Body Mass Index and Operating Times in Vascular Procedures.

INTRODUCTION: The influence of body mass index (BMI) on operating times in central and peripheral vascular surgical procedures was investigated. REPORT: A national cohort of Danish patients who underwent a vascular procedure between 1983 and 2012 was used for analysis. Data were analysed with pairwise comparisons of BMI groups for operating times using the independent samples Kruskall-Wallis test. DISCUSSION: A total of 3,255 carotid endarterectomies; 6,885 central vascular procedures; and 4,488 peripheral bypasses were included for the analysis. Median operating times for carotid endarterectomy and central vascular procedures were, respectively, 5 and 15 minutes longer in obese patients than in normal weight patients. This represents a 7% and 10% increase in median operating times, respectively. Linear and multi-adjusted linear regressions were conducted adjusting for confounders, showing a significant correlation between BMI and operating time. Obesity significantly increased the operating times in carotid endarterectomy and central vascular procedures. These may have ramifications for the individual operative stress but not necessarily on logistical operation planning.

From tissue iron retention to low systemic haemoglobin levels, new pathophysiological biomarkers of human abdominal aortic aneurysm.

Iron deposits are observed in tissue of abdominal aortic aneurysm (AAA) patients, although the underlying mechanisms are not completely elucidated. Therefore we explored circulating markers of iron metabolism in AAA patients, and tested if they could serve as biomarkers of AAA. Increased red blood cell (RBC)-borne iron retention and transferrin, transferrin receptor and ferritin expression was observed in AAA tissue compared to control aorta (immunohistochemistry and western blot). In contrast, decreased circulating iron, transferrin, mean corpuscular haemoglobin concentration (MCHC) and haemoglobin concentration, along with circulating RBC count, were observed in AAA patients (aortic diameter >3 cm, n=114) compared to controls (aortic diameter <3 cm, n=88) (ELISA), whereas hepcidin concentrations were increased in AAA subjects (MS/MS assay). Moreover, iron, transferrin and haemoglobin levels were negatively, and hepcidin positively, correlated with aortic diameter in AAA patients. The association of low haemoglobin with AAA presence or aortic diameter was independent of specific risk factors. Moreover, MCHC negatively correlated with thrombus area in another cohort of AAA patients (aortic diameter 3-5 cm, n=357). We found that anaemia was significantly more prevalent in AAA patients (aortic diameter >5 cm, n=8,912) compared to those in patients with atherosclerotic aorto-iliac occlusive disease (n=17,737) [adjusted odds ratio=1.77 (95% confidence interval: 1.61;1.93)]. Finally, the mortality risk among AAA patients with anaemia was increased by almost 30% [adjusted hazard ratio: 1.29 (95% confidence interval: 1.16;1.44)] as compared to AAA subjects without anaemia. In conclusion, local iron retention and altered iron recycling associated to high hepcidin and low transferrin systemic concentrations could lead to reduced circulating haemoglobin levels in AAA patients. Low haemoglobin levels are independently associated to AAA presence and clinical outcome.

Does breastfeeding influence future sperm quality and reproductive hormones?

No human study has investigated the possible impact of breastfeeding on semen quality and levels of reproductive hormones, but a recent study of another hypothesis indicated an association with oligozoospermia. We investigated the association between breastfeeding, semen quality and levels of reproductive hormones. From a Danish pregnancy cohort established in 1984-1987, 347 sons were selected according to maternal smoking during pregnancy and followed up with questionnaires, semen analysis and blood sampling in 2005-2006. Complete data were available for 269 men aged 18-21 years. Breastfeeding was not statistically significantly associated with sperm concentration, total sperm count, sperm motility or morphology, oligozoospermia, follicle-stimulating hormone, inhibin B, luteinizing hormone, sex hormone-binding globulin (SHBG), the calculated level of free testosterone, free oestradiol, the free testosterone/free oestradiol ratio or the follicle-stimulating hormone/inhibin B ratio. Total testosterone and total oestradiol was 16% (p = 0.01) and 14% (p = 0.06), respectively, lower among men never breastfed in comparison with men breastfed exclusively for 1 month or longer. When taking SHBG into account, neither free testosterone nor free oestradiol was different between the two groups. This study shows no association between breastfeeding and sperm quality or reproductive hormones and a strong association is unlikely. A larger study would be needed to detect more subtle effects.

Accuracy of clinical data in a population based vascular registry.

INTRODUCTION: Clinical databases are increasingly being employed to evaluate the quality of treatments, including patients with peripheral vascular disease. Valid data is vital to the value of these analyses. OBJECTIVE: To assess the validity of clinical data in a population-based national vascular registry. DESIGN: Traditional reproducibility study was supplemented by refilling of data by an independent observer, thereby creating three data sets for comparison. MATERIALS AND METHODS: Twenty prospectively recorded electronic forms from each department were selected randomly from the Danish National Vascular Registry. Data forms were refilled by the surgeons of the department concerned, and by an independent member of the board of the Danish National Vascular Registry. Refilling was performed blinded to the original forms. CONCLUSIONS: A high degree of accuracy of clinical data can be achieved. An independent observer makes it possible to evaluate the classification of observer dependent parameters and explain differences in the reproducibility of data.

Insulin action in growth hormone-deficient and age-matched control rats: effect of growth hormone treatment.

The isolated effect of growth hormone on carbohydrate metabolism in rat skeletal muscle was studied in growth hormone-deficient dwarf rats (dw/dw) treated with either recombinant human growth hormone or saline for 10 days. In addition, age-matched heterozygous (DW/dw) (normal weight and plasma IGF-I) control rats were treated with saline. Growth hormone increased weight gain from 0.1+/-0.1 (s.e.m) to 3.6+/-0.1 g/day and plasma IGF-I concentration from 364+/-23 to 451+/-32 ng/ml. Glucose metabolism in skeletal muscle perfused with basal, submaximal and maximal concentrations (0, 600 and 60 000 pmol/l respectively) of insulin was not changed by growth hormone. No change could be detected in the total number of glucose transporters (GLUT1 and GLUT4) in the skeletal muscles, except from a lower amount of GLUT4 in the soleus muscle in the heterozygous control group. However, at submaximal insulin concentrations, skeletal muscle glucose uptake and transport were significantly lower in the heterozygous control group compared with the growth hormone-deficient group. This could indicate either a direct long-term effect of growth hormone or more likely a secondary effect attributable to the difference in body weight (205.2+/-3.1 vs 361. 6+/-5.9 g for dwarf rats and heterozygous controls respectively), and thereby muscle fibre size, between the groups probably resulting in lower average interstitial insulin and glucose concentrations at a given plasma concentration in the heterozygous rats. It is concluded that restoration of subnormal growth hormone concentrations for 10 days has no effect on insulin-stimulated glucose metabolism in skeletal muscle in vitro.

Growth hormone induces muscle fibre type transformation in growth hormone-deficient rats.

The effect of recombinant human growth hormone (rhGH) on growth and composition of muscle was studied in growth hormone-deficient rats (dw/dw) treated for 10 days with either rhGH (GH) or with placebo (PLA). Age-matched control rats (DW/dw) (AGE) were treated as PLA. Growth rate increased (P < 0.05) when rats were treated with rhGH and plasma insulin-like growth factor-1 concentration was higher (P < 0.05) in GH and AGE than in PLA. The wet weight of the soleus (SOL) and the extensor digitorum longus muscles (EDL) was less in PLA compared to GH and AGE (P < 0.05). In the SOL, the amount of myosin heavy chain (MHC) I was lower (69.1 +/- 1.7%) (Mean +/- SEM) in PLA compared to both GH (85.3 +/- 2.3%) and AGE (76.4 +/- 1.6%) (P < 0.05). At the same time the amount of MHC IIA/IIX was higher (30.9 +/- 2.2%) in PLA compared to GH (14.7 +/- 2.3%) and AGE (23.6 +/- 1.6% (P < 0.05)). In EDL, treatment with rhGH did not significantly affect MHC-isoforms or the fibre type composition, but 11% more MHC IIB and 11% less MHC IIA/IIX was observed in PLA compared to AGE (P < 0.05) suggesting a long-term effect of growth hormone. MHC-isoform data were confirmed using histochemistry. In addition, in the SOL, the maximal activity of 3-hydroxyacyl-CoA dehydrogenase (HAD) in GH and AGE was higher (22 and 27%, respectively) than in PLA (P < 0.05). In the EDL, no differences were observed in maximal activity of HAD. In conclusion, the data support a role for growth hormone in muscle fibre growth and differentiation.

Hypoxia and contractions do not utilize the same signaling mechanism in stimulating skeletal muscle glucose transport.

We have investigated whether hypoxia and muscle contractions stimulate glucose transport in perfused rat muscle to the same extent, additively and with the same sensitivity to the microbial products calphostin C and wortmannin. Hindlimb glucose uptake increased gradually from 3.4+/-0.5 to a maximal level of 12.7+/-0.6 micromol g-1 h-1 (n=11) after 50 min of hypoxia. Compared with hypoxia, the effect of maximal electrical stimulation of the sciatic nerve on muscle glucose uptake was more than two-fold higher (27+/-2 micromol g-1 h-1 (n=14)). This was due to a higher contraction- vs. hypoxia-induced glucose transport rate in oxidative fibers. The stimulatory effect of hypoxia and electrical stimulation was not additive. Contraction-induced muscle glucose transport was inhibitable by both calphostin C and wortmannin in the micromolar range, whereas the effect of hypoxia was totally insensitive to these drugs. Our data suggest that diacylglycerol/phorbol ester-sensitive protein kinase C is involved in stimulation of muscle glucose transport by contractions and that in contrast to the prevailing concept, hypoxia and contractions do not stimulate muscle glucose transport by the same signaling mechanism.

Arteriovenous fistulas aggravate the hemodynamic effect of vein bypass stenoses: an in vitro study.

PURPOSE: The purpose of this study was to assess the impact of arteriovenous fistulas combined with varying degrees of stenosis on distal bypass hemodynamics and Doppler spectral parameters. METHODS: In an in vitro flow model bypass stenoses causing 30%, 55%, and 70% diameter reduction were induced 10 cm upstream of a fistula with low outflow resistance. Flow and intraluminal pressure were measured proximal to the stenosis and downstream of the fistula. The waveform parameters peak systolic velocity, end-diastolic velocity, pulsatility index, and pulse rise time were determined from midstream Doppler spectra obtained 10 cm downstream of the fistula. All measurements were carried out with open and clamped fistula. RESULTS: At 30% diameter reducing stenosis opening of the fistula induced a 12% systolic pressure drop across the stenosis but had no adverse effect on the Doppler waveform parameters. At 55% stenosis the pressure drop increased from 16% to 31% after fistula opening. This increased pressure drop was associated with a further reduction in peak systolic velocity, a decrease in pulsatility index, and an enhanced pulse rise time prolongation. Fistula opening at 70% stenosis increased the systolic pressure drop from 31% to 48% and had significant impact on all waveform parameters. CONCLUSIONS: Distal arteriovenous fistulas enhance pressure loss across stenoses and affect downstream velocity waveform configuration. The presence of a combined fistula and a stenosis mimics the distal hemodynamic conditions of a more severe stenosis. Assessment of the hemodynamic impact of fistulas must be undertaken in the evaluation of in situ vein bypass stenoses.

Validation of a new transit time ultrasound flowmeter in man.

OBJECTIVES: To validate the new CardioMed CM 4000 transit time ultrasound apparatus for intraoperative measurement of volume blood flow in vivo in man. DESIGN: Open, prospective series. MATERIALS: Thirteen patients undergoing in situ saphenous vein grafting for chronic critical leg ischaemia and 12 patients subjected to myocardial revascularisation with the internal thoracic artery as coronary bypass. METHODS: During operations, volume blood flows were measured simultaneously by exsanguination from the cut distal end of the in situ saphenous vein graft or the internal thoracic artery and by the transit time flowmeter equipment. In addition, the feasibility to detect arteriovenous fistula during in situ saphenous vein grafting was examined. RESULTS: Within the examined blood flow range, the volume blood flow determined by the transit time method corresponded to the directly measured blood flow. For in situ saphenous vein grafts: y = -2.4 + 0.95.x (r = 0.99; 35 measurements in 13 patients), and for internal thoracic artery grafts: y = -9.6 + 1.1.x (r = 0.99; 21 measurements in 12 patients), where y is blood flow determined by transit time, and x is directly measured blood flow by exsanguination (r = correlation coefficient) as calculated by the least squares regression method. Fistula detection was easy and swift. CONCLUSIONS: The transit time apparatus was simple to use during intraoperative settings and gave fast, precise measurements of volume blood flow.

Femorodistal bypass grafting: quality of life and socioeconomic aspects.

OBJECTIVES: To investigate the socioeconomic aspects and the outcome of femorodistal bypass grafting operations in terms of general health state. DESIGN: Prospective open clinical study. MATERIAL: 168 operations in 153 patients. METHODS: A structured questionnaire was used to assess quality of life, and each patient was classified into a health state group defined by levels of disability and distress. RESULTS: Before operation 23 patients were actively employed, 96 were old age pensioners, 29 received invalidity pension, and five were long term sick. 80% were living in their own home without any help. Only 19 patients were actively employed at follow up, 12 of these had been working before the operation, and seven other patients had taken up paid work. About three-quarters of the patients could manage daily life without help after the operation, and 82% had no or only mild distress. There were significant changes with respect to physical mobility in all groups and emotional status in one group. In all other cases a significant change could not be shown. The median Quality of Life score at follow up was 0.986 (n = 102, variance 0.022). The immediate costs were 1.5 million pounds. CONCLUSIONS: The classification into disability and distress groups was informative, but the methods for assessment of the results of vascular surgery on quality of life, evaluation of patient satisfaction and of patients' expectations must be further developed.

Dynamic quantification, visualisation and animation of blood velocities and flows in infrarenal aortic aneurysms in vivo by three-dimensional MR phase velocity encoding.

OBJECTIVES: Nuclear magnetic resonance (MR) phase velocity encoding techniques were developed for assessment of three-dimensional blood flow patterns and regional blood flows in infrarenal aortic aneurysms in vivo. METHODS: Twenty patients with abdominal aortic aneurysms were investigated before elective surgery with a 1.5 Tesla MR-scanner. Standard multislice spin-echo sequences were used for aneurysm imaging. A flow-adjusted gradients sequence (FLAG) provided three-dimensional vector plots depicting local blood flow velocities as functions of time and anatomical position. Computer-generated animated presentations of the vectors were developed to ease data analysis and interpretation. RESULTS: The blood flow patterns in infrarenal aortic aneurysms were much more complex than previously believed. Their main characteristics were simultaneous breakdown of the antegrade flow and creation of major retrograde flow components. Major pattern determinants included inlet geometry and lumen morphology, especially presence or absence of a thrombus. CONCLUSIONS: The frictional forces generated within the lumen as a result of the breakdown of laminar flows are probably translated to the aneurysm wall and contribute to thrombus formation, aneurysm growth and risk of rupture.

[Thoracoabdominal aortic aneurysms. Treatment, complications and early results]. / Torakoabdominale aortaaneurismer. Behandling, komplikationer og tidlige resultater.

Over a four and a half year period ten patients operated upon for thoraco-abdominal aortic aneurysm. One patient died, and another developed paraparesis. Review of the literature and the experience obtained by using an intraluminal aortic graft for the proximal anastomosis is presented. Reduction of aortic cross-clamping time is essential in reducing complications, of which paraparesis is the most common. The employment of an intraluminal prosthesis whenever possible seems advantageous in achieving this goal. Patients with thoraco-abdominal aortic aneurysms can be treated with an acceptably low mortality and morbidity.

Early results of 132 aortic or aorto-iliac arterial reconstructions with the new Stretch ePTFE vascular prosthesis.

OBJECTIVE: The purpose of the present study is to document the short term clinical results after implantation of the new Stretch ePTFE (Gore-Tex) arterial prostheses in patients with aortic or aorto-iliac occlusive atherosclerotic disease or aneurysm. STUDY DESIGN: A descriptive, prospective and non-randomized clinical series with clinical follow-up at three and 12 months. SETTING: The study was performed at an Academic Vascular Surgery Unit. PATIENTS: Within 20 months we consecutively implanted 379 prostheses (tubes or bifurcations): 132 Stretch ePTFE (Gore-Tex) and 247 Dacron (Unigraft, Braun-Melsungen) grafts. RESULTS: There was no intraoperative deaths. Nine of 217 patients (= 4%) with occlusive atherosclerotic disease died < 30 days postoperatively; the mortality rate for asymptomatic aortic aneurysm was 8% (7/91), for symptomatic aneurysm 13% (4/30), and for ruptured aneurysm 22% (8/36). The primary patency of the aortic or aorto-iliac grafts was 99%, secondary patency at three months and one year 100 per cent. One patient with Stretch prosthesis developed a superficial groin infection, and one developed infection of an aortic tube graft. In the Dacron series six patients developed superficial groin infection, and two deep infections occurred. No graft-enteric fistulas or erosions were seen, and by clinical examination no anastomotic aneurysm developed. Five patients had in situ replacement of a pan-infected Dacron bifurcation graft with a Gore-Tex Stretch graft. With an observation time from 50 to 400 days these five patients are well without clinical signs of infection. CONCLUSIONS: These short term results with implantation of aortic or aorto-iliac Stretch ePTFE prostheses are encouraging and will provide the basis for a continuing performance trial with long term follow-up and reporting.

The value of sigmoideoscopy in the diagnosis of ischemic colitis following aortic reconstruction.

During a 4 1/2-years period sigmoideoscopy was performed when patients developed diarrhea and/or unexpected low abdominal pain within the first days following aortic reconstruction. In our investigation rigid sigmoideoscopy, revealed all the cases of major ischemic colitis.

Isolated necrotizing panarteritis of the gallbladder. Case report.

Two cases of isolated gallbladder involvement by necrotizing panarteritis histologically resembling classic polyarteritis nodosa are reported and the literature is reviewed. No reports suggest that isolated gallbladder involvement may evolve to systemic ('classic') polyarteritis nodosa. Finding of necrotizing panarteritis in the gallbladder without clinical evidence of systemic/multiorgan disease does not warrant extensive investigations.

Transposition of the sartorius muscle in the treatment of infected vascular grafts in the groin.

Out of 15 consecutive deep graft-infections during a 5-year-period, 12 cases were treated by local debridement, disinfectants, graft replacement and sartorius muscle transposition. The treatment was successful in 10 cases, which have shown no sign of re-infection. Three grafts occluded during the observation period (2 weeks, 2 months and 15 months), resulting in amputation in one patient. The method is recommended as the treatment of choice in Szilagyi type III infections limited to the groin.

Closed pancreatic transection treated by Roux-en-Y anastomosis.

Two patients with closed pancreatic transection, were treated by Roux-en-Y pancreaticojejunostomy. The management of closed isolated pancreatic transection is discussed.

Endoscopic fine-needle aspiration cytology of the stomach. A new diagnostic procedure.

In order to improve the diagnosis of submucosal gastric malignancies, a new method of endoscopic fine-needle aspiration cytology was evaluated. The method is compared with conventional forceps biopsy and brush cytology, and technical problems are discussed. It is concluded that endoscopic fine-needle aspiration cytology is a simple and safe procedure, but further development of the method and more clinical experience are required before the diagnostic capability of the method can be established.