Cardioplegia Application with A Hand-Squeezed Cardioplegia Bag. Is It Safe?

OBJECTIVES: Cardioplegia solutions have a role not only in arresting the heart but also in protecting the myocardium from ischemia. While antegrade cardioplegia is given by the heart-lung machine in many centers, it is given by a hand-squeezed bag in very few centers. The pressure of cardioplegia given antegrade from the heart-lung machine is certain (60-90 mmHg). The pressure applied in the cardioplegia method, which is given antegrade with a hand-squeezed bag, is uncertain and variable. We compared the antegrade cardioplegia method applied with a hand-squeezed bag with the antegrade cardioplegia method applied with a roller pump from the heart-lung machine in terms of protecting the myocardium from ischemia. METHODS: Seventy-six patients who did not have an acute myocardial infarction, had normal preoperative cardiac marker (troponin and CK-MB) values, did not undergo redo open heart surgery, had an ejection fraction of 50% and above, and underwent elective two or three-vessel isolated coronary artery bypass surgery were evaluated. While tepid (30-32°C) blood cardioplegia was administered antegrade to 33 patients (Group A) with a hand-squeezed bag, the other 34 patients (Group B) received tepid (30-32°C) antegrade blood cardioplegia from the heart-lung machine. The perioperative and postoperative data of the patients were recorded and compared. To evaluate myocardial damage, postoperative cardiac markers and echocardiography data were evaluated and compared at the fourth hour after the cross-clamp was removed in both groups. RESULTS: When evaluated in terms of preoperative demographic data, preoperative mean EF values and intraoperative data, there was no statistical difference between both groups. When we evaluated in terms of myocardial protection, the mean TnT level was 4.31 ± 1.95 at the 4th hour in Group A and 3.91 ± 1.69 in Group B. Mean 4th hour CK-MB level was 40.84 ± 9.07 in Group A and 38.56 ± 8.07 in Group B. Mean change in EF (%) was -4.09 ± 4.41 in Group A and 3.53 ± 4.53 in Group B. In line with the current data when we evaluated in terms of myocardial protection, we found that there is no statistical difference between the two groups (P = 0.373; P = 0.158; P = 0.523). There was no statistical difference between both groups, in terms of postoperative arrhythmias. None of the patients died, and no patients required an intra-aortic balloon pump. RESULTS: As a result of our study, cardioplegia administration with a certain constant pressure from the roller pump and hand-squeezed bag with uncertain pressure does not make a difference, in terms of myocardial protection. We think that the content and amount of cardioplegia and the preferred time for repeated cardioplegia applications are more important for the protection of the myocardium. METHODS: 76 patients who did not have an acute myocardial infarction, had normal preoperative cardiac marker (troponin and CK-MB) values, did not undergo redo open heart surgery, had an ejection fraction of 50% and above, and underwent elective two or three-vessel isolated coronary artery bypass surgery were evaluated. While tepid(30-32 ° C) blood cardioplegia was administered antegrade to 33 patients(Group A) with a hand-squeezed bag, the other 34 patients(Group B) received tepid(30-32 °C) antegrade blood cardioplegia from the heart-lung machine. The perioperative and postoperative data of the patients were recorded and compared. To evaluate myocardial damage, postoperative cardiac markers and echocardiography data were evaluated and compared at the fourth hour after the cross-clamp was removed in both groups. RESULTS: When evaluated in terms of preoperative demographic data, preoperative mean EF values and intraoperative data there was no statistical difference between both groups. When we evaluated in terms of myocardial protection, the mean TnT level was 4.31 ± 1.95 at the 4th hour in group A and 3.91 ± 1.69 in group B. Mean 4th hour CK-MB level was 40.84 ± 9.07 in group A and 38.56 ± 8.07 in group B. Mean change in EF (%) was -4.09 ± 4.41 in group A and 3.53 ± 4.53 in group B. In line with the current data when we evaluated in terms of myocardial protection; we found that there is no statistical difference between the two groups (p = 0.373; p = 0.158; p = 0.523). There was no statistical difference between both groups in terms of postoperative arrhythmia's. None of the patients died and none of the patients required an intra-aortic balloon pump.

The practicalities of establishing a porcine isolated heart model.

BACKGROUND: The isolated heart apparatus is over 100 years old, but remains a useful research tool today. While designs of many large animal systems have been described in the literature, trouble-shooting and refining such a model to yield a stable, workable system has not been previously described. This paper outlines the issues, in tabular form, that our group encountered in developing our own porcine isolated heart rig with the aim of assisting other workers in the field planning similar work. The paper also highlights some of the modern applications of the isolated heart apparatus. Methods Landrace pigs (50-80 kg) were used in a pilot project to develop the model. The model was then used in a study examining the effects of various cardioplegic solutions on function after reanimation of porcine hearts. During the two projects, non-protocol issues were documented as well as their solutions. These were aggregated in this paper. RESULTS: Issues faced by the group without explicit literature solutions included pig size selection, animal acclimatisation, porcine transoesophageal echocardiography, cannulation and phlebotomy for cross-clamping, cardioplegia delivery, heart suspension and rig tuning. CONCLUSION: Prior recognition of issues and possible solutions faced by workers establishing a porcine isolated heart system will speed progress towards a useable system for research. The isolated heart apparatus remains applicable in transplant, ischaemia reperfusion, heart failure and organ preservation research.

Retrospective analysis of eliminating modified ultrafiltration after pediatric cardiopulmonary bypass.

Modified ultrafiltration (MUF) is a technique which is commonly used immediately post-cardiopulmonary bypass (CPB) for open heart surgery in children. There are many advantages of MUF, but there are also a number of less reported disadvantages. At our institution, after considering all of the available data, a decision was made to no longer perform MUF. The primary motivation being the simplified and miniaturized CPB circuit would reduce hemodilution, decrease our likelihood of reaching our transfusion trigger during CPB and, potentially, improve safety. This study reports the before and after data from this practice change. A total of 160 patients less than 8kg were studied over 38 months and divided into neonatal and pediatric cohorts. Parameters reported in this study include: demographics, hematocrit, blood product transfusion, hemostasis, hemodynamics and outcomes. Although retrospective, our analysis supports an advantage of preventing hemodilution (via circuit miniaturization) versus reversing hemodilution (via MUF) at our institution with the patient population we examined.

Left atrial dissection related to retrograde cardioplegia cannula insertion.

Left atrial dissection (LAD) is a rare complication and is defined as a gap from the mitral or tricuspid annular area to the interatrial septum or left atrial wall. Because of its low incidence, this entity is not fully understood. LAD is related to mitral valve surgery as well as coronary artery disease, arrhythmia, trauma, and tumors, and occurs spontaneously. Transesophageal echocardiography is the most useful diagnostic modality for LAD, but multimodality investigation supports accurate diagnosis. We experienced a case of LAD related to retrograde cardioplegia cannula insertion which was treated successfully with internal drainage.

Use of del Nido Cardioplegia for Adult Cardiac Surgery at the Cleveland Clinic: Perfusion Implications.

Cardiac arrest by cardioplegia provides a reproducible and safe method to induce and maintain electromechanical cardiac quiescence. Techniques of intraoperative myocardial protection are constantly evolving. For the past three decades, modified Buckberg cardioplegia solution has been used for adult cardiac surgery at the Cleveland Clinic. This formulation serves as the crystalloid component, which is delivered 4:1 with oxygenated patient's blood to crystalloid. Meanwhile, our use of the del Nido cardioplegia solution in adult patients, heretofore primarily used in pediatric cardiac surgical centers, has been increasing over the past several years. Single-dose, cold blood del Nido cardioplegia can be delivered antegrade if the duration of the operation will be limited and if there is no significant coronary artery disease or aortic insufficiency that would limit the distribution of cardioplegia. The addition of del Nido cardioplegia to our cardioplegia armamentarium allows us to customize our myocardial protection strategies for different surgical needs. This article aims to provide information on technical aspects of del Nido cardioplegia in adult cardiac surgery and its use at the Cleveland Clinic in the adult surgical population.

Use of del Nido cardioplegia solution and a low-prime recirculating cardioplegia circuit in pediatrics.

The evolution of myocardial protection techniques has been both the source of milestone advancements and controversial debate in cardiac surgery. Our institution has modified a low-prime cardioplegia system (CPS) and adopted a single-dose cardioplegia solution (del Nido cardioplegia) for our congenital heart disease population. The goal of this article is to describe our CPS and outline our myocardial protection protocol. These techniques have allowed us to minimize circuit surface area, operate uninterrupted, and safely protect the myocardium during extended ischemic periods.

History and use of del Nido cardioplegia solution at Boston Children's Hospital.

Cardioplegia is an integral and essential method of myocardial protection for patients of all ages requiring cardiac surgery in which the heart must be stopped. Numerous cardioplegia solutions and delivery methods have been developed. The del Nido cardioplegia solution has been in use for 18 years at Boston Children's Hospital. This is a unique four parts crystalloid to one part whole blood formulation that is generally used in a single-dose fashion. Although the formulation was originally developed for use in pediatric and infant patients, its use for adult cardiac surgery has been expanding. National and international inquiries to our institution regarding this cardioplegia have been increasing over the last 2 years. We present the developmental history, supporting theory, and current protocol for use of what is now referred to as del Nido cardioplegia.

A dental mirror provides excellent exposure of the right coronary artery during cardioplegia.

It sometimes is very difficult to achieve good exposure of the orifice of the right coronary artery through a typical aortotomy when inserting the cannula for the selective antegrade administration of cardioplegic solution to the right coronary artery. A simple technique of exposing the orifice of the right coronary artery using a dental mirror is described.

A simple method for cardioplegia administration and suture control using foley catheter during ascending aorta replacement and aortic root surgery.

There is no standardised approach for cardioplegia administration during ascending aorta replacement (AAR) and the techniques used so far are quite variable and show important limitations. In order to overcome these limitations, we propose a simple and inexpensive technique using a Foley catheter for cardioplegia administration and bleeding control in case of AAR or aortic root surgery. The benefits of our technique are the technical simplicity and the low cost that makes this approach an ideal solution for cardioplegia administration in all cases of AAR.

Air-handling capabilities of blood cardioplegia delivery systems in a simulated pediatric model.

Blood cardioplegia delivery systems are employed in most pediatric open heart cases to arrest the heart and keep it preserved during aortic cross-clamping. They are also used as part of a modified ultrafiltration system at the end of cardiopulmonary bypass. We evaluated and compared the air-handling capabilities of different types of blood cardioplegia delivery devices. A simple circuit incorporating a cardiotomy reservoir, a roller pump, a cardioplegia test system, and two emboli detection and classification sensors were used to investigate the air-handling capabilities of the following cardioplegia delivery systems: GISH Vision, Maquet Plegiox, Medtronic Trillium MYOtherm XP, Sorin Group BCD Vanguard, Sorin Group CSC14, and Terumo Sarns Conducer and Bubble Trap. The 0.25-in. circuit was primed with 400mL of Lactated Ringer's. Outdated packed red blood cells were added to obtain a hematocrit of 24-28%. System pressure was maintained at 50mmHg. Air (0.1, 0.3, 0.5mL) was injected at a speed of 0.1mL/s into the circuit just after the pump head. Gaseous microemboli (GME) were measured prior to the cardioplegia system and after the device to evaluate the air-handling characteristics. The tests were run at 100, 200, and 400mL/min blood flow for both 4 and 37°C. There were no significant differences among the groups when comparing precardioplegia delivery system GME, thus demonstrating that all devices received the same amount of injected air. When comparing the groups for postcardioplegia delivery system GME, significant differences were noted especially at the 400mL/min blood flow rate. These results suggest that for the devices compared in this study, the Maquet Plegiox and the Medtronic Trillium MYOtherm XP eliminated GME the best.

Temperature control using a heat exchanger of a cardioplegic system in cardiopulmonary bypass model for rats.

Small animal cardiopulmonary bypass (CPB) model would be a valuable tool for investigating pathophysiological and therapeutic strategies on bypass. However, the rat CPB models have a number of technical limitations. Effective maintenance and control of core temperature by heat exchanger (HE) is among them. The purpose of this study was to confirm the effect of rectal temperature maintenance and hypothermic control using a HE of cardioplegia system in CPB model for rats. The miniature circuit consisted of a reservoir, HE, membrane oxygenator, and roller pump; the static priming volume was 40 cc. In the first stage of experiment, 10 male Sprague-Dawley rats were divided into two groups; HE group was subjected to CPB with HE from a cardioplegia system, and control group was subjected to CPB with warm water circulating around the reservoir. Partial CPB was conducted at a flow rate of 40 mg/kg/min for 20 min after venous cannulation (via the internal jugular vein) and arterial cannulation (via the femoral artery). Rectal temperature was measured after anesthetic induction, after cannulation, 5, 10, 15, and 20 min after CPB. Arterial blood gas with hematocrit was also analyzed, 5 and 15 min after CPB. In the second stage with the same experimental setting, rectal temperatures were lowered in 10 rats to the target temperature of 32 degrees C. After reaching the target temperature, animals were rewarmed. Rectal temperature was measured after cannulation, 5, 10, 15, 20, 25, and 30 min after CPB. Arterial blood gas with hematocrit was also analyzed, 5 and 15 min after CPB. Rectal temperature change differed between the two groups (P < 0.01). The temperatures of the HE group were well maintained during CPB, whereas the control group was under progressive hypothermia. Rectal temperature 20 min after CPB was 36.16 +/- 0.32 degrees C in the HE group and 34.22 +/- 0.36 degrees C in the control group. In the second set of experiments, the hypothermia targeted (32 degrees C) was reached in 15 min (from 35.56 +/- 1.05 degrees C to 31.75 +/- 0.47 degrees C). The rats were successfully rewarmed within the observation period of 30 min. Arterial blood gases and hematocrits showed no further significant findings. We confirmed the effect of rectal temperature maintenance and hypothermic control using an HE of cardioplegia system in CPB model for rats. This model would be a valuable tool for further use in hypothermic CPB experiments in rats.

Intermittent antegrade cardioplegia: isolated heart preservation with the Asporto heart preservation device.

BACKGROUND: A major problem in procurement of donor hearts is the limited time a donor heart remains viable. After cardiectomy, ischemic hypoxia is the main cause of donor heart degradation. The global myocardial ischemia causes a cascade of oxygen radical formation that cumulates in an elevation in hydrogen ions (decrease in pH), irreversible cellular injury, and potential microvascular changes in perfusion. OBJECTIVE: To determine the changes of prolonged storage times on donor heart microvasculature and the effects of intermittent antegrade perfusion. MATERIALS AND METHODS: Using porcine hearts flushed with a Ribosol-based cardioplegic solution, we examined how storage time affects microvascular myocardial perfusion by using contrast-enhanced magnetic resonance imaging at a mean (SD) of 6.1 (0.6) hours (n = 13) or 15.6 (0.6) hours (n = 11) after cardiectomy. Finally, to determine if administration of cardioplegic solution affects pH and microvascular perfusion, isolated hearts (group 1, n = 9) given a single antegrade dose, were compared with hearts (group 2, n = 8) given intermittent antegrade cardioplegia (150 mL, every 30 min, 150 mL/min) by a heart preservation device. Khuri pH probes in left and right ventricular tissue continuously measured hydrogen ion levels, and perfusion intensity on magnetic resonance images was plotted against time. RESULTS: Myocardial perfusion measured via magnetic resonance imaging at 6.1 hours was significantly greater than at 15.6 hours (67% vs 30%, P = .00008). In group 1 hearts, the mean (SD) for pH at the end of 6 hours decreased to 6.2 (0.2). In group 2, hearts that received intermittent antegrade cardioplegia, pH at the end of 6 hours was higher at 6.7 (0.3) (P = .0005). Magnetic resonance imaging showed no significant differences between the 2 groups in contrast enhancement (group 1, 62%; group 2, 40%) or in the wet/dry weight ratio. CONCLUSION: Intermittent perfusion maintains a significantly higher myocardial pH than does a conventional single antegrade dose. This difference may translate into an improved quality of donor hearts procured for transplantation, allowing longer distance procurement, tissue matching, improved outcomes for transplant recipients, and ideally a decrease in transplant-related costs.

Coronary Sinus Rupture Repair: Patency Is Important.

We report a case of coronary sinus (CS) injury with a retrograde cardioplegia catheter and repair that compromised CS patency. This resulted in acute global cardiac dysfunction shortly after weaning from bypass, which reversed after patch repair with confirmed CS patency. The case report shows that acute CS occlusion may not be tolerated in some humans.

Technique and results for integration of the quest MPS all-blood cardioplegia delivery unit for modified ultrafiltration.

All blood cardioplegia delivery units offer the advantage of removing additional crystalloid volumes associated with multidose crystalloid or 4:1 blood cardioplegia. Further reductions in crystalloid and prime volumes can be achieved if the cardioplegia delivery unit can be integrated as the modified ultrafiltration (MUF) unit as well. This article reports our technique and results for integration of the Quest MPS all-blood cardioplegia delivery unit (Quest Medical, Allen, TX) for modified ultrafiltration. The charts of 50 consecutive patients were reviewed. Patient age ranged from 3 days to 5 years. There were nine neonates. Patient weight ranged from 1.7 to 20.4 kg. Standard prime volumes were 400 cc for patients weighing less than 12 kg, and 800 cc for patients weighing more than 12 kg. Cardiopulmonary bypass time ranged from 32 to 231 minutes. All patients were perfused with corporeal temperatures above 31 degrees C except Norwood cases. MUF time ranged from 5 to 15 minutes with an average of 10.2 minutes. Volume removed ranged from 100 to 600 cc with an average of 239 cc. There was one mortality (2%), which was unrelated to MUF. Additional prime volume was not required to initiate MUF through the MPS cardioplegia unit. The Quest MPS all-blood CPG unit can be safely and effectively integrated as a MUF unit without additional prime volumes. This approach allows for mild hypothermic cardiopulmonary bypass, multidose all-blood CPG, and MUF to be used with tremendous limitation of crystalloid usage.

Immediate post-LVAD implant support: two approaches.

Increased use of left ventricular assist devices (LVAD) as bridges to transplant has revealed the need for short-term right heart support for deairing and right ventricular recovery. The two approaches described are implemented as the patient is weaned from regular cardiopulmonary bypass. Dependent on patient needs, the surgeon may select a high-flow or low-flow approach to what is essentially right heart bypass. Both methods use the existing venous drainage from the right side of the heart. The higher flow returns blood through a 0.25-in tube connected to a modified adult vent (AV) to the pulmonary artery (PA). This provides flows as high as 3.5 L/min. The low-flow method uses the cardioplegia line, which goes unused during LVAD insertion. It is attached to the same modified AV cannula, placed into the PA, with flows between 400 and 600 ml/min. Each method has its advantages, disadvantages, and quirks. The results are functionally successful in allowing support of the right heart and deairing of the ventricular device.

An isolated limb infusion technique: a guide for the perfusionist.

Isolated limb perfusion with the administration of cytotoxic drugs has been successfully used to treat melanomas of the extremity since it was first introduced in 1958. The use of hyperthermia (40 degrees C) combined with chemotherapy agents, primarily melphalan, has resulted in greater cytotoxicity in laboratory studies, which led to the application of hyperthermia in clinical studies during the 1960s. The effectiveness of this regional technique and the absence of any good systemic therapy made hyperthermic-isolated limb perfusion (HILP) the main treatment for patients with regionally advanced melanoma. HILP involves open surgical dissection and cannulation of the peripheral vessels and is associated with moderate morbidity rates. Blood transfusions, systemic drug leak, infection, and damage to the blood vessels and nerves are all potential hazards associated with this technique. Recently, however, there has been increased interest in an alternative technique termed isolated limb infusion (ILI), which was first reported in 1994 from the Sydney Melanoma Unit in Australia. Based on a few single institution experiences, it was found that there are fewer morbidities associated with HILP than with ILI but no compromise in patient outcomes. ILI is a less invasive procedure involving the use of angiographically placed catheters inserted percutaneously through the femoral vessels that does not require blood donor exposure or use of a heart lung machine. Preliminary data suggest that the resultant local hypoxia and acidosis induced by this procedure potentiates the cytotoxic effects of melphalan. Response rates comparing ILI to HILP seem similar, and both are markedly better than systemic chemotherapy. ILI may be a more desirable option because morbidity is greatly reduced and outcomes appear similar. There is a potential role for the perfusionist in the application of ILI, an evolving area of cancer therapy.

Equipment for inducing cold cardioplegic arrest.

A technique for the infusion of the cardioplegic solution used at St. Thomas' Hospital is described. A flanged aortic root needle is used for patients with competent aortic valves and hand-held metal cannulas for those with aortic regurgitation.