Modified Sandwich-graft Technique Employing Aorfix and Viabahn Stent-grafts to Preserve Hypogastric Flow in Cases of Complex Aortoiliac and Isolated Common Iliac Artery Aneurysms Including the Internal Iliac Artery Ostium.

OBJECTIVE: The aim was to assess the early and mid-term safety and clinical outcomes of a modified sandwich-graft technique (MSGT) that employed the Aorfix and Viabahn stent-grafts to preserve hypogastric flow in cases of complex aortoiliac and isolated common iliac artery (CIA) aneurysms including internal iliac artery (IIA) ostium who were not suitable for an iliac branch device (IBD). METHODS: A review of prospective collected data of all consecutive cases of treatment of complex aortoiliac or isolated CIA aneurysms including IIA ostium using the MSGT to preserve the hypogastric flow in three European centres between April 1, 2010, and December 31, 2013, was performed. All patients included were unfit for open repair and not suitable for an IBD. RESULTS: During the study period, 21 patients met the study criteria and had 25 MSGTs. The mean follow-up duration was 17.2 months. The technical success rate was 100%, with no perioperative mortality and stent-graft or MSGT-treated IIA occlusions. There were two cases with Type Ib endoleaks and one Type III endoleaks intraoperatively that were successfully managed. There was also no reported early and late pelvic ischaemia. The primary patency rate was 90.5%, and two cases of MGST treated IIA occlusions with no reported symptoms of pelvic ischaemia during follow-up. CONCLUSIONS: MSGT was a safe and feasible strategy to preserve hypogastric flow in cases of complex aortoiliac and isolated CIA aneurysms including IIA ostium and who were not suitable for IBD, with encouraging early and mid-term outcomes.

Moving forward with elective vascular work: a reflection on the impact of COVID-19 on a regional vascular hub.

INTRODUCTION: Following the initial COVID-19 surge in the UK, there was a national incentive for elective vascular surgery to be restricted to 'clean' sites to reduce perioperative cross-infection and subsequent mortality. We assessed the risk of dying from perioperatively acquired COVID-19 during the peak of the London outbreak. METHODS: Forty-three consecutive patients who had vascular (n=48) procedures in March and April 2020 at a regional hub serving five London hospitals were analysed. The patients were screened for COVID-19 in the 30-day postoperative period and the main outcome measure was mortality from COVID-19. A comparison was then made with patients who underwent minimally invasive procedures in our integrated interventional radiology department. Median follow-up was 41 days (interquartile range 8-58) overall. RESULTS: Three patients (7%) in the vascular group (median age 61 years, all diabetic, two male) died from COVID-19, all of whom tested positive postoperatively. Two others became positive but recovered. In comparison, two patients (2%) in the interventional radiology group died from COVID-19; however, one was positive prior to their procedure. CONCLUSION: Only urgent vascular cases should be performed during a COVID-19 surge. However, with growing waiting lists for elective surgery following the pandemic's second wave, further restrictions may not be a viable long-term solution. When prevalence of the disease is lower and if resources allow, resumption of care at 'hot' sites should be considered, if safety measures can be implemented. The advantages of minimally invasive surgery may also reduce risk.

Fossil evidence for the origin of aquatic locomotion in archaeocete whales.

Recent members of the order Cetacea (whales, dolphins, and porpoises) move in the water by vertical tail beats and cannot locomote on land. Their hindlimbs are not visible externally and the bones are reduced to one or a few splints that commonly lack joints. However, cetaceans originated from four-legged land mammals that used their limbs for locomotion and were probably apt runners. Because there are no relatively complete limbs for archaic archaeocete cetaceans, it is not known how the transition in locomotory organs from land to water occurred. Recovery of a skeleton of an early fossil cetacean from the Kuldana Formation, Pakistan, documents transitional modes of locomotion, and allows hypotheses concerning swimming in early cetaceans to be tested. The fossil indicates that archaic whales swam by undulating their vertebral column, thus forcing their feet up and down in a way similar to modern otters. Their movements on land probably resembled those of sea lions to some degree, and involved protraction and retraction of the abducted limbs.

Propionibacterium acnes endocarditis: a case series.

OBJECTIVES: Propionibacterium acnes remains a rare cause of infective endocarditis (IE). It is challenging to diagnose due to the organism's fastidious nature and the indolent presentation of the disease. The purpose of this study was to describe the clinical presentation and management of P. acnes IE with an emphasis on the methods of diagnosis. METHODS: We identified patients from the Cleveland Clinic Infective Endocarditis Registry who were admitted from 2007 to 2015 with definite IE by Duke Criteria. Propionibacterium acnes was defined as the causative pathogen if it was identified in at least two culture specimens, or identified with at least two different modalities: blood culture, valve culture, valve sequencing or histopathological demonstration of microorganisms. RESULTS: We identified 24 cases of P. acnes IE, 23 (96%) of which were either prosthetic valve endocarditis or IE on an annuloplasty ring. Invasive disease (71%) and embolic complications (29%) were common. All but one patient underwent surgery. Propionibacterium acnes was identified in 12.5% of routine blood cultures, 75% of blood cultures with extended incubation, 55% of valve cultures, and 95% of valve sequencing specimens. In 11 of 24 patients (46%), no causative pathogen would have been identified without valve sequencing. CONCLUSIONS: Propionibacterium acnes almost exclusively causes prosthetic valve endocarditis and patients often present with advanced disease. The organism may not be readily cultured, and extended cultures appear to be necessary. In patients who have undergone surgery, valve sequencing is most reliable in establishing the diagnosis.

The case for saphenous ablation versus simple proximal ligation.

New modalities of treatment for primary varicose veins are being increasingly used. This is because traditional stripping and sapheno-femoral junction ligation is requires a general anaesthetic and is associated with postoperative pain and bruising. This article aims to address the evidence and long-term follow up of the new surgical techniques and compare them to traditional sapheno-femoral ligation.

Cytochemical localization of 5'-nucleotidase activity in retinal photoreceptor cells.

Further cytochemical studies on the ultrastructural localization of 5'-nucleotidase in the rat retina have revealed activity to be associated with the complex synapses formed by the rod spherules of the receptors and the bipolar and horizontal cell processes. Activity was also seen on the axolemma of receptor fibers. In the rod inner segment strong reaction product is located intracellularly. In the rod outer segment the enzyme appears to be located only on the cytoplasmic side of the disc membrane and not intradiscally . Retinal pigment cells are rich in 5'-nucleotidase. Their microvilli accompany the tips of the receptor cells and show enzyme activity in an ecto position. A role for 5'-nucleotidase is possible in the metabolism of guanylate and adenylate nucleotides both of which are important for visual transduction processes.

Cytochemical localization of 5'-nucleotidase in the frog (Rana pipiens) retina. A histochemical and cytochemical study.

Localization of 5'-nucleotidase in the frog retina was investigated using histochemical and cytochemical techniques. Light-microscopic observations revealed the presence of this enzyme in the inner retinal layers (the nerve fiber layer, ganglion cell layer, and inner plexiform layer). Ultrastructural investigations revealed that the enzyme activity is associated with the plasma membranes of the Müller cell processes, whereas the Müller cell processes present in the outer retinal layers did not demonstrate any detectable enzyme activity. This observation would appear to confirm our previous findings, that 5'-nucleotidase is an ectoenzyme, but its distribution in frog retina differs from that in rodents and it is only present in the inner layers of the retina. The prominent localization of 5'-nucleotidase on the glial plasma membrane may be viewed in the context of the widely accepted interaction between neurones and glial cells. Since nucleotides do not penetrate the plasma membrane, a mechanism to produce membrane-permeable adenosine, important for neuronal function, is postulated. It is known that 5'-nucleotidase produces adenosine by hydrolyzing adenosine 5'-monophosphate (5'-AMP). Therefore one would expect that the glial membrane-bound enzyme can accomplish the final step in this mechanism by producing the adenosine in the extracellular spaces.

Observer variability in volumetric blood flow measurements in leg arteries using duplex ultrasound.

Duplex ultrasound volumetric flow measurements have not found a major clinical use because of variability caused by errors in estimating cross-sectional area (CSA) and in measuring time averaged mean velocity (TAMeV). We determined inter- and intraobserver variation in volumetric blood flow measured at rest in the common femoral artery (CFA) and its main branches, the superficial femoral (SFA) and profunda femoris (PFA) arteries, in 20 normal subjects. The product of TAMeV and CSA was taken as volumetric flow. The coefficient of variation of TAMeV was consistently greater than that of CSA. Interobserver variation for blood flow (16.2%, 20.2% and 40.3% for CFA, SFA and PFA, respectively) was larger than intraobserver variation (13.0%, 15.1%, 21.2%). In conclusion, these data define the minimum changes in VQ that can be realistically detected and indicate that, with modern duplex Doppler equipment, volumetric flow can be used as a reliable haemodynamic measure for monitoring patients before and after surgical or radiological intervention.

Use of fine needle aspiration cytology in the management of the solitary cold thyroid nodule.

The aim of this study was to evaluate the use of fine needle aspiration cytology (FNA) in the management of the solitary cold thyroid nodule and set up a thyroid cytology service in a district general hospital. One hundred and eight patients underwent FNA and then went on to have thyroid lobectomy. The results of cytology were compared with histology. The percentage of cancers was 8% and of benign lesions 92%. The overall accuracy of FNA was 86%. There were no false positive results and one false negative result. If one includes a suspicious cytology as positive then six of seven cancers were diagnosed by FNA. Also, 49 benign colloid nodules were accurately diagnosed by FNA and could have avoided surgery (55% of the Series). We conclude that fine needle aspiration cytology is a useful adjunct to the management of the solitary cold thyroid nodule and should be used with other clinical information to decide the best form of treatment for the patient.

Cytochemical localization of Na(+)-K(+)-adenosine triphosphate activity in the proximal convoluted tubule cells of the gerbil Meriones crassus.

The present work describes the cytochemical localization of Na(+)-K(+)-ATPase in the proximal convoluted tubule cells of the gerbil Meriones crassus. By using CeCl3 as capture agent, a fine, uniform reaction product was distributed mainly across the basolateral membranes and at the apical surface. This study provides evidence that the ATPase enzyme studied is actually Na(+)-K(+)-ATPase because acetate buffer (bleaching agent) had no decalcifying effect, nor did the subsequent application of levamisole, an inhibitor of alkaline phosphatase, which can hydrolize ATP. Such findings may serve to provide insights into the regulatory role of the Na(+)-K(+)-ATPase in intra-extra cellular balance in the basolateral membranes of the proximal convoluted tubule cells of this desert animal which show thick basal laminae with their membrane-bound bodies. However, there is a lack of knowledge regarding the transport function of the assayed enzyme and these bodies.

Successful therapeutic regimens for treating Brucella melitensis and Brucella abortus infections in cows.

Three therapeutic regimens were evaluated in 121 cows naturally infected with Brucella melitensis or Brucella abortus, using a combination of long-acting oxytetracycline (LA-OTC), streptomycin (ST) and OTC-intramammary infusion (IMI). Cessation of shedding of Brucella in udder secretions and absence of Brucella in selected tissues were considered criteria for successful treatment. Regimen A (tested on 35 cows) consisted of LA-OTC 25 mg/kg administered intramuscularly (i.m.) every 3 days for 42 days, ST 25 mg/kg i.m. daily for 8 days, and OTC-IMI 20 ml/teat daily for 4 days. Regimen B (tested on 53 cows) was similar to regimen A, except that ST was administered every 2 days for 16 days and OTC-IMI every 2 days for 8 days. Both regimens were equally effective in eliminating Brucella organisms from all cows involved in the tests and no relapses were recorded. However, regimen C, which was similar to regimen A, except that ST was administered every 3 days for 24 days and OTC-IMI every 3 days for 12 days, resulted in the elimination of Brucella organisms from only 30 (91%) of 33 cows. Before commencement of the therapeutic regimens, B. melitensis biovar 1 or 2 had been repeatedly isolated from udder secretions of 103 cows and B. abortus biovar 1 from mammary secretions of 18 cows.

Blood flow measurements in lower limb arteries using duplex ultrasound.

The increase in blood flow in exercise is to provide more oxygen to tissues. The kinetics of flow at the common femoral artery bifurcation were established in normal subjects together with its relationship with oxygen uptake. Furthermore, the changes in flow were evaluated in patients undergoing superficial femoral artery angioplasty. After a known anaerobic test (Wingate test), normal subjects underwent a preferential increase in profunda femoris artery flow (ninefold increase), compared with superficial femoral artery flow (fourfold increase), indicating predominantly thigh exercise. The relationship between oxygen uptake and lower limb blood flow was studied before, during and after moderate intensity exercise. Oxygen uptake was measured by mass spectrometry and assessed by breath-by-breath analysis. The rate of increase for limb blood flow, as indicated by the time constant, was faster (28.8 +/- 4.4 s; mean +/- sem) than oxygen uptake (41.5 +/- 7.2 s) at the onset of exercise. This implies that limb blood flow is in excess of the oxygen requirements of muscle and therefore not the critical determinant for oxygen uptake by muscle. Flow in the lower limb arteries was measured before and after superficial femoral artery angioplasty in 22 patients. In addition, collateral blood flow was estimated using a mathematical model. Follow-up was carried out to 1 year. At 1 month, a significant decrease in profunda femoris artery flow (from 224 +/- 84 to 98 +/- 43 ml min-1, P < 0.05, paired t test) and a marked diminution in collateral flow (from 186 +/- 34 to 18 +/- 8 ml min-1, P < 0.05) was noted with no change in total limb blood flow. As expected, a significant increase in superficial femoral artery blood flow was seen (148 +/- 79 to 312 +/- 94 ml min-1, P < 0.05). From the studies, it can be seen that non-invasive duplex ultrasound flow measurements can reliably be obtained in the lower limb, allowing the kinetics of flow after exercise and the changes in flow after surgical intervention to be evaluated. This work provides a foundation for the study of oxygen kinetics and limb blood flow in athletes, the elderly and patients with peripheral vascular disease.

An observational study of 256 cases of vascular trauma in the north western province of Pakistan.

During the past 10 years Peshawar has dealt with increasing casualties with penetrating trauma inflicted by a wide variety of missiles. The aim of this study was to assess whether delay in arrival and mode of presentation affects the outcome of patients with penetrating vascular trauma. Prospective data were collected on 256 vascular injuries in 248 patients (median age, 29 years; range, 7-60 years) between January 1995 and June 1998. Early presentation (group A, 55 cases, < 12 h) was compared with late presentation (group B, 201 cases, > 12 h). The majority of injuries (93%) were caused by fire-arms. Arterial injuries accounted for 71% of the total, venous injuries accounted for 10% and 19% were mixed. The site of injury was the lower limb (61%), upper limb (32%), abdominal cavity (5%) and neck (2%). Patients presented with absent pulses (56%), haemorrhage (46%), false aneurysms (8%), A-V fistula (5%) and 11% presented with more than one sign. There were significantly more lower limb amputations in group A than group B (23% versus 5%; P < 0.05), with fractures having a positive association with lower limb amputations (odds ratio, 0.32; 95% CI, 0.13-0.94; P < 0.05). Group A had a higher mortality than group B (18% versus 7%; P < 0.05). This study shows that patients with vascular trauma can be managed successfully with clinical assessment alone. Patients with fractures were more likely to suffer eventually from lower limb loss. Due to self-selection, arrival at the hospital less than 12 h after sustaining vascular injury was associated with a higher mortality than those presenting after 12 h.