Dynamic four-dimensional computed tomography (4D CT) imaging for re-entry risk assessment in re-do sternotomy - first experience.

BACKGROUND: Repeat cardiac surgeries are well known to have higher rates of complications, one of the important reasons being injuries associated with re-do sternotomy. Routine imaging with CT can help to minimise this risk by pre-operatively assessing the anatomical relation between the sternum and the underlying cardiovascular structures, but is limited by its inability to determine the presence and severity of functional tethering and adhesions between these structures. However, with the evolution of wide area detector MD CT scanners, it is possible to assess the presence of tethering using the dynamic four-dimensional CT (4D CT) imaging technique. METHODS: Nineteen patients undergoing re-do cardiac surgery were pre-operatively imaged using dynamic 4D CT during regulated respiration. The datasets were assessed in cine mode for presence of differential motion between sternum and underlying cardiovascular structures which indicates lack of significant tethering. RESULTS: Overall, there was excellent correlation between preoperative imaging and intraoperative findings. The technique enabled our surgeons to meticulously plan the procedures and to avoid re-entry related injuries. CONCLUSIONS: Our initial experience shows that dynamic 4D CT is useful in risk stratification prior to re-do sternotomy by determining the presence or absence of tethering between sternum and underlying structures based on assessment of differential motion. Furthermore we determined the technique to be superior to non-dynamic assessment of retrocardiac tethering.

The radial artery: Open harvesting technique.

The radial artery is an important conduit in coronary artery surgical revascularization due to its robust long-term clinical outcomes. The use of the radial artery has become popularized in recent times. Therefore it is essential for junior surgeons to master harvest techniques that are safe, reliable, and easy to replicate.

Starting and finishing a cardiac case: Sternotomy, hemostasis, and closure.

The cardiac multimedia literature is abundant, but a significant gap exists in educational videos demonstrating routine essential steps such as the sternotomy or the closure. These components are common and carry significant mortality and morbidity should a sternal complication occur, highlighting the importance for the cardiothoracic surgeon to master these steps.

Video-assisted thoracoscopy in the management of intrapleural extravasation of cytotoxic chemotherapy.

The extravasation of cytotoxic agents into subcutaneous tissue is a serious complication of chemotherapy. Unfortunately, if such extravasation occurs into the pleural space, limited data is available to guide appropriate management. We present the first report in the literature of video-assisted thoracoscopy combined with a topoisomerase II inhibitor and iron chelator, dexrazoxane, in the successful management of this complication.

Custodiol versus blood cardioplegia in complex cardiac operations: an Australian experience.

OBJECTIVES: A single or dual-dose strategy for myocardial protection is attractive in long operations, in avoiding the need to interrupt the procedure to re-administer cardioplegia. We hypothesized that a single administration of Bretschneider histidine-tryptophan-ketoglutarate (HTK) crystalloid solution (Custodiol) offers myocardial protection comparable with repeated tepid blood cardioplegia. METHODS: We reviewed a prospectively compiled single-centre database containing all adult cardiac procedures performed from January 2005 to January 2011. Preoperative demographic and investigative data, operative variables and postoperative (30-day) mortality and morbidity were compared between the Custodiol and blood cardioplegia groups. The study primary endpoints were 30-day mortality, return to the operating theatre, myocardial infarction, stroke, postoperative requirement for an intra-aortic balloon pump, new renal failure, prolonged ventilation and re-admission to hospital within 30 days. Propensity score matching was performed to correct for any bias that may have been associated with the usage of Custodiol. RESULTS: A total of 1900 cardiac surgical procedures were identified of which 126 (7%) utilized Custodiol and 1774 (93%) used blood cardioplegia as the primary cardioplegic agent. After propensity-score matching, we were able to match 71 Custodiol cases one-to-one to those receiving blood cardioplegia. There were no statistically significant differences noted for any of the endpoints studied after propensity-score matching. In particular, the proportion of mortality (blood cardioplegia: 1 vs Custodiol 4%, P = 0.63) any mortality/morbidity (blood cardioplegia: 35 vs Custodiol: 39% P = 0.46) was similar between the groups. CONCLUSIONS: The use of Custodiol is convenient, simple and at least as safe as tepid blood cardioplegia for myocardial protection in complex cardiac operations. A randomized prospective comparison of myocardial protection strategies is warranted.

Gastrointestinal complications after cardiac surgery: 10-year experience of a single Australian centre.

BACKGROUND: Gastrointestinal (GI) complications after cardiac surgery are uncommon, but are associated with high morbidity and mortality as well as significant hospital resource utilization. METHODS: We analysed a prospectively collected database containing all adult cardiac surgery procedures performed from July 2001 to March 2011 at Monash Medical Centre and Jessie McPherson Private Hospital. Patients with post-operative GI complications were compared to patients without GI complications who were operated in the same period. RESULTS: The incidence of GI complications was 1.1% (61 out of 5382 patients) with an overall 30-day mortality of 33% (versus 3% in the non-GI complication group). The most common complications were GI bleeding, gastroenteritis and bowel ischaemia. Patients who had GI complications were significantly older, had higher incidence of renal impairment, chronic lung disease and anticoagulation therapy and were more likely to be in cardiogenic shock. Emergency procedures, combined coronary artery bypass grafting and valve surgery and aortic dissection cases were more common in the GI complication group. The GI complication group also had higher incidence of return to theatre, renal failure, stroke, septicaemia and multi-organ failure. CONCLUSIONS: GI complications after cardiac surgery remain an uncommon but dreadful complication associated with high mortality. Our findings should prompt a high degree of clinical vigilance in order to make an early diagnosis especially in high risk patients. Further studies aiming to identify independent predictors for GI complications after cardiac surgery are warranted.

Baroreflex control of heart rate by oxytocin in the solitary-vagal complex.

Previous work demonstrated that oxytocinergic projections to the solitary vagal complex are involved in the restraint of exercise-induced tachycardia (2). In the present study, we tested the idea that oxytocin (OT) terminals in the solitary vagal complex [nucleus of the solitary tract (NTS)/dorsal motor nucleus of the vagus (DMV)] are involved in baroreceptor reflex control of heart rate (HR). Studies were conducted in male rats instrumented for chronic cardiovascular monitoring with a cannula in the NTS/DMV for brain injections. Basal mean arterial pressure and HR and reflex HR responses during loading and unloading of the baroreceptors (phenylephrine/sodium nitroprusside intravenously) were recorded after administration of a selective OT antagonist (OT(ant)) or OT into the NTS/DMV. The NTS/DMV was selected for study because this region contains such a specific and dense concentration of OT-immunoreactive terminals. Vehicle injections served as a control. OT and OT(ant) changed baroreflex control of HR in opposite directions. OT (20 pmol) increased the maximal bradycardic response (from -56 +/- 9 to -75 +/- 11 beats/min), whereas receptor blockade decreased the bradycardia (from -61 +/- 13 to -35 +/- 2 beats/min). OT(ant) also reduced the operating range of the reflex, thus decreasing baroreflex gain (from -5.68 +/- 1.62 to -2.83 +/- 1.05 beats x min(-1) x mmHg(-1)). OT injected into the NTS/DMV of atenolol-treated rats still potentiated the bradycardic responses to pressor challenges, whereas OT injections had no effect in atropine-treated rats. The brain stem effect was specific because neither vehicle administration nor injection of OT or OT(ant) into the fourth cerebral ventricle had any effect. Our data suggest that OT terminals in the solitary vagal complex modulate reflex control of the heart, acting to facilitate vagal outflow and the slowdown of the heart.