Repair of adult Scimitar syndrome with an intra-atrial conduit.

The management of Scimitar syndrome in adulthood is controversial, with no guidelines for surgical correction. We present the case of a 66-year-old woman who presented late in life with Scimitar syndrome and a significant left-to-right shunt. We describe repair using an intra-atrial conduit from the anomalous vein to the foramen ovale, with a successful outcome.

Fatigue testing median sternotomy closures.

OBJECTIVE: Sternal dehiscence is commonly due to wire cutting through bone. With a biological model, we measured the rate of cutting through bone, of standard steel wire closure, peristernal steel wire, figure-of-eight closure, polyester and sternal bands sternotomy closure techniques. METHODS: Polyester, figure-of-eight, peristernal and sternal band closures were tested against standard closure eight times using adjacent paired samples, to eliminate biological variables. Fatigue testing was performed by a computerized materials-testing machine, cycling between loads of 1 and 10 kg. The displacements at maximum and minimum loads were measured during each cycle. Cutting through, manifested by the displacement at the maximum load between the 1st and 150th cycles was measured. The percentage cut-through of each closure method versus standard closure was calculated. RESULTS: The differences in the displacement between each of the polyester (1.01 mm), figure-of-eight (0.52 mm), peristernal (0.72 mm) and sternal band (0.66 mm) groups versus standard closure (0.22, 0.22, 2.1, 3.2 mm) in the paired samples were statistically significant (Student's paired t-test; P<0.01). There were statistically significant differences in the percentage cut-through of polyester, figure-of-eight, peristernal and sternal bands (ANOVA, P<0.001), versus standard closure. CONCLUSIONS: In our sheep sternum model, we have quantified the differing rate of cutting through bone of five types of median sternotomy closure techniques. We have controlled for bone variables by testing each closure versus standard closure using paired adjacent bone samples. Peristernal and sternal band closure techniques are significantly superior to standard closure. The use of polyester and figure-of-eight closures requires caution.

Pericardiectomy using an oscillating saw.

We describe the use of a microoscillating saw on the heart to remove calcific pericardium. This microoscillating saw proved indispensable to achieve a safe pericardiectomy in a 55-year-old woman with thick, severe idiopathic calcific constrictive pericarditis.

Routine sternal closure using interlocking multitwisted wires.

We describe a method of sternal closure that enhances sternal stabilization and minimizes bleeding from sternal fractures caused by retraction. With the technique of interlocking multitwisted wires the initial placement of the wire sutures is the same as in traditional sternal closure, however the twisting technique is improved, with multiple twisting including four twisted strands. Our method of closure is effective, simple and quick to perform and has several advantages over conventional or figure-of-eight closure. This closure is also biomechanically more rigid than conventional or figure-of-eight closure. We therefore recommend routine sternal closure using interlocking multitwisted wires.

A biomechanical study of median sternotomy closure techniques.

OBJECTIVE: Sternal dehiscence is a complication of median sternotomy incisions with high mortality and morbidity. Different techniques of sternal closure have been described. Rigid fixation of the sternum results in earlier union. We measured the rigidity of sternotomy fixation using a mechanical model in order to differentiate different techniques of sternal closure using their biomechanical characteristics. METHODS: We measured the force-displacement curves of six different fixation techniques using a metal sternal model using a computerized materials-testing machine. We tested straight wires (the most commonly used surgical technique), figure-of-8 wires, 'repair' technique (used when a wire breaks), Ethibond, Sterna-band and a 'multitwist' closure described for the first time. RESULTS: At 20 kg force, twisted wires used for sternotomy closures start to untwist. The most rigid closure was a multitwist closure that displaced only 0.37 mm at a force of 20 kg. Straight wires displaced 0.78 mm, figure-of-8 wires 1.20 mm, Sterna-band 1.37 mm, repair wires 5.08 mm, Ethibond 9.37 mm. The single factor Anova test for the rigidity of the different closures had P-values <0.0001. CONCLUSIONS: We applied a mathematical model to calculate chest wall forces during coughing, in order to determine the force placed upon a sternotomy closure. We conclude that severe coughing may cause wires to untwist. We discuss potential applications of different wire closures based on their characteristics.

Intestinal infarction following carbon monoxide poisoning.

A 65 year old patient admitted with carbon monoxide poisoning developed acute pulmonary oedema during treatment with hyperbaric oxygen. After initial recovery he developed extensive intestinal ischaemia which rapidly led to death. It is suggested that intestinal vasoconstriction due to left ventricular failure made the gut much more vulnerable to the hypoxic effects of carbon monoxide than the brain and heart.