Adam Zimmet

Cadaveric Lobar Lung Transplantation: Technical Aspects

BACKGROUND The use of lobar transplantation and other size reduction techniques has allowed larger donor lungs to be utilized for smaller recipients who tend to have longer waiting times for transplantation. However, despite these advantages, the techniques have not been widely adopted. We outline the surgical and sizing issues associated with this technique. METHODS A retrospective review of 23 consecutive patients who received lung transplantation with anatomic lobar reduction was performed, focusing on surgical technique and outcomes. RESULTS All 23 patients received an anatomic lobar reduction of between 1 and 3 lobes. Survival analysis showed no difference between the lobar reduction cohort and the other historically comparable lung transplant patients from our institution (p=0.115). Percent predicted forced vital capacity and forced expiratory volume in 1 second at 3 months correlated with transplanted donor to recipient total lung capacity ratio, confirming the importance of correct sizing. CONCLUSIONS Anatomic lobar reduction in lung transplantation is a safe and effective means of transplanting pediatric and small adult recipients, and urgently listed patients.

Phrenic Nerve Injury During Cardiac Surgery: Mechanisms, Management and Prevention

Phrenic nerve injury is a well-recognised complication of cardiac surgery that can lead to disabling effects from diaphragmatic dysfunction, especially in children and patients with a history of chronic obstructive airway disease. Various mechanisms of injury have been recognised including hypothermia, mechanical trauma and possibly ischaemia. A clear understanding of these mechanisms is important in order to modify surgical techniques to prevent this serious complication of cardiac surgery.

Carbon dioxide insufflation in open-chamber cardiac surgery: A double-blind, randomized clinical trial of neurocognitive effects

OBJECTIVE The aims of this study were first to analyze neurocognitive outcomes of patients after open-chamber cardiac surgery to determine whether carbon dioxide pericardial insufflation reduces incidence of neurocognitive decline (primary end point) as measured 6 weeks postoperatively and second to assess the utility of carbon dioxide insufflation in cardiac chamber deairing as assessed by transesophageal echocardiography. METHODS A multicenter, prospective, double-blind, randomized, controlled trial compared neurocognitive outcomes in patients undergoing open-chamber (left-sided) cardiac surgery who were assigned carbon dioxide insufflation or placebo (control group) in addition to standardized mechanical deairing maneuvers. RESULTS One hundred twenty-five patients underwent surgery and were randomly allocated. Neurocognitive testing showed no clinically significant differences in z scores between preoperative and postoperative testing. Linear regression was used to identify factors associated with neurocognitive decline. Factors most strongly associated with neurocognitive decline were hypercholesterolemia, aortic atheroma grade, and coronary artery disease. There was significantly more intracardiac gas noted on intraoperative transesophageal echocardiography in all cardiac chambers (left atrium, left ventricle, and aorta) at all measured times (after crossclamp removal, during weaning from cardiopulmonary bypass, and at declaration of adequate deairing by the anesthetist) in the control group than in the carbon dioxide group (P < .04). Deairing time was also significantly longer in the control group (12 minutes [interquartile range, 9-18] versus 9 minutes [interquartile range, 7-14 minutes]; P = .002). CONCLUSIONS Carbon dioxide pericardial insufflation in open-chamber cardiac surgery does not affect postoperative neurocognitive decline. The most important factor is atheromatous vascular disease.

Surgical management of tricuspid valve endocarditis in the current era: A review

The incidence of isolated tricuspid valve infective endocarditis is increasing. Medical management is the mainstay of treatment but surgical intervention is required in a subset of patients. Surgical treatment options include valve excision and replacement or valve reconstruction. We searched PubMed and the Cochrane library to identify articles to be included in this review of surgical outcomes. References of selected articles were crosschecked for other relevant studies. Surgical management of tricuspid valve endocarditis can be achieved with satisfactory outcomes. However, the optimal indication and timing of surgery remain unclear, and the frequent association with intravenous drug use complicates management. Repair techniques are preferable though there is no clear evidence supporting one method over another.

Prospective, randomized, controlled trial of polymer cable ties versus standard wire closure of midline sternotomy

Objective Midline sternotomy remains the most common access incision for cardiac operations. Traditionally, the sternum is closed with stainless steel wires. Wires are well known to stretch and break, however, leading to pain, nonunion, and potential deep sternal wound infection. We hypothesized that biocompatible plastic cable ties would achieve a more rigid sternal fixation, reducing postoperative pain and analgesia requirements. Methods A prospective, randomized study compared the ZIPFIX (De Puy Synthes, West Chester, Pa) sternal closure system (n = 58) with standard stainless steel wires (n = 60). Primary outcomes were pain and analgesia requirements in the early postoperative period. Secondary outcome was sternal movement, as assessed by ultrasound at the postoperative follow‐up visit. Results Groups were well matched in demographic and operative variables. There were no significant differences between groups in postoperative pain, analgesia, or early ventilatory requirements. Patients in the ZIPFIX group had significantly more movement in the sternum and manubrium on ultrasound at 4 weeks. Conclusions ZIPFIX sternal cable ties provide reliable closure but no demonstrable benefit in this study in pain or analgesic requirements relative to standard wire closure after median sternotomy.

A novel combination technique of cold crystalloid perfusion but not cold storage facilitates transplantation of canine hearts donated after circulatory death

BACKGROUND Donation after circulatory death (DCD) represents a potential new source of hearts to increase the donor pool. We showed previously that DCD hearts in Greyhound dogs could be resuscitated and preserved by continuous cold crystalloid perfusion but not by cold static storage and could demonstrate excellent contractile and metabolic function on an in vitro system. In the current study, we demonstrate that resuscitated DCD hearts are transplantable. METHODS Donor Greyhound dogs (n = 12) were divided into perfusion (n = 8) and cold static storage (n = 4) groups. General anesthesia was induced and ventilation ceased for 30 minutes to achieve circulatory death. Donor cardiectomy was performed, and for 4 hours the heart was preserved by controlled reperfusion, followed by continuous cold perfusion with an oxygenated crystalloid perfusate or by static cold storage, after which orthotopic heart transplantation was performed. Recovery was assessed over 4 hours by hemodynamic monitoring. RESULTS During cold perfusion, hearts showed continuous oxygen consumption and low lactate levels, indicating aerobic metabolism. The 8 dogs in the perfusion group were weaned off bypass, and 4 hours after bypass produced cardiac output of 4.73 ± 0.51 liters/min, left ventricular power of 7.63 ± 1.32 J/s, right ventricular power of 1.40 ± 0.43 J/s, and left ventricular fractional area shortening of 39.1% ± 5.2%, all comparable to pre-transplant values. In the cold storage group, 3 of 4 animals could not be weaned from cardiopulmonary bypass, and the fourth exhibited low-level function. CONCLUSIONS Cold crystalloid perfusion, but not cold static storage, can resuscitate and preserve the DCD donor heart in a canine model of heart transplantation, thus rendering it transplantable. Controlled reperfusion and cold crystalloid perfusion have potential for clinical application in DCD transplantation.

Pericardial Synovial Sarcoma: A Rare Clinical Entity

Synovial sarcoma is an extremely rare form of primary malignancy of the pericardium. We present a case of primary synovial sarcoma of the pericardium followed by a review of the literature.

Improving the Exposure of the Left Hilum for Lung Transplantation: The Value of a Simple Pericardial Stitch.

We read with interest the recently published article by Calcaterra and colleagues [1] on their surgical technique of exposure of a difficult left lung hilum during bilateral sequential lung transplantation, especially in the setting of idiopathic pulmonary fibrosis (IPF). The authors have adopted a technique used during off-pump coronary artery bypass procedures to facilitate the exposure of the left lung hilum. After pericardiotomy, the authors have used a pericardial stitch, an episiotomy pack, and a snugger to lift the heart. The authors use their technique in the setting of IPF to expose the left lung hilum to avoid mechanical retraction of the heart and the associated hemodynamic compromise, which may need cardiopulmonary bypass support. The authors are to be congratulated on their description of an elegant technique. We would like to describe a simple technique for the exposure of the left lung hilum during lung transplantation to avoid mechanical retraction of the heart, which achieves the same result as the technique used by Calcaterra and colleagues. In general, we routinely use a bilateral anterolateral thoracotomy incision without division of the sternum during bilateral sequential lung transplantation. We agree with the authors on the issue of selective use of cardiopulmonary bypass in the setting of severe pulmonary hypertension. We use a 0 or 20 pledgetted braided suture passed through the pericardium near the apex of the heart, inferior to the left hilum and posterior to the left phrenic nerve (Fig 1). The suture is placed under tension by attaching it to the drapes on the right side. This rotates and dislocates the heart toward the right side and also brings up the hilum toward the thoracotomy wound. As a result, no mechanical retraction is required during pneumonectomy and lung implantation. Our technique can be used routinely during left lung transplantation and more so in patients with difficult exposure of the left lung hilum, as in IPF.

Novel Sternal Protection Device for Cardiac Surgery Via Median Sternotomy Incision

Objective Sternal bleeding during cardiac surgery is currently controlled using bone wax or other chemical substances that may result in adverse effects and affect wound healing and recovery. The purpose of this study was to identify a safe, cost-effective, and easy-to-use technique to reduce sternal bleeding and sternal trauma during cardiac surgery. Methods After sternotomy, a sternal protection device was placed over each hemisternal section before insertion of the retractor and remained in situ until the end of surgery. Sternal bleeding and ease of use were assessed and recorded during surgery. Sternal trauma was assessed and recorded within 5 minutes of removal of the device, and overall satisfaction (Global Impression) and any intraoperative adverse events or device malfunction were reported at surgery completion. Patients were followed up 24 hours and 4 weeks after surgery. Results Twelve patients completed the study. Adverse events reported were not considered related to the device. No sternal trauma was identified in any patient. In 9 of 11 patients, sternal bleeding was reduced after insertion of the device. The device was generally considered easy to use, although some difficulty was encountered when used with the Internal Mammary Artery retractor. Conclusions Our data suggest that the device is safe and able to reduce sternal bleeding during surgery using sternal retractors. We recommend further studies in a larger population of patients with a control group to evaluate the devices ability to reduce the morbidity associated with sternal bleeding and sternal trauma.

Donor Lung Procurement by Surgical Fellow with an Expectation of High Rate of Lung Utilisation

There is an ever increasing demand for donor lungs in patients waiting for transplantation. Lungs of many potential donors will be rejected if the standard criteria for donor assessment are followed. We have expanded our donor lung pool by accepting marginal donors and establishing a donation after circulatory death program. We have achieved comparable results using marginal donors and accepting donor lungs following donation after circulatory death. We present our assessment and technical guidelines on lung procurement taking into consideration an increasingly complex cohort of lung donors. These guidelines form the basis of the lung procurement training program involving surgical Fellows at the Alfred Hospital in Melbourne, Australia.