Prediction of poor exposure in endoscopic mitral valve surgery using computed tomography.

OBJECTIVES: In endoscopic mitral valve surgery, optimal exposure is crucial. This study aims to develop a predictive model for poor mitral valve exposure in endoscopic surgery, utilizing preoperative body profiles and computed tomography images. METHODS: We enrolled patients undergoing endoscopic mitral valve surgery with available operative video and preoperative computed tomography. The degree of valve exposure was graded into 0 (excellent), 1 (fair), 2 (poor) and 3 (very poor). Intrathoracic dimensions-anteroposterior width (chest anteroposterior) and left-to-right width (chest width) of the thorax, height of right hemi-thorax (chest height), angle between the left ventricular axis and the horizontal plane (left ventricle apex angle), heart width, level of diaphragm in midline, and vertical distance between the midline diaphragm level and the highest top of the right diaphragm (Δdiaphragm) were measured. RESULTS: Among 263 patients, mitral valve exposure was graded as 0 in 131 (49.8%), 1 in 72 (27.4%), 2 in 46 (17.5%) and 3 in 14 (5.3%). Body mass index, chest width, left ventricle apex angle, heart width and Δdiaphragm were identified as independent predictors of grades 2 and 3 exposure by stepwise logistic regression analysis, with an area under the receiver operating characteristic curve of 0.822 (P < 0.001). Univariate logistic regression for grade 3 exposure prediction revealed that Δdiaphragm had the largest area under the curve (0.826, P < 0.001). CONCLUSIONS: Poor mitral valve exposure occurred in approximately one-fourth of the endoscopic surgery series and might be predicted preoperatively using body mass index and computed tomography measurements to help determine the surgical approach.

Simulation-based training for endoscopic mitral valve repair: the impact on basic surgical skills for placement of sutures at mitral valve annulus during 2-h training workshop.

OBJECTIVES: The aim of this study was to evaluate the impact of simulation-based training on surgical skills during 2-h learning labs during surgical annual meeting. METHODS: During the 36th European Association of Cardiothoracic Surgery annual meeting a learning drylab for simulation-based training for endoscopic mitral valve repair was set up. For this purpose, a validated high-fidelity endoscopic mitral valve surgery simulator and a validated suturing map were used. The training lasted 2 h. Technical pre- and post-assessment were carried out based on time and accuracy to place a suture at the posterior mitral valve annulus. The suture had to be placed within 60 s. The suture was considered anatomically correct if it entered and exited the annulus at the designated place (on the posterior annulus) and accurate if placed within the right width (8-12 mm). RESULTS: In total, 46 participants were included in this study, of whom 18 (38%) were experienced/staff surgeons, 23 (51%) fellows and 5 (11%) residents. Before the training, 48% of the participants failed to place any suture for pre-assessment. After completing the training, 100% of the participants succeeded in placing an anatomically correct suture. There was a significant improvement in the time taken [pre-assessment mean 45 (standard deviation: 25) s vs post-assessment mean 18 (standard deviation: 12) s, P < 0.001] and the accuracy to place a suture in the mitral valve annulus after completing the training (pre-assessment 32.6% vs post-assessment 65.2%, P < 0.001). CONCLUSIONS: This study shows a significant improvement in endoscopic skills for mitral valve surgery after completing a 2-h training with a high-fidelity endoscopic mitral valve surgery simulator. This suggests that simulation trainings during scientific annual meetings are effective on surgical skills.

Spontaneously Resolved Systolic Anterior Motion of Native Mitral Valve Leaflet After Transcatheter Mitral Valve Replacement.

Systolic anterior motion of a mitral leaflet can occur by various mechanisms and it is one of the causes of left ventricular outflow tract obstruction after transcatheter mitral valve replacement. We present a case of systolic anterior motion that resolved spontaneously as the anterior mitral leaflet adhered to the prosthesis. (Level of Difficulty: Intermediate.).

Trotter and Gleser's (1958) equations outperform Trotter and Gleser's (1952) equations in stature estimation of the US White males.

Trotter and Gleser presented two sets of stature estimation equations for the US White males in their 1952 and 1958 studies. Following Trotter's suggestion favouring the 1952 equations simply due to the smaller standard errors, the 1958 equations have been seldom used and have gone without additional systematic validation tests. This study aims to assess the performance of the Trotter and Gleser 1952, Trotter and Gleser 1958, and FORDISC equations for the White males in a quantitative and systematic way, particularly when applied to the WWII and Korean War casualties. In sum, 27 equations (7 from the 1952 study, 10 from the 1958 study, and 10 from FORDISC) were applied to the osteometric data of 240 accounted-for White male casualties of the WWII and Korean War. Then, the bias, accuracy, and Bayes factor for each set of stature estimates were calculated. The results show that, overall, Trotter and Gleser's 1958 equations outperform the 1952 and FORDISC equations in terms of all three measures. Particularly, the equations with higher Bayes factors produced stature estimates where distributions were closer to that of the reported statures than those with lower Bayes factors. When considering Bayes factors, the best performing equation was the "Radius" equation from the 1958 study (BF = 15.34) followed by the "Humerus+Radius" equation from FORDISC (BF = 14.42) and the "Fibula" equation from the 1958 study (BF = 13.82). The results of this study will provide researchers and practitioners applying the Trotter and Gleser stature estimation method with a practical guide for equation selection. Key Points: The performance of three stature estimation methods was compared quantitatively.Trotter and Gleser's (1952, 1958) and FORDISC White male equations were included.Overall, Trotter and Gleser's 1958 method outperformed the other methods.This study provides a practical guide for stature estimation equation selection.

Long-Term Outcomes of the Maze Procedure Combined with Endoatriectomy for Patients with Calcified Left Atria.

PURPOSE: Left atrial calcification (LAC) is found in long-lasting rheumatic valvular disease and is almost always accompanied by atrial fibrillation (AF). In the presence of LAC, endoatriectomy is required when performing the maze procedure. However, the technical feasibility of endoatriectomy and the long-term outcomes of the maze procedure in patients with LAC are uncertain. METHODS: The medical records of 18 consecutive patients who underwent combined endoatriectomy and maze procedure were analyzed retrospectively. RESULTS: Accompanying operations were mitral valve replacement (n = 16) and commissurotomy (n = 2). There was 1 operative death from sepsis following mediastinitis. When patients were divided into "broad" (n = 11) and "limited" (n = 7) groups, with the extent of LAC either greater or less than half of the left atrium, respectively, there was no intergroup difference in postoperative complications. During follow-up (median, 11.4 years), AF recurred in 11 patients. At the last follow-up visits, electrocardiography revealed significantly fewer patients in the broad group maintaining sinus rhythm (1/11 vs 4/6, P = 0.03). The 10-year AF recurrence-free survival rates were 13.9% and 66.7% in the broad and limited groups, respectively (P = 0.01). CONCLUSIONS: The maze procedure combined with endoatriectomy seems technically feasible with acceptable long-term rhythm outcomes if the LAC extent is limited.

Aortic Valve Replacement by Subannular Endomyocardial Implantation of Valve Prosthesis in Behçet's Disease.

The novel anastomosis technique, "subannular endomyocardial implantation of valve prosthesis (SEIV)," focuses on excluding aortic annular tissue from suture line to avoid vascular inflammation in Behçet's disease (BD). We aimed to validate that SEIV could prevent prosthetic valve detachment (PVD) after aortic valve replacement (AVR) in BD patients and retrospectively analyzed the medical records of five BD patients who underwent AVR. There was no operative death. Two complete atrioventricular blocks occurred; in one of them, a permanent pacemaker (PPM) was inserted before discharge. The other one was discharged without a PPM; however, he died suddenly 32 days postoperatively. The median follow-up period was 3.3 years. There was a case of PVD with newly developed Valsalva sinus aneurysm requiring the Bentall operation at 3.6 years postoperatively. In conclusion, SEIV might prevent PVD in BD patients who underwent AVR. However, aortic root pathology related to BD activity and resulting PVD may occur later.

Routine Mediastinal Drainage Fluid Culture for Early Diagnosis of Poststernotomy Mediastinitis.

BACKGROUND: Early diagnosis of poststernotomy mediastinitis (PSM) is challenging. Since 2016, we have routinely performed mediastinal drainage fluid culture (MDFC) in patients undergoing sternotomy. This study aimed to determine the utility of MDFC for early diagnosis of PSM. METHODS: Between November 2016 and April 2020, we conducted MDFC in 1,012 patients on the third postoperative day and prospectively observed for PSM occurrence for 3 months. If bacteria were identified, additional MDFC or blood culture was performed to reduce the possibility of false positives. Based on MDFC results, the decision for early treatment for PSM was at the attending physician's discretion. RESULTS: Bacteria were identified in MDFC of 29 patients, eight of whom subsequently developed PSM. Among 983 patients with negative MDFC, only 15 developed PSM. In multivariate analysis, previous sternotomy history and positive MDFC were predictors of PSM. Positive MDFC was regarded as true positive if (1) PSM occurred subsequently, and/or (2) the same bacteria were identified in additional MDFC/blood culture. Non-occurrence of PSM in the absence of antibiotic treatment was regarded as false-positive MDFC. The sensitivity, specificity, and positive and negative predictive values of routine MDFC for diagnosis of mediastinal infection were 46.4, 99.0, 56.5, and 98.5%, respectively. When categorizing cases with positive MDFC based on the identified bacteria, the positive predictive value was highest (76.9%) when Staphylococci were identified. CONCLUSION: Routine MDFC after sternotomy can facilitate early diagnosis of PSM. Early treatment for PSM may be indicated in patients in whom Staphylococci are identified in the MDFC.

Minimally Invasive Surgical Treatment of Hepatic Hydrothorax Complicated by Empyema: A Case Report.

Hepatic hydrothorax complicated by empyema is difficult to manage. A 53-year-old man with liver cirrhosis was admitted for refractory right pleural effusion. He had a pleural catheter inserted 2 months prior. Pleural fluid appeared as exudate, and bacteria were identified in the pleural fluid culture. After confirming full ipsilateral lung expansion, minimally invasive surgery was performed. A diaphragmatic defect found by creating a pneumoperitoneum was closed, followed by talc pleurodesis. Postoperatively, overnight positive-pressure ventilation and 5-day peritoneal drainage were performed; chest tube drainage dramatically reduced over this time. At the 10-month follow-up, no recurrence of pleural effusion or signs of infection were observed.

Case Report: Intravascular Ultrasound-guided Intervention for Anastomosis Stenosis of the Left Main Coronary Artery Post-Cabrol Technique.

Introduction: Some cases of percutaneous coronary intervention (PCI) for the anastomotic site between the Cabrol-type conduit and the left main coronary artery (LMCA) have been reported. Nevertheless, the combination of PCI with a detailed description of lesion appearance using virtual histology-intravascular ultrasound (VH-IVUS) has never been reported. In this study, we present a case of acute myocardial infarction that was successfully treated with intravascular ultrasound (IVUS)-guided PCI for focal stenosis at the anastomotic site, and the plaque composition was studied in detail. Case Presentation: A 35-year-old Korean male with Behçet's disease was diagnosed with acute myocardial infarction. He had previously undergone three cardiothoracic surgeries including two aortic replacements, followed by modified Bentall operation with a Cabrol-type aortocoronary anastomosis. Coronary angiogram (CAG) showed focal critical stenosis at the anastomosis site between the conduit and the LMCA, and VH-IVUS showed fibrotic plaque with mainly fibrous tissue but without a confluent necrotic core. PCI was performed using a drug-eluting stent (4.5 × 12 mm, SynergyTM, Boston Scientific, Marlborough, MA, USA). Since a repeat CAG and IVUS post-surgery showed an under-expanded stent strut, post-dilation ballooning was additionally performed. Subsequently, the repeat IVUS revealed wellapposed and optimized deployment of the drug-eluting stent with full lesion coverage. Final CAG showed optimal angiographic results. After successful PCI, the patient's anginal symptoms improved dramatically, and he was successfully discharged from our hospital. Conclusion: This study presents an IVUS-guided PCI case for an anastomotic site between the conduit and the LMCA. It is the first to investigate the characteristics of this lesion through VH-IVUS, which demonstrated the presence of fibrous plaques at the anastomotic site. IVUS radiofrequency data allow for a detailed assessment of plaque composition and provide new insights into the histopathological nature of stenotic lesions at the anastomotic site, especially in patients with chronic inflammatory diseases like Behçet's disease.

Open surgical treatment of subclavian artery pseudoaneurysm after endovascular repair: a case report.

BACKGROUND: Subclavian artery aneurysms are rare but may cause life-threatening complications. Surgical repair has been performed as a treatment of choice, but recently, with the development of endovascular treatment, many endovascular repairs have been performed to prevent surgical complications. CASE PRESENTATION: A patient undergoing endovascular repair with a subclavian artery aneurysm was diagnosed with a type II endoleak with an enlarged aneurysmal sac. Surgical repair was performed to remove the aneurysmal sac compressing the adjacent organs. CONCLUSIONS: The highly mobile subclavian artery has abundant collaterals. Therefore, regular follow-up is essential for endovascular repair. Surgical repair is effective when adjacent organs are compressed by the aneurysm sac.

Differentiation of multiple visceral artery aneurysm rupture from major bleeding after coronary artery bypass grafting.

BACKGROUND: Visceral artery aneurysm is a very rare disease, but it is clinically important because of the high risk of rupture involved. These ruptures must be differentiated from those that occur during hospitalization after extra-abdominal surgery. METHODS: During hospitalization after off-pump coronary artery bypass grafting, a 77-year-old woman developed hypovolemic symptoms and had decreased hemoglobin. There was no obvious bleeding, but while screening for possible complications after cardiac surgery, abdominal computed tomographic angiography showed multiple visceral artery aneurysms of the gastroduodenal and pancreaticoduodenal arteries along with hemoperitoneum. RESULTS: The patient underwent coil embolization of the visceral artery aneurysm and was discharged without any complications. CONCLUSIONS: In patients with coronary artery disease with risk factors for atherosclerosis, if anemia occurs without apparent bleeding after surgery, visceral artery aneurysm should be considered as a differential diagnosis.

Successful subclavian transcatheter aortic valve replacement in a nonagenarian patient: Case report and review of literature.

RATIONALE: In super-aged patients with severe symptomatic aortic stenosis, transcatheter aortic valve replacement (TAVR) is a good treatment option, and the number of TAVR-eligible elderly patients is expected to grow exponentially. We present the case of a nonagenarian woman with severe aortic stenosis who underwent successful subclavian TAVR. PATIENT CONCERNS: A 90-year-old Korean woman was brought to our department with dyspnea. On physical examination, a grade IV systolic murmur was auscultated in both the upper sternal borders and the left lower sternal border. DIAGNOSIS: A transthoracic echocardiogram showed heavy calcification of the aortic valve with an increase in both peak velocity (4.36 m/s) and mean pressure (44.8 mm Hg), indicating severe symptomatic aortic stenosis. INTERVENTIONS: After a heart team conference involving interventional cardiologists, cardiac surgeons, and anesthesiologists, subclavian TAVR was performed. Using the left subclavian artery, we successfully deployed a self-expandable valve prosthesis (CoreValveTM Evolut RTM, Medtronic Inc., Minneapolis, MN). OUTCOMES: After TAVR, transthoracic echocardiogram showed a decline in both peak velocity (2.06-2.14 m/s) and mean pressure (7.42-7.95 mm Hg) with an increase in the aortic valve area (1.12 cm2). The patient's dyspnea symptoms improved dramatically. LESSONS: In addition to femoral TAVR, subclavian TAVR may be feasible and safe in super-aged patients.

Acute biological mitral valve thrombosis after the left atrial venting in a patient with a venoarterial extracorporeal membrane oxygenator.

BACKGROUND: Left atrial venting through atrial septotomy in patients with decreased left ventricular (LV) contractility after venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a simple and effective method for treating LV decompression. MATERIALS & METHODS: We report a case of prosthetic mitral valve thrombosis after left atrial venting in a patient with VA-ECMO. RESULTS: In patients undergoing mitral valve replacement, left atrial venting reduces the flow through the mitral valve and forms a prosthetic thrombosis. DISCUSSION: Therefore, excessive left atrial venting should be avoided. Other venting methods that can maintain the flow through the mitral valve should be considered after mitral valve replacement.

Bayes factor: A useful tool to quantitatively evaluate and compare performance of multiple stature estimation equations.

When stature estimation of incomplete skeletal remains is necessary, researchers select an estimation equation which will produce the most accurate estimates. The purpose of this study is to propose that, given prior information of a target sample, the Bayes factor can be a useful tool to quantitatively evaluate and compare performance of multiple equations in this regard. This study also explores the best-performing equations to reconstruct statures of Korean War casualties with a demonstration of equation comparisons by the Bayes factor. Thirty-three sets of stature estimates were generated using different equations based on the osteometric data of the Korean War casualties. The distribution of each set was compared to that of the population (i.e., Korean servicemen during the Korean War) using the Bayes factors and posterior probabilities generated by the R codes in the LearnBayes package. A higher Bayes factor indicates a closer similarity between the two distributions under comparison. The equation with the highest Bayes factor in this study was Choi et al.'s (1997) humerus equation (bf=9.84), followed by the femur equation of the same authors (bf=5.3). The Bayesian approach has advantages over the traditional frequentist approach primarily based on the p-value. Particularly, the Bayes factor can provide practical interpretations on the models under comparison, which allows for a quantitative prioritization of different models. Researchers can obtain more accurate stature estimates of a target sample by using the equation of the highest Bayes factor.

Minimally invasive surgical strategy for refractory hepatic hydrothorax.

OBJECTIVES: Treatment of refractory hepatic hydrothorax, a complication of liver cirrhosis, is complex. We aimed to investigate the usefulness of the '4-step approach', which is a minimally invasive surgical strategy combining 4 therapeutic modalities: (i) pneumoperitoneum to localize diaphragmatic defects; (ii) thoracoscopic pleurodesis; (iii) postoperative positive-pressure ventilation; and (iv) peritoneal drainage for abdominal decompression. METHODS: We retrospectively analysed the medical records of 12 patients with hepatic hydrothorax who underwent surgical treatment using the 4-step approach from January 2013 to December 2017. Nine of them (75.0%) were Child C cases; the median model for end-stage liver disease score was 20.5. The diaphragmatic defects localized after forming a pneumoperitoneum were treated with primary closure followed by thoracoscopic pleurodesis, postoperative positive-pressure ventilation and peritoneal drainage. RESULTS: Diaphragmatic defects were localized in all patients except one. The median postoperative positive-pressure ventilation duration was 20.1 h. Peritoneal drainage was performed for a median duration of 5 days; the peritoneal drains were removed at a median of 8 postoperative days. The median duration of postoperative hospital stay until discharge/transfer was 9.5 days. No operative mortalities occurred. The median duration of follow-up was 10.9 months. Eight deaths (66.7%) occurred during the follow-up period; however, no deaths were surgery-associated. Ipsilateral pleural effusion recurred in 3 patients (25%), among whom reoperation was performed in 1 without recurrence at the 13-month follow-up. CONCLUSIONS: The 4-step approach seems to be a safe and effective minimally invasive surgical strategy for treating refractory hepatic hydrothorax.

Various Treatment Modalities in Hepatic Hydrothorax: What Is Safe and Effective?

PURPOSE: Hepatic hydrothorax is a complication of decompensated liver cirrhosis that is difficult and complex to manage. Data concerning the optimal treatment method, other than liver transplantation, are limited. This study aimed to compare the clinical features and outcomes of patients treated with various modalities, while focusing on surgical management and pigtail drainage. MATERIALS AND METHODS: Forty-one patients diagnosed with refractory hepatic hydrothorax between January 2013 and December 2017 were enrolled. RESULTS: The mean Child-Turcotte-Pugh and model for end stage liver disease scores of the enrolled patients were 10.1 and 19.7, respectively. The patients underwent four modalities: serial thoracentesis (n=11, 26.8%), pigtail drainage (n=16, 39.0%), surgery (n=10, 24.4%), and liver transplantation (n=4, 9.8%); 12-month mortality rate/median survival duration was 18.2%/868 days, 87.5%/79 days, 70%/179 days, and 0%/601.5 days, respectively. Regarding the management of refractory hepatic hydrothorax, surgery group required less frequent needle puncture (23.5 times in pigtail group vs. 9.3 times in surgery group), had a lower occurrence of hepatorenal syndrome (50% vs. 30%), and had a non-inferior cumulative overall survival (402.1 days vs. 221.7 days) compared to pigtail group. On multivariate analysis for poor survival, body mass index <19 kg/m², refractory hepatic hydrothorax not managed with liver transplantation, Child-Turcotte-Pugh score >10, and history of severe encephalopathy (grade >2) were associated with poor survival. CONCLUSION: Serial thoracentesis may be recommended for management of hepatic hydrothorax and surgical management can be a useful option in patients with refractory hepatic hydrothorax, alternative to pigtail drainage.

Nosocomial Infection in Adult Patients Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation.

Data on the frequency of nosocomial infections during extracorporeal membrane oxygenation (ECMO) in adult populations remain scarce. We investigated the risk factors for nosocomial infections in adult patients undergoing venoarterial ECMO (VA-ECMO) support. From January 2011 to December 2015, a total of 259 patients underwent ECMO. Of these, patients aged 17 years or less and patients undergoing ECMO for less than 48 hours were excluded. Of these, 61 patients diagnosed with cardiogenic shock were evaluated. Mean patient age was 60.6 ± 14.3 years and 21 (34.4%) patients were female. The mean preoperative Sequential Organ Failure Assessment (SOFA) score was 8.6 ± 2.2. The mean duration of ECMO support was 6.8 ± 7.4 days. The rates of successful ECMO weaning and survival to discharge were 44.3% and 31.1%, respectively. There were 18 nosocomial infections in 14 (23.0%) patients. These included respiratory tract infections in 9 cases and bloodstream infections in a further 9. In multivariate analysis, independent predictors of infection during ECMO were the preoperative creatinine level (hazard ratio [HR], 2.176; 95% confidence interval [CI], 1.065-4.447; P = 0.033) and the duration of ECMO support (HR, 1.400; 95% CI, 1.081-1.815; P = 0.011). A higher preoperative creatinine level and an extended duration of ECMO support are risk factors for infection. Therefore, to avoid the development of nosocomial infections, strategies to shorten the length of ECMO support should be applied whenever possible.

Surgical resection of cardiac myxoma-a 30-year single institutional experience.

BACKGROUND: Primary cardiac tumors are rare and myxoma constitutes the majority. The present study summarizes our 30-year clinical outcomes of surgical myxoma resection. METHODS: Between January 1986 and December 2015, 93 patients (30 men, 63 women; mean age, 54.7 ± 16.6 years) underwent surgical myxoma resection. The most common origin site was the left atrium. Surgery was performed via a biatrial approach in 74.2%, atrial septotomy through right atriotomy in 17.2%, and left atriotomy only in 8.6%. Mean myxoma size based on longest length was 4.73 ± 1.92 cm (range, 1.2-11.0 cm). RESULTS: The mean follow-up duration was 9.9 ± 7.8 years (range, 0-29 years). In-hospital mortality was 3.2%. The most common postoperative complication was atrial fibrillation (4.3%). The 5-, 10-, and 30-year survival rates were 92.9%, 87.2%, and 75.5%, respectively. Recurrence occurred in two patients (2.1%), which were detected at 20 and 79 months after the first surgery, respectively. CONCLUSIONS: Long-term survival after myxoma resection was excellent and recurrence was rare. Based on our experience, surgical method did not affect the outcome.

Supraclavicular transposition of aberrant left vertebral artery for hybrid treatment of aortic arch aneurysm: a case report.

BACKGROUND: Vertebral artery variations are common in thoracic aortic patients. If patients have the aberrant left vertebral artery, the more difficult to determine the treatment modality. CASE PRESENTATION: We report the case of a 63-year-old man with an aberrant left vertebral artery originating from an aneurysmal aortic arch. The patient underwent a successful hybrid thoracic endovascular aortic repair after aortic arch debranching and transposition of the aberrant left vertebral artery to the left common carotid artery through a supraclavicular incision without sternotomy. CONCLUSIONS: The aberrant left vertebral artery originating from the aortic arch can be safely transposed to the left common carotid artery through a supraclavicular approach.

Postoperative air leak grading is useful to predict prolonged air leak after pulmonary lobectomy.

BACKGROUND: Results of studies to predict prolonged air leak (PAL; air leak longer than 5 days) after pulmonary lobectomy have been inconsistent and are of limited use. We developed a new scale representing the amount of early postoperative air leak and determined its correlation with air leak duration and its potential as a predictor of PAL. METHODS: We grade postoperative air leak using a 5-grade scale. All 779 lobectomies from January 2005 to December 2009 with available medical records were reviewed retrospectively. We devised six 'SUM' variables using air leak grades in the initial 72 h postoperatively. RESULTS: Excluding unrecorded cases and postoperative broncho-pleural fistulas, there were 720 lobectomies. PAL occurred in 135 cases (18.8%). Correlation analyses showed each SUM variable highly correlated with air leak duration, and the SUM4to9, which was the sum of six consecutive values of air leak grades for every 8 h record on postoperative days 2 and 3, was proved to be the most powerful predictor of PAL; PAL could be predicted with 75.7% and 77.7% positive and negative predictive value, respectively, when SUM4to9 ≥ 16. When 4 predictors derived from multivariable logistic regression of perioperative variables were combined with SUM4to9, there was no significant increase in predictability compared with SUM4to9 alone. CONCLUSIONS: This simple new method to predict PAL using SUM4to9 showed that the amount of early postoperative air leak is the most powerful predictor of PAL, therefore, grading air leak after pulmonary lobectomy is a useful method to predict PAL.