Liver Transplant After Normothermic Regional Perfusion From Controlled Donors After Circulatory Death: The Norwegian Experience

BACKGROUND

In order to meet the increasing demand for donor organs, the concept of donation after circulatory death (DCD) was reintroduced in Norway, first as a pilot study, followed by the use of DCD as institutional practice. We report the current Norwegian experience with liver transplant after DCD.

METHODS

After acceptance from next of kin, life support was withdrawn from patients with devastating brain injury and cardiac arrest observed. After a 5-minute "no-touch" period, extracorporeal membrane oxygenation for post mortem normothermic regional perfusion (NRP) by extracorporeal membrane oxygenator circuit was established. Data from all liver transplant recipients receiving controlled DCD (cDCD) livers in Oslo were analyzed.

RESULTS

From 2015 to 2017, a total of 8 patients underwent liver transplant with cDCD and NRP liver grafts in Norway. Median Model for End-Stage Liver Disease score was 26 (range, 6-40). There were no cases of delayed graft function or graft loss. Seven patients have reached 1 year of follow-up, and 1 patient has reached 6 months. Two patients have recurrence of primary disease (primary sclerosing cholangitis and steatohepatitis). All patients had normalized liver function at last follow-up. Two patients underwent procedures for biliary complications. In 1 patient, leakage from the cystic duct was successfully handled endoscopically by stenting. In the other patient, a suspected stricture on magnetic resonance imaging led to an endoscopic retrograde cholangiopancreatography, which did not confirm signs of biliary stenosis. There was 1 instance of hepatic artery stenosis, which was managed with endovascular technique.

CONCLUSION

The results after liver transplant using cDCD with NRP are good. The rate of complications seems to be within the same range as when using conventional donation after brain death grafts.

Open Abdomen Treated with Negative Pressure Wound Therapy: Indications, Management and Survival

BACKGROUND

Open abdomen treatment (OAT) is a significant burden for patients and is associated with considerable mortality. The primary aim of this study was to report survival and cause of mortality after OAT. Secondary aims were to evaluate length of stay (LOS) in intensive care unit (ICU) and in hospital, time to abdominal closure and major complications.

METHODS

Retrospective review of prospectively registered patients undergoing OAT between October 2006 and June 2014 at Trondheim University Hospital, Norway.

RESULTS

The 118 patients with OAT had a median age of 63 (20-88) years. OAT indications were abdominal compartment syndrome (ACS) (n = 53), prophylactic (n = 29), abdominal contamination/second look laparotomy (n = 22), necrotizing fasciitis (n = 7), hemorrhage packing (n = 4) and full-thickness wound dehiscence (n = 3). Eight percent were trauma patients. Vacuum-assisted wound closure (VAWC) with mesh-mediated traction (VAWCM) was used in 92 (78 %) patients, the remaining 26 (22 %) had VAWC only. Per-protocol primary fascial closure rate was 84 %. Median time to abdominal closure was 12 days (1-143). LOS in the ICU was 15 (1-89), and in hospital 29 (1-246) days. Eighty-one (68 %) patients survived the hospital stay. Renal failure requiring renal replacement therapy (RRT) (OR 3.9, 95 % CI 1.37-11.11), ACS (OR 3.1, 95 % CI 1.19-8.29) and advanced age (OR 1.045, 95 % CI 1.004-1.088) were independent predictors of mortality in multivariate analysis. The nine patients with an entero-atmospheric fistula (EAF) survived.

CONCLUSION

Two-thirds of the patients treated with OAT survived. Renal failure with RRT, ACS and advanced age were predictors of mortality, whereas EAF was not associated with increased mortality.

Influence of CT on Tumor Classification of Laryngeal Carcinomas

The routine use of CT in 51 consecutive patients with squamous cell carcinoma of the larynx revealed cartilage involvement or extra-laryngeal tumor growth consistent with a T4 tumor which made 14 patients candidates for laryngectomy. Only 5 of these had a T4 classification by clinical examination while 8 cases were upstaged from T3. Except for one supraglottic tumor upstaged from T2 to T4, CT did not change the classification for T1 and T2 tumors, Whose localization was mainly glottic, and there were 2 false-negative examinations. It is concluded that CT is mandatory only in advanced tumors of the glottic region or when the anterior commissure is involved. However, in suspected malignancies of the sub- or supraglottic regions CT should always be carried out because these patients are at an increased risk of unexpected deep tumor growth.

Surgery for ruptured abdominal aortic aneurysm and early mortality in women. Risk factors and complication profile

AIM

Repair of ruptured abdominal aortic aneurysm (rAAA) is reported to have a higher mortality in women than in men. The aim was to study whether this difference could be verified in our institution and secondary if difference in risk- and complication profiles could explain the higher 30 day mortality after surgery for rAAA in women.

METHODS

During the period 1983-2009 1649 patients, 1348 men and 301 women, were operated consecutively for infrarenal abdominal aortic aneurysm (AAA); 430 patients had rAAA, 98 women and 332 men. Co-morbidities were identified from the patients' medical records. Outcome measures within 30 days were mortality, cardiac disease (heart attack, heart failure), cerebrovascular disease (stroke, TIA), renal insufficiency (serum creatinine >140 µmol/L), major amputation, bowel infarction, pancreatitis and graft related complications.

RESULTS

Compared to men, women had higher 30 d mortality after surgery for rAAA (54.1% vs. 36.3%, P=0.002). Women were significantly older than men (76 years vs. 73 years, P=0.001). In the period 1995-2009 women had more autoimmune diseases than men (P=0.045). There was no significant difference between men and women for the other measured outcomes.

CONCLUSION

During the period 1995-2009, autoimmune disease were more common among women than men. For all other parameters recorded, there were no differences in risk - or complication profile that could explain the higher 30 d mortality in female patients after surgery for rAAA.

Noninvasive coronary angiography with 64-channel multidetector computed tomography in patients with acute coronary syndrome

BACKGROUND

Advances in computer tomography (CT) imaging technology in recent years have facilitated the possibility of noninvasive coronary angiography.

PURPOSE

To compare the diagnostic accuracy of 64-channel multidetector computed tomography (MDCT) with conventional invasive coronary angiography (ICA) for the detection of significant coronary stenosis in patients with acute coronary syndrome (ACS).

MATERIAL AND METHODS

MDCT was performed in 60 patients classified with non-ST-elevation infarction (NSTEMI) or unstable angina and scheduled for ICA within 3 days. The diagnostic accuracy of MDCT was evaluated using quantitative coronary angiography (QCA) as the gold standard.

RESULTS

48 out of 60 patients had interpretable scans by both MDCT and ICA. On a segment-based analysis, 488 out of 665 segments with a diameter of > or =1.5 mm, as defined by QCA, were interpretable by MDCT. Sensitivity was 78%, specificity 87%, positive predictive value 47%, and negative predictive value 97% in detecting and excluding significant coronary stenosis, as defined with MDCT. On a per patient-based analysis, sensitivity was 89%, specificity 50%, positive predictive value 84%, and negative predictive value 60%.

CONCLUSION

Limited diagnostic accuracy restricts the usefulness of coronary MDCT in patient groups with a high pretest probability of disease, such as in acute coronary syndrome.

The prevalence of carotid artery stenosis in an unselected hospitalized stroke population

AIM

The aim of this study was to describe the number and severity of carotid artery stenosis in an unselected stroke population in hospital.

METHODS

The carotid arteries were investigated consecutively with color-coded duplex scanning in patients suspected of having stroke and admitted to a stroke unit during a 6-month period. Percent internal carotid artery stenosis by diameter reduction was described.

RESULTS

A total of 144 patients were included in the investigation and the mean age was 75 years. The final diagnosis was stroke in 126 patients, while 18 had transient ischemic attacks. On the side, relevant to the neurologic deficit, a stenosis of >70% diameter reduction was observed in 4 patients and occlusion in 3. Severe stenosis and occlusion was found to have almost the same incidence on the contralateral side. Altogether 46 stenoses >30% (16.3%) were observed in 282 arteries investigated. The distribution was equal between the two sides.

CONCLUSION

These findings indicate that few patients are eligible for surgery. However, routine duplex ultrasound examination in stroke patients gives information whether there are carotid arterial lesions, which could be a source of emboli. Such information can also be a guide for further medical treatment and lifestyle modification.

Effect of blood donation on maximal oxygen consumption

AIM

This study determined the effect of donating one unit of blood on various physiological parameters associated with a VO2(max) test.

METHODS

Ten healthy, male subjects (23+/-4 years, 178+/-7.6 cm, 74.4+/-12.3 kg) completed a VO2(max) test 24 h before donating one unit of blood (~500 mL) and 24 h after donating blood. The Bruce protocol was used to determine the subjects' VO2(max). Physiological responses were measured at the end of the VO2(max) test. A repeated measures ANOVA was used to determine if there were significant (P<0.05) differences in the subjects' physiological responses between the VO2(max) before and after blood donation.

RESULTS

Significant differences were found in VO2(max) (mean+/-SD, 3.18+/-0.74 vs 2.87+/-0.53 L.min(-1)), cardiac output (Q, 25+/-5 vs 22.5+/-3.3 L.min(-1)), stroke volume (SV, 134+/-37 vs 121+/-22 mL.beat(-1)), delivery of oxygen (DO(2), 5+/-.87 vs 3.97+/-.68 L.min(-1)), and hemoglobin concentration (Hb, 153+/-12 vs 135+/-16 gm.L(-1)). No significant changes were observed for heart rate (HR); arteriovenous oxygen difference (a-vO(2) diff), systolic blood pressure (SBP), and diastolic blood pressure (DBP).

CONCLUSIONS

These findings indicate that donating one unit of blood decreased VO2(max) due to the decrease in Q, which resulted from the decrease in SV since HR was unchanged. The lower VO2(max) along with the decrease in DO(2) would be expected to have a negative effect on athletic performance.

Carotid endarterectomy: time-trends and results during a 20-year period

AIM

The aim of this study was to evaluate the results following surgery for carotid artery stenosis in a single institution during a 20-year period.

METHODS

In a retrospective study, 556 operations were performed in 496 patients during the period 1983-2002. Comorbidities, mortality, stroke and other surgical and general complications were recorded. Follow-up was performed and data retrieved from medical records, questionnaires, and visits to local hospitals. Data on late mortality were retrieved from the Norwegian Registrar's Office of birth and deaths.

RESULTS

The mean age was 66.9 years (range 43-84 years), and 60% were men; 84% had symptomatic carotid artery stenosis. General anesthesia was applied in 95.5%. A shunt was used in 61.3%, and patch angioplasty in 95.1%. Autologous vein patch was used in almost all cases and there were no cases of patch rupture. Postoperative myocardial infarction occurred in 16 (2.9%) of the patients, and 5 were fatal. All types of stroke within 30 days of surgery occurred in 23 (4.1%) including 1 fatal stroke, and 7 patients died of other causes. The total stroke/mortality rate was 5.4%. Patients with previous coronary artery bypass had a favorable outcome regarding long-time survival. In contrast, increasing age, diabetes, renal failure and intermittent claudication predicted reduced long-term survival. No operations were performed for recurrent stenosis.

CONCLUSIONS

We have used fairly the same policy regarding operative technique during the 20-year period and the results are in agreement with those presented in large international trials. The long-term results were favorable, and improved over time, probably due to better preoperative evaluation of the patients, better timing of surgery and treatment of comorbidities.

A phase 1, dose-escalation trial of STA-5312, a microtubule inhibitor with a novel binding site, in advanced or metastatic solid malignancies

13040

Background: STA-5312 is a novel microtubule inhibitor with a distinct binding site from other agents such as vincristine, colchicine, or paclitaxel, which has demonstrated antitumor activity against a range of solid tumors in chemotherapy-resistant cancer. Methods: The trial assessed the safety, toxicity, pharmacokinetics (PK) and maximum tolerated dose (MTD) level of STA-5312 when administered as an IV infusion weekly for the first 3 weeks of a 4 week cycle. Assessment of activity is a secondary objective. The starting dose level was 6mg/m2. Dose escalation was based on evaluation of toxicity through the first cycle, with dose doubling in cohorts of 1–2 patients (pts) until a grade (gr) 2 or greater toxicity occurred, followed by at least 3 pts/cohort and 50% dose escalations. After a dose limiting toxicity (DLT), cohorts were expanded to at least 6 pts and subsequent escalations limited to 33%. The dose below the lowest dose at which 1/3 of 6 or more patients show DLT will be declared the MTD. PK sampling was performed during cycle 1. Results: To date, 25 pts have been treated: median age 58 years (35–77), ECOG performance status of 0–2, and median treatment duration 43 days. No serious drug-related toxicity was observed until a DLT (ataxia) was reported in the only patient treated at 64mg/m2, leading to de-escalation to 48 mg/m2, where the only patient experienced aphasia and ataxia. Enrollment is being expanded at a lower dose level of 32 mg/m2. Other adverse events attributable to STA-5312 include (>10%) anemia, fatigue, constipation, nausea, and anorexia. Exposure (AUC) was linear with respect to dose. Five patients have had disease stabilization. Conclusions: STA-5312 appears to be well tolerated when given weekly in doses up to 32mg/m2. The MTD has not been determined and enrollment is ongoing.

[Table: see text]

Data Quality of Surgery for Carotid Artery Stenosis. Are the National Vascular Registries Reliable?

OBJECTIVES

To study completeness of reporting carotid endarterectomies, including peri-operative stroke and mortality rate, in a national vascular registry, NorKar, and a national administrative registry, The Norwegian Patient Register (NPR).

DESIGN

Comparative registry-based national study.

MATERIALS

Member hospitals of NorKar, including 89% of carotid endarterectomies in Norway, were compared with relevant data in NPR for the years 2000-2002.

METHODS

We compared procedure-codes, diagnosis-codes, in-hospital death and the occurrence of peri-operative stroke after treatment for carotid artery stenosis in the two registries to evaluate completeness.

RESULTS

Compared with the NPR numbers, 16% of carotid endarterectomies were missing in the reports from member hospitals of NorKar. Further, during this three-year period, there was an under-reporting of seven strokes and two deaths. The discrepancy was most pronounced in 2001.

CONCLUSIONS

There is an under-reporting of patients operated on for carotid artery stenosis in NorKar according to NPR numbers as well as an under-reporting of early deaths and strokes. There is a need for better quality data in the NorKar Registry. Registry quality would be likely to improve if patient identifiable data were available in both registries.

Ruptured abdominal aortic aneurysm secondary to tuberculous spondylitis

A 69-year-old man was admitted with low back pain and signs of nerve root compression. A computed tomography (CT) scan showed abscess formation in the left psoas region, spondylodiscitis L3-L4 and a ruptured abdominal aortic aneurysm. The aortic aneurysm was replaced with a bifurcated vascular graft. One week later, laminectomy at the L4-level was done. In a small abscess, Mycobacterium bovis was found. The condition was considered to be a mycobacterial spondylitis secondary to BCG instillations of the urinary bladder for carcinoma. The patient received antituberculous medication for 9 months. Subsequently bone transplantation and internal fixation of the spine became necessary. Three years after surgery he is in good condition and there are no signs of graft infection on CT. Spondylitis and mycotic aortic aneurysm should be kept in mind in patients who have been treated for carcinoma of the bladder with BCG instillations.

Three-dimensional microarchitecture of the plates (primary, secondary, and carinar process) in the developing tooth of Lytechinus variegatus revealed by synchrotron X-ray absorption microtomography (microCT)

This paper reports the first noninvasive, volumetric study of entire cross-sections of a sea urchin tooth in which the individual calcite structural elements could be resolved. Two cross-sectionally intact fragments of a Lytechinus variegatus tooth were studied with synchrotron microCT (microcomputed tomography) with 1.66 microm voxels (volume elements). These fragments were from the plumula, that is the tooth zone with rapidly increasing levels of mineral; one fragment was from a position aboral of where the keel developed and the second was from the zone where the keel was developing. The primary plates, secondary plates, carinar process plates, prisms, and elements of the lamellar-needle complex were resolved. Comparison of the microCT data with optical micrographs of stained thin sections confirmed the identifications and measured dimensions of the characteristic microarchitectural features. The interplay of reinforcing structures (plates and prisms) was more clearly revealed in the volumetric numerical data sets than in single or sequential slices. While it is well known that the primary plates and prisms in camarodont teeth are situated to improve resistance to bending (which can be termed primary bending), the data presented provide a new understanding of the mechanical role of the carinar process plates, that is, a geometry consistent with that required in the keel to resist lateral or transverse bending of the tooth about a second axis. The increase in robustness of teeth incorporating lateral keel reinforcement suggests that the relative development of carinar processes (toward a geometry similar to that of L. variegatus) is a character which can be used to infer which sea urchins among the stirodonts are most primitive and among the camarodonts which are more primitive.

Multiple microscopy modalities applied to a sea urchin tooth fragment

Two synchrotron X-ray microscopy methods, phase-contrast microradiography (the propagation method) and absorption microCT (high-resolution computed tomography or microtomography), and laser-scanning confocal microscopy (visible wavelength) were used to study a fragment of the keel of a tooth of the sea urchin Lytechinus variegatus. Stripes observed in the phase-contrast images of the fragment were also seen in confocal micrographs. MicroCT showed that the stripes were due to two parallel planar arrays of low-absorption channels within the bulk of the keel. In the phase microradiographs, maximum contrast stripes appear when a channel image from one row coincides with a channel image from the second row; otherwise, contrast is minimal. Long channels do not appear to have been observed previously in keels of sea urchin teeth.

Synchrotron X-ray studies of the keel of the short-spined sea urchin Lytechinus variegatus: absorption microtomography (microCT) and small beam diffraction mapping

In sea urchin teeth, the keel plays an important structural role, and this paper reports results of microstructural characterization of the keel of Lytechinus variegatus using two noninvasive synchrotron x-ray techniques: x-ray absorption microtomography (microCT) and x-ray diffraction mapping. MicroCT with 14 keV x-rays mapped the spatial distribution of mineral at the 1.3 microm level in a millimeter-sized fragment of a mature portion of the keel. Two rows of low absorption channels (i.e., primary channels) slightly less than 10 microm in diameter were found running linearly from the flange to the base of the keel and parallel to its sides. The primary channels paralleled the oral edge of the keel, and the microCT slices revealed a planar secondary channel leading from each primary channel to the side of the keel. The primary and secondary channels were more or less coplanar and may correspond to the soft tissue between plates of the carinar process. Transmission x-ray diffraction with 80.8 keV x-rays and a 0.1 mm beam mapped the distribution of calcite crystal orientations and the composition Ca(1-x)Mg(x)CO(3) of the calcite. Unlike the variable Mg concentration and highly curved prisms found in the keel of Paracentrotus lividus, a constant Mg content (x = 0.13) and relatively little prism curvature was found in the keel of Lytechinus variegatus.

X-ray microCT study of pyramids of the sea urchin Lytechinus variegatus

This paper reports results of a novel approach, X-ray microCT, for quantifying stereom structures applied to ossicles of the sea urchin Lytechinus variegatus. MicroCT, a high resolution variant of medical CT (computed tomography), allows noninvasive mapping of microstructure in 3-D with spatial resolution approaching that of optical microscopy. An intact pyramid (two demipyramids, tooth epiphyses, and one tooth) was reconstructed with 17 microm isotropic voxels (volume elements); two individual demipyramids and a pair of epiphyses were studied with 9-13 microm isotropic voxels. The cross-sectional maps of a linear attenuation coefficient produced by the reconstruction algorithm showed that the structure of the ossicles was quite heterogeneous on the scale of tens to hundreds of micrometers. Variations in magnesium content and in minor elemental constitutents could not account for the observed heterogeneities. Spatial resolution was insufficient to resolve the individual elements of the stereom, but the observed values of the linear attenuation coefficient (for the 26 keV effective X-ray energy, a maximum of 7.4 cm(-1) and a minimum of approximately 2 cm(-1) away from obvious voids) could be interpreted in terms of fractions of voxels occupied by mineral (high magnesium calcite). The average volume fraction of mineral determined for a transverse slice of the demipyramid near where it joins an epiphysis was 0.46; for a slice 3.3 mm adoral it was 0.70. Local volume fractions of mineral approached 1, and, away from resolvable voids, considerable portions of the demipyramids had volume fractions of calcite at or below approximately 0.33. MicroCT imaging of a demipyramid before and after infiltration with a high absorptivity fluid (sodium polytungstate) confirmed the determination of the volume fractions of minerals.

X-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth

Two noninvasive X-ray techniques, laboratory X-ray absorption microtomography (microCT) and X-ray diffraction mapping, were used to study teeth of the sea urchin Lytechinus variegatus. MicroCT revealed low attenuation regions at near the tooth's stone part and along the carinar process-central prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase (calcite, Ca(1-x)Mg(x)CO(3)) cannot account for all of the linear attenuation coefficient decrease in the two zones: this suggested that soft tissue is localized there. Transmission diffraction mapping (synchrotron X-radiation, 80.8 keV, 0.1 x 0.1mm(2) beam area, 0.1mm translation grid, image plate area detector) simultaneously probed variations in 3-D and showed that the crystal elements of the "T"-shaped tooth were very highly aligned. Diffraction patterns from the keel (adaxial web) and from the abaxial flange (containing primary plates and the stone part) differed markedly. The flange contained two populations of identically oriented crystal elements with lattice parameters corresponding to x=0.13 and x=0.32. The keel produced one set of diffraction spots corresponding to the lower x. The compositions were more or less equivalent to those determined by others for camarodont teeth, and the high Mg phase is expected to be disks of secondary mineral epitaxially related to the underlying primary mineral element. Lattice parameter gradients were not noted in the keel or flange. Taken together, the microCT and diffraction results indicated that there was a band of relatively high protein content, of up to approximately 0.25 volume fraction, in the central part of the flange and paralleling its adaxial and abaxial faces. X-ray microCT and microdiffraction data used in conjunction with protein distribution data will be crucial for understanding the properties of various biocomposites and their mechanical functions.

Kinetic studies of the degradation of oxycarbonyloxymethyl prodrug of Adefovir and Tenofovir in solution

The decomposition kinetics of bis-POC PMEA and bis-POC PMPA followed pseudo-first order kinetics with the corresponding mono-POC ester detected as the only observable degradation product for all the pH values studied. The rates of hydrolysis of bis-POC PMEA over the pH range studied was described by [formula: see text] The 18O incorporation studies revealed that hydrolysis of bis-POC PMEA at pH 7.0 primarily proceeds via P-O cleavage with an additional minor pathway involving C-O bond cleavage. Hydrolysis of bis-POC PMPA was found to be about 2 fold slower than bis-POC PMEA at pH values above 6.0.

Liquid chromatographic determination of FP-21399 in plasma of patients with HIV infection

A high-performance liquid chromatographic (HPLC) analysis method for the novel anti-HIV drug FP-21399 in human plasma was developed. The method employed the combination of organic solvent extraction and solid phase extraction. Analysis of FP 21399 and two major metabolites was achieved within 18 min using a reverse phase Puresil Cl 8 analytical column (4.6 x 150 mm, 5 microm, Waters) with a mobile phase of water-acetonitrile containing 20 mM triethylamine acetate (apparent pH 7.0). Linear gradient of mobile phase was applied as water-acetonitrile from 78:22 (v/v) to 55:45 over 8 min, and held at this ratio for the next 4 min. An ultraviolet-visible detector was operated at 265 mn from 0 to 8 min and at 600 mn from 8 min and after. The retention time of FP-21399 was 8.8 min and a linear response was observed over the concentration range 0.01 100 microg ml(-1) (r = 0.994). Lower limit of quantitation was found to be 0.01 microg ml(-1). Intra- and inter-assay precision varied in the range of 0.2 to 8% and 1-12%, respectively. The bias ranged from -17-3% for all analyses. A series of clinical plasma specimens were successfully analyzed using this method. The strategies for the method optimization on HIPLC separation and extraction procedure are discussed as well.

Improved high-performance liquid chromatographic method for analysis of L-carnitine in pharmaceutical formulations

A reversed-phase high performance liquid chromatographic method for analysis of L-carnitine is described. The improved method is able to provide a high resolution between L-carnitine and crotonoylbetaine, a major impurity and degradation product, and suitable for quantitative analysis of L-carnitine in pharmaceutical formulations, such as solution, tablets, and capsules. The resolution, linearity, accuracy and reproducibility of the method are discussed.

Lipoprotein(a), other lipoproteins and hemostatic profiles in patients with ischemic stroke: the relation to cardiogenic embolism

Lipoprotein and hemostatic profiles including coagulation inhibitors were determined in 136 patients with acute ischemic stroke. Based on clinical examination, cerebral computed tomography, Doppler ultrasonography of precerebral arteries and transthoracic echocardiography, the strokes were classified as cardioembolic (n = 38), non-cardioembolic (n = 92), and mixed cardioembolic/hypertensive (n = 6). Patients with cardioembolic stroke were older than patients with non-cardioembolic stroke. Lipoprotein(a) was higher in the cardioembolic than in the non-cardioembolic group. Lipoprotein(a) was not significantly correlated to the other lipid levels and may represent an independent lipid risk factor. The non-cardioembolic group had higher levels of total cholesterol, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, low-density lipoprotein cholesterol, apolipoprotein A1, and apolipoprotein B. The cardioembolic group had higher concentrations of fibrinogen and D-dimer, and lower levels of antithrombin, protein C, protein S and heparin cofactor 2 than the non-cardioembolic group. The differences in the hemostatic profile are consistent with thrombosis due to activated coagulation being more involved in the pathogenesis of cardioembolic than of non-cardioembolic stroke. Lipoprotein(a) seems to be more associated with coagulation markers of thrombosis than with atherosclerosis, whereas the other lipids mainly seem to be risk factors for atherosclerosis.

Type I collagen-phosphophoryn interactions: specificity of the monomer-monomer binding

It has been postulated that phosphophoryn (PP) molecules bind specifically to type I collagen fibrils as the key event in inducing matrix mineralization in dentin. The nature and specificity of the collagen molecule-PP interaction has been examined by rotary shadowing-electron microscopy of mixtures of native, monomeric lathyritic rat skin collagen and purified rat incisor PP. An antibody to the amino-telopeptide of the collagen alpha1(I)-chain was used to determine the N-terminal end of the collagen molecules. Solutions of collagen and PP in 0.01 M ammonium formate (+/- antibody) were mixed and spread in 70% glycerol-30% 0.01 M ammonium formate on freshly cleaved mica surfaces using the sandwich technique. After rotary shadowing with Pt and backcoating with a carbon film, the spreads were viewed in a JEOL 1200EX TEM. The PP appeared as 15-nm diameter globules, the collagen as semi-flexible 270 nm filaments. At neutral pH and low PP/collagen mixing ratios, a single interaction site was evident, centered at approximately 210 nm from the N-terminus. The binding interaction induced a local conformational change in the collagen, bending the molecule and reducing its effective length. The sequence within the collagen-PP-binding domain has a net-positive charge but contains both positively and negatively charged groups.

Rapid intraoperative construction of autologous small caliber blood vessels

Autologous pericardium, briefly tanned in glutaraldehyde, is an excellent biomaterial when used in various cardiac procedures, including repair and replacement of heart valves. A generalized lack of calcification and an absence of inflammatory response in these combined experiences has led the authors to consider the use of treated autologous pericardium for the construction of substitute small caliber blood vessels. Rapid, intraoperative construction of a vascular graft from autologous pericardium, briefly treated in 0.62% glutaraldehyde, is accomplished through the use of two concentric, mating helical stents that support a rectangular pattern of tissue into a cylindrical, nonkinking, compliant conduit. A disposable automated assembly tool provides for precise assembly of the tissue and stents. The tools and methods for construction of vascular grafts from nonvascular tissue are known as the Rapidgraft (Ramus Medical Technologies, Santa Barbara, CA). The technique can be used with any suitable tissue. Accelerated fatigue test studies have confirmed that stent supported pericardial grafts are capable of withstanding physiologic pressures and flows beyond 7 equivalent years. Six autologous pericardial grafts measuring 5 mm in diameter by 5.5 cm in length showed 100% patency beyond 5 months in a growing calf carotid artery model. Pathological examination of explanted grafts confirm the presence of a continuous endothelial lined surface, infiltration of the tissue by fibrous connective tissue such that the individual layers of the pericardial vessel wall could not be identified, and there was no inflammatory response. Based on the encouraging results in animal studies, a small multicenter clinical trial has been initiated to evaluate the performance of the Rapidgraft as a replacement conduit for the radial artery in cases in which the radial artery has been harvested as a coronary artery bypass conduit. Results from the radial artery trial will be used as an indication to evaluate the Rapidgraft as a coronary artery substitute. We conclude that the material properties, including the biological origin of a vessel wall, may be significant determinants of graft patency, and that the Rapidgraft may be an answer to the need for small caliber arterial graft with the potential for long-term patency and durability.

Effects of lower body pressure changes on pulmonary function

PURPOSE

During and following exercise there are a number of changes in pulmonary function, among which is a decrease in forced vital capacity (FVC). Several potential mechanisms may explain this decreased FVC, including an exercise-induced increase in thoracic blood volume.

METHODS

We tested the hypothesis that altered thoracic blood volume alone, as produced by the application of 30 mm Hg lower body negative (LBNP) or positive pressure (LBPP) for 5 min, would change FVC and forced expiratory volume in 1 s (FEV1.0). Further, we tested whether the changes in pulmonary function were related to initial lung volume and whether the lower body pressure changes led to an altered lung compliance as measured by static pressure-volume curves.

RESULTS

Results indicated that with LBNP, FVC, and FEV1.0 were significantly increased by approximately 0.15 L and 0.18 L, respectively. When LBPP was applied, FVC and FEV1.0 were decreased by approximately 0.18 and 0.14 L, respectively. The increase in FVC with LBNP was significantly related to the original FVC (r = 0.66, P < 0.05). There was no significant correlation between the increase in FEV1.0 and the original FEV1.0 (r = 0.48, P > 0.05). Pulmonary compliance was not changed significantly by the application of LBPP.

CONCLUSIONS

These results suggest that part of the change in pulmonary function following heavy exercise is related to an increased thoracic blood volume. The lack of change in lung compliance suggests that the effect of altered thoracic blood volume is to displace air and not to change the mechanical properties of the lungs.

[Computer tomography of pathological neck lesions]

The introduction of high resolution computed tomography (CT) has significantly improved the quality of imaging of neck masses. Incremental dynamic scanning immediately after a quick bolus injection of contrast medium is essential in a majority of patients in order to obtain an optimum of information. This is especially true in the identification, mapping and staging of malignant lesions, which is the main indication for the examination. CT is also very sensitive, and yields detailed information about the location and extent of cystic and other benign lesions. Owing to the low attenuation of fat, the examination is very specific with respect to lipomas. CT has low specificity in the differentiation between benign and malignant lesions, and between cysts and solid tumours of the thyroid gland. In thyroid and parathyroid imaging other modalities such as ultrasound and scintigraphy are often more specific.

[Lymphatic complications after lower limb vascular surgery]

A series of five patients with lymph fistula and two with lymphocele is described. Lymphatic complications in the groin and thigh following infrainguinal arterial surgery may increase the risk of wound infection and prolong the stay in hospital. During operation for lymph fistula and lymphocele, precise identification of the site of lymph leakage during exploration of the wound is mandatory. This can be obtained by intradermal injection of Patent blue 2.5% medially and laterally on the dorsum of the foot approximately one hour before operation. Operation for lymph fistula should be performed as soon as the diagnosis has been verified, especially if a prosthetic graft has been used. A lymphocele should be treated conservatively unless the patient is suffering from localized pain or ischemia of the skin caused by pressure of the underlying swelling.

[Antithrombotic therapy in cerebrovascular disorders]

Warfarin is recommended as primary prophylactic therapy for patients older than 60 years with non-valvular atrial fibrillation and for patients with additional risk factors for thromboembolism. Warfarin should also be given as secondary prophylaxis. Patients with contraindications to warfarin should be given aspirin. Anticoagulant therapy is recommended against progressive ischemic stroke and in cardiogenic cerebral embolism, although conclusive evidence of the benefit is lacking. In the case of transient ischemic attacks and minor stroke, antiplatelet therapy reduces the risk of subsequent stroke by approximately 25 percent. Antiplatelet therapy is probably indicated in cases of acute, stable ischemic stroke.

Long-term anticoagulant therapy in cerebrovascular disease: does bleeding outweigh the benefit?

OBJECTIVE

The aim of the present study was to determine the risk of major haemorrhagic complications, stroke and other cardiovascular events, and mortality during long-term anticoagulant therapy (ACT) in patients with cerebrovascular disease not included in any prospective trials.

DESIGN

The data were collected retrospectively.

SETTING

All patients with symptomatic cerebrovascular disease discharged from the Stroke Unit, Aker University Hospital, Oslo, with ACT (warfarin) during 1983 through to 1986 were included.

SUBJECTS

The material consists of 161 patients with a mean age of 67.8 (range 40-90) years. The reason for initiating ACT was frequent transient ischaemic attacks (TIAs) in 52 patients, stroke in progression (SIP) in 33 patients, and probable embolic stroke in 76 patients. International normalized ratio (INR) of 4.2-2.8 was aimed at.

MAIN OUTCOME MEASURES

Major haemorrhagic complications, recurrent stroke and survival was determined for the total material, and in the subgroups non-valvular atrial fibrillation (NVAF, n = 49), TIAs, and SIP.

RESULTS

The mean duration of ACT was 21.1 (range 0.5-60.2) months with a total of 282.9 patient-years. The rate of major (including fatal) haemorrhagic complications was 4.6% per year, and the rate of fatal haemorrhagic complications was 1.4% per year. The complication rates in the subgroups of patients did not differ significantly from that in the total material. Only two out of the 13 major haemorrhagic complications occurred during the initial 6 months of ACT. No strokes occurred in the TIA subgroup. The rate of recurrent stroke (excluding intracranial haemorrhage) was 3.9% per year for all patients, 4.7% per year for the patients with NVAF, and 4.2% per year for the patients with SIP.

CONCLUSIONS

The total results suggest a positive net effect of ACT in patients with NVAF and TIAs. Without comparable data, no definite conclusions concerning the effect of ACT on patients with SIP can be drawn. The rate of bleeding complications was similar to that in other studied materials and is not negligible. In patients with SIP and TIAs, ACT beyond 6 months should probably only be continued if aspirin is not tolerated or has proven ineffective in the particular patient.

[Closed functional treatment of fractures of the ulnar shaft]

Various treatments of isolated fractures of the ulnar shaft have been attempted. The rates of non-union have varied widely, and impaired movement of the elbow and wrist is common at the end of the treatment. We present a series of eight patients who were treated initially with an above-elbow plaster, followed by a brace on the lower arm. All fractures healed with good functional results.

[Duplication of the small intestine. Unusual cause of abdominal pain]

Duplications of the alimentary tract are rare. Since 1982 only three patients with such anomalies have been treated in the Department of Paediatric Surgery at the University Hospital in Trondheim, Norway. We describe the last patient treated, where duplication of the ileum was found upon laparotomy, performed because of exaggerated recurrent abdominal pain. Duplications may be found anywhere along the alimentary tract and diagnosis can be difficult. The duplications can be found upon laparotomy for suspected appendicitis or bowel obstruction. The condition may also be suspected upon antenatal ultrasonography and in the event of abdominal symptoms after birth.

Influence of CT on tumor classification of laryngeal carcinomas

The routine use of CT in 51 consecutive patients with squamous cell carcinoma of the larynx revealed cartilage involvement or extralaryngeal tumor growth consistent with a T4 tumor which made 14 patients candidates for laryngectomy. Only 5 of these had a T4 classification by clinical examination while 8 cases were upstaged from T3. Except for one supraglottic tumor upstaged from T2 to T4, CT did not change the classification for T1 and T2 tumors, whose localization was mainly glottic, and there were 2 false-negative examinations. It is concluded that CT is mandatory only in advanced tumors of the glottic region or when the anterior commissure is involved. However, in suspected malignancies of the sub- or supraglottic regions CT should always be carried out because these patients are at an increased risk of unexpected deep tumor growth.

[A cerebrovascular unit. Experiences after 8-years of activity]

The authors review experience gained from developing and running a non-intensive stroke unit during the years 1983-91. The number of patients treated per year has increased from 65 to 149. The average length of stay in hospital has dropped from 21 to 15 days. About 87% of the patients had verified stroke, 7% had transient ischemic attacks (TIAs). Other intracranial diseases were found in 3.3%. The mortality rate was low (5%) 48% of the patients were transferred to a rehabilitation centre, 37% were discharged to their homes, with or without out-patient care, and 10% were discharged to nursing homes. Early and systematic investigations and multi-disciplinary rehabilitation in a specialized stroke unit increases the quality of care for patients suffering from stroke. A shorter stay in hospital gives a bonus in the form of reduced health expenditures.