Kilsoo Yie

Angiographic results of the radial artery graft patency according to the degree of native coronary stenosis

OBJECTIVE Radial arteries are gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there are limited reports about its angiographic patency compared with that of the internal thoracic artery or saphenous vein according to the degree of native coronary stenosis. Therefore, we tried to evaluate the mid-term angiographic results of the radial artery graft patency focusing on the native coronary stenotic status in a prospective manner. METHODS From March 2000 to September 2006, a total of 488 patients underwent coronary artery bypass grafting using radial artery graft at our institution. From this group, 123 patients (mean age of 59.02+/-8.9 years (range 34-73 years)) were enrolled in the present study, and underwent a postoperative angiography after surgery (mean 32 months). The angiograms were assessed visually and quantitatively. RESULTS A total of 382 distal anastomoses were performed and 352 anastomosis remained patent (92.1%). Left internal thoracic artery showed the most excellent patency in all of the conduits (128/129, 99.2%). Overall the radial artery graft patency was 92% (160/174). In the univariate analysis, patency was significantly worse for targets of the right coronary system (left coronary system 129/135, 94.4% vs right coronary system 31/39, 79.4%. p<0.05) and the radial artery graft showed a higher patency rate in the case of a severe stenotic lesion that preoperatively revealed more than 90% stenosis (defined as critical stenotic lesion) than in the case of a less severe lesion (50%<stenosis<90%) (100/102, 98% vs 60/72, 83.3%. p<0.05). The methods used for proximal anastomosis failed to affect radial artery patency (p=0.123). Multivariate analysis revealed the target vessel stenotic degree (50%<stenosis<90%) was closely related to radial artery graft failure (p=0.002, Exp (B)=0.067, CI=0.012, -0.373). CONCLUSIONS Regardless of the small study population, our data revealed that the radial artery conduit showed good midterm patency when it grafted to the critical stenotic lesion (over 90%). One might pay attention to the grafting strategy when the preoperative coronary angiogram reveals less than 90% of coronary stenosis, especially in the right coronary system but a larger and well-designed study should be warranted to confirm these findings.

Phlegmasia Cerulea Dolens after Coronary Artery Bypass Surgery: What Should We Know

Phlegmasia cerulea dolens (PCD) is one of the most critical disorders of acute deep vein thrombosis in that it can cause permanent disability secondary to the compartment syndrome. Although several etiological factors have been proposed, PCD after coronary artery bypass surgery is extremely rare and its definitive pathophysiology is still under debate. We herein present a case of PCD that resulted in the compartment syndrome after coronary artery bypass surgery. Early recognition and decompression of PCD are crucial for saving the affected limbs.

Thrombi in the Main Pulmonary Artery Stump After a Fontan Operation

At the time of a Fontan operation, complete pulmonary stump obliteration should be performed rather than pulmonary artery ligation to prevent thrombus formation in the main pulmonary artery stump, currently a rare finding [1]. We present a case in which thrombi were noted in the completely oversawn main pulmonary artery stump. The images provided illustrate an uncommon but potentially serious and easily preventable complication among Fontan patients.

Activated clotting time test alone is inadequate to optimize therapeutic heparin dosage adjustment during post-cardiopulmonary resuscitational extracorporeal membrane oxygenation (e-CPR).

Background: We conducted an observational study to evaluate the relationship between activated clotting time (ACT) and activated partial thromboplastin time (aPTT) tests, anticipating the possibility that the ACT will become a substitute test for the aPTT in post-CPR extracorporeal membrane oxygenation (e-CPR). Patients and Methods: Three hundred and fifteen paired ACT and aPTT samples were derived from 60 in-hospital e-CPR patients and were divided into three groups according to the observed ACT value: low level (ACT<170 s, Group A), intended target level (ACT 170–210 s Group B) and high level (ACT>210 s, Group C). The relationship of aPTT in each group was analyzed. Results: The mean ACT and aPTT values were 189.39 ± 48.27 s (IQR, 163–202) and 71.85 ± 45.32 s (IQR, 44.5–81.8), respectively. Although the observed mean ACT value of 189.39 s was similar to the intended mean target value of 190 s (p=0.823), the observed mean aPTT value (71.85 s) was significantly lower than the predicted mean target value (77.5 s, p=0.027). Despite the mean ACT values being significantly different in each group (p<0.0001), the mean aPTT values were not statistically different between Groups A and B (p = 0.317). Of the Group B samples (n = 139), only 31 samples (22.3%) met the optimal therapeutic aPTT range. Pearson’s correlation coefficient for Group B showed only a weak correlation between ACT and aPTT (r=0.177; p=0.037). Conclusions: Our study demonstrates that the ACT test alone does not seem to be enough to optimize therapeutic heparin dosage adjustment during e-CPR.

Early operative mortality with tricuspid valve replacement does not simply depend on surgery itself; late-tricuspid regurgitation is a marker of late-stage myocardial and valvular heart disease

We have read with great interest the article by Sung et al. [1] titled ‘Is tricuspid valve replacement (TVR) a catastrophic operation?’ They showed only 1.3% in-hospital mortality among 80 cases of TVR and suggested reasonable explanations for this favourable result: younger age, better myocardial protection, larger prostheses and modified ultrafiltration. Firstly, we would like to emphasise that TVR itself is not a risky or complicated operation that increases early mortality compared with tricuspid valve (TV) repair [2]. Until now, in the majority of rheumatic tricuspid regurgitation (TR) cases, TVR was performed after left valvular surgery or as a treatment for late TR. Late TR might be caused by left-heart disease, right ventricle (RV) dilatation and dysfunction, persistent pulmonary hypertension, chronic atrial fibrillation or by organic TV disease. The outcome of isolated TVR is poor, because right ventricular (RV) dysfunction has already occurred at the time of TVR. Mangoni et al. [3] showed outcomes following isolated TVR with in-hospital mortality of 20% in this article; 87% of patients had isolated TVR following a previous left-valve operation. Compared with this, we would like to ask the authors, ‘How many patients had isolated TVR after (non-concomitant) left heart valve surgery?’ We speculate that in this study, isolated TVR (n = 24) was almost always from endocarditis or congenital disease; nearly zero patients had isolated TVR due to left rheumatic valvular surgery. Moreover, compared with previous papers, the ratio of re-operation is low (50%) and the ratio of initial TVR as a concomitant operation is high (29% among the 56 concomitant operations). This suggests that it is not the operative technique (as they mentioned above) but the early TVR that might have improved the surgical outcomes. We would like to emphasise that due to

Peripheral vascular reconstruction using deep vein graft for critically ill patients

The great saphenous veins are gaining wide popularity as acceptable native vascular grafts, but in terms of flow capacity, their small caliber may be unsuitable for immediate replacement of arterial flow. Ten peripheral vascular or central venous reconstructions were performed using superficial femoral vein free grafts for re-establishment of immediate high-flow patency. Seven of the patients were men with a mean age of 61.5 ± 17.9 years (range, 21–81 years). The majority of the patients were of preoperative or intraoperative critically ill statuses in that they had extensive infection (n = 5), bleeding (n = 4), renal failure (n = 3) or hepatic failure (n = 1). The mean preoperative physiology score of the vascular POSSUM was 24.1 ± 8.8 (range, 15–37), and the mean operative severity score was 18.4 ± 4.9 (range, 10–26). All patients survived and recovered from systemic infection or critical hemodynamic instability. During the mean 28.9 months of follow-up, complications such as aneurysmal dilation, recurrent infection, graft stenosis/occlusion, lower limb edema and other clinical problems that required attention were not observed. In conclusion, we determined that deep veins can be applied as ideal graft conduits for reconstructing the major peripheral vessels under complicated conditions in select patients.

Unknown etiology aortic aneurysm complicated with multiple vertebral erosions and aortoenteric fistula

HISTORY was admitted for abrupt onset of massive hematemesis. He was a nonsmoker, and had no history of hypertension, fever, back pain, or trauma. No other abnormal findings were identified on physical examination, chest radiograph, or laboratory values, except anemia. The leukocyte count and C-reactive protein level were normal. Endoscopy showed active pulsatile bleeding from an ulcer in the third portion of the duodenum (Fig 1, A). On radiologic study, abdominal aortic aneurysm with vertebral erosion was identified (Fig 2). Considering the patients’ young age, surgery was performed on an urgent basis. The aortoenteric fistula was isolated and primarily closed. Grossly, there was no evidence of infection such as pus, fragile nature, or odor. Resection of the diseased aorta with a Dacron graft replacement was performed. There were 2 holes, 1.5 cm and 1.0 cm, respectively, directly connected to the vertebral body, and red thrombus filled the cavities (Fig 1, B). Atherosclerosis was not found in the aortic lumen. Bovine pericardium was used for patch closure of the vertebral erosion holes. The postoperative period was uneventful, and the patient was discharged 7 days after surgery. All

FEMORAL VEIN AS BYPASS GRAFT FOR SUBCLAVIAN VENOUS OCCLUSION IN A HAEMODIALYSIS PATIENT

We would like to present a case of a right subclavian vein to the left internal jugular vein bypass using a femoral vein free graft for the purpose of immediate dialysis without time delay under sepsis. A 74-year-old man with a 25 year history of diabetic nephropathy was admitted to the emergency centre with sudden loss of an arteriovenous fistula (AVF). Prior to this incidence, he had had a history of difficult vascular access, including seven AVF operations, as well as central vein catheterization. This included bilateral internal jugular vein and bilateral subclavian catheterization. Recently, haemodialysis (HD) was being performed through his left upper arm, and a 6 mm artificial graft and other shunt pathways were all obstructed or non-functioning. In the fistulogram, the graft on the left side was occluded by multiple thrombi, and the right upper arm native AVF flow also rapidly diminished and collateralized on the right subclavian area. Both subclavian veins were near totally occluded (Fig. 1A). Catheter-directed thrombectomy/thrombolysis and subclavian vein balloon dilation was initially successful, but graft occlusion recurred the next day. Furthermore, during HD, the patient experienced a sudden cardiac arrest. A percutaneous cardiopulmonary bypass system (PCPS) was introduced, and a femoral catheter for HD was inserted. Five days later, high fever and leukocytosis with lung infiltration persisted for the next 2 weeks, and a very large retroperitoneal haematoma was identified on follow-up computed tomography. Blood cultures from the retroperitoneal haematoma, femoral dialysis catheter and peripheral vein confirmed methicillin-resistant Staphylococcus aureus (MRSA). Stent insertion for the stenotic subclavian vein was initially considered but eventually abandoned because of high risk of pulmonary embolism. Despite a high vascular POSSUM score of 37 points, life-saving surgery was mandatory. After the non-functioning and infected left upper arm artificial AVF graft was resected, a right subclavian to left jugular vein bypass using the superficial femoral vein (SFV) graft was performed (angiographic findings, Fig. 1B). Two days later, fever and leucocytosis resolved and HD was successfully performed through the right reconstructed AVF. MRSA were cultured from the intraoperatively removed left arm artificial graft. During the follow-up period of 12 months, HD has been performed without any events. During the 12 month follow-up period, HD has been without any remarkable issue. There is neither complication of high return pressure, upper limb oedema nor central vein stenosis recurrence. There is also no lower limb oedema in the graft donation site. Central vein stenosis is a critical complication and a well-functioning AVF is crucial for HD. However, resection is unavoidable when the artificial graft becomes a septic focus. In this circumstance, a large calibre and infection-resistant autogenetic graft is essential to save the life. Percutaneous endovascular intervention is a potential option but has poor long-term patency, requiring repetitive interventions. There is some ‘conceptual dogma’ regarding the SFV graft. Included in this dogma is that surgery using the SFV must be an extensive, dangerous and time-consuming operation. However, despite a high POSSUM score, multiple procedures and critical circumstances (i.e. sepsis, previous cardiac arrest), our patient survived without any complication such as lower leg oedema, HD delay and pulmonary complications. We believe that our good result mainly depended on the worth of the SFV graft itself.

A fatal complication during bedside extracorporeal membrane oxygenation: caused by catheter twisting

Fig. 2. (A) Simple chest antero-posterior view. (B) Abdomen supine plane film. Note the twisted venous line. In this situation, ECMOflowcan beabruptly cut off. A trans-thoracic echocardiogram is usually obtained whenever the ECMO line is inserted. However, radioisotope control is rarely used because of the risks of transfer-time accidents and contrast induced nephropathy (CIN). In this case, transesophageal or trans-thoracic echocardiography was not used, which was a mistake that resulted in the death of this patient due to the twisted catheters. Fig. 1. (A) Simple chest antero-posterior view. (B) Abdomen supine plane film. Bilateral pulmonary infiltrates and two peripherally inserted extracorporeal membrane oxygenation catheters were identified. Generally, the long venous (inflow) cannula is placed in the right femoral vein, because it is easier to access the inferior vena cava (favorable anatomy, shorter distance); the short (outflow) cannula is usually placed in the left groin. In this case, however, the right femoral vein puncture for the long venous (inflow) cannula during the CPCR was unsuccessful and the catheters were placed on the same side.

Off-pump total left anterior descending area re-vascularisation using left internal thoracic artery auto Y graft; angiographic early and 3-year follow-up results

BACKGROUND We evaluated the efficacy of a well-prepared left internal thoracic artery (LITA) auto Y graft for simultaneous left anterior descending artery (LAD) and diagonal artery (DA) re-vascularisation in selected patients for the reduction of the number of required grafts and improved graft patency, while limiting technical problems. METHODS Twenty well-controlled diabetic patients, mean age 62.8+/-8.3, 17 males and three females, underwent isolated elective off-pump coronary artery bypass grafting using the LITA auto Y graft from July 2003 to August 2004. RESULTS In-hospital data and angiographic results at 6 months after the surgery showed that there was no early mortality, early graft failure and major morbidity except for two cases of superficial wound infection. The 3-year follow-up results including angiographic findings (mean of 37+/-3.3-month follow-up) demonstrated that all patients are alive and have excellent graft patency in both the LAD and DA. Only two cases required right coronary artery (RCA) stenting during the follow-up period. Compared with our previous routine LITA composite Y graft technique, it is assumed that LITA auto Y graft technique may reduce the number of mobilised conduits or avoided sequential anastomosis. CONCLUSIONS This small study showed that our technique is technically feasible and may be safely performed to the selective patients. The LITA auto Y graft might be an additional surgical option, in terms of not only preserving the other grafts and maintaining patency in the LAD area bypass, but also preventing the need for sequential anastomoses.