Reduction of postoperative hypothermia with a new warming device: a prospective randomized study in off-pump coronary artery surgery

Hypothermia has been used for decades in cardiac surgery to limit the ischemic insult to the heart. With the diffusion of off-pump coronary artery surgery, the practice of arresting and cooling the heart has been abandoned. At University of Miami Miller School of Medicine, we tested a new warming device by performing a prospective study in which 50 patients were randomized to either the use of the Kimberly-Clark warming system or to standard methods of control of body temperature. The two groups were compared in terms of core body temperature (CBT), intra- and postoperative blood loss, blood products transfusions, extubation time, intensive care unit (ICU) and hospital length of stay and incidence of infections. Five patients in the control group and 0 patients in the study group dropped their CBT below 35 degrees C during the operation (P<0.01). Total blood loss, measured in terms of cell-saver and chest tube drainage, was 27 % and 14 % less for the study group (P<0.01). Hospital length of stay was 1.2 day less in the study group (P<0.01). The Kimberly-Clark Patient Warming System allowed for better control of core body temperature during off pump coronary artery bypass surgery compared to traditional techniques. This translated in less intra and postoperative blood loss and shorter hospital length of stay. Other advantages, such as decreased blood-products transfusions, decreased incidence of infections, decreased ICU length of stay and overall reduction of costs might be evident on larger study groups.

Case report of cardiac arrest, abdominal compartment syndrome, and thoracic aortic injury with endovascular repair of thoracic aortic tear

The introduction of thoracic endografts has revolutionized the management of thoracic aortic disease. Currently, endografts are not FDA-approved for treating thoracic aortic injury (TAI). We report a case of TAI who presented in hemorrhagic shock and preoperative cardiac arrest who was successfully treated with large volume resuscitation, closed chest cardiac massage, exploratory laparotomy, and thoracic endografting.

Endovascular Repair of Thoracic Aortic Tears

BACKGROUND

Standard treatment of traumatic thoracic aortic transection (TTAT) is open repair by left thoracotomy with or without the use of partial cardiopulmonary bypass. However, open repair is associated with high rates of morbidity and mortality, particularly in multiply injured trauma patients. We reviewed our experiences of endovascular repair of acute TTAT.

METHODS

Between February 2001 and February 2006, 30 patients (male 24, female 6, mean age 43 years) who had sustained severe blunt trauma with multiple injuries (mean injury severity score = 42) underwent endovascular repair for TTAT. Devices used included commercially available proximal abdominal aortic extension cuffs and thoracic stent-grafts. Either low dose or no systemic heparin was used. Arterial access was obtained by femoral-iliac cutdown (n = 19) or completely percutaneous through the femoral artery (n = 11). Mean follow-up was 11.6 months (range, 1 to 48 months).

RESULTS

Technically success was achieved in 100% of patients, as determined by angiographic and computed tomographic (CT) scan exclusion of TTAT. Mean operating time was 132 minutes. Mean blood loss was 300 cm3. Three patients had complications: 1 iliac artery rupture, 1 cerebellar stroke, and 1 partial stent collapse. There were 2 perioperative deaths. There were no instances of procedure-related paralysis. Clinical and CT follow-up did not reveal evidence of endoleak, stent migration, or late pseudoaneurysm formation.

CONCLUSIONS

The adaptation of commercially available stent-graft devices to treat TTAT is technically feasible, and can be performed with low rates of morbidity and mortality. The long-term durability of endovascular repair of TTAT remains unknown, but early and midterm results appear promising.

Off-Pump Coronary Artery Grafting in Patients with Left Main Coronary Artery Disease

BACKGROUND

Left main coronary artery disease (LMCD) is considered a relative contraindication to off-pump coronary artery bypass (OPCAB) grafting. This study evaluates the safety and feasibility of OPCAB in these patients compared to an on-pump group (cardiopulmonary bypass, CPB) with LMCD.

METHODS

Between January 2000 and July 2002, 95 patients with left main coronary artery stenosis >50% underwent coronary revascularization. Seventy-three unselected patients underwent OPCAB and 22 underwent revascularization using CPB. The techniques used for OPCAB included the use of deep traction sutures in the posterior pericardium and stabilizers to expose the distal coronary targets. Intraluminal coronary shunts were routinely used during construction of the anastomoses. Variables were analyzed using a Student's paired t-test with statistical significance defined as p < 0.05.

RESULTS

The mean age in the OPCAB group was 59.9 years and the CPB group 61.8 years (p = 0.54). There were 56 males (77%) in the OPCAB and 18 (82%) in the CPB groups. Mean preoperative left ventricular ejection fraction (LVEF) was 40.3% in OPCAB and 47.3% in CPB (p = 0.015). Average number of grafts was 3.1 in OPCAB and 4.1 in CPB (p = 0.0038). There were no conversions to CPB in those patients initially chosen to undergo OPCAB. There were no early deaths in OPCAB. There was one death in CPB. Mean hospital length of stay was 6.9 days for OPCAB and 9.1 for CPB (p = 0.0159).

CONCLUSIONS

Patients with LMCD can undergo OPCAB grafting safely and effectively despite reduced LVEF. LMCD should no longer be seen as a contraindication to perform OPCAB grafting.

The History and Development of Direct Coronary Surgery without Cardiopulmonary Bypass*

The history of direct myocardial revascularization without cardiopulmonary bypass dates to 1961 in the dawn of coronary artery surgery. With the introduction and development of techniques of extracorporeal circulation around the same time, beating heart surgery was largely abandoned. Over the subsequent decades, cardiopulmonary bypass and electromechanical cardioplegic arrest became popular as means of revascularization in a bloodless and motionless field. While coronary artery surgery on the arrested heart remained undisputed for decades, myocardial revascularization on the beating heart was pursued by a few pioneering surgeons around the world, based on the belief that coronary revascularization could be performed equally well without the detrimental effects of cardiopulmonary bypass and electromechanical arrest. Various concepts and techniques developed during the 1980s by these pioneers enabled minimally invasive coronary surgery to be performed in the early 1990s. This break from the mainstream allowed selective myocardial revascularization using a minimal incision and no cardiopulmonary bypass to develop and constructed a base for future extensive revascularizations off-pump. With the subsequent explosion of new techniques for coronary exposure and myocardial stabilization, complete revascularization without cardiopulmonary bypass became possible with consistent results. Emerging from the preview of only a few surgeons just a decade ago, off-pump surgery is currently one of the accepted modalities for complete myocardial revascularization worldwide. This paradigm shift in the approach to myocardial revascularization has led to exiting new future possibilities, such as beating heart totally endoscopic coronary artery surgery.

Redo-OPCAB via left thoracotomy using symmetry aortic connector system: a report of two cases

Left thoracotomy is an established approach for redo coronary artery bypass grafting (CABG). This approach has also been successfully used in off-pump coronary artery bypass (OPCAB). Traditionally, the grafts have been anastomosed proximally to the descending thoracic aorta or the left subclavian artery. Recently, proximal connectors have been introduced by various manufacturers for use on ascending aorta during primary CABG and OPCAB. One such device is the Symmetry aortic connector system (St. Jude Medical, Minneapolis, MN). These devices have obviated the need for partial occluding clamps for the construction of the proximal anastomoses and hence are extremely useful when the aorta is heavily calcified. We used this device successfully in two patients undergoing redo-OPCAB, where the proximal anastomosis was constructed on the descending aorta. In so doing, we also used the shortest possible length of vein graft since the descending aorta at that level was much closer than the left subclavian artery. This can be an additional factor in redo-operations where the availability of vein can be an issue.

Beating-heart valve surgery in patients with renal failure requiring hemodialysis

BACKGROUND AND AIM OF THE STUDY

The safety and efficacy of beating-heart valve surgery as a myocardial protection strategy was evaluated in patients with renal failure requiring hemodialysis.

METHODS

This was a retrospective review of nine patients (four males, five females; mean age 46.7 years; mean duration of hemodialysis 47 +/- 49 months) who underwent beating-heart valve surgery at the present authors' institution between April 2000 and September 2002.

RESULTS

The mean cardiopulmonary bypass time was 77.2 +/- 8 min. Perioperatively, two patients died (one from sepsis; one from complication of anticoagulation). There were no deaths in the follow up since discharge, with average follow up 18.3 months (range: 9-27 months). Other complications included reintubation for <24 h (one case), AV graft thrombosis (one patient) and stroke (one patient, as mentioned above). There were no new cardiac (including arrhythmia and low cardiac output syndrome) or metabolic complications (including hyperkalemia and fluid overload).

CONCLUSION

This is the first report of beating-heart valve surgery using simultaneous antegrade and retrograde perfusion with normothermic blood. Despite being small in size, the study demonstrated the safety of this approach in a high-risk population with renal failure requiring hemodialysis. The results suggested a low incidence of complications, and short ICU and hospital stays.

Initial experience with sutureless proximal anastomoses performed with a mechanical connector leading to clampless off-pump coronary artery bypass surgery

BACKGROUND

We report our early experience with the Symmetry Aortic Connector (St. Jude Medical, St. Paul, MN) used for sutureless proximal aortosaphenous vein graft anastomoses without any cross clamp during coronary bypass procedures.

METHODS

Between November 2001 and August 2002, 206 saphenous vein to aorta proximal anastomoses were created in 132 patients using the Symmetry device. All procedures were performed as part of off-pump coronary artery bypass surgery without any aortic clamping. Intraoperative variables and postoperative data were collected and analyzed retrospectively.

RESULTS

All 206 anastomoses (100%) were successfully completed with the connector. Severe atherosclerotic disease of the aorta was documented in 16 patients (12%). Four anastomoses (2%) required additional suture placement. Predeployment problems occurred with 3 grafts (2.5%) during loading of the connector. Average number of distal bypasses was 3.2 per patient. One patient (0.7%) required reoperation for bleeding from a proximal anastomosis. Six patients (4.5%) had perioperative myocardial infarction documented by electrocardiographic changes. Thirty-day operative mortality was 3% (4 patients). Intraoperative transit time flow measurement was performed in all cases (100%). Postoperative angiography in 43 patients at a median 3 months postoperatively revealed occlusion of 9 of the 81 saphenous vein grafts (11%).

CONCLUSIONS

The initial experience with a proximal saphenous vein graft to aorta anastomosis using the Symmetry connector demonstrates safety and ease of use. There is however some concern with early graft closure. A prospective randomized study is needed to clarify these concerns.

Novel use of an FDA-approved BiVAD for total cardiopulmonary support

We describe the use of an Abiomed BVS 5000i with an oxygenator spliced into the right side for total cardiopulmonary support after orthotopic heart transplantation. As compared to ECMO, we believe that the mechanical ventricular unloading seen with this type of assist device increases the likelihood of myocardial recovery. This report demonstrates that even with an in-line oxygenator, adequate flow can be delivered to both the RVAD and LVAD, providing complete cardiopulmonary support.

Factors affecting late survival after surgical remodeling of left ventricular aneurysms

OBJECTIVES

Surgical remodeling of the left ventricle has involved various techniques of volume reduction. This study evaluates factors that influence long-term survival results with 3 operative methods.

METHODS

From 1979 to 2000, 157 patients (134 men, mean age 61 years) underwent operations for class III or IV congestive heart failure, angina, ventricular tachyarrhythmia, and sudden death after anteroseptal myocardial infarction. The preoperative ejection fraction was 28% +/- 0.9% (mean +/- standard error), and the pulmonary artery occlusive pressure was 15 +/- 0.07 mm Hg. Cardiogenic shock was present in 26 patients (16%), and an intra-aortic balloon pump was used in 48 patients (30%). The type of procedure depended on the extent of endocardial disease and was aimed at maintaining the ellipsoid shape of the left ventricle cavity. In group I patients (n = 65), radical aneurysm resection and linear closure were performed. In group II patients (n = 70), septal dyskinesis was reinforced with a patch (septoplasty). In group III patients (n = 22), ventriculotomy closure was performed with an intracavitary oval patch.

RESULTS

Hospital mortality was 16% (25/157) and was similar among the groups. Actuarial survival up to 18 years was better with a preoperative ejection fraction of 26% or greater (P =.004) and a pulmonary artery occlusive pressure of 17 mm Hg or less (P =.05). Survival was worse in patients who had intra-aortic balloon pump support (P =.03). Five-year survival for all patients in group III was higher than for patients in group II (67% vs 47%, P =.04).

CONCLUSIONS

Factors that improved long-term survival after left ventricular surgical remodeling were intraventricular patch repair, preoperative ejection fraction of 26% or greater, and pulmonary artery occlusive pressure of 17 mm Hg or less without the need for balloon pump assist.

Thoracic malignancies associated with AIDS

The immunocompromised state is a major risk factor for the development of malignant tumors. Individuals with human immunodeficiency virus (HIV), and acquired immunodeficiency syndrome (AIDS) represent a large segment of the immunocompromised group of patients. Kaposi's sarcoma, B-cell non-Hodgkin's lymphoma, primary central nervous system lymphoma, and invasive cervical carcinoma are malignant tumors that are all AIDS-defining illnesses. Lung cancer is also seen with a higher frequency in AIDS patients. Malignant tumors are more aggressive in this group of patients as compared with the general population. Prognosis is poor, although with the improved survivals seen with new treatment in these patients, aggressive therapy is still warranted.

Oral amiodarone reduces incidence of postoperative atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is a common occurrence after heart operations that use cardiopulmonary bypass. It can cause life-threatening complications as well as delay discharge and increase hospitalization costs. The purpose of this study was to evaluate the effect of orally administered low-dose amiodarone on the incidence of new onset postoperative AF.

METHODS

In this prospective study, 226 consecutive adult patients (group A) who had various heart operations utilizing cardiopulmonary bypass between April and November of 1998 at the University of Miami/Jackson Memorial Hospital, were given oral amiodarone (200 mg three times a day), starting immediately after arrival in the intensive care unit until the day of hospital discharge. The incidence of new AF in this group of patients was assessed and compared with a historical group of 239 patients (group B) who had had cardiac operations with cardiopulmonary bypass in the preceding 9 months at the same institution.

RESULTS

Preoperative patient characteristics and procedure types were similar in the two groups. Among the 226 patients in group A, 13 (5.7%) had history of AF. Of the remaining 213 patients, new-onset AF occurred postoperatively in 10 (4.7%). Among the 239 patients in group B, 16 (6.7%) had history of AF. Of the remaining 223 patients, 44 (19.7%) developed new-onset AF (p < 0.001). Group A patients had a shorter length of hospital stay than those in group B (6.5 versus 7.8 days) but had a similar incidence of complications other than AF (23 of 226 patients in group A versus 24 of 239 in group B). The drug was well tolerated.

CONCLUSIONS

Postoperative low-dose amiodarone given orally to patients who had cardiopulmonary bypass was well tolerated and appeared to reduce the incidence of new-onset AF and decrease the length of hospital stay.

Malignancies associated with the immunocompromised state

Neoplastic disease occurs more frequently in immunocompromised patients than in the general population. These tumors occur at an earlier age and behave more aggressively. Their origin is linked to viral infection and other causes of immunodeficiency, such as antirejection drugs. Despite aggressive therapy, these patients have a poor prognosis when compared with immunocompetent individuals with similar tumors.

Surgical management of empyema

The cause and presentation of empyema thoraces has changed little since it was first described. The natural history of the disease can be divided into different stages. Different therapeutic measures, medical and surgical, are available for the treatment at various stages. The management of empyema is discussed, emphasizing the surgical aspects.

Malignant tracheo-esophageal fistula: use of esophageal endoprosthesis

Malignant tracheo-esophageal fistula (TEF) is a serious complication of cancer arising usually in the esophagus, lung, or tracheobronchial tree. Repeated aspiration and pneumonia lead to rapid deterioration and death. The prognosis is dismal and curative resections are curiosities. Surgical bypass of the lesion has been performed but is associated with 25-61% mortality. Other treatments have been employed, such as enterostomies, esophageal endoprostheses, and supportive care. The reported mortality of palliative procedures using endoprostheses, surgical bypass, or exclusion in almost identical. A retrospective review of the data over the past decade revealed a trend toward insertion of endoprostheses. Insertion of endoprostheses can be performed in an endoscopy suite, under sedation, and has fewer major complications than occur with a surgical approach. The periprocedure mortality rate for these patients is 15%, compared to a 29-47% perioperative mortality for patients undergoing surgery. Even so, patients after surgical procedures could survive for 8 months or more, which is better than survival after endoprosthesis intubation. We conclude that insertion of an esophageal endoprosthesis should be the usual preferred option for palliative treatment of malignant TEF. However, for special candidates a surgical procedure is a valid option.

Complications of transhiatal esophagectomy

A total of 23 papers published between 1981 and 1992, reporting a total of 1,353 patients, were reviewed for intraoperative and postoperative complications of transhiatal esophagectomy. Intraoperative complications included massive bleeding, tracheal injuries, cardiac arrhythmias, and incidental splenectomies. Even though the chest was not opened, the commonest postoperative complications were pulmonary. Leakage from the cervical anastomosis was seen in as many as 15% of all patients, but almost all resolved spontaneously. Postoperative benign strictures were seen in almost as many patients. Hoarseness due to recurrent laryngeal nerve injury, symptomatic gastro-esophageal reflux, chylothorax, Horner's syndrome, subphrenic abscess, hiatal hernia, and biliary cutaneous fistula were some of the other postoperative complications. An overview of these complications is presented, along with suggested methods of avoiding them and their treatment. The overall mortality for the 1,353 patients was 7.17%.