Patent Internal Mammary Artery Research Articles

Eleven-year outcomes of U-clips in totally robotic coronary artery bypass grafting versus standard hand-sewn running suture in robotic-assisted coronary artery bypass grafting.

The aim of this study was to evaluate the clinical outcomes of patients undergoing off-pump robotic coronary artery bypass grafting (CABG) with either interrupted nitinol U-Clips in totally endoscopic coronary artery bypass (TECAB) or standard running suture anastomosis in robotically assisted direct coronary artery bypass (RADCAB) over a decade. From January 2007 to December 2017, 280 patients underwent robotic off-pump CABG using the da Vinci S/Si Surgical System in our centre. TECAB with interrupted nitinol U-Clips anastomosis was performed in the left internal mammary artery (LIMA) to LAD grafting in 126 patients and RADCAB (n = 154) of the LIMA to LAD was completed with standard running suture. After discharge, patients were contacted through telephone interview and were invited to attend the outpatient clinic every 6 months or 1 year. The graft patency was assessed by coronary angiography or computed tomography angiography. All cases were completed without conversion to median sternotomy or cardiopulmonary bypass. A total of 275 single internal mammary artery (IMA) grafts (271 LIMAs, 4 right internal mammary arteries) and 5 bilateral IMA grafts were used as single graft or composite grafts. All the patients were discharged without in-hospital mortality or adverse outcomes. The average follow-up was 89.7 ± 30.4 months (range, 14-143 months). The cumulative survival rates (P = 0.53), the cumulative IMA patency rates (P = 0.83), and the rates of freedom from major adverse cerebrovascular and cardiovascular events (P = 0.41) between TECAB and RADCAB all showed no significant difference in the follow-up. Robotic off-pump CABG using IMA grafts is safe and can provide reliable long-term outcomes. Compared with the standard hand-sewn running suture technique in RADCAB, interrupted suture with the nitinol U-Clips in TECAB showed similar long-term clinical results and graft patency in LIMA to LAD bypass grafting.

Non-Invasive Assessment of Left Internal Mammary Artery Patency Using Transluminal Attenuation Gradient

Objective: This study aimed to discuss the value of using dual-source computed tomography (CT) to calculate the transluminal attenuation gradient (TAG) and TAG with corrected contrast opacification (TAG-CCO) and quantitatively evaluate left internal mammary artery (LIMA) patency. Method: A total of 32 patients accepting coronary artery bypass grafting were continuously assessed and examined by computed tomography angiography (CTA) of the LIMA before operation. TAG, TAG-CCO, and transluminal diameter gradient (TDG) were then calculated. Blood flow velocity in the LIMA was measured during the operation, and correlation analysis was carried out. Results: TAG, TAG-CCO, and TDG presented significantly positive correlations with blood flow velocity in the LIMA (r = 0.48 r = 0 56 and r = 0.65 respectively, p < 0.05). Conclusion: The greater the absolute values of TAG and TAG-CCO, the lower the blood flow velocity in the LIMA; thus, evaluating LIMA patency presents a certain clinical value.

Harmonic Scalpel for Internal Mammary Artery Harvest

Internal mammary artery (IMA) harvest by using a harmonic scalpel for coronary artery bypass grafting (CABG) have not been sufficiently evaluated. This review aimed to assess the outcomes of IMA harvest by a harmonic scalpel and to compare by conventional electrocautery. The study materials were based on literature retrieval. In total Eight articles describing IMA harvest by a harmonic scalpel for 1,893 patients, and pateints with IMA harvest by electrocautery were taken as controls. IMA harvest by a harmonic scalpel was associated with less thermal injury with potentially better preservation of the endothelial cells, satisfactory intraoperative IMA flow, and promising postoperative IMA patency. Apart from the harvesting merits, the harmonic scalpel had many other advantages in terms of clinical outcomes, such as decreased postoperative mortality and morbidity rates. Nevertheless, IMA harvesting by using a harmonic scalpel is associated with longer harvest time, prolonged operative time, and increased hospitalisation expenses. Therefore, they could be used in selected and non-emergent patients for CABG. Key Words: Coronary artery bypass grafting, Internal mammary artery, Surgical instruments.

Patency of conduits in patients who received internal mammary artery, radial artery and saphenous vein grafts

BackgroundWhere each patient has all three conduits of internal mammary artery (IMA), saphenous vein graft (SVG) and radial artery (RA), most confounders affecting comparison between conduits can be mitigated. Additionally, since SVG progressively fails over time, restricting patient angiography to the late period only can mitigate against early SVG patency that may have occluded in the late period.MethodsResearch protocol driven conventional angiography was performed for patients with at least one of each conduit of IMA, RA and SVG and a minimum of 7 years postoperative. The primary analysis was perfect patency and secondary analysis was overall patency including angiographic evidence of conduit lumen irregularity from conduit atheroma. Multivariable generalized linear mixed model (GLMM) was used. Patency excluded occluded or “string sign” conduits. Perfect patency was present in patent grafts if there was no lumen irregularity.ResultsFifty patients underwent coronary angiography at overall duration postoperative 13.1 ± 2.9, and age 74.3 ± 7.0 years. Of 196 anastomoses, IMA 62, RA 77 and SVG 57. Most IMA were to the left anterior descending territory and most RA and SVG were to the circumflex and right coronary territories. Perfect patency RA 92.2% was not different to IMA 96.8%, P = 0.309; and both were significantly better than SVG 17.5%, P < 0.001. Patency RA 93.5% was also not different to IMA 96.8%, P = 0.169, and both arterial conduits were significantly higher than SVG 82.5%, P = 0.029. Grafting according to coronary territory was not significant for perfect patency, P = 0.997 and patency P = 0.289. Coronary stenosis predicted perfect patency for RA only, P = 0.030 and for patency, RA, P = 0.007, and SVG, P = 0.032.When both arterial conduits were combined, perfect patency, P < 0.001, and patency, P = 0.017, were superior to SVG.ConclusionsAll but one patent internal mammary artery or radial artery grafts had perfect patency and had superior perfect patency and overall patency compared to saphenous vein grafts.

Keeping the Patent Internal Mammary Artery out of Harm’s way at Future Reoperation

With increase in long term survival after coronary artery bypass surgery and Left Internal Mammary Artery (LIMA) patency reaching up to 96% at 15 years, re-sternotomy for repeat cardiac surgery in the presence of a patent LIMA is not unusual [1]. Today, decades after the introduction of Coronary Artery Bypass Grafting (CABG) as a routine procedure in many medical centres, 1 in every 5 to 7 patients who have undergone one CABG may need a reoperation [2].

Keeping the Patent Internal Mammary Artery out of Harm’s way at Future Reoperation

With increase in long term survival after coronary artery bypass surgery and Left Internal Mammary Artery (LIMA) patency reaching up to 96% at 15 years, re-sternotomy for repeat cardiac surgery in the presence of a patent LIMA is not unusual [1]. Today, decades after the introduction of Coronary Artery Bypass Grafting (CABG) as a routine procedure in many medical centres, 1 in every 5 to 7 patients who have undergone one CABG may need a reoperation [2].

Determination of the Frequency of Right and Left Internal Mammary Artery Embolization in Single Ventricle Patients: A Two-Center Study.

Embolization of systemic to pulmonary artery collaterals to regulate pulmonary arterial flow or pressure of the cavopulmonary circulation in patients with single ventricle is a common practice. The relative incidence and impact of this practice on future interventions like coronary artery bypass grafting is poorly understood. This study aims to evaluate the frequency and implications of internal mammary artery (IMA) embolization in the single ventricle (SV) population. A retrospective chart review was performed of SV patients who underwent cardiac catheterization before and after Fontan procedure between February 2007 and 2017. Data were collected from two tertiary care centers in the Midwest. Of the 304 SV patients, 62 (20.4%) underwent embolization of one or more IMAs, whereas 242 (79.6%) did not. The rate of embolization of IMA was 40.5% in one center and 14.5% in the second center. Among patients who received IMA embolization, left internal mammary artery (LIMA) embolization was seen in 6 (9.7%) patients. Majority of patients underwent either right internal mammary artery (RIMA) embolization (n = 25; 40.3%) or RIMA and LIMA embolization (n = 27; 43.5%). IMA embolization in SV patients is common. Embolizing IMAs early in life will likely eliminate a valuable graft option for coronary artery bypass grafting should it be required in the future care of these patients. Multi-center, prospective, nation-wide studies are warranted to examinecoronary artery disease in the SV population and true frequency of IMA embolization. Delineation of which IMAs were embolized is a necessary in surgical and cardiac intervention national data, such as Society of Thoracic Surgeons (STS) database. All measures should be taken to preserve IMAs patency, if deemed feasible and safe.

Coronary artery revascularization in infants, children, and adolescents: The internal mammary artery is still the conduit of choice.

In infants, children, and adolescents, the most common indication for coronary artery bypass graft surgery (CABG) has been Kawasaki disease or acquired familial hypercholesterolemia. However, pediatric CABG is now more commonly performed for coronary artery injuries which occur during or following arterial switch operations (ASO), the ross procedure, and tetralogy of Fallot repairs (TOF).1-3 CABG has also been performed in adults who present with acquired coronary atherosclerotic disease and have congenital lesions such as TOF.4 In adult CABG surgery, the internal mammary artery (IMA) is the conduit of choice because of its superior long-term patency. However, in infants, children, and adolescents, concerns have been raised regarding the use of the IMA because of competitive flow, the smaller diameter of the IMA, the size of the target vessel, the need for the IMA to provide the entire blood supply for large areas of the myocardium, and the potential of the IMA for somatic growth. In this edition of the Journal, Arnaz et al5 report their experience with CABG surgery in 10 children ranging from 88 days to 15 years. The indications for CABG included complications related to the ASO and the Ross procedure and iatrogenic injuries due to the anomalous location of coronary arteries during TOF repairs. Three patients died during the postoperative period, but none of the deaths were due to coronary ischemia. Eight patients received an IMA graft and two patients received saphenous vein grafts. Four of the eight IMA grafts underwent follow-up angiograms which showed patent IMA grafts in all patients. In two of these patients, the IMA grafts showed somatic growth after 9.5 and 18 years. None of the surviving seven patients had any recurrent angina, new Q waves, or a reduction in ejection fraction. Although the number of patients in this series is small, it confirms the results of other studies which have demonstrated that the IMA has excellent long-term patency and adapts well to somatic growth.6-8 Concerns regarding excessive stretching of the IMA as the children grow older have not materialized. Furthermore, the IMA's blood flow has been more than adequate to meet the demands of the myocardium in these younger patients. Arnaz et al5 have reaffirmed that the IMA can be successfully utilized in infants, children, and adolescents during complex procedures, even when emergent revascularization is necessary, and should be the conduit of choice in these young patients.

Long-Term Clinical and Computed Tomography Angiographic Follow-up After Totally Endoscopic Coronary Artery Bypass Grafting.

Totally endoscopic coronary artery bypass grafting was shown to be feasible and safe, with excellent clinical and angiographic mid-term results. Data on long-term outcome are lacking. Therefore, we aimed to investigate the long-term rate of major adverse cardiac and cerebrovascular events and left internal mammary artery patency rate in patients undergoing arrested heart totally endoscopic coronary artery bypass grafting. From 2001 to 2012, a total of 208 arrested heart-totally endoscopic coronary artery bypass grafting patients were prospectively included. Mean ± SD age was 58.8 ± 9.4 years, and mean ± SD Society of Thoracic Surgeons score was 0.5 ± 0.5%. Major adverse cardiac and cerebrovascular events were defined as a composite of death, myocardial infarction, stroke, re-percutaneous coronary intervention, re-coronary artery bypass graft, and target vessel revascularization. Left internal mammary artery patency was assessed using cardiac computed tomography and depicted according to the established Fitzgibbon classification. Mean ± SD follow-up was 6.9 ± 2.3 years. At 1, 5, and 10 years, survival rate was 100%, 98.3%, and 95.8%, respectively. The freedom from clinical events at 1, 5, and 10 years were major adverse cardiac and cerebrovascular events (93.5%, 85.9%, and 83.0%), myocardial infarction (99.0%, 97.4%, and 95.9%), target vessel revascularization (96.0%, 94.3%, and 91.7%), re-percutaneous coronary intervention (94.5%, 91.6%, and 84.2%), and re-coronary artery bypass graft (100%, 99.5%, and 99.5%), respectively. Left internal mammary artery patency rate at 1, 5, and 10 years was 100%, 94.9%, and 88.1%, respectively. Arrested heart-totally endoscopic coronary artery bypass grafting shows excellent clinical long-term results with a left internal mammary artery patency rate comparable with conventional coronary artery bypass graft at 10 years after surgery.

Coronary artery steal syndrome in patient after coronary arteries by-pass surgery and left subclavian artery stenting-is the maintenance of a patent internal mammary artery still necessary?

Coronary artery steal syndrome in patient after coronary arteries by-pass surgery and left subclavian artery stenting-is the maintenance of a patent internal mammary artery still necessary?

Coronary artery steal syndrome in patient after coronary arteries by-pass surgery and left subclavian artery stenting-is the maintenance of a patent internal mammary artery still necessary?

The use of the left internal mammary artery (LIMA) is preferred for the revascularization of a stenosed or occluded left anterior descending artery (LAD). Occlusion or stenosis of proximal part of the left subclavian artery (LSA) could induce reverse blood flow in LIMA called coronary subclavian steal syndrome (CSSS) and should be revascularized before coronary artery bypass grafting (CABG) surgery with LIMA. If restenosis of previously stented LSA occurs after CABG surgery with LIMA another revascularization is inevitable. However, the revascularization of LSA could reveal that increased blood pressure in LAD persistent through years due to present CSSS could substantially influence blood pressure change in coronary arteries and LIMA graft. This phenomenon can raise the question if it is necessary to maintain patent LIMA-LAD graft.

Reusing the patent internal mammary artery as a conduit in redo coronary artery bypass surgery.

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, in patients with previous internal mammary artery/internal thoracic artery (ITA) grafts, can the internal mammary artery/ITA be reused/recycled in redo coronary artery bypass surgery? Fourteen papers were found using the reported search of which 10 represented the best evidence to answer the clinical question. There was variation in patient selection, the number of patients reported, outcome measures recorded, and methods and duration of follow-up. The results were mostly in favour of using a recycled ITA when it could be safely harvested. Most studies were retrospective. One large series of 60 patients who underwent redo coronary artery bypass grafting (CABG) using previously implanted ITAs had a mean time to reoperation of 117 ± 68 months. They reported no operative deaths; no patients required further or subsequent target vessel revascularization; 30-day mortality was 8.3% and myocardial infarction rate was 3%. Another two series of 16 and 12 patients underwent recycling of arterial grafts during coronary artery revascularization with no perioperative deaths in either. Postoperative angiography was performed in 10 patients in one of these studies, which showed excellent flow in all redone left internal thoracic artery (LITA) grafts. One study reported results from a prospective cohort of 9 patients who underwent redo coronary artery bypass grafting. Interval between operations was between 1 and 132 months. There was no perioperative mortality, but 1 patient required reintervention (to an interposition vein graft). A further study of 4 patients who underwent redo CABG using ITAs that were patent but with severe stenosis at the distal anastomosis had no mortality. Postoperative angiography showed patency of all grafts. There have also been 4 case reports on reusing the ITA/ITA in redo CABG with no damage to the reused LITA, no perioperative mortality and satisfactory follow-up at up to 29 months. Evidently, the recycled ITA can be used in redo coronary artery bypass grafting. Papers found were retrospective series or case reports. As such, there is no direct comparison in outcomes between the recycled ITA and first-time ITA harvest or any other conduit for CABG. In conclusion, we find that when it is possible to harvest a previously used ITA, studies have shown it to be a safe and viable conduit in redo CABG with good long-term outcomes.

Feasibility and safety of continuous retrograde administration of Del Nido cardioplegia: a case series.

BackgroundDel Nido (DN) cardioplegia, a calcium-free, hyperkalemic solution containing lidocaine and magnesium has been developed to help reduce intracellular calcium influx and the resulting myocyte damage in the immediate postischemic period following cardiac arrest. DN cardioplegia has been used for pediatric cardiac surgery but its use in complex reoperative surgery has not been studied. We specifically report the outcomes of patients undergoing reoperative cardiac surgery after previous coronary artery bypass grafting with a patent internal mammary artery (IMA).MethodsPatients undergoing reoperative cardiac surgery with prior coronary bypass grafting surgery were studied between 2010 and 2013. Fourteen patients were identified who required continued retrograde cardioplegia administration. In all cases, an initial antegrade dose was given, followed by continuous retrograde administration. Demographics, co-morbidities, intra-operative variables including cardioplegia volumes, post-operative complications, and patient outcomes were collected.ResultsThe mean age of all patients was 73.3+/−6.7 years, and 93 % were male. Aortic cross clamp time and cardiopulmonary bypass times were 81+/−35 and 151+/−79 mins, respectively. Antegrade, retrograde and total cardioplegia doses were 1101+/−398, 3096+/−3185 and 4367+/−3751 ml, respectively. An average of 0.93+/−0.92 inotropes and 1.50+/−0.76 pressors were used on ICU admission after surgery. ICU and total hospital lengths of stay were 5.5+/−7.4 and 9.6+/−8.0 days, respectively. Complications occurred in two patients (14 %) (pneumonia and prolonged mechanical ventilation) and new arrhythmias occurred in five patients (36 %) (four new-onset atrial fibrillation and one pulseless electrical activity requiring 2 min of chest compression). No perioperative myocardial infarctions were noted based on electrocardiograms and cardiac serum markers. Postoperatively, left ventricular function was preserved in all patients whereas two patients (14 %) had mild decrease in right ventricular function as assessed by echocardiography. No mortality was observed.ConclusionDel Nido cardioplegia solution provides acceptable myocardial protection for cardiac surgery that requires continuous retrograde cardioplegia administration. DN cardioplegia’s administration in a continuous retrograde fashion with a patent IMA is believed to provide adequate myocardial protection while avoiding injuring the IMA through dissection and clamping.

One-year clinical and angiographic results of hybrid coronary revascularization

ObjectiveTo evaluate 1-year clinical and angiographic results after hybrid coronary revascularization (HCR) combining off-pump left internal mammary artery (LIMA) grafting through an inferior J-hemisternotomy with percutaneous coronary intervention (PCI). MethodsProspective, single-arm clinical feasibility study including 100 consecutive patients with multivessel disease undergoing staged HCR. The primary endpoint was the major adverse cardiac and cerebrovascular event rate at 1 year. Secondary endpoints included 1-year all-cause death, stroke, myocardial infarction, repeat revascularization, and angiographic graft and stent patency. ResultsOne-year clinical follow-up data were available in all patients. The primary endpoint was met by 20 patients (20%). Individual endpoints were as follows: 1 death due to heart failure; 1 stroke, 2 procedure-related myocardial infarctions; and 1 spontaneous myocardial infarction during follow-up. A total of 16 patients underwent repeat revascularization: 5 surgical reinterventions during the index hospitalization for angiographically suspected internal mammary artery graft dysfunction, and 3 repeat PCIs. Only 1 patient had evidence of ischemia. After discharge, PCI was performed in 6 patients who had recurrent angina, and in 2 asymptomatic patients who had angiographic restenosis. At the 1-year angiographic follow-up, 87 of 89 (98%) patients had patent internal mammary artery grafts. Angiographic restenosis was present in 10 of 100 lesions treated by PCI. ConclusionsAngiographically controlled HCR was associated with a high repeat revascularization rate. The 1-year 98% LIMA-graft patency rate, and low risk of death and stroke, seem promising for the long-term outcome. Non–left anterior descending coronary artery lesion revascularization remains a challenge.

First-time, isolated surgical aortic valve replacement after prior coronary artery bypass surgery: results from the RECORD multicenter registry.

This multicenter study was undertaken to determine the immediate and long-term outcomes in patients undergoing a primary surgical aortic valve replacement (AVR) who had a previous coronary artery bypass graft surgery with patent grafts. One hundred and thirteen consecutive patients (mean EuroSCORE II, 10.3 ± 7.7%, median 8.0%) who underwent first-time isolated AVR after coronary artery bypass grafting (CABG) were the subjects of this multicenter study. The procedure was performed through a full sternotomy in 95.7% of cases, a patent internal mammary artery graft was clamped in 76.6% of patients. The temperature of cardioplegia was ≤12 °C in 62.8% of patients and systemic temperature was <32 °C in 23.9% of patients. Thirty-day mortality was 4.4%. Stroke was observed in 8.0% of patients, low cardiac output syndrome in 14.1%, prolonged tracheal intubation in 20.8%, and intensive care unit stay was longer than five days in 19.5% of patients. Among patients with a patent internal mammary graft (91 patients), clamping of this graft (5.7% vs. 0%, p = 0.57) was associated with a nonsignificant trend toward increased 30-day mortality. One-, three- and five-year survival rates were 91.5%, 90.4%, and 88.4%, respectively. Patients undergoing isolated AVR after prior CABG have a good immediate and late survival. A history of prior CABG should not be considered an absolute indication for transcatheter AVR.

Aortic Valve Replacement after Previous Coronary Artery Bypass Grafting with Patent Internal Mammary Artery

With the aging population, more patients who have undergone previous coronary artery bypass grafting (CABG) are surviving long enough to require subsequent aortic valve replacement (AVR). Conventional redo AVR after prior CABG involves resternotomy, dissection and clamping of the patent bypass graft vessel. Favorable results have been reported for AVR following previous CABG; however, the problems of this procedure includes that injury to the patent bypass grafts can result in catastrophic complications. Increasing patient age and comorbidities may increase operative mortality, less invasive percutaneous aortic valve intervention has advanced. However, because there are no sufficient data comparing transcatheter aortic valve intervention with surgical AVR, currently, the surgical approach should still be consider as the standard of treatment for AVR following previous CABG. We report a patient in whom successful conventional AVR was underwent after previous CABG with patent left internal mammary artery.

Arterial grafts do not counteract target vessel occlusion

Grafted, non-occluded coronary arteries might contribute substantially to the myocardial blood supply and serve as a basis for vascular collateralization which preserves the myocardium in the event of graft occlusion. Early studies indicated that grafting with saphenous vein, but not internal mammary arteries, accelerates coronary atherosclerosis. This has not been extensively studied for the radial artery, which like the internal mammary artery (IMA) is largely resistant to atherosclerosis. A differential effect of various grafts might facilitate identification of disease-modifying principles. Our surgical cohort represented an opportunity to analyse new native coronary occlusions by comparison with preoperative angiograms. One hundred and two patients underwent angiography 1.3-3.9 years after coronary artery bypass surgery, primarily in order to compare the patency of radial artery, IMA and saphenous vein grafts. Out of 290 stenotic, grafted vessels, 67 (23%) occluded during follow-up. Native occlusion occurred in 47% of the patients and correlated with serum-cholesterol. In a per target analysis, independent predictors of postoperative native occlusion were the right coronary artery territory, patent corresponding graft, the corresponding graft being an IMA and end-to-side anastomosis. Target vessel occlusion is similar with radial artery and saphenous vein grafts and proceeds rapidly even in the current era of secondary prophylaxis against atherosclerosis. Competitive graft flow appears to promote occlusion. Contrary to previous studies, we do not find vein grafts to be inferior to IMA grafts with respect to preservation of native vessel patency.

Sign of decreased coronary blood flow from ST depression and PVCs during a left lower lobectomy of the lung in a patient with a left internal mammary arterial bypass graft

Lung resection surgery in patients with a previous internal mammary artery (IMA) graft to coronary arteries is challenging, because the arterial graft may be injured during dissection of adhesions between the graft and the lung [1-3]. A 68-year-old male patient, diagnosed with a squamous cell carcinoma in the left lower lobe of the lung, required a left lower lobectomy. The patient (height, 160.4 cm; weight, 73.5 kg) was on the following medications: Aspirin, clopidogrel, losartan, amlodipine, and atorvastatin. Three years previously the patient had a coronary artery bypass graft surgery including a left IMA graft to the left anterior descending (LAD) artery. An electrocardiogram (ECG) showed normal sinus rhythm, occasional premature ventricular contractions (PVCs), and left ventricular hypertrophy. A preoperative transthoracic echocardio gram showed mild inferior wall hypokinesia. Preoperative coronary angiography revealed a patent left IMA to LAD artery flow. After the patient arrived in the operating room, catheteri zation was performed on the patient's right radial artery. The patient was induced with 1-3.5 vol% sevoflurane after receiving 100 mg of propofol and 60 mg of lidocaine by intravenous injection. Tracheal intubation using a double lumen endotracheal tube (37 Fr) was performed for one-lung ventilation 3 minutes after the patient received 50 mg of rocuronium by intravenous injection. A central venous catheter was inserted into the right internal jugular vein due to the fear of graft pedicle injury and because we prefer the right internal jugular vein due to its straight course. At the start of the surgery, the patient’s blood pressure was stable (mean systolic pressure, 100-120 mmHg; diastolic pressure, 40-60 mmHg). After the thoracotomy, a severe adhesion between the upper lobe and the surrounding parietal pleura was noticed. The operator compressed the pericardium to control the bleeding using a sponge stick without considering the left internal mammary artery (LIMA) pedicle. During this period, ST-segment depression occurred, a series of PVCs appeared in about 5-6 seconds, and blood pressure decreased on the direct arterial pressure monitor (systolic pressure, 60 mmHg; diastolic pressure, 30 mmHg). Phenylephrine (20 μg/cc from a micro solution set) was dripped to increase blood pressure. The operator was notified immediately, the sponge stick compression was stopped, and the ECG and the blood pressure recovered to the previous state. Subsequent

Systemic hyperkalemia and mild hypothermia for valve surgery in patients with patent internal mammary artery graft

Myocardial protection is compromised in patients with a patent internal mammary artery (IMA) graft. We assessed the advantages of systemic hyperkalemia with mild hypothermia for valve surgery in patients with a patent IMA graft. Nine patients (mean age 71.5+/-7.0 years) with a patent IMA graft underwent valve surgery from May 2004 to July 2009. Of those, eight underwent aortic valve replacement and one mitral repair, with two double-valve surgery. Antegrade and retrograde blood cardioplegia were performed intermittently, and systemic potassium was given to all. The lowest bladder temperature was 27.2+/-2.4 degrees C, and the initial and peak systemic potassium levels were 6.8+/-1.4 and 8.0+/-1.6 mEq/l, respectively, while potassium at the end of the cardiopulmonary bypass procedure after sufficient modified ultrafiltration was reduced to 5.5+/-0.6 mEq/l. There was one hospital death due to ischemic colitis. Cardiac arrest was easily achieved in each patient without IMA or aortocoronary graft injury. The postoperative peak creatine kinase-MB level was 33+/-17 IU/l, with no ST changes seen in electrocardiogram findings or new asynergy seen in echocardiogram findings. Systemic hyperkalemia and mild hypothermia for valve surgery in patients with a patent IMA graft is a good option to reduce graft and myocardial injuries.

Simple Techniques to Manage the Patent Internal Mammary Artery in Redo Cardiac Surgery

The presence of a patent internal mammary artery (IMA) represents a well-known technical challenge in redo cardiac surgery. Dissection of the IMA and controlling its flow during cardioplegic delivery has thus been considered essential steps. This maneuver however, is associated with the risk of damaging the IMA. Herein, we report a technique, which involves no attempts to dissect, or clamp the IMA in 44 consecutive redo cardiac surgery procedures. The results demonstrate that this technique is simple, safe, and reduces the chance of IMA injury.