radiation.Detailed flow information, such as can be provided by this technique, is valuable in medical applications. Blood cells can serve as the particles that scatter lights and the laser scanning can be applied to surgically exposed blood vessels in a patient or in a animal model. The information available with this method can help study or monitor conditions such as sickle cell anemia in which abnormal blood cells do not move smoothly through blood vessels or become stuck. It can also be used to study the formation of atheromatous plaques. One factor in the creation of these plaques on artery walls is the accumulation of platelets and leukocytes. Understanding what prevents blood cells from flowing normally and what causes them to accumulate would be a significant improvement in our understanding of vascular disease.This work was supported by the National Center for Research Resources of the National Institutes of Health (PHS 5 P41-RR003155).

Massive Melena Caused by a Carcinoid of the Small Intestine: Report of a Case

We report a case of massive melena caused by a carcinoid of the small intestine. A 28-year-old woman was admitted to our department after presenting with massive melena. The source of the bleeding could not be localized by upper or lower gastrointestinal endoscopy, computed tomography (CT), or labeled red blood cell scintigraphy. Enteroscopy allowed visualization only up to the jejunum, and we could not localize the lesion. The melena subsided with conservative treatment, but the patient was readmitted 4 months later when she suffered another episode of massive melena. A contrast CT scan performed immediately showed extravascular leakage and the retention of contrast medium in the ileum. Thus, she underwent an emergency surgery, during which endoscopy confirmed a small ileal tumor accompanied by pulsating bleeding from the exposed blood vessels at its center. The small intestine was partially resected, including the swollen lymph nodes, the size of small beans. Pathological examination confirmed a carcinoid tumor 1 cm in diameter, with an arterial rupture at its center and lymph node metastasis.

Successful treatment of a giant exposed blood vessel in a gastric ulcer by endoscopic sclerotherapy with N-butyl-2-cyanoacrylate

Successful treatment of a giant exposed blood vessel in a gastric ulcer by endoscopic sclerotherapy with N-butyl-2-cyanoacrylate

Delivery of Liposomal Doxorubicin (Doxil) in a Breast Cancer Tumor Model: Investigation of Potential Enhancement by Pulsed-High Intensity Focused Ultrasound Exposure

To investigate the potential of using pulsed high-intensity focused ultrasound (HIFU) exposures to enhance the delivery, and hence therapeutic effect of liposomal doxorubicin (Doxil) in a murine breast cancer tumor model. Tumors were grown in the bilateral flanks of mice using a mammary adenocarcinoma cell line. Experiments consisted of exposing one of two tumors to pulsed-HIFU, followed by tail vein injections of Doxil. Tumor growth rates were monitored, and assays carried out for doxorubicin concentration in these tumors as well as in a second (squamous cell carcinoma) tumor model and in muscle. Laser scanning confocal microscopy was used with fluorescent probes to observe both the uptake of polystyrene nanoparticles and dilation of exposed blood vessels. Additional experiments involving histologic analysis and real-time temperature measurements were performed to determine the safety of the exposures. Pulsed-HIFU exposures were shown to be safe, producing no apparent deleterious effects in the tumors. The exposures, however, were not found to enhance the delivery of Doxil, and consequently did not allow for lower doses for obtaining tumor regression. Imaging with a fluorescent dextran showed blood vessels to be dilated as a result of the exposures. Experiments with polystyrene nanoparticles of similar size to the liposomes showed a greater abundance to be present in the treated tumors. Although past studies have shown the advantages of pulsed-HIFU exposures for enhancing delivery, this was not observed with the liposomes, apparently because of their inherent ability to preferentially accumulate into tumors on their own. Potential mechanisms for enhanced uptake of non-liposomal nanoparticles are discussed.

A clinical analysis of 836 cases with electric injury.

Eight hundred thirty-six patients with electric injury were admitted to Shanghai Power Hospital from 1972 to 1998. The majority of electric injury patients were young or middle-aged industrial workers from both cities and rural areas. These patients were classified into three categories depending on the type of electric injury: (1) electric shock; (2) electric contact burn injury; (3) electric arc burn. In our study of wound management, we focused on three areas: first, the choice of operation time in electric burn injury; second, the methods of wound management on the injured extremities, especially the hands and upper limbs; third, functional site wounds that included some exposed blood vessels. Nerves and tendons were covered and repaired by various flaps. Through the analysis of 836 electric injury cases, we summarized our experience of treating electric injury with the purpose of increasing our knowledge in the area of electric injury prevention and treatment.

Occlusion of blood vessels using high-intensity focused ultrasound

Vascular injury may result from both trauma and invasive medical procedures. High-intensity focused ultrasound (HIFU) was used to occlude surgically exposed blood vessels of anesthetized rabbits, as a mechanism of hemostasis applicable to vascular injury. A HIFU transducer, with a spherically curved aperture area of 6.34 cm2, a focal length of 4 cm, and a frequency of 3.3 MHz, was used. The transducer was equipped with a conical housing filled with water, providing a coupling medium to the vessels. Femoral arteries and veins were occluded after a HIFU treatment of approximately 30–60 s, at a focal intensity of 3000 W/cm2. The vessels were severed after the treatment to confirm complete occlusion. No bleeding was observed. Gross and microscopic examination of the vessels revealed two major mechanisms of occlusion, dissection of the vessel wall and shrinkage of the vessel. In the dissection mechanism, a flap of the inner wall of the vessel peeled as a result of the HIFU treatment and caused a blockage of the blood flow, while in the shrinkage mechanism a mechanical constriction of the vessel lumen caused the blockage. HIFU may provide a valuable method for hemostasis of injured vessels by treating a region of the blood vessel, proximal to the hemorrhaging site.

Endoscopic Hemostasis in Hemorrhagic Gastric Ulcer—Effectiveness of the Hemoclipping, Ethanol Injections and Heat Probe—

Abstract: The hemostatic effects of hemoclipping, the pure ethanol local injection method and the heat probe methods on hemorrhagic gastric ulcers associated with exposed blood vessels, were compared. The locations of the ulcers and exposed blood vessles, as well as characteristics and the severity of the hemorrhage were discussed. The hemoclipping method was used on 59 patients, the pure ethanol local injection on 32 patients, and the heat probe methods on 26 patients. The hemoclipping and pure ethanol local injection methods were effective in all of the patients in whom the exposed blood vessels were present around the margin of ulcers. The efficacy rate was 91%, 92% and 92%, respectively, when exposed blood vessels were found at the base of the ulcer. The efficacy rate was 94%, 100% and 80% for the three hemostatic methods, respectively, when an oozing hemorrhage was present. The three methods had an efficacy rate of 100% when only blood clots were present. The efficacy rate for a spurting hemorrhage was 86%, 71% and 67%, respectively, for the three methods. The hemoclipping and pure ethanol local injection were effective in 100% of slight and moderate hemorrhage cases, while the heat probe method was effective in only 89% of moderate cases. The efficacy rate was 85%, 85% and 83%, respectively, for severe cases. Overall, the efficacy rate was 93% for the hemoclipping method, 94% for the pure ethanol local injection and 92% for the heat probe method, and there was no significant difference between the three methods with regard to the overall efficacy rate.

Clinical evaluation of endoscopic hemostasis for bleeding gastric and duodenal ulcers

The present study shows the excellent efficacy of endoscopic hemostatic therapy by ethanol injection. At the same time, the results emphasize the significant efficacy of intensive pharmaceutical treatment for peptic ulcer patients with clinical symptoms of hematemesis and/or melena. Concerning endoscopic hemostatic therapy, we prefer ethanol injection therapy to most other methods, such as laser irradiation, microtase or heat probe, because the ethanol injection method is the most simple, inexpensive, safe, technically easy, can be performed any time and in any place, and is more effective than other methods. In rare cases where direct ethanol injection into the exposed blood vessels is difficult, we do not hesitate to select other contact methods such as heat probe or microtase.

Endoscopic diagnosis and treatment of Dieulafoy's ulcer.

Dieulafoy's ulcer often develops unmanageable severe gastrointestinal hemorrhage and sometimes takes a fatal course. In the past surgical operations were considered to be the only life-saving measure for this lesion. Since 1979, 46 lesions of Dieulafoy's ulcer in 45 cases with active bleeding from exposed blood vessels were treated during emergency endoscopy by the hemostatic method of pure ethanol injection. Transient hemostasis was obtained in all cases. Rebleeding occurred in 5 cases (11%) and pure ethanol injection was performed again. Hemostasis was obtained in all cases, but one case again had rebleeding due to an overlooked Dieulafoy's ulcer located in the gastric fundus. Emergent surgical operation was performed in this case. No case required elective surgery and no deaths were attributed to bleeding. Our method achieved complete hemostasis at a rate of 98% (44 cases) for Dieulafoy's ulcer. The pure ethanol injection method is one of the most effective hemostatic methods for the Dieulafoy's ulcer.

A new method for vascular occlusion. Photochemical initiation of thrombosis.

A new photochemical method has been used to produce focal thrombosis and occlusion of the blood vessels on the surface of the myelin wings of rabbit retinas. Following intravenous injection of rose bengal, the vessels next to the disc on the nasal wing were exposed to filtered light (550 nm, the absorption maximum of rose bengal) for four minutes. As a control, the vessels on the temporal wing of each rabbit eye were exposed to filtered light for four minutes before the injection of rose bengal. Complete vascular occlusion was produced on the nasal wing in all eyes, with no visible alterations on the temporal wing. Progressive reopening of the arteries on the nasal wing was observed at three days, with reopening of the veins visible by seven days. Reperfusion of capillaries had occurred by 21 days. Light and electron microscopic examination of blood vessels on the nasal wing after light exposure with rose bengal showed disrupted endothelial cells in all exposed blood vessels and platelet aggregates in the arteries and arterioles. No morphologic abnormalities were observed in the temporal wings. This method should be useful in studying the effects of vascular occlusion in the retina and could lead to a new treatment modality for subretinal, iris, or corneal neovascularization.

Clinical Benefits of Intravenously Administered Famotidine in the Treatment of Upper Gastrointestinal Hemorrhage Caused by Peptic Ulcer and Stress Ulcer Disease

Bleeding may stop spontaneously in mild or moderate cases of GI bleeding. Therefore, to prove that H2-receptor antagonists effectively stop GI bleeding, evaluation of the results of treatment in patients who are classified as severe cases by the Nagao taxonomy is needed. Data from the literature show that mortality is higher in patients with specific endoscopic findings, such as active bleeding, visible vessels, clot, or stain, than it is in patients without these findings. The criteria for establishing whether H2-receptor antagonists effectively control GI bleeding in severe cases include a reduction in mortality, in the rate of recurrent bleeding, or in the rate of emergency surgery. Data gathered from a current multicenter trial assessing the efficacy of 20 mg famotidine administered intravenously twice daily show that the rate of emergency surgery in patients with bleeding ulcer is 8.6%, which is substantially less than the 54.2% rate found in a retrospective review of patients treated before the introduction of H2-receptor antagonists. In addition, there were no deaths among famotidine-treated patients. Similarly, among patients with bleeding caused by stress ulcer, the percentage who were treated with famotidine and required emergency surgery was much less than that in the historical control group (15.8% versus 40.0%). Famotidine was effective in greater than or equal to 88% of patients with peptic ulcers and in 78.9% of patients with stress ulcers. Recurrent bleeding occurred more often in patients with exposed blood vessels. Intravenously administered famotidine is, therefore, effective for the control of GI bleeding caused by severe peptic ulcer and stress ulcer disease.

What are the signs of recent hemorrhage, and what do they mean? Criteria for massive bleeding.

Hematemesis, melena, shock, vague symptoms, anemia, blood examinations and endoscopic findings are reviewed as signs of recent hemorrhage. An assessment of the condition of patients with upper GI bleeding is important for planning treatment. Therefore, in order to be able to evaluate a method of treatment of GI bleeding, reports referring to treatment of GI bleeding must contain a clear record of the severity of the patient's state and of the bleeding source. A common criterion for massive bleeding has been proposed. Specifically, a patient suffering from shock who needs more than 1,000 ml of blood or plasma expander by rapid transfusion within one hour, or more than 2,000 ml within the initial 24 hours, to stabilize his circulation, and whose Hb level is 8.0 g/dl or less, should be graded as having massive bleeding. Gastric ulcers with exposed blood vessels need endoscopic YAG laser hemostasis or ethanol injection therapy as quickly as possible, since 43% of the cases rebleed within 72 hours under conventional drug therapy, and such rebleeding can be prevented by the endoscopic hemostatic methods.

Endoscopic control of gastrointestinal hemorrhage by local injection of absolute ethanol: a basic assessment of the procedure.

To investigate the hemostatic mechanism of local ethanol injection, ethanol was injected into the gastric mucosa of five adult mongrel dogs and one guinea pig and histologic changes at acute and healing stages were followed. Following a local injection of absolute ethanol, the blood flow in small vessels at the site of injection became instantaneously arrested. Histopathologically, thrombosis of blood vessels in the mucosa and submucosa with edema, predominantly submucosal, was found 10 min after the ethanol injection. There was little or no inflammatory cell infiltration in the injected region. By 4 days after the injection, the base of the formed ulcer became stabilized with a uniform white coating, which, microscopically, was mainly composed of a thick layer of necrotized mucosal tissue. Ethanol showed fixative activity when applied to tissues at concentrations of greater than or equal to 20% although an ethanol concentration of at least 70% was required to accomplish adequate tissue fixation. With 95% or lower concentrations of ethanol, dehydration of tissue was insufficient, and hemostasis due to local vasoconstriction was less conspicuous than with absolute alcohol. Nevertheless, a fixative effect with consequent degeneration and necrosis of cells and secondary thrombosis was evident even at these ethanol concentrations. In patients treated with this hemostatic procedure, exposed blood vessels in the gastric ulcer became necrotized and corroded by fixation with injected absolute ethanol and disappeared from the base of the ulcer within 24 hr as seen in the animals.