The Profile of Early Sedation Depth and Clinical Outcomes of Mechanically Ventilated Patients in Korea

Background@#Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. @*Methods@#From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation–Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. @*Results@#Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence inter val [CI], 0.55– 0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% 0.56–0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79–1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65–2.17; P = 0.582). @*Conclusion@#In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

The Impact of an Attending Intensivist on the Clinical Outcomes of Patients Admitted to the Cardiac Surgical Intensive Care Unit after Coronary Artery Bypass Grafting

Background@#We aimed to investigate the associations of critical care provided in a cardiac surgical intensive care unit (CSICU) staffed by an attending intensivist with improvements in intensive care unit (ICU) quality and reductions in postoperative complications. @*Methods@#Patients who underwent elective isolated coronary artery bypass grafting (CABG) between January 2007 and December 2012 (the control group) were propensity- matched (1:1) to CABG patients between January 2013 and June 2018 (the intensivist group). @*Results@#Using propensity score matching, 302 patients were extracted from each group. The proportion of patients with at least 1 postoperative complication was significantly lower in the intensivist group than in the control group (17.2% vs. 28.5%, p=0.001). In the intensivist group, the duration of mechanical ventilation (6.4±13.7 hours vs. 13.7±49.3 hours, p=0.013) and length of ICU stay (28.7±33.9 hours vs. 41.7±90.4 hours, p=0.018) were significantly shorter than in the control group. The proportions of patients with prolonged mechanical ventilation (2.3% vs. 7.6%, p=0.006), delirium (1.3% vs. 6.3%, p=0.003) and acute kidney injury (1.3% vs. 5.3%, p=0.012) were significantly lower in the intensivist group than in the control group. @*Conclusion@#A transition from an open ICU model with trainee coverage to a closed ICU model with attending intensivist coverage can be expected to yield improvements in CSICU quality and reductions in postoperative complications.

Outcomes and Patency of Complex Configurations of Composite Grafts Using Bilateral Internal Thoracic Arteries

Background@#It is generally agreed that using a bilateral internal thoracic artery (BITA) composite graft improves long-term survival after coronary artery bypass grafting (CABG). Although the left internal thoracic artery (LITA)-based Y-composite graft is widely adopted, technical or anatomical difficulties necessitate complex configurations. We aimed to investigate whether BITA configuration impacts survival or patency in patients undergoing coronary revascularization. @*Methods@#Between January 2006 and June 2017, 1,161 patients underwent CABG at Seoul National University Bundang Hospital, where the standard technique is a LITA-based Y-composite graft with the right internal thoracic artery (RITA) sequentially anastomosed to non-left anterior descending (LAD) targets. Total of 160 patients underwent CABG using BITA with modifications. Their medical records and imaging data were reviewed retrospectively to investigate technical details, clinical outcomes, and graft patency. @*Results@#Modifications of the typical Y-graft (group 1, n=90), LITA-based I-graft (group 2, n=39), and RITA-based composite graft (group 3, n=31) were used due to insufficient RITA length (47%), problems using LITA (28%), and target vessel anatomy (25%). The overall 30- day mortality rate was 1.9%. Among 116 patients who underwent computed tomography or conventional angiography at a mean interval of 29.9±33.1 months postoperatively, the graft patency rates were 98.7%, 95.3%, and 83.6% for the LAD, left circumflex artery, and right coronary artery territories, respectively. Patency rates for the inflow, secondary, and tertiary grafts were 98.2%, 90.5%, and 80.4%, respectively. The RITA-based graft (group 3) had the lowest patency rate of the various configurations (p<0.011). @*Conclusion@#LITA-based Y composite graft, showed satisfactory clinical outcomes and patency whereas modifications of RITA- based composite graft had the lowest patency and 5-year survival rates. Therefore, when using RITA-based composite graft, other options should be considered before proceeding atypical configurations.

Clinical Outcomes of Surgical Repair with a Composite Graft for Abdominal Aortic Aneurysm Accompanied by Iliac Artery Aneurysm

Background@#Iliac artery aneurysm is frequently found in patients undergoing surgical repair of an abdominal aortic aneurysm. The use of commercial bifurcated grafts is insufficient for aorto-biiliac replacement with complete iliac artery aneurysm resection. We evaluated the effectiveness of handmade composite grafts for this purpose. @*Methods@#A total of 233 patients underwent open surgery for abdominal aortic aneurysm between 2003 and 2019, including 155 patients (67%) treated with commercial grafts and 78 patients (33%) treated with handmade composite grafts. Their operative characteristics, postoperative outcomes, and late outcomes were retrospectively reviewed. @*Results@#The early mortality rate did not differ significantly between the groups. On average, the handmade composite graft technique took approximately 15 minutes longer than the commercial graft technique (p=0.037). Among patients who underwent elective surgery, no significant differences between the conventional and composite groups were observed in the major outcomes, including red blood cell transfusion volume (2.8±4.7 units vs. 3.1±4.7 units, respectively; p=0.680), reoperation for bleeding (2.7% vs. 3.1%, respectively; p>0.999), bowel ischemia (0% vs. 1.6%, respectively; p=0.364), and intensive care unit stay duration (1.9±6.6 days vs. 1.6±2.4 days, respectively; p=0.680). The incidence of target vessel occlusion also did not differ significantly between groups. @*Conclusion@#The increased technical demand involved with handmade composite grafting did not negatively impact the outcomes. This technique may be a viable option because it overcomes problems associated with commercial grafts.

Comparison of Radiofrequency Ablation and Cryoablation for the Recovery of Atrial Contractility and Survival

BACKGROUND: Limited comparative data are available on the efficacy of cryoablation versus radiofrequency ablation in patients with atrial fibrillation. This study aimed to compare radiofrequency ablation and cryoablation with regard to clinical outcomes and the restoration of sinus rhythm or atrial contractility. METHODS: A total of 239 patients who underwent surgical ablation between August 2003 and December 2016 at our institution were included. The patients were divided into 2 groups according to the energy device that was used (group A: n=140, radiofrequency ablator; group B: n=99, cryoablator). Echocardiographic data, overall survival, and major cardiovascular and cerebrovascular event (MACCE)-free survival were compared between the 2 groups. RESULTS: At 1 year of follow-up, the atrial contractility recovery rate was 32.2% (19 of 59) in group A and 48.8% (21 of 44) in group B. In addition, cryoablation was found to be a predictive factor for the recovery of atrial contractility (cryoablation vs. radiofrequency ablation: odds ratio, 2.540; 95% confidence interval, 1.063–6.071; p=0.036). The left ventricular ejection fraction was significantly higher in group B (53.1%±11.5% vs. 59.1%±6.3%, p=0.001). The median follow-up duration was 36 months. The 5-year overall survival rate was 80.1%±3.6% in group A and 92.1%±2.9% in group B (p=0.400). The 5-year MACCE-free survival rate was 70.3%±4.0% in group A and 70.9%±5.6% in group B (p=0.818). CONCLUSION: Cryoablation was associated with a higher atrial contractility restoration rate and better left ventricular function than radiofrequency ablation. However, no significant relationship was observed between the energy source and overall or MACCE-free survival.

Mid-Term Results of Minimally Invasive Direct Coronary Artery Bypass Grafting / 대한흉부외과학회지

BACKGROUND: Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients. METHODS: All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data—including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention—were collected. RESULTS: The mean age of the patients was 69.4±11.1 years and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in the intensive care unit and in the hospital were 1.5 and 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of 85.3%±0.09% and a 5-year MACCE-free survival rate of 72.8%±0.1%. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at 9.7±10.8 months postoperatively. CONCLUSION: MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.

Mid-Term Results of Minimally Invasive Direct Coronary Artery Bypass Grafting

BACKGROUND@#Minimally invasive direct coronary artery bypass grafting (MIDCAB) has the advantage of allowing arterial grafting on the left anterior descending artery without a sternotomy incision. We present our single-center clinical experience of 66 consecutive patients.@*METHODS@#All patients underwent MIDCAB through a left anterior small thoracotomy between August 2007 and July 2015. Preoperative, intraoperative, postoperative and follow-up data—including major adverse cardiovascular and cerebrovascular events (MACCE), graft patency, and the need for re-intervention—were collected.@*RESULTS@#The mean age of the patients was 69.4±11.1 years and 73% were male. There was no conversion to an on-pump procedure or a sternotomy incision. The 30-day mortality rate was 1.5%. There were no cases of stroke, although 2 patients had to be re-explored for bleeding, and 81.8% were extubated in the operating room or on the day of surgery. The median stay in the intensive care unit and in the hospital were 1.5 and 9.6 days, respectively. The median follow-up period was 11 months, with a 5-year overall survival rate of 85.3%±0.09% and a 5-year MACCE-free survival rate of 72.8%±0.1%. Of the 66 patients, 32 patients with 36 grafts underwent a postoperative graft patency study with computed tomography angiography or coronary angiography, and 88.9% of the grafts were patent at 9.7±10.8 months postoperatively.@*CONCLUSION@#MIDCAB is a safe procedure with low postoperative morbidity and mortality and favorable mid-term MACCE-free survival.

A Case Treated with Extracorporeal Membrane Oxygenation for Disseminated Cytomegalovirus Infection after Liver Transplantation / 대한이식학회지

Cytomegalovirus (CMV) is a clinically important pathogen in immunocompromised patients, especially after organ transplantation. However, there have been several reports of severe CMV infections in immunocompetent patients. This report presents a case of an immunocompetent patient who presented with fulminant hepatitis requiring liver transplantation. Because CMV was detected upon histopathologic review of the explanted liver, it was later assumed that CMV may be the primary cause of hepatitis. However, at the time of transplantation, we did not suspect CMV hepatitis. Following transplantation and initiation of immunosuppression, the patient developed viral sepsis with a disseminated CMV infection. Respiratory failure because of CMV pneumonia worsened despite antiviral therapy, and venovenous extracorporeal membrane oxygenation (ECMO) was initiated. Although ECMO has been traditionally contraindicated in patients with sepsis, this patient recovered and was successfully weaned off ECMO. CMV should be included in the differential diagnosis of fulminant hepatitis, even in immunocompetent patients, especially when liver transplantation is considered.

Change of Proximal Descending Aortic False Lumen after Conventional Repair of Acute Type I Dissection: Is It Always Unfavorable?

BACKGROUND: Some patients show favorable changes in the descending aortic false lumen after conventional repair of acute type A dissection, although the incidence of favorable changes has been reported to be low. We aimed to investigate the incidence of positive postoperative changes in the false lumen and the factors associated with positive outcomes. METHODS: In 63 patients who underwent surgery for type A acute dissection as well as serial computed tomography (CT) scanning, morphological parameters were compared between the preoperative, early postoperative (mean interval, 5.4 days), and late CT scans (mean interval, 31.0 months) at three levels of the descending thoracic aorta. RESULTS: In the early postoperative CT images, complete false lumen thrombosis and/or true lumen expansion at the proximal descending aorta was observed in 46% of the patients. In the late images, complete thrombosis or resolution of the proximal descending false lumen occurred in 42.9% of the patients. Multivariate analysis found that juxta-anastomotic false lumen thrombosis was predictive of favorable early changes, which were in turn predictive of continuing later improvement. CONCLUSION: Even after conventional repair without inserting a frozen elephant trunk, the proximal descending aortic false lumen showed positive remodeling in a substantial number of patients. We believe that the long-term prognosis of type A dissection can be improved by refining surgical technique, and particularly by avoiding large intimal tears at the anastomosis site during the initial repair.

Sternal Healing after Coronary Artery Bypass Grafting Using Bilateral Internal Thoracic Arteries: Assessment by Computed Tomography Scan

BACKGROUND: This study aimed to investigate sternal healing over time and the incidence of poor sternal healing in patients undergoing coronary artery bypass graft (CABG) surgery using bilateral internal thoracic arteries. MATERIALS AND METHODS: This study enrolled 197 patients who underwent isolated CABG using skeletonized bilateral internal thoracic arteries (sBITA) from 2006 through 2009. Postoperative computed tomography (CT) angiography was performed on all patients at monthly intervals for three to six months after surgery. In 108 patients, an additional CT study was performed 24 to 48 months after surgery. The axial CT images were used to score sternal fusion at the manubrium, the upper sternum, and the lower sternum. These scores were added to evaluate overall healing: a score of 0 to 1 reflected poor healing, a score of 2 to 4 was defined as fair healing, and a score of 5 to 6 indicated complete healing. Medical records were also retrospectively reviewed to identify perioperative variables associated with poor early sternal healing. RESULTS: Three to six months after surgery, the average total score of sternal healing was 2.07+/-1.52 and 68 patients (34.5%) showed poor healing. Poor healing was most frequently found in the manubrium, which was scored as zero in 72.6% of patients. In multivariate analysis, the factors associated with poor early healing were shorter post-surgery time, older age, diabetes mellitus, and postoperative renal dysfunction. In later CT images, the average sternal healing score improved to 5.88+/-0.38 and complete healing was observed in 98.2% of patients. CONCLUSION: Complete sternal healing takes more than three months after a median sternotomy for CABG using sBITA. Healing is most delayed in the manubrium.

Dual Extracorporeal Membrane Oxygenation Support for Bridging Lung Transplantation in Acute Exacerbation of Idiopathic Pulmonary Fibrosis / 대한구급학회지

When patients with severe respiratory failure are treated with venovenous extracorporeal membrane oxygenation (VV-ECMO), severe pulmonary hypertension due to right ventricular (RV) failure is possible. This is a serious complication that requires immediate therapeutic intervention. We report an extraordinary experience of additional venoarterial extracorporeal membrane oxygenation (VA-ECMO) support for RV failure in a patient who was being treated with VV-ECMO as a bridge to lung transplantation. A 61-year-old man was diagnosed with acute exacerbation of idiopathic pulmonary fibrosis. While waiting for lung transplantation, he was placed on VV-ECMO and developed RV failure. After insertion of additional VA ECMO, RV dysfunction was dramatically improved. He underwent heart-lung transplantation after 23 days of dual ECMO support.

Synchrotron Microangiography of the Rat Heart Using the Langendorff Model

BACKGROUND AND OBJECTIVES: The ability to study microvessels of a beating heart in real time at the level of the capillary is essential for research. However, there are no proven methods currently available to achieve this. The conventional absorption-contrast agents have limitations for studying capillaries. Microangiography with using synchrotron phase-contrast X-ray technology and no contrast agent has recently been reported on. We tried to verify this previous report, and we wanted to visualize the microvessels of a rat heart using air as a contrast agent. MATERIALS AND METHODS: We made the Langendorff apparatus in a hutch of the Pohang Accelerator Laboratory. The images were obtained with a white beam and a monochromatic beam. The visual images were magnified using 3x and 20x optical microscope lenses, and the images were captured with a charge-coupled device camera. RESULTS: We could not duplicate the previously reported findings in which microvessels were visualized without the use of contrast agent. But with using air as a contrast agent, the microvasculature of rat hearts was clearly identified at a spatial resolution of 1.2 microm. Air being absorbed inside a capillary was also observed. Vessels under 10 microm diameter were unable to be visualized with using iodine as a contrast agent. CONCLUSION: Phase contrast imaging already allows spatial resolution of 1 microm, which is enough to inspect capillaries. We were able to obtain images of cardiac capillaries with using air as a contrast agent. Yet air has the fatal limitations in that it causes embolism and ischemia. A more suitable contrast agent or imaging method needs to be developed in order to study the microvessels of a beating heart.

The Norwood-Rastelli Procedure for Left Ventricular Outflow Tarct Obstruction with a Ventricular Septal Defect: Three case report / 대한흉부외과학회지

Between 2001 and 2006, 3 neonates that had multilevel left ventricular outflow tract obstruction and a ventricular septal defect underwent the Norwood-Rastelli procedure. The body weights ranged from 2.9 to 3.1 kg. The patients had a near normal sized mitral valve and left ventricle. We simultaneously performed a modified Norwood procedure with native tissues-to-tissue anastomosis without circulatory arrest, and a Rastelli type procedure using a non-valved conduit from the right ventricle to the pulmonary artery and intracardiac patch baffling from the left ventricle to the pulmonary valve via the ventricular septal defect. The postoperative courses were uneventful. During follow-up, there was one late mortality caused by a cardiac catheterization related complication at 7 months after surgery. One patient required a Rastelli conduit change. Two patients are doing well during a follow-up period of 1 and 5 years, respectively.

Mid- and Long Term Outcome of Fontan Procedure: Extracardiac Conduit Fontan versus Lateral Tunnel Fontan / 대한흉부외과학회지

BACKGROUND: This paper reviews our experience retrospectively to examine the clinical results and effectiveness of lateral tunnel (LT) and extracardiac conduit (ECC) Fontan procedures at a single institution. MATERIAL AND METHOD: One hundred and sixty five Fontan procedures were performed (67 LT and 98 ECC) between January 1996 and December 2006. Preoperative and postoperative hemodynamic values, arrhythmia, hospital and intensive care unit stay, chest tube drain, morbidity and mortality were reviewed. RESULT: The overall operative mortality in the LT and ECC groups was 4.5% (3) and 2.0% (2), respectively. There was a significant difference in the immediate postoperative transpulmonary gradient (LT 8.5+/-2.5 vs ECC 6.6+/-2.4, p-value<0.001) and central venous pressure (LT 18.3+/-3.8 vs ECC 15.6+/-2.4, p-value=0.001) between the two groups. The mean follow-up in the LT and ECC groups was 74.1+/-31.5 and 38.1+/-29.1 months, respectively. There was one late death. The actuarial survival at 10 years in the LT and ECC groups was 92% and 89%, respectively. In arrhythmia, the ECC patients showed a slightly low incidence but the difference was not statistically significant. CONCLUSION: Both the LT and ECC Fontan procedures showed comparable early and mid-term outcomes in terms of the surgical morbidity and mortality, postoperative hemodynamics, and mid-term survival. The ECC Fontan procedure reduces the risk of arrhythmia in the follow up period.

Thoracoscopic Surgery for Catamenial Pneumothorax / 대한흉부외과학회지

Recurrent spontaneous pneumothorax associated with menstrual cycle was described first by Maurer in 1958. Lilington and colleague established the term 'catamenial pneumothorax' and reported 5 patients in 1972. Catamenial pneumothorax is defined as recurrent spontaneous pneumothorax occurring within 72 hours before or after the onset of menstruation, but the pathophysiology is not clearly understood. We report a recent experience of 37 years-old woman with catamenial pneumothorax, who was treated by thoracoscopic surgery.

The Recent Outcomes after Repair of Tetralogy of Fallot Associated with Pulmonary Atresia and Major Aortopulmonary Collateral Arteries / 대한흉부외과학회지

BACKGROUND: Tetralogy of Fallot (TOF) with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) is complex lesion with marked heterogeneity of pulmonary blood supply and arborization anomalies. Patients with TOF with PA and MAPCAs have traditionally required multiple staged unifocalization of pulmonary blood supply before undergoing complete repair. In this report, we describe recent change of strategy and the results in our institution. MATERIAL AND METHOD: We established surgical stratagies: early correction, central mediastinal approach, initial RV-PA conduit interposition, and aggressive intervention. Between July 1998 and August 2004, 23 patients were surgically treated at our institution. We divided them into 3 groups by initial operation method; group I: one stage total correction, group II: RV-PA conduit and unifocalization, group III: RV-PA conduit interposition only. RESULT: Mean ages at initial operation in each group were 13.9+/-16.0 months (group I), 10.4+/-15.6 months (group II), and 7.9+/-7.7 months (group III). True pulmonary arteries were not present in 1 patient and the pulmonary arteries were confluent in 22 patients. The balloon angioplasty was done in average 1.3 times (range: 1~6). There were 4 early deaths relating initial operation, and 1 late death due to incracranial hemorrhage after definitive repair. The operative mortalities of initial procedures in each group were 25.0% (1/4: group I), 20.0% (2/10: group II), and 12.2% (1/9: group III). The causes of operative mortality were hypoxia (2), low cardiac output (1) and sudden cardiac arrest (1). Definitive repair rates in each group were 75% (3/4) in group I, 20% (2/10, fenestration: 2) in group II, and 55.6% (5/9, fenestration: 1) in group III. CONCLUSION: In patients of TOF with PA and MAPCAs, RV-PA connection as a initial procedure could be performed with relatively low risk, and high rate of definitive repair can be obtained in the help of balloon pulmonary angioplasty. One stage RV-PA connection and unifocalization appeared to be successful in selected patients.

Early Failure of the Shelhigh Pulmonary Valve Conduit in Ross Operation: Two case reports / 대한흉부외과학회지

It is very difficult to choose the ideal valved conduit used in right ventricle outflow reconstruction in child. We can use the cryopreserved homograft but there is a limit of appplication because of its difficulties in the size matching and supply capacity. The Shelhigh(R) porcine-valved conduit is commercially available and used as an alternative choice in these days. We report two cases of early Shelhigh conduit failure in right ventricular outflow tract after Ross operation in congenital aortic stenosis.