Fournier's gangrene revealing an acute arterial occlusion: A case report

INTRODUCTION AND IMPORTANCE

Fournier gangrene (FG) is a rare form of necrotizing fasciitis that affects both the deep and superficial layers of the perineal genital region. When left untreated, Fournier gangrene can rapidly advance, leading to substantial morbidity and mortality. Herein, we present a case of Fournier's gangrene, which revealed acute arterial occlusion. To the best of our knowledge, few cases of Fournier's gangrene secondary to arterial occlusion have been reported.

CASE PRESENTATION

We report the case of a 37-year-old man with no known medical history who presented with fever and painful swelling of the scrotum. Physical examination revealed a large black spot on the scrotum surrounded by erythema, suggestive of Fournier's gangrene. We performed an extended debridement of the scrotal area. Three days later, the patient complained of severe pain in the left foot accompanied by numbness. Lower limb computed tomographic angiography (CTA) revealed multiple arterial occlusions. Thrombectomy and anticoagulation therapy were crucial in managing the vascular thrombosis and preventing the further extension of the gangrene.

CLINICAL DISCUSSION

This case underscores the importance of recognizing diverse etiologies of Fournier's gangrene, including vascular involvement, and emphasizes the need for a multidisciplinary approach. Early identification, aggressive surgical debridement, and broad-spectrum antibiotics remain the cornerstone of management, with the added consideration of anticoagulation in cases involving vascular thrombosis.

CONCLUSION

FG is a rare yet potentially life-threatening condition. Its multifaceted etiologies, including vascular factors, underscore the complexity of its presentation and challenges for timely diagnosis. The recognition of vascular involvement as a potential etiology of FG warrants further in-depth exploration.

A systematic review of the relationship between muscle oxygen dynamics and energy rich phosphates. Can NIRS help?

BACKGROUND

Phosphocreatine dynamics provide the gold standard evaluation of in-vivo mitochondrial function and is tightly coupled with oxygen availability. Low mitochondrial oxidative capacity has been associated with health issues and low exercise performance.

METHODS

To evaluate the relationship between near-infrared spectroscopy-based muscle oxygen dynamics and magnetic resonance spectroscopy-based energy-rich phosphates, a systematic review of the literature related to muscle oxygen dynamics and energy-rich phosphates was conducted. PRISMA guidelines were followed to perform a comprehensive and systematic search of four databases on 02-11-2021 (PubMed, MEDLINE, Scopus and Web of Science). Beforehand pre-registration with the Open Science Framework was performed. Studies had to include healthy humans aged 18-55, measures related to NIRS-based muscle oxygen measures in combination with energy-rich phosphates. Exclusion criteria were clinical populations, laboratory animals, acutely injured subjects, data that only assessed oxygen dynamics or energy-rich phosphates, or grey literature. The Effective Public Health Practice Project Quality Assessment Tool was used to assess methodological quality, and data extraction was presented in a table.

RESULTS

Out of 1483 records, 28 were eligible. All included studies were rated moderate. The studies suggest muscle oxygen dynamics could indicate energy-rich phosphates under appropriate protocol settings.

CONCLUSION

Arterial occlusion and exercise intensity might be important factors to control if NIRS application should be used to examine energetics. However, more research needs to be conducted without arterial occlusion and with high-intensity exercises to support the applicability of NIRS and provide an agreement level in the concurrent course of muscle oxygen kinetics and muscle energetics.

TRIAL REGISTRATION

https://osf.io/py32n/ .

KEY POINTS

1. NIRS derived measures of muscle oxygenation agree with gold-standard measures of high energy phosphates when assessed in an appropriate protocol setting. 2. At rest when applying the AO protocol, in the absence of muscle activity, an initial disjunction between the NIRS signal and high energy phosphates can been seen, suggesting a cascading relationship. 3. During exercise and recovery a disruption of oxygen delivery is required to provide the appropriate setting for evaluation through either an AO protocol or high intensity contractions.

In young patients with stroke of undetermined etiology, large vessel occlusions are less frequent in the group with high-risk patent foramen ovale

INTRODUCTION

Patent foramen ovale (PFO) is present in a significant proportion of young patients with stroke of undetermined etiology, but is not always causal. Therefore, classifications (RoPE, PASCAL) have been developed to determine the probability that PFO is the stroke cause. However, the presence of an initial arterial occlusion as a prediction factor was not studied when these classifications were built. Our aim was to evaluate the presence of arterial occlusion in young patients with stroke of undetermined etiology with/without high-risk PFO.

METHODS

From a prospectively-built monocentric database, we identified patients aged≥18 to<60-years with strokes of undetermined etiology and complete etiological work-up, including transesophageal echocardiography. We divided patients in two groups: (i) with high-risk PFO [i.e. PFO with large interatrial shunt (>30 microbubbles) or associated with atrial septal aneurysm] and (ii) with low-risk/without PFO. We recorded the presence of arterial occlusion and large vessel occlusion (LVO) in the acute phase.

RESULTS

We included 96 patients; 55 (57%) had high-risk PFO. Their median age was 48 (40-52) years, and 28 (29%) were women. The percentages of patients with arterial occlusion and with LVO were lower in the high-risk PFO group than in the low-risk/without PFO group: 11 (20%) versus 19 (46%) (P=0.008), and 5 (9%) versus 15 (37%) (P=0.002), respectively. There was no difference in the median RoPE score between groups (P=0.30).

CONCLUSION

The presence of LVO could represent a "red flag" of PFO causality in stroke of undetermined etiology, and could be implemented in future PFO-related stroke classifications.

[Internistic clarification of retinal vascular occlusions]

Retinal vascular occlusions require close cooperation of different medical disciplines to ensure optimal care of the affected patients. The medical clarification between arterial and venous occlusions is comparable but in the case of retinal arterial occlusions it should be carried out immediately. The most important associated diagnoses are arterial hypertension, diabetes mellitus, dyslipidemia, and atrial fibrillation. In younger patients and in the absence of risk factors, a search for rarer causes should be carried out giant cell arteritis in particular should be excluded. In both types of occlusions a causative glaucoma must also be considered.

Patient with basilar artery occlusion related to metastatic melanoma

Posterior circulation stroke accounts for approximately 20% of all ischemic strokes. The basilar artery, which is the main vessel of the posterior circulation, supplies most of the brainstem, occipital lobes and part of the cerebellum and thalami. We present a case of a 73-year-old man with known metastatic melanoma while undergoing immunotherapy presented to the emergency department with a history of progressive shortness of breath, generalize weakness, and dysphagia. The patient's imaging workup revealed brain metastasis. While hospitalized had a sudden onset of loss of consciousness which lasted a few minutes and was back to baseline. An hour later he had another episode of loss of consciousness with absence of brainstem signs. Urgent head computerized tomography showed basilar artery occlusion. Patient was transferred to the intensive care unit and started on intravenous heparin (DVT/PE dosing protocol) and supportive care. At present there is lack of high-quality evidence from randomized controlled trial to guide as how best manage patients with basilar artery occlusion.

Potential considerations with estimating blood flow restriction pressure in the lower body using a narrower cuff

Blood flow restriction pressures are typically set as a percentage of the arterial occlusion pressure. For those who do not have the ability to measure the arterial occlusion pressure, estimation equations are available. However, notable considerations are needed when estimating pressure with a narrow cuff (5 cm) in the lower body. A previously published equation in this journal was developed but was created only using 55% of the sample because the arterial occlusion of the others could not be obtained within the manufacturer's pressure limit. The purpose of this article was twofold: (1) to investigate how previous studies have implemented the equation and (2) to highlight potential concerns of using this equation. Two databases were used to locate articles that used the equation from Loenneke et al. (2015). We found that this equation had been cited 10 times to estimate arterial occlusion pressure with some notable concerns. Some did not use a 5 cm wide cuff, while others used it for participants who had arterial occlusion pressures exceeding 300 mmHg. To highlight the latter, we also applied the Loenneke et al. (2015) lower body equation to participants with arterial occlusion pressures known to exceed 300 mmHg to demonstrate potential concerns. This retrospective analysis found that 52% of the sample with known pressures over 300 mmHg (40 out of 77) would be estimated below 300 mmHg. This paper highlighted important considerations for those trying to estimate arterial occlusion pressure in the lower body with a narrow cuff (5 cm).

Recurrent upper extremity arterial thrombosis preceding a diagnosis of COVID-19

Arterial thrombosis occurs when there is endothelial damage in the setting of hypercoagulability and arterial blood stasis. COVID-19 has been theorized to cause both endothelial damage and promote hypercoagulability by causing an imbalance of clotting factors. In many studies, there have been a large proportion of COVID-19 patients that suffered a thromboembolic event, in both the venous and arterial systems. Our patient, who did not have a significant past medical history, presented with a recurrent brachial artery occlusion despite medical and surgical management, and subsequently tested positive for COVID-19 late in his admission. In conclusion, there is high suspicion that there is a relationship between COVID-19 infection and recurrent arterial thrombosis.

Common and uncommon vascular injuries and endovascular treatment associated with pelvic blunt trauma: a real-world experience

Pelvic fractures are common in cases of blunt trauma, which is strongly associated with mortality. Transcatheter arterial embolization is a fundamental treatment strategy for fatal arterial injuries caused by blunt pelvic trauma. However, vascular injuries due to blunt pelvic trauma can show various imaging findings other than arterial hemorrhage. We present a pictorial review of common and uncommon vascular injuries, including active arterial bleeding, pseudoaneurysm, arteriovenous fistula, arterial occlusion, vasospasm, and active venous bleeding. Knowledge of these vascular injuries can help clinicians select the appropriate therapeutic strategy and thus save lives.

Change in somatosensory evoked potentials detect an acute arterial stent occlusion in lower extremity during spinal surgery: Case report

The authors report a case in which an acute thrombosis of a pre-existing arterial stent occurs in a patient's lower extremity during a lumbar spinal fusion surgery. The event was detected by acute changes in somatosensory evoked potentials (SSEPs) which were being monitored during the procedure. The neurophysiology technologist reported a 10 % increased latency and 50 % loss of amplitude in the left posterior tibial nerve recordings. While still in the operating room, further investigation, including doppler and arteriogram, demonstrated a complete occlusion of one of the two contiguous stents within the superficial femoral artery (SFA). A vascular surgeon was then able to emergently perform trans-arterial thrombectomy and restore flow through the extremity while still in the operating room. The observed events demonstrate the ability of SSEP monitoring to potentially detect arterial occlusion early, allowing for a rapid diagnosis and expedient treatment, in this case immediate, thus avoiding significant limb threatening morbidity.

Modeling, Simulation and Validation of Alteration in Blood Flow and Regional Oxygenation Under Arterial Occlusion

The paper presents the mathematical modeling along with an experimental approach for the identification of arterial occlusion condition. Arterial occlusion occurs due to development of constriction and/or thrombus in the lumen of the artery. A geometry of the thrombus has been modeled for the analysis of the arterial occlusion condition in modeling part. The proposed model of the thrombus has been simulated using Comsol® multiphysics considering different hemodynamic parameters. Variation in regional oxygen saturation (rSO₂) of the arterial occlusion condition has been validated with experimental process, where occlusion of the artery has been done by applying external pressure. The experimental study has been conducted to monitor alteration in rSO₂ level profile for occlusion using near infrared spectroscopy (NIRS) methodology. NIRS signal data has been collected from twenty-three subjects with no reported musculoskeletal, psychiatric, or any other neurological deficits using Mespere NeurOs® oxymeter. Experimental data reveal that the oxygenation level decreases considerably due to arterial occlusion as compared to the healthy condition at 95% of confidence interval (p < .05). Dynamic time warping algorithm reveals that variation in rSO₂ due to proposed thrombus geometry has more similarity with experimental study.

Hyperosmolar Hyperglycaemic State (HHS) complicated by life-threatening large vessel occlusive arterial thrombosis - A mini case series and important reminder for clinicians

Hyperosmolar Hyperglycaemic State (HHS) is a known life-threatening complication of Type 2 Diabetes Mellitus (T2DM). As the incidence of T2DM continues to grow, it is important to remember some of its lesser-known complications. HHS has been described in the literature to result in small vessel thrombosis, leading to coronary or cerebral arterial thrombosis, resulting in acute myocardial infarction or cerebrovascular accidents. The underlying pathology of this relates to the prothrombotic and hyperviscous state caused by HHS. On our review of the literature, however, we are unable to find a consistent description or HHS complicated by large vessel thrombotic occlusion. The authors of this paper present a mini case series describing two cases of HHS which were complicated by life or limb-threatening large vessel occlusive arterial thrombosis. This is particularly unique as we have otherwise only been able to identify single case reports in the existing literature from other authors. The purpose of this case discussion is to highlight this rare complication of HHS and to encourage clinicians to remember that HHS is not just a physiological or biochemical derangement, can also lead to true surgical emergencies requiring immediate treatment.

Post-occlusive reactive hyperemia and skeletal muscle capillary hemodynamics

Post-occlusive reactive hyperemia (PORH) is an accepted diagnostic tool for assessing peripheral macrovascular function. While conduit artery hemodynamics have been well defined, the impact of PORH on capillary hemodynamics remains unknown, despite the microvasculature being the dominant site of vascular control. Therefore, the purpose of this investigation was to determine the effects of 5 min of feed artery occlusion on capillary hemodynamics in skeletal muscle. We tested the hypothesis that, upon release of arterial occlusion, there would be: 1) an increased red blood cell flux (fRBC) and red blood cell velocity (VRBC), and 2) a decreased proportion of capillaries supporting RBC flow compared to the pre-occlusion condition.

METHODS

In female Sprague-Dawley rats (n = 6), the spinotrapezius muscle was exteriorized for evaluation of capillary hemodynamics pre-occlusion, 5 min of feed artery occlusion (Occ), and 5 min of reperfusion (Post-Occ).

RESULTS

There were no differences in mean arterial pressure (MAP) or capillary diameter (Dc) between pre-occlusion and post-occlusion (P > 0.05). During 30 s of PORH, capillary fRBC was increased (pre: 59 ± 4 vs. 30 s-post: 77 ± 2 cells/s; P < 0.05) and VRBC was not changed (pre: 300 ± 24 vs. 30 s post: 322 ± 25 μm/s; P > 0.05). Capillary hematocrit (Hctcap) was unchanged across the pre- to post-occlusion conditions (P > 0.05). Following occlusion, there was a 20-30% decrease in the number of capillaries supporting RBC flow at 30 s and 300 s-post occlusion (pre: 92 ± 2%; 30 s-post: 66 ± 3%; 300 s-post: 72 ± 6%; both P < 0.05).

CONCLUSION

Short-term feed artery occlusion (i.e. 5 min) resulted in a more heterogeneous capillary flow profile with the presence of capillary no-reflow, decreasing the percentage of capillaries supporting RBC flow. A complex interaction between myogenic and metabolic mechanisms at the arteriolar level may play a role in the capillary no-reflow with PORH. Measurements at the level of the conduit artery mask significant alterations in blood flow distribution in the microcirculation.

Don't forget arterial thrombosis in patients with COVID-19: A case series

Introduction

The acute disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS COV-2) is accompanied by a hypercoagulable state. Multiple publications have described the venous thromboembolic events associated with coronavirus disease 2019 (COVID-19) but arterial thromboembolic events have yet to be described.

Cases description

We describe five COVID-19 patients that developed severe morbidity as a result of occlusive arterial thromboembolic events occurring despite treatment with low molecular weight heparin. All cases presented with an acute confusional state and were accompanied by rapid elevations of lactate and D-dimers and leukocytes. The end organs involved were the kidneys, spleen, liver, lungs, central nervous system, intestines and limbs. Only one of the five patients survived.

Conclusion

COVID-19 is associated with not only venous but also arterial thromboembolic events. Further research is required to clarify the incidence, causes and possible modes of prevention of this potentially lethal disease complication.

Reliability of capillary refill time for evaluation of tissue perfusion in simulated vascular occluded limbs

PURPOSE

No standardized execution or evidence demonstrates the area of the digit giving the most accurate capillary refill time (CRT). This study investigated the reliability and validity of CRT, and the relative merits of areas where the test could be performed.

METHODS

In all, 127 healthy volunteers were assessed for normal CRT at the fingernail, lateral paronychia, and proximal and distal pulps of the index finger. The predictive validity of the CRT for the diagnosis of compromised vascular perfusion was also investigated on 24 subjects, using an inflated tourniquet. Three raters assessed interobserver reliability.

RESULTS

The mean fingernail, lateral paronychia, proximal pulp, and distal pulp CRTs were 1.93, 1.78, 1.70, and 1.57 s, respectively. The tourniquet and non-tourniquet results demonstrated significant mean differences; however, the fingernail showed a subtle difference (1.22 s) compared with the proximal pulp (4.46 s). The CRT interobserver reliability was fair at the fingernail (intraclass correlation coefficient [ICC] = 0.51), but very poor in occluded limbs (ICC = 0.13). At the lateral paronychia and finger pulp, the interobserver reliability was reasonable (ICC = 0.75-0.81 [non-tourniquet] vs 0.62-0.68 [tourniquet]). In a receiver-operating characteristic curve analysis, the proximal pulp demonstrated better discrimination (area under the curve = 0.93, 95% CI 0.89-0.97, p  < 0.0001); the best cutoff point was calculated to be 3 s at the proximal pulp.

CONCLUSIONS

CRT use at appropriate areas is reliable. The most dependable site is the finger pulp, and the proposed cutoff is 3 s.

Acute aortoiliac occlusion in a patient with novel coronavirus disease-2019

The severe acute respiratory syndrome novel coronavirus-2 pandemic is affecting almost every country in the world. Even if the major symptoms of coronavirus disease-2019 are respiratory, different symptoms at presentation are now recognized. Venous thromboembolism has been reported in infected patients and few but increasing cases of arterial thrombosis have been described. We report a case of acute aortoiliac and lower limb artery occlusions in a patient presenting with severe coronavirus disease-2019 infection. The mechanism of the occlusion seemed to be distal embolization from a floating thrombus in the aortic arch caused by a major inflammatory state and virus infection. The patient underwent aortoiliac and lower limb artery mechanical thrombectomy, but required unilateral major amputation.

Correlation between CT angiography and digital subtraction angiography in acute ischemic strokes

OBJECTIVE

CT angiography (CTA) is not necessarily performed for all acute ischemic strokes due to variations in national guidelines across different regions. It follows that in the absence of CTA, missed identification of large vessel occlusion (LVO) potentially leads to opportunity lost for endovascular thrombectomy. Although the accuracy of CTA is well validated in chronic arterial stenosis, it has not been adequately investigated in acute ischemic stroke. We aimed to investigate the accuracy of CTA compared with digital subtraction angiography (DSA) in detecting LVO in acute ischemic stroke.

METHODS

This was a retrospective study of acute ischemic strokes with large vessel occlusion which underwent endovascular thrombectomy. We included patients who had a CTA prior to DSA and did not receive intravenous thrombolysis. Images were reviewed by 2 blinded assessors. Positive predictive value (PPV), and negative predictive value (NPV) of CTA were calculated against DSA.

RESULTS

Seventy-seven patients were included. The median age was 67 (IQR 57-78) and 46 (59.7 %) were male. Median NIHSS was 18 (IQR 12-22). There were 284 arterial segments categorized into 215 anterior arterial segments in 54 patients and 69 posterior arterial segments in 23 patients. The median time between CTA and DSA was 126 min (IQR 91-153 min). CTA showed PPV of 91.1 % and NPV of 95.1 % compared with DSA.

CONCLUSIONS

We showed that CTA was reasonably accurate in identifying large vessel occlusion in acute ischemic stroke. We propose that current regional guidelines should include CTA for all acute ischemic strokes.

Cholesterol embolization and arterial occlusion from the Heimlich maneuver

The Heimlich maneuver is a lifesaving bystander intervention to assist an individual with airway obstruction however, cholesterol embolization syndrome is a rare, but serious potential complication of the Heimlich maneuver. We present the case of the 56-year-old female presenting to the emergency department with acute right foot pain following performance of the Heimlich maneuver who was found to have distal arterial occlusion resulting from cholesterol embolization syndrome. The patient underwent right popliteal artery exploration, right popliteal and tibial thrombectomy, and popliteal patch angioplasty resulting in restoration of blood flow to her right foot.

Extragastrointestinal stromal tumor in the rectovaginal septum associated with acute arterial occlusion

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EGIST in rectovaginal septum with unusual presentation (excessive vaginal bleeding).

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EGIST was misdiagnosed by MRI as vaginal leiomyoma.

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The first report of untreated EGIST associated with acute arterial occlusion.

Extragastrointestinal stromal tumors (EGISTs) arise from atypical sites, such as the omentum, mesentery, retroperitoneal space, urinary bladder, or rectovaginal septum, and account for fewer than 10% of gastrointestinal stromal tumors (GISTs). Most EGISTs are asymptomatic at the time of diagnosis, due to the fact that they rarely cause symptoms until they grow to greater than 10 cm in diameter. Common presenting symptoms are a feeling of vaginal fullness and increased urinary frequency. Cases described in previous reports have been treated with surgery with or without targeted therapy. Here we report an unusual case of an EGIST at the rectovaginal septum presenting with excessive vaginal bleeding and acute arterial occlusion. This rectovaginal mass was successfully removed using the abdominoperineal approach and did not require targeted therapy.

Arterial thrombotic complications in COVID-19 patients

The coronavirus disease 2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been described to predispose to thrombotic disease in both the venous and arterial circulations. We report four cases of an acute arterial occlusion in COVID-19 patients and literature review on the occurrence of arterial thrombosis in patients with COVID-19. Our findings demonstrate that physicians should be vigilant for signs of thrombotic complications in both hospitalized and new COVID-19 patients.

Prophylactic internal iliac artery ligation versus balloon occlusion for placenta accreta spectrum disorders: A retrospective cohort study

OBJECTIVE

To compare surgical outcomes between women undergoing prophylactic internal iliac artery ligation or preoperative placement of balloon-occlusive devices at cesarean hysterectomy for placenta accreta spectrum (PAS) disorders.

METHODS

A retrospective cohort study was conducted at a tertiary-care referral center for PAS disorders in Ontario, Canada. Eligible electronic records were reviewed of women undergoing cesarean hysterectomy for PAS disorders between November 2012 and June 2018. Outcomes for the ligation and balloon groups were compared primarily on procedure-related complications and secondarily on total procedure time, bleeding and transfusion metrics, and intraoperative and postoperative complications.

RESULTS

Of the 79 cases of cesarean hysterectomy, 47 underwent balloon placement and 32 underwent ligation. Baseline characteristics between the groups were similar except for more emergency procedures in the ligation group (37.5% vs 12.8%, P=0.014). The balloon-related complication rate was 5/47 (10.6%), with no reported complications in the ligation group (P=0.077). Procedural time was longer in the balloon group (353 ± 14 vs 227 ± 13 minutes, P<0.001). Estimated blood loss was similar (1874 ± 245 mL vs 1713 ± 181 mL, P=0.590).

CONCLUSION

Women undergoing prophylactic placement of endovascular balloons at caesarean hysterectomy for PAS disorders had a 10.6% procedure-related complication rate and increased total procedure time, with no decrease in blood loss compared to those undergoing surgical ligation.

Complex liver retransplantation to treat graft loss due to long-term biliary tract complication after liver transplantation: A case report

BACKGROUND

Loss of graft function after liver transplantation (LT) inevitably requires liver retransplant. Retransplantation of the liver (ReLT) remains controversial because of inferior outcomes compared with the primary orthotopic LT (OLT). Meanwhile, if accompanied by vascular complications such as arterial and portal vein (PV) stenosis or thrombosis, it will increase difficulties of surgery. We hereby introduce our center's experience in ReLT through a complicated case of ReLT.

CASE SUMMARY

We report a patient who suffered from hepatitis B-associated cirrhosis and underwent LT in December 2012. Early postoperative recovery was uneventful. Four months after LT, the patient’s bilirubin increased significantly and he was diagnosed with an ischemic-type biliary lesion caused by hepatic artery occlusion. The patient underwent percutaneous transhepatic cholangial drainage and repeatedly replaced intrahepatic biliary drainage tube regularly for 5 years. The patient developed progressive deterioration of liver function and underwent liver re-transplant in January 2019. The operation was performed in a classic OLT manner without venous bypass. Both the hepatic artery and PV were occluded and could not be used for anastomosis. The donor PV was anastomosed with the recipient’s left renal vein. The donor hepatic artery was connected to the recipient’s abdominal aorta. The bile duct reconstruction was performed in an end-to-end manner. The postoperative process was very uneventful and the patient was discharged 1 mo after retransplantation.

CONCLUSION

With the development of surgical techniques, portal thrombosis and arterial occlusion are no longer contraindications for ReLT.

Knee extension with blood flow restriction: Impact of cuff pressure on hemodynamics

INTRODUCTION

Blood flow restriction (BFR) exercise has emerged as a method of increasing muscle size and strength with low intensity resistance training. While the cuff pressures used during BFR are typically a percentage of resting arterial occlusion pressure (AOP), the impact these cuff pressures have on blood flow during lower body exercise is unknown.

PURPOSE

To determine how various cuff pressures impact blood flow and tissue perfusion during exercise.

METHODS

Eleven healthy male participants completed four sets of knee extension (30 reps per set at 30% max torque) with 0%, 60%, 80%, and 100% of arterial occlusion pressure (AOP) was applied to the proximal portion of the thigh. Femoral artery blood flow, tissue oxygenation, and central hemodynamics were continuously recorded before, during, and after exercise. Electromyography (EMG) amplitude was recorded from the vastus lateralis during exercise.

RESULTS

Blood flow increased during exercise compared to rest across all cuff pressures (p < 0.001), however compared to 0%, the absolute blood flow was reduced by 34 ± 17%, 45 ± 22%, and 72 ± 19% for 60, 80, and 100% AOP, respectively. Furthermore, each cuff pressure resulted in similar relative changes in blood flow before, during, and after exercise. During exercise, tissue saturation index (TSI) decreased as cuff pressure increased (p ≤ 0.005) with the exception of 80 to 100% AOP. Deoxyhemoglobin increased (p ≤ 0.001) with cuff pressure.

CONCLUSION

Our data indicate that while BFR knee extension elicits an absolute hyperemic response at cuff pressures up to 100% resting AOP, the relative reductions in blood flow are consistent across rest, exercise and recovery.

A severe case of Menkes disease with repeated bone fracture during the neonatal period, followed by multiple arterial occlusion

Menkes disease (MD) is a lethal infantile neurodegenerative disorder with X-linked inheritance, characterized by progressive neurodegenerative symptoms caused by pathogenic variants in the ATP7A. Early diagnosis and treatment are important, although the diagnosis is difficult prior to 2 months of age. We present an unusually severe case of MD with skull fractures at the birth and repeated fractures during the neonatal period, with further examinations leading to diagnosis. The patient died due to hemorrhagic shock, due to multiple arterial occlusion despite initiation of copper-histidine therapy in early infancy. Bone fracture at birth and multiple arterial occlusion are very rare findings in MD. This unusual and severe presentation emphasizes the importance of early diagnosis and treatment. A congenital bone fracture should be considered as a possible presentation of MD, especially in cases without birth complications.

Diagnosis and Treatment of Arterial Occlusion after Knee Arthroplasty: The Sooner, the Better

Knee arthroplasty, including total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA), is an effective procedure for patients with severe knee joint diseases. Arterial occlusion after knee arthroplasty is a rare but severe complication. However, there are few comprehensive reviews or analyses focusing on it. In this study, we presented a case of successful treatment of acute arterial occlusion of the popliteal artery after TKA by emergent balloon angioplasty, and conducted a review and analysis of published cases with this complication. After search and screening, 36 studies with 47 cases of arterial occlusion after knee arthroplasty in the past 35 years (1984-2018) were included. Among the 47 patients, there were 22 men and 25 women. The mean age was 68 years old. A total of 43 patients had primary TKA while 2 had revision surgery for TKA and 2 for UKA. For arterial occlusions, 66% presented symptoms in less than 1 day after knee surgery and 95% of the occlusion sites were around the popliteal artery. For treatment, 89% chose surgical treatment. Compared with conservative treatment, surgical treatment was more effective (P < 0.01). The patients who underwent surgical treatment less than 1 day after diagnosis had less sequelae (P < 0.05). For arterial occlusion after knee arthroplasty, we should pay attention to the perioperative risk factors and presentations, and diagnose and treat surgically at an early stage.

Anatomical changes on the long term follow up

We report the case of a 13-year-old patient who complains of an acute superior visual field scotoma in the last 48hours. Best corrected visual acuity (BCVA) was 20/20 in both eyes. The right eye fundus examination revealed torsion of a prepapillary loop in the inferior branch of the retinal artery, associated with a arterial vascular attenuation and whitenning of the inferior retina that involved both nasal and temporal branches but spared the foveal region. During the follow-up the vascular loop dissapeared and only glial tissue was seen in front of the optic nerve head. BCVA remained 20/20 in both eyes. This report shows the evolution of the vascular loop after an occlusion. The absence of blood flow produces a collapse of the arterial walls, in time the vascular loop is replaced by glial tissue.

Acute lymphoblastic leukemia presenting with mesenteric ischemia

Malignancy can induce a hypercoagulable state and lead to an increased risk of thromboembolic events. The pathogenesis of the prothrombotic state in cancer is complicated but is thought to involve several mechanisms. Thrombosis predominantly affects the venous circulation and infrequently the arteries. Arterial occlusion as an initial manifestation of acute leukemia is unusual. This is a case of a 44-year-old male admitted with complete thrombotic occlusion of the superior mesenteric artery and treated with emergent thrombectomy. Hematologic work-up was consistent with a diagnosis of T-cell acute lymphoblastic leukemia. To our knowledge, this is the first case of complete occlusion of the superior mesenteric artery presenting as the initial manifestation of T-cell acute lymphoblastic leukemia.

Effects of load on the acute response of muscles proximal and distal to blood flow restriction

To determine the effects of load and blood flow restriction (BFR) on muscular responses, we asked 12 participants to perform chest presses under four different conditions [30/0, 30/40, 50/0, and 50/40, presented as percentage one-repetition maximum (1RM)/percentage arterial occlusion pressure (AOP)]. Muscle thickness increased pre- to post-exercise [chest: mean 0.29, 95% confidence interval (CI) 0.21, 0.37 cm; triceps: mean 0.44, 95% CI 0.34, 0.54 cm], remaining elevated for 15 min post-exercise. Electromyography amplitude was greater with 50% 1RM and increased over time for the first three repetitions of each set of chest presses. The last three repetitions differed across time only. AOP increased from pre- to post-exercise, augmented by BFR [30/0: mean 31, 95% CI 18, 44 mmHg; 30/40: mean 39, 95% CI 28, 50 mmHg; 50/0: mean 32, 95% CI 23, 41 mmHg; 50/40: mean 46, 95% CI 32, 59 mmHg). Tranquility decreased and physical exhaustion increased from the pre- to post-condition, with both parameters returning to the baseline 15 min post-exercise level. In conclusion, load and BFR do not elicit meaningful differences in the acute response of chest press exercise taken to failure.

Autoregulating Cerebral Tissue Selfishly Exploits Collateral Flow Routes Through the Circle of Willis

OBJECTIVE

Ischemic stroke is a leading cause of death and disability. Autoregulation and collateral blood flow through the circle of Willis both play a role in preventing tissue infarction. A steady-state model of the cerebral arterial network was used to investigate the interaction of these mechanisms when autoregulation is impaired ipsilateral to an occluded artery.

MATERIALS AND METHODS

Twelve structural variants of the circle of Willis were modelled with left internal carotid artery occlusion and coupled with (1) a passive model of the cerebral vascular bed, (2) a steady-state model of an autoregulating cerebral vascular bed, and (3) a model in which the contralateral hemisphere autoregulates and the ipsilateral hemisphere does not.

RESULTS

Results showed that if the autoregulatory response is impaired ipsilaterally, then, in the autoregulating hemisphere, cerebral flows are preserved at the expense of those on the ipsilateral side.

CONCLUSIONS

Thus, although autoregulation is an essential facilitator of collateral flow through the circle of Willis, contralateral autoregulation can exacerbate flow reductions if not balanced by the same response in the vascular beds on the ipsilateral side. The status of the autoregulatory response in both hemispheres can strongly influence cerebral blood flows and tissue survival and should, therefore, be monitored in stroke.

Safety and preliminary efficacy of intravenous tirofiban in acute ischemic stroke patient without arterial occlusion on neurovascular imaging studies

BACKGROUND

There has been no effective treatment for acute ischemic stroke (AIS) patients who presented to the Emergency Department >4.5h without a visible arterial occlusion on the neurovascular imaging studies. In this study, we aimed to investigate whether intravenous antiplatelet agent tirofiban was safe and potentially effective in AIS patients who had no visible arterial occlusion and was outside of treatment window for Alteplase. The goal of this study was to collect preliminary data to plan a future phase II study.

METHOD

Twenty-five patients received intravenous tirofiban therapy. The safety outcomes were assessed by the incidence of symptomatic intracerebral hemorrhage (sICH), systematic bleeding and mortality. Efficacy outcomes were evaluated with National Institutes of Health Stroke Scale (NIHSS) score at day 7 (or discharge) and modified Rankin Scale (mRS) at 90days. Outcomes for these patients were compared with a historical age-gender-admission-NIHSS matched cohort treated with aspirin and/or clopidogrel.

RESULTS

The rate of intracerebral hemorrhage, systematic bleedings, and death were not found in both groups. At day 7 or discharge, the neurological function improved significantly in both treatment groups. However, the NIHSS score was lower in tirofiban group compared with the control group (2 vs.3, p=0.045). At 3months, more patients in tirofiban group had favorable outcomes (mRS 0-1) compared with control group (84% vs. 52%; adjusted odds ratio: 10.57; 95% CI: 1.54-72.33; p=0.016).

CONCLUSIONS

Intravenous tirofiban appears to be safe and potentially effective for the ischemic stroke patients with no artery occlusion on neurovascular imaging studies and being out of the window for thrombolytic therapy. A next logic step is to plan for a phase II study.

Comparison between enhanced susceptibility-weighted angiography and time of flight sequences in the detection of arterial occlusion in acute ischemic stroke

PURPOSE

Optimizing the MRI protocol in acute ischemic stroke remains a challenging issue. In this field, susceptibility-weighted sequences have proved their superiority over T2*. Besides the strengthened susceptibility effect, enhanced susceptibility-weighted angiography (eSWAN) sequence provides also a time-of-flight (TOF) effect, allowing the exploration of the intracranial arterial circulation. The objective of our study was to compare eSWAN and 3D TOF, considered as the reference, in the detection of arterial occlusion in acute stroke.

METHODS

Patients who underwent MRI between March and July 2014 for suspected acute stroke with an acute ischemic lesion on diffusion-weighted imaging (DWI) were prospectively included in this study. eSWAN and TOF images were analyzed under double-blind conditions by a junior radiologist and a senior neuroradiologist for the detection of arterial occlusion. eSWAN images were assessed in order to estimate the inter-observer agreement. After a consensus, eSWAN and TOF data were compared to calculate inter-modality agreement.

RESULTS

Thirty-four patients were included. Inter-observer agreement was excellent (kappa: 0.96) for eSWAN detection of occlusion. After consensus, comparison between TOF and eSWAN showed substantial agreement (kappa: 0.71). eSWAN provided better detection of distal occlusions, but poorer performance for detection of siphon occlusions.

CONCLUSIONS

Shortest echoes eSWAN images enabled detection of arterial occlusion with substantial agreement with TOF images. The susceptibility vessel sign associated with the TOF effect improved the identification of distal occlusions. In acute stroke protocol, eSWAN may represent a valuable alternative to T2* and TOF sequences.

Influence of cuff material on blood flow restriction stimulus in the upper body

The purpose of this study was to examine the acute skeletal muscle and perceptual responses to blood flow restriction (BFR) exercise to failure between narrow nylon and elastic inflatable cuffs at rest and during exercise. Torque and muscle thickness was measured pre, post, and 5, 20, 40, and 60 min post-exercise with muscle activation being measured throughout exercise. Resting arterial occlusion pressure was different between the nylon [139 (14) mmHg] and elastic [246 (71) mmHg, p < 0.001] cuffs. However, when exercising at 40 % of each cuff's respective arterial occlusion pressure [nylon: 57 (7) vs. elastic: 106 (38) mmHg, p < 0.001], there were no differences in repetitions to failure, torque, muscle thickness, or muscle activation between the cuffs. Exercising with cuffs of different material but similar width resulted in the same acute muscular response when the cuffs were inflated to a pressure relative to each individual cuff.

The role of endoglin in post-ischemic revascularization

Following arterial occlusion, blood vessels respond by forming a new network of functional capillaries (angiogenesis), by reorganizing preexisting capillaries through the recruitment of smooth muscle cells to generate new arteries (arteriogenesis) and by growing and remodeling preexisting collateral arterioles into physiologically relevant arteries (collateral development). All these processes result in the recovery of organ perfusion. The importance of endoglin in post-occlusion reperfusion is sustained by several observations: (1) endoglin expression is increased in vessels showing active angiogenesis/remodeling; (2) genetic endoglin haploinsufficiency in humans causes deficient angiogenesis; and (3) the reduction of endoglin expression by gene disruption or the administration of endoglin-neutralizing antibodies reduces angiogenesis and revascularization. However, the precise role of endoglin in the several processes associated with revascularization has not been completely elucidated and, in some cases, the function ascribed to endoglin by different authors is controversial. The purpose of this review is to organize in a critical way the information available for the role of endoglin in several phenomena (angiogenesis, arteriogenesis and collateral development) associated with post-ischemic revascularization.

The influence of participant characteristics on the relationship between cuff pressure and level of blood flow restriction

Purpose

Previous investigations to establish factors influencing the blood flow restriction (BFR) stimulus have determined cuff pressures required for complete arterial occlusion, which does not reflect the partial restriction prescribed for this training technique. This study aimed to establish characteristics that should be accounted for when prescribing cuff pressures required for partial BFR.

Methods

Fifty participants were subjected to incremental blood flow restriction of the upper and lower limbs by proximal pneumatic cuff inflation. Popliteal and brachial artery diameter, blood velocity and blood flow was assessed with Doppler ultrasound. Height, body mass, limb circumference, muscle–bone cross-sectional area, adipose thickness (AT) and arterial blood pressure were measured and used in different models of hierarchical linear regression to predict the pressure at which 60 % BFR (partial occlusion) occurred.

Results

Combined analysis revealed a difference in cuff pressures required to elicit 60 % BFR in the popliteal (111 ± 12 mmHg) and brachial arteries (101 ± 12 mmHg). MAP (r = 0.58) and AT (r = −0.45) were the largest independent determinants of lower and upper body partial occlusion pressures. However, greater variance was explained by upper and lower limb regression models composed of DBP and BMI (48 %), and arm AT and DBP (30 %), respectively.

Conclusion

Limb circumference has limited impact on the cuff pressure required for partial blood flow restriction which is in contrast to its recognised relationship with complete arterial occlusion. The majority of the variance in partial occlusion pressure remains unexplained by the predictor variables assessed in the present study.

Monitoring of partial and full venous outflow obstruction in a porcine flap model using laser speckle contrast imaging

BACKGROUND

In microsurgery, there is a demand for more reliable methods of post-operative monitoring of free flaps, especially with regard to tissue-threatening obstructions of the feeding arteries and draining veins. In this study, we evaluated laser speckle contrast imaging (LSCI) and laser Doppler flowmetry (LDF) to assess their possibilities to detect partial and full venous outflow obstruction, as well as full arterial occlusion, in a porcine flap model.

METHODS

Cranial gluteal artery perforator flaps (CGAPs) were raised, and arterial and venous blood flow to and from the flaps was monitored using ultrasonic flow probes. The venous flow was altered with an inflatable cuff to simulate partial and full (50% and 100%) venous obstruction, and arterial flow was completely obstructed using clamps. The flap microcirculation was monitored using LSCI and LDF.

RESULTS

Both LDF and the LSCI detected significant changes in flap perfusion. After partial (50%) venous occlusion, perfusion decreased from baseline, LSCI: 63.5 ± 12.9 PU (p = 0.01), LDF 31.3 ± 15.7 (p = 0.64). After 100% venous occlusion, a further decrease in perfusion was observed: LSCI 54.6 ± 14.2 PU (p < 0.001) and LDF 16.7 ± 12.8 PU (p < 0.001). After release of the venous cuff, LSCI detected a return of the perfusion to a level slightly, but not significantly, below the baseline level 70.1 ± 11.5 PU (p = 0.39), while the LDF signal returned to a level not significant from the baseline 36.1 ± 17.9 PU (p > 0.99). Perfusion during 100% arterial occlusion decreased significantly as measured with both methods, LSCI: 48.3 ± 7.7 (PU, p < 0.001) and LDF: 8.5 ± 4.0 PU (p < 0.001). During 50% and 100% venous occlusion, LSCI showed a 20% and 26% intersubject variability (CV%), respectively, compared to 50% and 77% for LDF.

CONCLUSIONS

LSCI offers sensitive and reproducible measurements of flap microcirculation and seems more reliable in detecting decreases in blood perfusion caused by venous obstruction. It also allows for perfusion measurements in a relatively large area of flap tissue. This may be useful in identifying areas of the flap with compromised microcirculation during and after surgery.

Novel method to assess arterial insufficiency in rodent hind limb

BACKGROUND

Lack of techniques to assess maximal blood flow capacity thwarts the use of rodent models of arterial insufficiency to evaluate therapies for intermittent claudication. We evaluated femoral vein outflow (VO) in combination with stimulated muscle contraction as a potential method to assess functional hind limb arterial reserve and therapeutic efficacy in a rodent model of subcritical limb ischemia.

MATERIALS AND METHODS

VO was measured with perivascular flow probes at rest and during stimulated calf muscle contraction in young, healthy rats (Wistar Kyoto, WKY; lean Zucker rats, LZR) and rats with cardiovascular risk factors (spontaneously hypertensive [SHR]; obese Zucker rats [OZR]) with acute and/or chronic femoral arterial occlusion. Therapeutic efficacy was assessed by administration of Ramipril or Losartan to SHR after femoral artery excision.

RESULTS

VO measurement in WKY demonstrated the utility of this method to assess hind limb perfusion at rest and during calf muscle contraction. Although application to diseased models (OZR and SHR) demonstrated normal resting perfusion compared with contralateral limbs, a significant reduction in reserve capacity was uncovered with muscle stimulation. Administration of Ramipril and Losartan demonstrated significant improvement in functional arterial reserve.

CONCLUSIONS

The results demonstrate that this novel method to assess distal limb perfusion in small rodents with subcritical limb ischemia is sufficient to unmask perfusion deficits not apparent at rest, detect impaired compensation in diseased animal models with risk factors, and assess therapeutic efficacy. The approach provides a significant advance in methods to investigate potential mechanisms and novel therapies for subcritical limb ischemia in preclinical rodent models.

Update on disorders and treatment of the guttural pouch

The most common disorders of the equine guttural pouches are empyema, tympany, mycosis, and temporohyoid osteoarthropathy. Diagnosis of these conditions is made primarily by imaging with endoscopy, radiographs, computed tomography, and/or MRI. Medical treatment with anti-inflammatories, antimicrobials, and/or antifungals may be successful in some cases, but many of these disorders necessitate surgical intervention. Direct surgical approaches to the guttural pouch are difficult because of their complex anatomy and relationship with important structures, thus precipitating a move toward minimally invasive procedures when possible.

Assessment of microcirculation of the skin using Tissue Viability Imaging: A promising technique for detecting venous stasis in the skin

BACKGROUND

Venous occlusion in the skin is difficult to detect by existing measurement techniques. Our aim was to find out whether Tissue Viability Imaging (TiVi) was better at detecting venous occlusion by comparing it with results of laser Doppler flowmetry (LDF) during graded arterial and venous stasis in human forearm skin.

METHODS

Arterial and venous occlusions were simulated in 10 healthy volunteers by inflating a blood pressure cuff around the upper right arm. Changes in the concentration of red blood cells (RBC) were measured using TiVi, while skin perfusion and concentration of moving red blood cells (CMBC) were measured using static indices of LDF during exsanguination and subsequent arterial occlusion, postocclusive reactive hyperaemia, and graded increasing and decreasing venous stasis.

RESULTS

During arterial occlusion there was a significant reduction in the mean concentration of RBC from baseline, as well as in perfusion and CMBC (p<0.008). Venous occlusion resulted in a significant 28% increase in the concentration of RBC (p=0.002), but no significant change in perfusion (mean change -14%) while CMBC decreased significantly by 24% (p=0.02). With stepwise increasing occlusion pressures there was a significant rise in the TiVi index and reduction in perfusion (p=0.008), while the reverse was seen when venous flow was gradually restored.

CONCLUSION

The concentration of RBC measured with TiVi changes rapidly and consistently during both total and partial arterial and venous occlusions, while the changes in perfusion, measured by LDF, were less consistent. This suggests that TiVi could be a more useful, non-invasive clinical monitoring tool for detecting venous stasis in the skin than LDF.

The role of thrombolytics in acute and chronic occlusion of the hand

Distal arm and hand ischemia from vessel thrombosis or embolism remains a difficult clinical challenge. The causes of ischemia are variable and include connective tissue disease, embolism, atherosclerosis, and iatrogenic etiology. Although reports are limited, treatment with catheter-directed thrombolysis has favorable results in cases of acute thrombosis, with most patients (80%) demonstrating improvement. Digital amputation rates are less than 10% and the hand is often salvaged. Bleeding and access-site complications remain prevalent in patients undergoing intra-arterial thrombolysis. This review discusses etiology, treatment approaches, outcomes, and complications when thrombolytic therapy is used for distal arm and hand ischemia.

Diagnostic ultrasonography for peripheral vascular emergencies

Over the past decade, emergency and critical care physicians have been empowered with the ability to use bedside ultrasonography to assist in the evaluation and management of a variety of emergent conditions. Today a single health care provider at the bedside with Duplex ultrasound technology can evaluate peripheral vascular calamities that once required significant time and a variety of health care personnel for the diagnosis. This article highlights peripheral thromboembolic disease, aneurysm, pseudoaneurysm, and arterial occlusion in the acute care setting.

Occluded middle cerebral artery vascular stump mimicking aneurysm: case report and review of literature

The stump of an occluded middle cerebral artery (MCA) is a rare but important aneurysm mimic. A 57-year-old male was admitted due to recurrent onset of transient ischemic attack. Computed tomography angiography (CTA) and digital subtraction angiography (DSA) showed a total obstruction in the right MCA with moyamoya phenomenon at distal trunks and a protruding lesion in the left MCA bifurcation. The patient was diagnosed with left MCA bifurcation aneurysm. Intraoperatively, the lesion was found to be an occluded right MCA stump. Encephalomyoarteriosynangiosis was performed, and the patient remained symptom-free at the 6-month follow-up. The possibility of a vascular stump should be considered when an aneurismal lesion is present at the MCA bifurcation with moyamoya phenomenon at distal trunks.

Forearm muscle oxygenation responses during and following arterial occlusion in patients with mitochondrial myopathy

The aim was to study whether mitochondrial myopathy induces different oxygenation (deoxy[Hb+Mb] and oxy[Hb+Mb]) responses during and following arterial occlusion. In 10 mitochondrial myopathy patients (MMpatients) (age: 29±7 years; body mass: 59.9±15.7kg; heigth: 166.2±11.4cm) and age- and gender-matched healthy subjects (age: 28±9 years; body mass: 72.7±16.9kg; height: 174.4±8.7cm) arterial occlusion was performed by inflating a cuff to 240mmHg. Deoxy[Hb+Mb] and oxy[Hb+Mb] were registered during (AOoxy and AOdeoxy) and following (POdeoxy and POoxy) arterial occlusion. Amplitude of AOdeoxy did not differ (p=0.47) between MMpatients (44.9±28.0μM) and healthy subjects (38.6±22.8μM), The time constant of the exponential model was greater in MMpatients (263.4±49.1s vs. 200.3±73.7s, p=0.03). Following cuff release, in both populations a transient increase in total[Hb+Mb] was observed induced by different kinetics of POoxy and POdeoxy. The increase in POoxy (TD=6.6±2.2s and 11.9±3.5s; τ=3.8±1.4s and 6.4±2.9s for MMpatients and healthy subjects, respectively) was faster (p<0.001 for TD and τ) compared to the decrease in POdeoxy (TD=13.2±3.6s and 26.5±4.6s; τ=-6.2±2.2s and -9.6±2.4s for MMpatients and healthy subjects, respectively). POoxy and POdeoxy showed faster kinetics (p<0.001 and p<0.01 for TD and τ, respectively) in MMpatients compared to healthy subjects. MMpatients display altered oxygenation responses during and following arterial occlusion reflecting pathology related changes in the relationship between muscle blood flow and oxygen uptake.

Occlusion of the anterior cerebral artery after head trauma

Intracranial arterial occlusion is rarely encountered in association with head injury. Only six cases of traumatic occlusion of the anterior cerebral artery (ACA) have previously been reported. In this paper, the authors describe a case of a posttraumatic occlusion of ACA. A 35-year-old male presented to the emergency room with severe head injury. Computed tomography (CT) scan displayed diffuse brain swelling with multiple skull fractures. Follow up CT scan showed extensive cerebral infarction in the territory of ACA. The patient underwent CT angiography that demonstrated occlusion of the ACA by a fracture of the anterior fossa. He died after 3 d. ACA traumatic occlusion is a rare condition, with poor prognosis. In this case, fracture was responsible for dissection and direct obstruction of the artery.

Four characteristics of vascular echo suggesting arterial thromboembolism: differentiation from aggravation of atherosclerotic peripheral artery disease

BACKGROUND

Arterial thromboembolism (ATE) leading to acute arterial occlusion can involve life-threatening complications, including limb loss and death, without prompt thrombectomy. Several ATEs are hard to differentiate from acute aggravation of atherosclerotic peripheral artery disease (PAD). We determined four characteristics of vascular echos suggesting ATE for the differentiation from PAD and validated their use.

METHODS AND RESULTS

Twenty patients (11 men and 9 women; mean age, 74 years) with ATE confirmed by therapeutic findings and 19 patients with PAD including occlusive lesions (14 men and 5 women; mean age, 78 years) were enrolled. Four hallmarks of vascular echo suggesting ATE were defined as the manifestation of the intima-media complex next to the adventitia (M1), mild to moderate echolucency of the intravascular structure (M2), mobility of the intravascular structure (M3), and the pulsatile movement of the arterial wall (M4) in occlusive arterial lesions. In the ATE group, 6 patients had three positive items, and 14 patients had four positive items. In the PAD group, ten patients had no positive items, and nine patients had one positive item. Using a cutoff score of more than 3 for ATE, the sensitivity was 100%, the specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 100%.

CONCLUSIONS

The presented characteristics of vascular echo suggesting ATE could be useful for making the differential diagnosis against PAD.

Different patterns of intestinal response to injury after arterial, venous or arteriovenous occlusion in rats

AIM: To investigate the differences in injury patterns caused by arterial, venous or arteriovenous mesenteric occlusion.

METHODS: Male Wistar rats were separated equally into four groups. Occlusion was performed by clamping the superior mesenteric artery (A), the mesenteric vein (V) or both (AV) for 30 min, followed by 60 min of reperfusion. A control group received sham surgery only. Intestinal sections were examined for histological damage and serum tumor necrosis factor-α (TNF-α), endothelin-1 (ET-1), P-selectin, antithrombin III (ATIII) and soluble intracellular adhesion molecule-1 (ICAM-1) concentrations were measured.

RESULTS: All groups showed significant mucosal injury compared to controls. Furthermore, mucosal injury was significantly more severe in the V and AV groups compared to the A group (3.6 ± 0.55, 3.4 ± 0.55 and 2 ± 0.71, respectively, P = 0.01). ICAM-1 was similarly elevated in all groups, with no significant differences between the groups. P-selectin levels were significantly elevated in the V and AV groups but not the A group (1.4 ± 0.5 ng/mL, 2.52 ± 0.9 ng/mL and 0.02 ± 0.01 ng/mL, respectively, P = 0.01) and ET-1 was significantly elevated in the A and V groups but not the AV group (0.32 ± 0.04 pg/mL, 0.36 ± 0.05 pg/mL and 0.29 ± 0.03 pg/mL, respectively, P = 0.01) compared to sham controls. ATIII levels were markedly depleted in the V and AV groups, but not in the A group (29.1 ± 5.2 pg/mL, 31.4 ± 21.8 pg/mL and 55.8 ± 35.6 pg/mL, respectively, P = 0.01), compared to controls. Serum TNF-α was significantly increased in all groups compared to sham controls (1.32 ± 0.87 ng/mL, 1.79 ± 0.20 ng/mL and 4.4 ± 0.69 ng/mL, for groups A, V and AV, respectively, P = 0.01), with higher values in the AV group.

CONCLUSION: Different patterns of response to ischemia/reperfusion are associated with venous, arterial or arteriovenous occlusion. Venous and arteriovenous occlusion was associated with the most severe alterations.