Spatial-photonic Ising machine by space-division multiplexing with physically tunable coefficients of a multi-component model.

This paper proposes a space-division multiplexed spatial-photonic Ising machine (SDM-SPIM) that physically calculates the weighted sum of the Ising Hamiltonians for individual components in a multi-component model. Space-division multiplexing enables tuning a set of weight coefficients as an optical parameter and obtaining the desired Ising Hamiltonian at a time. We solved knapsack problems to verify the system's validity, demonstrating that optical parameters impact the search property. We also investigated a new dynamic coefficient search algorithm to enhance search performance. The SDM-SPIM would physically calculate the Hamiltonian and a part of the optimization with an electronics process.

Low-Rank Combinatorial Optimization and Statistical Learning by Spatial Photonic Ising Machine.

The spatial photonic Ising machine (SPIM) [13D. Pierangeli et al., Large-Scale Photonic Ising Machine by Spatial Light Modulation, Phys. Rev. Lett. 122, 213902 (2019).PRLTAO0031-900710.1103/PhysRevLett.122.213902] is a promising optical architecture utilizing spatial light modulation for solving large-scale combinatorial optimization problems efficiently. The primitive version of the SPIM, however, can accommodate Ising problems with only rank-one interaction matrices. In this Letter, we propose a new computing model for the SPIM that can accommodate any Ising problem without changing its optical implementation. The proposed model is particularly efficient for Ising problems with low-rank interaction matrices, such as knapsack problems. Moreover, it acquires the learning ability of Boltzmann machines. We demonstrate that learning, classification, and sampling of the MNIST handwritten digit images are achieved efficiently using the model with low-rank interactions. Thus, the proposed model exhibits higher practical applicability to various problems of combinatorial optimization and statistical learning, without losing the scalability inherent in the SPIM architecture.

Association between socioeconomic status and net survival after primary lung cancer surgery: a tertiary university hospital retrospective observational study in Japan.

BACKGROUND: Inequalities in opportunities for primary lung cancer surgery due to socioeconomic status exist. We investigated whether socioeconomic inequalities exist in net survival after curative intent surgery at a tertiary university hospital, in Japan. METHODS: Data from the hospital-based cancer registry on primary lung cancer patients who received lung resection between 2010 and 2018 were linked to the surgical dataset. An area deprivation index, calculated from small area statistics and ranked into tertiles based on Japan-wide distribution, was linked with the patient's address as a proxy measure for individual socioeconomic status. We estimated net survival of up to 5 years by deprivation tertiles. Socioeconomic inequalities in cancer survival were analyzed using an excess hazard model. RESULTS: Of the 1039 patient-sample, advanced stage (Stage IIIA+) was more prevalent in the most deprived group (28.1%) than the least deprived group (18.0%). The 5-year net survival rates (95% confidence interval) from the least to the most deprived tertiles were 82.1% (76.2-86.6), 77.6% (70.8-83.0) and 71.4% (62.7-78.4), respectively. The sex- and age-adjusted excess hazard ratio of 5-year death was significantly higher in the most deprived group than the least deprived (excess hazard ratio = 1.64, 95% confidence interval: 1.09-2.47). The hazard ratio reduced toward null after additionally accounting for disease stage, suggesting that the advanced stage may explain the poor prognosis among the deprived group. CONCLUSION: There was socioeconomic inequality in the net survival of patients who received curative intent surgery for primary lung cancer. The lower socioeconomic status group might be less likely to receive early curative surgery.

Detecting the location of lung cancer on thoracoscopic images using deep convolutional neural networks.

OBJECTIVES: The prevalence of minimally invasive surgeries has increased the need for tumor detection using thoracoscopic images during lung cancer surgery. We conducted this study to analyze the efficacy of a deep convolutional neural network (DCNN) for tumor detection using recorded thoracoscopic images of pulmonary surfaces. MATERIALS AND METHODS: We collected 644 intraoperative thoracoscopic images of changes in pulmonary appearance from 427 patients with lung cancer between 2012 and 2021. The lesion areas on the thoracoscopic images were detected by bounding boxes using an advanced version of YOLO, a well-known DCNN for object detection. The DCNN model was trained and evaluated by a 15-fold cross-validation scheme. Each predicted bounding box was considered successful detection when it overlapped more than 50% of the lesion areas annotated by board-certified surgeons. RESULTS AND CONCLUSIONS: Precision, recall, and F1-measured values of 91.9%, 90.5%, and 91.1%, respectively, were obtained. The presence of lymphatic vessel invasion was associated with successful detection (p = 0.045). The presence of pathological pleural invasion also showed a tendency toward successful detection (p = 0.081). The proposed DCNN-based algorithm yielded an accuracy of more than 90% tumor detection. These algorithms will help surgeons detect lung cancer displayed on a screen automatically.

[Minimally Invasive Surgery for Mediastinal Tumor].

We have been performing multiport thoracoscopic surgery as a minimally invasive procedure for mediastinal tumors. The criteria for thoracoscopic surgery are as follow;tumor under 6 cm without invasion of great vessels, chest wall, or lung. We started one port surgery since 2017 and robot-assisted thoracoscopic surgery since 2018. We retrospectively reviewed these three approaches for mediastinal tumor for 12 years. 269 patients underwent surgery for mediastinal tumor, 141 patients by multiport surgery, 21 patients by one port surgery, and 38 patients by robot-assisted thoracoscopic surgery. Of 203 patients with anterior mediastinal tumors, 141 patients underwent thymectomy for thymic tumors (72 patients by multiport surgery, 9 patients by one port surgery, 17 patients by robot-assisted thoracoscopic surgery, and 43 patients by open surgery). There was no difference in tumor size, but the operating time and blood loss were significantly less in one port surgery than in multiport surgery or robot-assisted thoracoscopic surgery. The approaches have become more diverse, with a wider choice of surgical techniques, allowing us to offer more radical minimally invasive surgeries.

Postoperative Delirium in Lung Cancer Anatomical Resection-Analysis of Risk Factors and Prognosis.

BACKGROUND: The incidence of postoperative delirium after anatomical lung resection ranges from 5 to 16%. This study aimed to analyze the risk factors and prognosis of postoperative delirium in anatomical lung resection for lung cancer. METHODS: This study included 1351 patients undergoing anatomical lung resection between April 2010 and October 2020. We analyzed the perioperative risk factors of postoperative delirium. We also compared postoperative complications and survival between the delirium and non-delirium groups. RESULTS: Postoperative delirium was identified in 44 (3.3%) of 1351 patients who underwent anatomical lung resection for lung cancer. Age, peripheral vascular disease, depression, and current smoking status were independent risk factors for postoperative delirium in the multivariate analysis. The percentage of postoperative delirium was 0.6% in never smokers and 6.0% in current smokers. The delirium and non-delirium groups showed significant differences in overall survival (p = 0.0144) and non-disease-specific survival (p = 0.0080). After propensity score matching, the two groups did not significantly differ in overall survival (p = 0.9136), non-disease-specific survival (p = 0.8146), or disease-specific survival (p = 0.6804). CONCLUSIONS: Age, peripheral vascular disease, depression, and current smoking status were considered independent risk factors for postoperative delirium in anatomical lung resection for lung cancer. Smoking cessation for at least four weeks before surgery is recommended for reducing incidence of post-operative delirium.

Endovascular Treatment for Acute Ischemic Stroke After Video-Assisted Thoracoscopic Pulmonary Lobectomy in Patients With Lung Cancer: A Report of Four Cases and Literature Review.

BACKGROUND: Postoperative cerebral embolic stroke is a serious complication of pulmonary lobectomy, occurring in 1.1% of patients undergoing lobectomy through video-assisted thoracoscopic surgery (VATS). The mechanism of this complication is thought to be embolic stroke caused by thrombus formed due to stagnation in the pulmonary vein stump after VATS lobectomy. There have been few reports demonstrating the utility of endovascular treatment (EVT) for cerebral embolic stroke after VATS lobectomy. CASE DESCRIPTION: In our case series, cerebral embolic stroke occurred after VATS pulmonary lobectomy for lung cancer, including the left upper lobe in three cases and the right lobe in one. The median duration of ischemic stroke after VATS was 4.5 days (interquartile range, 2-9 days). The median time from stroke onset to puncture was 130 min. Successful recanalization was achieved in all cases, and two patients achieved favorable clinical outcomes (modified Rankin scale, 0-2). CONCLUSION: We report a case series of four patients who underwent EVT for acute embolic stroke after VATS lobectomy for lung cancer. EVT is considered a reasonable and feasible therapeutic option for this condition.

Homeobox transcription factor engrailed homeobox 1 is a possible diagnostic marker for adenoid cystic carcinoma and polymorphous adenocarcinoma.

Diagnostic utility of a homeobox transcription factor, engrailed homeobox 1 (En1) in the histopathology of salivary gland neoplasms was studied. The expression of En1 was immunohistochemically examined in 51 cases of adenoid cystic carcinoma (AdCC) and 143 cases of other salivary gland neoplasms. In all 51 AdCCs, En1 was expressed in 30-100% of tumor cells. In eight of nine polymorphous adenocarcinomas (PACs), En1 was expressed in 40-100% of tumor cells. Less than 5% of tumor cells expressed En1 in three of 12 epithelial-myoepithelial carcinomas, one of 17 basal cell adenomas (BCAs), and one of 34 pleomorphic adenomas (PAs). Among 55 other carcinoma cases, 1-30% of tumor cells expressed En1 in three salivary duct carcinomas (SDCs) ex PA. None of the myoepitheliomas and Warthin tumors expressed En1. When the cut-off value of the percentage of En1-expressing cells was set to 25%, all 51 AdCCs, eight of nine PACs and one SDC ex PA were En1-positive and the others were En1-negative. En1 is expressed consistently in AdCCs, frequently in PACs, but rarely in other salivary gland neoplasms. En1 is a possible diagnostic marker for AdCC and PAC in the histopathology of salivary gland neoplasms.

Infinite ergodicity that preserves the Lebesgue measure.

In this study, we prove that a countably infinite number of one-parameterized one-dimensional dynamical systems preserve the Lebesgue measure and are ergodic for the measure. The systems we consider connect the parameter region in which dynamical systems are exact and the one in which almost all orbits diverge to infinity and correspond to the critical points of the parameter in which weak chaos tends to occur (the Lyapunov exponent converging to zero). These results are a generalization of the work by Adler and Weiss. Using numerical simulation, we show that the distributions of the normalized Lyapunov exponent for these systems obey the Mittag-Leffler distribution of order 1/2.

Postoperative Atrial Fibrillation in Lung Cancer Lobectomy-Analysis of Risk Factors and Prognosis.

BACKGROUND: The incidence of postoperative atrial fibrillation (POAF) after pulmonary lobectomy ranges from 6.4 to 12.6%. This study aimed to analyze the postoperative risk factors and prognosis for POAF in lobectomy for lung cancer. METHODS: Data were collected from patients undergoing pulmonary lobectomy from April 2010 to March 2019. We analyzed risk factors for POAF among perioperative factors and compared postoperative complications or overall survival between POAF and non-POAF groups. We classified POAF as either the temporary or non-temporary type and compared perioperative factors, postoperative complications, and overall survival. RESULTS: POAF was identified in 49 (5.2%) of the 947 lobectomies. The POAF group included more males, patients with poor performance status (PS), history of paroxysmal atrial fibrillation (AF), chronic obstructive pulmonary disease (COPD), and intraoperative blood transfusions. Poor PS, COPD, previous paroxysmal AF, and intraoperative blood transfusion were independent risk factors for POAF in multivariate analysis. The POAF group had a poorer prognosis than the non-POAF group (p = 0.0045). POAF was divided into 29 temporary and 20 non-temporary types. The onset date of non-temporary-type POAF was significantly later than that of the transient type (P < 0.01), and diabetes mellitus was significantly higher in non-temporary-type POAF. Non-temporary-type POAF had a significantly poorer prognosis in terms of overall survival (p = 0.005). CONCLUSIONS: Poor PS, COPD, history of PAF, and intraoperative blood transfusion were independent risk factors for POAF. Non-temporary-type POAF occurred significantly later than transient type and caused poorer prognosis after lobectomy for lung cancer.

Mucinous lung adenocarcinoma, particularly referring to EGFR-mutated mucinous adenocarcinoma.

The current 2015 World Health Organization (WHO) classification of lung tumors does not adequately categorize mucinous lung adenocarcinoma. Thus far, only two variants of mucinous adenocarcinoma have been studied: invasive mucinous adenocarcinoma and colloid adenocarcinoma. Moreover, common types of invasive adenocarcinoma when they produce mucin are yet to be elucidated, particularly epidermal growth factor receptor (EGFR)-mutated mucinous adenocarcinoma. In this study, we extracted mucinous adenocarcinoma of both the common types and the two variants. Further, we immunohistochemically and molecular-biologically examined their clinicopathological characteristics, mutation patterns, and expressions of thyroid transcription factor-1 (TTF-1), hepatocyte nuclear factor-4 alpha (HNF-4a) and mucins, particularly referring to EGFR-mutated adenocarcinoma. Among 1159 surgically resected invasive adenocarcinomas, 189 mucinous adenocarcinomas (16%) were identified. Among these, 20%, 34% and 9.5% were EGFR mutated, KRAS mutated and ALK rearranged, respectively. Compared with EGFR-mutated nonmucinous adenocarcinoma, EGFR-mutated mucinous adenocarcinoma had no female predominance, lower grades of histological differentiation and lower TTF-1 and higher HNF-4a expressions. Moreover, for the first time, we indicated that mucin production was an independent prognostic factor for EGFR-mutated adenocarcinomas and the mucin-staining pattern of negative MUC5AC and positive MUC5B was characteristic in these adenocarcinomas. We suggest that EGFR-mutated mucinous adenocarcinoma has a different tumorigenic pathway than nonmucinous EGFR-mutated adenocarcinoma.

Negative reactions of BRAF mutation-specific immunohistochemistry to non-V600E mutations of BRAF.

BRAF mutations are rare driver mutations in non-small cell lung cancer (NSCLC), accounting for 1%-2% of the driver mutations, and the mutation spectrum has a wide range in contrast to other tumors. While V600E is a dominant mutation in melanoma, more than half of the mutations in NSCLCs are non-V600E. However, treatment with dabrafenib plus trametinib targets the BRAF V600E mutation exclusively. Therefore, distinguishing between V600E and non-V600E mutations is crucial for biomarker testing in NSCLC in order to determine treatment of choice. Immunohistochemistry (IHC) using the BRAF V600E mutation-specific antibody is clinically used in melanoma patients, but little is known about its application in NSCLC, particularly with regard to the assay performance for non-V600E mutations. In the present study, we examined 117 tumors with BRAF mutations, including 30 with non-V600E mutations, using BRAF mutation-specific IHC. None of the tumors with non-V600E mutations, including two compound mutations, showed a positive reaction. Furthermore, all V600E mutations were positive except for one case with combined BRAF V600E and K601_W604 deletion. Our findings confirmed that the BRAF V600E mutation-specific IHC is specific without any cross-reactions to non-V600E mutations, suggesting that this assay can be a useful screening tool in clinical practice.

Effects of alveolar recruitment maneuver on end-expiratory lung volume during one-lung ventilation.

PURPOSE: To investigate the effects of alveolar recruitment maneuver (ARM) during one-lung ventilation (OLV) on end-expiratory lung volume (EELV) of the dependent lung. METHODS: Patients who were planned to undergo lung resection surgery for lung tumors and needed OLV for at least 1 h were included in the study. After turning the patients into the lateral position under total intravenous anesthesia, OLV was commenced using a double-lumen endobronchial tube. EELV was measured using the nitrogen washout technique at 20 min after OLV started (baseline) and 15, 30, 45, 60 min after ARM was performed on the dependent lung. RESULTS: Among 42 patients who completed the study, EELV increased at 15 min after ARM by 20% or greater compared with baseline in 21 patients (responders). Responders were significantly shorter in height (158 vs. 165 cm, p = 0.01) and had smaller preoperative functional residual capacity (2.99L vs. 3.65L, p = 0.02) than non-responders. Before ARM, responders had significantly higher driving pressure (14.2 vs. 12.4 cmH2O, p = 0.01) and lower respiratory system compliance (23.6 vs. 31.4 ml/cmH2O, p = 0.0002) than non-responders. Driving pressure temporarily dropped after ARM in responders, while no significant change was observed in non-responders. Fourteen out of 21 responders kept EELV 20% or more increased EELV than baseline at 60 min after ARM. CONCLUSION: EELV of the dependent lung was increased by 20% or greater in half of the patients responding to ARM. The increased volume of the dependent lung caused by ARM was maintained for 60 min in two-thirds of the responders.

Long-term outcomes of intensity-modulated radiotherapy following extra-pleural pneumonectomy for malignant pleural mesothelioma.

BACKGROUND: The purpose was to evaluate safety and efficacy of intensity-modulated radiotherapy (IMRT) following extra-pleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM). MATERIAL AND METHODS: Patients with MPM of clinical stage I-III, which were macroscopic completely resected with EPP were eligible for this prospective study. The ipsilateral hemithorax was irradiated with a prescribed dose of 50.4 Gy. When the high-risk surgical margins or FDG-avid regions were identified, simultaneous integrated boost (SIB) with 56.0 Gy or 61.6 Gy was applied. RESULTS: Twenty-one patients were enrolled. SIB was applied to five patients. The planned IMRT fractions were completed in all, but four patients who suffered from severe fatigue or radiation pneumonitis. With a potential median follow-up of 6.3 years, overall survival was 37.5% at 3 years since the IMRT. The median survival time was 17.5 and 27.0 months since the IMRT and the initial treatment, respectively. Three patients have survived for more than 5 years. Distant metastasis was observed in 15 patients. Local recurrence was also observed in 2 of the 15 patients. Acute toxicities of Grade 3 or worse were observed in 15 patients, including 9 with hematological, 3 with pneumonitis and 6 with fatigue, nausea or vomiting. Five patients developed Grade 3 or worse late toxicities associated with IMRT, consisting of one with persistent Grade 4 thrombocytopenia, one with brain infarction and congestive liver dysfunction, and three with elevation of serum transaminase or biliary enzyme. No Grade 5 toxicity was observed. Patients with N2 showed significantly worse survival than those with N0-1 (18.2% vs. 60.0% at 3 years, p = .014). CONCLUSION: IMRT following EPP achieved excellent local control for MPM, that might lead to the long-term survival in selected patients. However, treatment burden including acute and late toxicities should be considered in this treatment approach.

A phase II trial evaluating the efficacy and safety of perioperative pirfenidone for prevention of acute exacerbation of idiopathic pulmonary fibrosis in lung cancer patients undergoing pulmonary resection: West Japan Oncology Group 6711 L (PEOPLE Study).

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) often accompanies lung cancer, and life-threatening acute exacerbation (AE) of IPF (AE-IPF) is reported to occur in 20 % of IPF patients who undergo lung cancer surgery. Pirfenidone is an anti-fibrotic agent known to reduce disease progression in IPF patients. A phase II study was conducted to evaluate whether perioperative pirfenidone treatment could reduce the incidence of postoperative AE-IPF patients with lung cancer. METHODS: Pirfenidone was orally administered to IPF patients who were candidates for lung cancer surgery; pirfenidone was dosed at 600 mg/day for the first 2 weeks, followed by 1200 mg/day. Surgery was performed after at least 2 weeks of 1200-mg/day administration. The primary endpoint was non-AE-IPF rate during postoperative days 0-30, compared to the null value of 80 %, and the secondary endpoint was safety. Radiologic and pathologic diagnoses of IPF and AE-IPF were confirmed by an independent review committee. RESULTS: From June 2012 to January 2014, 43 cases were enrolled, and 39 were eligible (full analysis set [FAS]). Both pirfenidone treatment and surgery were performed in 36 patients (per protocol set [PPS]). AE-IPF did not occur in 37/39 patients (94.9 % [95 % confidential interval: 82.7-99.4 %, p = 0.01]) in the FAS, and in 38/39 patients (97.2 % [95 % confidential interval: 85.5-99.9 %, p = 0.004] in the PPS. A grade 5 adverse event (death) occurred in 1 patient, after AE-IPF; no other grade 3-5 adverse events were observed. CONCLUSIONS: Perioperative pirfenidone treatment is safe, and is promising for reducing AE-IPF after lung cancer surgery in IPF patients. TRIAL REGISTRATION: This clinical trial was registered with the University Hospital Medical Information Network (UMIN) on April 16th, 2012 (REGISTRATION NUMBER: UMIN000007774 ).

Efficacy of Supraglottic Airway for Preventing Lung Injury Associated with Coughing at Extubation after Pulmonary Lobectomy.

BACKGROUND: The use of double-lumen endobronchial tubes (DLTs) is necessary for differential lung ventilation during pulmonary lobectomy. However, when used with conventional extubation procedures, coughing is more likely and is associated with an increased risk for parenchymal air leak along the staple line and possible subsequent lung injury. We examined the prevalence of coughing-associated air leaks at extubation and the efficacy of using supraglottic airways (SGAs) to prevent air leaks with post-lobectomy extubation. METHODS: This study included 150 patients with pulmonary emphysema diagnosed using preoperative computed tomography, who underwent pulmonary lobectomy between April 2010 and March 2015. The patients were chronologically enrolled in two groups: the DLT group (60 patients) from April 2010 to August 2012, and the SGA group (90 patients) from September 2012 to March 2015. (Note: the DLT group only included cases without air leak present just prior to extubation). Data were collected on specific patient characteristics and operative and postoperative factors. RESULTS: Coughing at extubation occurred in 15 (25.0 %) of 60 DLT patients, and parenchymal air leaks developed in 10 (66.7 %) of these 15. Comparison of groups revealed the SGA group was significantly lower for the following: patients with coughing at extubation (P < 0.001), coughing-associated air leaks at extubation (P < 0.001), air leaks >7 days (P = 0.006), reoperation due to air leaks (P = 0.013), and duration of chest tube drainage (P < 0.001). CONCLUSIONS: The SGA is effective for preventing air leaks associated with coughing during conventional DLT extubation in post-lobectomy patients.

Port-site recurrence after complete resection of stage I thymoma by video-assisted thoracoscopic surgery: report of a case.

A 62-year-old female with myasthenia gravis and a mediastinal tumor underwent extended thymothymectomy by video-assisted thoracoscopic surgery (VATS). The tumor was diagnosed as a stage I type B2 thymoma. Eight years after the initial surgery, an abnormal shadow was detected on the annual follow-up chest radiograph, and computed tomography showed a homogeneous 35 × 15 mm hemispherical mass under a port-site scar in the right anterior chest wall. The mass was between the second and third ribs and was found to be adherent to the lung during surgery, and was excised via lung and chest wall resection. The pathological examination confirmed that it was a type B2 thymoma invading the third rib, and the tumor was considered to be a port-site recurrence. Care should be taken during VATS to avoid contact between the tumor surface and the port tracts to prevent tumor cell implantation.

[Management of Patients with Preexisting Cardiac Complications during Thoracic Surgery for Lung Cancer].

UNLABELLED: In patients with preoperative cardiac complications such as myocardial ischemia, arrhythmia, or congestive heart failure, it is important to offer any necessary medical treatments, such as anticoagulation therapy, prior to surgery. This study investigated the perioperative results of surgical treatment for primary lung cancer in patients with cardiac complications. Data relating to 467 patients who underwent lung resection for lung cancer between April 2010 and March 2014 were collected. Perioperative factors for patients with preoperative cardiac complications and patients without preoperative cardiac complications were compared. Perioperative factors were also compared for a heparin bridging group and non-heparin bridging group in 53 anti-coagulation therapy patients. RESULTS: Fifty-three (11.3%) patients had preoperative cardiac complications;the majority of these had ischemic heart disease( n=31, 58.5%), while a significant minority had atrial fibrillation( n=14, 33.3 %). Of these, 42 patients(79.2%)were receiving anti-coagulation therapy;pre-operative bridging anti-coagulation using heparin was performed in 19 patients(45.2%). There were significant differences between those patients with preoperative cardiac complications, and those without preoperative cardiac complications, in terms of sex( male;81.1% vs 65.7%, p=0.024), mean age(73.1±1.0 year vs 68.4±0.7 year, p=0.001), and duration (days) of hospitalization after surgery(10.1±2.4 vs 7.8±2.0, p=0.023). There were significant differences between patients who received pre-operative heparin bridging anticoagulation, compared with those who did not, in terms of age(70.8±1.2 year vs 76.8±0.9 year, p=0.001)and duration (days) of hospitalization after surgery(10.5±2.1 vs 7.5±1.3, p=0.005). CONCLUSION: Fifty-three(11.3%)patients had preoperative cardiac complications. Recent changes in the demographics of surgical candidates, in terms of age, have increased the number of patients with surgical risk factors. Perioperative patient management has become more important than before.

Bilateral thoracotomy for horseshoe lung complicated with severe aspergilloma: a case report.

BACKGROUND: Horseshoe lung is a rare congenital malformation in which the lung protrudes from the mediastinum to the other side. Owing to the high frequency of other fatal cardiovascular complications, it is often diagnosed in childhood and rarely unnoted until adulthood. We report a case of horseshoe lung in an older patient who underwent thoracotomy. CASE PRESENTATION: The patient was a 69-year-old man with chronic obstructive pulmonary disease (COPD) and a history of heavy smoking. The patient was admitted to the hospital because of acute exacerbation of COPD. Computed tomography revealed horseshoe lung and pulmonary sequestration with pneumonia. This was the first time that he was diagnosed with horseshoe lung; however, he had been treated for pneumonia multiple times before. Surgery for the horseshoe lung was recommended; however, the patient declined it because his symptoms of acute COPD exacerbation were relieved by medication. Aspergillus infection of the horseshoe lung led to frequent bloody sputum, and the patient's respiratory condition gradually worsened. Two years after the initial diagnosis, the patient decided to undergo the surgery. Surgery was performed in the order of left and right thoracotomies, with posterolateral thoracotomies performed bilaterally. Surgery was difficult because of strong adhesions around the inflamed lung; however, the lung was removed in one lump. The patient was extubated on postoperative day (POD) 1, and rehabilitation was initiated. His high sputum volume caused postoperative pneumonia, and the patient was again placed on a ventilator on POD 9. He underwent open-window surgery for concomitant pyothorax. The patient was weaned off the ventilator when the inflammation improved and was discharged on POD 133. The patient lived at home, developed severe pneumonia 4 months later, and died of respiratory failure. CONCLUSION: Pulmonary sequestration and horseshoe lungs are congenital malformations that require surgery. The selection of the optimal time for surgery is important.