Do vascular surgery patients need a cardiology work-up? A review of pre-operative cardiac clearance guidelines in vascular surgery.

OBJECTIVES: to outline the appropriate pre-operative cardiac work-up for patients who are scheduled for major peripheral vascular surgery. DESIGN: review of the literature. MATERIALS AND METHODS: a review of the literature focusing on studies that have correlated the pre-operative cardiac work-up patients receive to the cardiac morbidity and mortality following vascular surgery. Only studies with level A evidence were included. RESULTS: peri-operative beta blockade has been shown to decrease cardiac complications after vascular surgery in all risk groups. Non-invasive cardiac testing is only necessary for patients in the intermediate/high risk group. Coronary revascularization should only be considered after a positive non-invasive cardiac test. CONCLUSIONS: patients must be risk stratified pre-operatively based on history and physical examination. Low risk patients should receive peri-operative beta blockade only with no further non-invasive testing. On the other hand, intermediate and high risk patients should undergo non-invasive cardiac testing before going to the operating room.     

Characteristics and outcomes of recurrent atrial fibrillation after prior failed pulmonary vein isolation

Journal of Interventional Cardiac Electrophysiology - The mechanisms for atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) catheter ablation are unclear. Non-PV organized...     

The Production and Characterization of Novel Heavy-Chain Antibodies Against the Tandem Repeat Region of MUC1 Mucin

Camelidae are known to produce immunoglobulins (Igs) devoid of light chains and constant heavy-chain domains (CH₁). Antigen-specific fragments of these heavy-chain IgGs (VHH) are of great interest in biotechnology applications. This paper describes the first example of successfully raised heavy-chain antibodies in Camelus dromedarius (single-humped camel) and Camelus bactrianus (two-humped camel) against a MUC1 related peptide that is found to be an important epitope expressed in cancerous tissue. Camels were immunized against a synthetic peptide corresponding to the tandem repeat region of MUC1 mucin and cancerous tissue preparation obtained from patients suffering from breast carcinoma. Three IgG subclasses with different binding properties to protein A and G were purified by affinity chromatography. Both conventional and heavy-chain IgG antibodies were produced in response to MUC1-related peptide. The elicited antibodies could react specifically with the tandem repeat region of MUC1 mucin in an enzyme linked immunosorbant assay (ELISA). Anti-peptide antibodies were purified after passing antiserum over two affinity chromatography columns. Using ELISA, immunocytochemistry and Western blotting, the interaction of purified antibodies with different antigens was evaluated. The antibodies were observed to be selectively bound to antigens namely: MUC1 peptide (tandem repeat region), human milk fat globule membrane (HMFG), deglycosylated human milk fat globule membrane (D-HMFG), homogenized cancerous breast tissue and a native MUC1 purified from ascitic fluid. K_a values of specific polyclonal anti-peptide antibodies were estimated in C. dromedarius and C. bactrianus, as 7 × 10¹⁰ M^{? 1} and 1.4 × 10¹⁰ M^{? 1} respectively.     

Association of scientific and nonscientific factors to citation rates of articles of renowned orthopedic journals

Purpose

The physician often relies on the prestige of a journal to identify the most relevant articles to be read in his field. This investigation studied associations of scientific and nonscientific criteria with the citation frequency of articles in two top-ranked international orthopedic journals.

Methods

The 100 most (mean, 88 citations/5 years for cases) and 100 least (mean, two citations/5 years for controls) cited articles published between 2000 and 2004 in the Journal of Bone and Joint Surgery and the Bone & Joint Journal (formerly known as JBJS (Br)), two of the most distributed general orthopedic journals, were identified. The association of scientific and nonscientific factors on their citation rate was quantified.

Results

Randomized controlled trials, as well as multicenter studies with large sample sizes, were significantly more frequent in the high citation rate group. The unadjusted odds of a highly cited article to be supported by industry were 2.8 (95 % confidence interval 1.5, 5.6; p?<?0.05) if compared with a lowly cited article.

Conclusion

Beside scientific factors, nonscientific factors such as industrial support seem associated to the citation rate of published articles. This, together with publication bias, questions whether scientific facts reach the readers in a balanced fashion. Level of Evidence 3     

Real-time assessment of anteroposterior stability of spinal segments

Purpose

While anteroposterior instability of spinal segments is regarded as an important biomechanical aspect in the clinical evaluation of lumbar pathologies, the reliability of the available diagnostic tools is limited and an intraoperative method to quantify stability is lacking. The aim of this study was to develop and validate an instrument to measure the anteroposterior stability of a spinal segments in real-time.

Methods

Torsi of five fresh-frozen human cadavers were used for this study. After pedicle screw insertion, a specifically modified reposition tool composed with load and linear sensors was used to measure the segmental anteroposterior motion caused by 100 N anterior and posterior force during 5 loading cycles on either side of the instrumentation by two different operators. The spinal segments were then resected from the torsi and anteroposterior loading with ± 100 N was repeated in an advanced biomechanical spine testing setup as a reference measurement. The Inter-correlation coefficient (ICC) was used for validation of the “intraoperative” device.

Results

Inter-operator repeatability of the measurements showed an ICC of 0.93 (p < 0.0001) and the bilateral (left–right) comparison had an ICC of 0.73 (p < 0.0001). The ICC resulting from the comparison to the reference measurement was 0.82 (p < 0.0001) without offset correction, and 0.9 (p < 0.0001) with offset correction. The ICC converged at this value already after two of the five performed loading cycles.

Conclusion

An accurate and reliable measurement tool is developed and validated for real-time quantification of anteroposterior stability of spinal segments and serves as a basis for future intraoperative use.