Surgical repair for a parahiatal hernia with an esophageal hiatal hernia: A case report and literature review.

INTRODUCTION AND IMPORTANCE: A parahiatal hernia (PH) is a rare diaphragmatic hernia (DH) adjacent to but separated from the esophageal hiatus. The surgical repair for PH needs primary suture closure or complicated hernioplasty and the addition of an anti-reflux procedure. This report describes a case of PH with a symptomatic esophageal hiatal hernia managed using three-dimensional (3D) laparoscopy. CASE PRESENTATION: A 65-year-old woman with back pain and breathlessness was referred to our hospital for a DH. Computed tomography showed a diaphragmatic defect on the left side of the esophageal hiatus. Upper gastrointestinal endoscopy and 24-hour esophageal impedance-pH monitoring showed a symptomatic esophageal hiatal hernia. Laparoscopic repair for both hernias was performed using 3D laparoscopy. The DH orifice was located in the left crus of the diaphragm, and it was separated from the esophageal hiatus. These findings showed that this DH was a PH. The PH was repaired with primary suturing, and a hiatoplasty was performed. Toupet fundoplication was performed with a 270° posterior wrap of the gastric fornix. The patient has remained asymptomatic a year after surgery without any complications. CLINICAL DISCUSSION: 3D laparoscopy provides significant advantages in surgeries requiring precise suturing. PH repairs require complex procedures, including mesh repair or suturing. Approximately 44 % of PH cases also necessitate fundoplication. 3D laparoscopy was useful for the present case. CONCLUSIONS: A rare PH and a symptomatic type 1 hiatal hernia were repaired with 3D laparoscopy, which is helpful for PH treatment in cases requiring complicated procedures.

Effects of trastuzumab emtansine on canine urothelial carcinoma cells in vitro and in vivo.

Urothelial carcinoma (UC) is the most common malignancy of the urinary tract in dogs and has aggressive behaviour. Although human epidermal growth factor receptor 2 (HER2) is a known therapeutic target with evidence in canine UC, the efficacy of anti-HER2 antibody drugs remains unknown. This study aimed to investigate the effects of anti-HER2 antibody drugs including trastuzumab and trastuzumab emtansine (T-DM1) on canine UC cell lines in vitro and in vivo. Four canine UC cell lines (Nene, TCCUB, Love, and Sora) were used. In western blotting, HER2 protein expression was observed in all the cell lines. Although both trastuzumab and T-DM1 showed dose-dependent growth inhibitory activity in the cell lines, T-DM1 showed much stronger activity than that of trastuzumab. In flow cytometry analyses with the canine UC cell line (Sora), T-DM1 but not trastuzumab significantly increased the percentages of early and late apoptotic cells in annexin V apoptotic assays and the sub-G1 phase fraction in cell cycle analyses. For the in vivo experiment, the canine UC cells (Sora) were subcutaneously injected into nude mice. Four days after inoculation, trastuzumab, T-DM1, or vehicle was administered intraperitoneally once a week for three times. Tumour volumes were significantly smaller in the T-DM1 group compared to the trastuzumab and vehicle control groups. These findings indicate that T-DM1 exerts a stronger antitumour effect than that of trastuzumab on canine UC cells in vitro and in vivo, possibly by inducing apoptosis due to DM1.

Staged therapeutic surgery for progressive pulmonary regurgitation and pacemaker induced cardiomyopathy after the tetralogy of fallot repair.

BACKGROUND: Recently, improvements in the repair of tetralogy of Fallot have increased the need for reoperation in adulthood, and it's not rare that these reoperation candidates suffer from biventricular failure. However, there are no firm treatment guidelines, and each country, and even each facility, treats each case individually. CASE PRESENTATION: We report the successful staged treatment of pulmonary regurgitation and pacemaker-induced cardiomyopathy with biventricular failure in adulthood in a case of complete atrioventricular block after tetralogy of Fallot repair in childhood. We planned a staged therapeutic strategy with preoperative left ventricular volume reduction with medication, following surgical pulmonary valve replacement concomitant epicardial lead implantation on the lateral basal wall, placed just beneath the generator pocket through 3rd intercostal space. in addition to postoperative intervention with a defibrillator to adjust cardiac resynchronization therapy, resulted in improvement of symptoms. CONCLUSION: In a patient with biventricular failure after TOF repair, a staged treatment strategy involving medication, PVR, and CRT with a combination of epicardial and intravenous leads could be a useful treatment worth trying before heart transplantation.

Aortic Annular Enlargement with Modified Y-Incision Technique Devised from Preoperative Three-Dimensional Computed Tomography.

The Y-incision technique introduced by Dr. Bo Yang in 2021 is a very innovative technique that can enlarge the aortic annulus by two or more sizes without violating the left atrium or mitral valve. However, we encountered a case in which the left coronary artery ostium was located close to the left-non commissure. Therefore, we considered it would be dangerous to expand the incision to the left coronary annulus. We therefore devised a new technique that enlarges only the noncoronary annulus in an "L" fashion instead of a "Y" fashion. In performing this surgery, preoperative three-dimensional images were useful for understanding the anatomy when planning the aortic annular enlargement procedure. The L-incision technique can be a useful alternative method of aortic annulus enlargement.

Midterm Results of Mitral Valve Repair Using Loop Technique With Simple Height Reduction of the Large Posterior Leaflet.

OBJECTIVE: Systolic anterior motion (SAM) is one of the most serious problems in mitral valve repair. Height reduction is a key procedure to solve SAM, and there are limited data on the surgical results of height reduction procedure. This study is to assess the effectiveness and midterm results of simple height reduction procedure for SAM in patients with severe mitral regurgitation (MR). METHODS: From 2008 to 2022, 50 patients underwent loop technique with an additional simple height reduction procedure for prevention of SAM. We examined the midterm results of patients with simple height reduction regarding recurrent MR and reoperation. The follow-up period ranged from 171 to 3,816 days (median, 883 days). RESULTS: There were 338 patients (87%) who underwent loop technique without height reduction and 50 patients (13%) who underwent loop technique with height reduction. After the height reduction procedure, SAM was prevented in 44 patients, and 6 patients needed volume loading to suppress SAM. Freedom from recurrence of moderate to severe or severe MR at 1, 3, and 5 years was 98%, 88%, and 88% in the height reduction group versus 98%, 96%, and 94% in the group with loop technique alone (P = 0.074). Receiver operating characteristic curves showed that a systolic dimension of 26 mm had a sensitivity of 75% and a specificity of 83% for predicting SAM after height reduction. CONCLUSIONS: Loop technique with simple height reduction was a simple, secure, and effective procedure to prevent SAM and recurrent significant MR in the midterm periods.

Podoplanin promotes cell proliferation, survival, and migration of canine non-tonsillar squamous cell carcinoma.

Podoplanin (PDPN) is a prognostic factor and is involved in several mechanisms of tumor progression in human squamous cell carcinoma (SCC). Canine non-tonsillar SCC (NTSCC) is a common oral tumor in dogs and has a highly invasive characteristic. In this study, we investigated the function of PDPN in canine NTSCC. In canine NTSCC clinical samples, PDPN overexpression was observed in 80% of dogs with NTSCC, and PDPN expression was related to ki67 expression. In PDPN knocked-out canine NTSCC cells, cell proliferation, cancer stemness, and migration were suppressed. As the mechanism of PDPN-mediated cell proliferation, PDPN knocked-out induced apoptosis and G2/M cell cycle arrest in canine NTSCC cells. These findings suggest that PDPN promotes tumor malignancies and may be a novel biomarker and therapeutic target for canine NTSCC.

Podoplanin Drives Amoeboid Invasion in Canine and Human Mucosal Melanoma.

Mucosal melanoma metastasizes at an early stage of the disease in human and dog. We revealed that overexpression of podoplanin in tumor invasion fronts (IF) was related to poor prognosis of dogs with mucosal melanoma. Moreover, podoplanin expressed in canine mucosal melanoma cells promotes proliferation and aggressive amoeboid invasion by activating Rho-associated kinase (ROCK)-myosin light chain 2 (MLC2) signaling. PDPN-ROCK-MLC2 signaling plays a role in cell-cycle arrest and cellular senescence escape as a mechanism for regulating proliferation. Podoplanin induces amoeboid invasion in the IFs of mouse xenografted tumor tissues, similar to canine mucosal melanoma clinical samples. We further identified that podoplanin expression was related to poor prognosis of human patients with mucosal melanoma, and human mucosal melanoma with podoplanin-high expression enriched gene signatures related to amoeboid invasion, similar to canine mucosal melanoma. Overall, we propose that podoplanin promotes canine and human mucosal melanoma metastasis by inducing aggressive amoeboid invasion and naturally occurring canine mucosal melanoma can be a novel research model for podoplanin expressing human mucosal melanoma. IMPLICATIONS: Podoplanin could be a new therapeutic target to restrict the metastatic dissemination of canine and human mucosal melanoma.

Impact of cystatin C-derived glomerular filtration rate in patients undergoing transcatheter aortic valve implantation.

Background: Chronic kidney disease (CKD) impacts prognosis in patients undergoing transcatheter aortic valve implantation (TAVI). While estimated glomerular filtration rate (eGFR) calculated from serum creatinine [eGFR (creatinine)] is affected by body muscle mass which reflects frailty, eGFR calculated from serum cystatin C [eGFR (cystatin C)] is independent of body composition, resulting in better renal function assessment. Methods: This study included 390 consecutive patients with symptomatic severe aortic stenosis (AS) who underwent TAVI, and measured cystatin C-based eGFR at discharge. Patients were divided into two groups, with or without CKD estimated with eGFR (cystatin C). The primary endpoint of this study was the 3-year all-cause mortality after TAVI. Results: The median patient age was 84 years, and 32.8% patients were men. Multivariate Cox regression analysis indicated that eGFR (cystatin C), diabetes mellitus, and liver disease were independently associated with 3-year all-cause mortality. In the receiver-operating characteristic (ROC) curve, the predictive value of eGFR (cystatin C) was significantly higher than that of eGFR (creatinine). Furthermore, Kaplan-Meier estimates revealed that 3-year all-cause mortality was higher in the CKD (cystatin C) group than that in the non-CKD (cystatin C) group with log-rank p = 0.009. In contrast, there was no significant difference between the CKD (creatinine) and non-CKD (creatinine) groups with log-rank p = 0.94. Conclusions: eGFR (cystatin C) was associated with 3-year all-cause mortality in patients who underwent TAVI, and it was superior to eGFR (creatinine) as a prognostic biomarker.

Mitral valve repair with patch augmentation for atrial functional mitral regurgitation complicated with giant left atrium.

OBJECTIVE: We aimed to assess the results of posterior leaflet augmentation with an autologous pericardial patch in atrial functional mitral regurgitation. METHODS: Data of 16 patients with atrial functional mitral regurgitation who underwent posterior leaflet patch augmentation for mitral valve repair were retrospectively analyzed. This procedure was applied to a short posterior leaflet with a height of < 10 mm in P2. The median age was 72.5 [67.8-78.3] years. Preoperative New York Heart Association functional class was II in 7 (43.8%) and III or IV in 9 (56.2%) patients. Mitral regurgitation was moderate in 2 (12.5%) and severe in 14 (87.5%) patients. RESULTS: Operative mortality occurred in 1 (6.2%) patient due to cerebral infarction. One patient required valve replacement because of patch perforation early after operation. Mitral regurgitation was reduced to less than mild in 15 (93.8%) patients and less than trivial in 11 (68.8%) patients (P < 0.01) postoperatively. As for mid-term results, New York Heart Association functional class improved to I or II in 12 (75%) patients (P < 0.01). Two cases of thrombotic complication were observed. Remote recurrent regurgitation occurred in one case due to small patch size. The 3-year free rate of valve-related morbidity and regurgitation recurrence was 65.6% and 87.1%, respectively. The 5-year survival rate was 93.8%. CONCLUSIONS: Pericardial patch augmentation in atrial functional mitral regurgitation leads to good survival and mitral regurgitation recurrence-free rates. Steady anticoagulation and the use of larger patches would be necessary to reduce thrombotic complications and recurrent MR.

Evaluating the effect of high-density measurement mode on patient-specific quality assurance for head and neck cancer with ArcCHECK.

The high-density measurement (HDm) mode of the ArcCHECK device can achieve a twofold resolution enhancement compared to the standard measurement (Sm) mode. The aim of this study was to evaluate the effect of HDm on the gamma passing rate (GPR) for the patient-specific quality assurance (PSQA) in head and neck cancer. We retrospectively evaluated 30 patients who underwent volumetric modulated arc therapy (VMAT) for head and neck cancer. Absolute gamma analysis was performed on Sm and HDm data. We also investigated correlations between the modulation complexity score for VMAT (MCSv) and differences in the GPR between the two measurement modes. The global GPR of Sm and HDm was 81.0% ± 8.4% and 82.6% ± 7.6% for the 2%/2 mm criterion, 94.0% ± 4.1% and 94.9% ± 3.6% for the 3%/2 mm criterion, and 96.6% ± 2.4% and 97.0% ± 2.4% for the 3%/3 mm criterion, respectively. HDm slightly improved GPR (p < 0.01) for the 2%/2 mm criterion. Differences in GPR between Sm and HDm for the 2%/2 mm, 3%/2 mm, and 3%/3 mm criteria were 1.6% ± 3.0%, 0.8% ± 2.0%, and 0.4% ± 1.2%, respectively. No correlation was identified between the MCSv and the difference in GPR between Sm and HDm. Despite an improvement in GPR with HDm, the difference in GPR between Sm and HDm was approximately 2% even when the tighter criteria were used. Moreover, the change in the GPR between Sm and HDm did not depend on plan complexity. Thus, the effect of HDm on GPR is limited for the PSQA in VMAT for head and neck cancer.

A Novel Ring Knot Pusher With Closed Triangle Tip for Minimally Invasive Cardiac Surgery.

We created a novel ring-type knot pusher with a closed triangle tip, wherein the thread is never detached from the knot pusher head during the ligation process. This knot pusher has a small head and is suitable for complex fields, such as the subvalvular apparatus of the mitral valve, allowing the surgeons to observe the knot itself. Considering that the thread passes through the inner corner of the triangle during the tying-down process without swinging inside the triangle, this knot pusher allows for a stable and secure ligation.

[Tips for Successful Robot-assisted Mitral Valve Repair].

Robot-assisted valve repair refers to an intervention added to conventional minimally invasive cardiac surgery( MICS), which is covered by national insurance since April 2018. However, currently, this procedure is performed only at a few hospitals, which is attributable to the need for specialized facilities, as well as surgeon-related criteria including high technical expertise. Notably, the learning curve to stabilize robotic surgery is longer than that for conventional MICS. Our hospital introduced robot-assisted valve repair in June 2018, and we have performed >120 surgeries to date. Our policy focuses on "no compromise in the quality of valve repair". The loop technique is routinely used for valve repair, and the experience gained from median sternotomy and MICS is directly applied to robotic procedures. Robot-assisted surgery enhances surgical field visualization and improves operability even in cases of complex valve repair. In this article, I will describe the procedural innovations, secure establishment of cardiopulmonary bypass, surgical outcomes, and the current challenges in robot-assisted valve repair to achieve safe and improved results.

Histology of the tricuspid valve annulus and right atrioventricular muscle distance.

OBJECTIVES: Histologically, the mitral valve annulus comprises a collection of collagen fibres. However, the existence of collagen fibres in the tricuspid valve annulus has not been elucidated. Our goal was to clarify the histology of the tricuspid annulus. METHODS: Fifty human hearts without heart disease that were autopsied at Osaka City University Hospital between January 2009 and December 2017 were examined. The tricuspid valve was sectioned at 12 sites around the annulus, and the atrioventricular junction distance was measured. RESULTS: None of the tricuspid valve annulus samples had a continuous aggregation of collagen fibres that could be called an annulus. The interventricular space between the right atria and ventricles was composed of adipose tissue only on the anterosuperior and inferior sides, and no adipose tissue was found on the septal side. Comparing the atrioventricular muscle distance of the anterosuperior and inferior sides, the distance at the inferior side was statistically significantly larger than that of the anterosuperior side in 47 cases (P < 0.0001). CONCLUSIONS: There was no continuous circumferential aggregation of collagen fibres in the right atrioventricular junction. The distance between the right atrial and ventricular myocardium was greater at the inferior side than that at the anterosuperior side, which might lead to more inferior annular dilation versus anterosuperior dilation. These anatomical features will be fundamental for future discussions of the suturing method used in prosthetic ring annuloplasty for tricuspid regurgitation.

Three-dimensional transesophageal echocardiographic morphological evaluation of the tricuspid valve.

OBJECTIVES: The morphology of the tricuspid valve (TV), particularly valves with two posterior leaflets, is attracting attention. The present study was performed to investigate the usefulness of three-dimensional transoesophageal echocardiographic data for morphological evaluation of the TV . METHODS: Sixty patients underwent morphological evaluation of the TV by preoperative transoesophageal echocardiography followed by TV repair with median sternotomy, and each leaflet was measured intraoperatively. We analysed the TV morphology in 51 patients whose preoperative echocardiographic findings were consistent with intraoperative findings. RESULTS: The mid-systolic echo data, which included the annulus diameter of each leaflet, were correlated with the intraoperative evaluation findings compared with those in the mid-diastole. The annulus and area of the posterior leaflet were larger in patients with two than one posterior leaflet valve (42.4 ± 13.5 vs 30.7 ± 9.1 mm, P < 0.001 and 327 ± 185 vs 208 ± 77 mm2, P = 0.006, respectively). In the severe tricuspid regurgitation patients, the annulus of the posterior leaflet was larger and the annulus of the anterior leaflet was smaller in patients with two than one posterior leaflet valve [posterior: 48 mm [95% confidence interval (CI), 41-54 mm] vs 36 mm (95% CI, 27-45 mm), respectively; P = 0.043 and anterior: 38 mm (95% CI, 33-42 mm) vs 46 mm (95% CI, 40-52 mm), respectively; P = 0.025]. CONCLUSIONS: Patients who had a TV with two posterior leaflets had a larger annulus and area of the posterior leaflets. Preoperative three-dimensional transoesophageal echocardiography is useful for the morphological evaluation of the TV.

Outcomes of loop technique with ring annuloplasty: a > 10-year experience.

OBJECTIVE: We assessed the long-term outcomes of the loop technique with ring annuloplasty for mitral regurgitation from our > 10-year experience. METHODS: We retrospectively reviewed 362 patients who underwent the loop technique with ring annuloplasty via median sternotomy or right mini-thoracotomy for mitral regurgitation. The median follow-up duration was 4.1 years (interquartile range 2.3-5.8 years). RESULTS: This study involved 147 women and 215 men (median age, 66.5 years). Mitral regurgitation was caused by Barlow's disease in 27 patients. Seven patients required reoperations (recurrent regurgitation caused by technical issues, n = 3; progression of degenerative disease, n = 4). The 5- and 10-year cumulative incidences of reoperation considering death as the competing event were 1.4% and 5.4%, respectively. The 5- and 10-year postoperative cumulative incidences of moderate-to-severe recurrent mitral regurgitation were 4.7% and 13.0%, respectively. Residual regurgitation ≥ mild (hazard ratio, 6.99; 95% confidence interval, 1.520-32.12; P = .012) was an independent risk factor for reoperation. The independent risk factors for moderate-to-severe recurrent regurgitation were residual regurgitation ≥ mild (hazard ratio, 9.60; 95% confidence interval, 3.042-30.31; P < .001) and the loop-in-loop technique (hazard ratio, 3.40; 95% confidence interval, 1.058-10.90; P = .040). The median mean pressure gradient was sustained at almost 3.5 mmHg for > 7 years. CONCLUSIONS: The loop technique with ring annuloplasty provided excellent results with good hemodynamics beyond the mid-term. Residual regurgitation ≥ mild and the loop-in-loop technique may not be preferable for durable outcomes.

Aortomitral angle affects cardiovascular events after mitral valve repair for atrial functional mitral regurgitation.

PURPOSE: This study aimed to elucidate the geometric parameters of the aortomitral (AM) complex affecting postoperative cardiovascular events (CVEs) in patients with atrial functional mitral regurgitation (MR). METHODS: From October 2008 to August 2018, we performed mitral and tricuspid valve repairs in 58 patients with atrial functional MR. We examined the determinants of CVEs using preoperative and postoperative echocardiographic data. Furthermore, we analyzed the effect of left atrial (LA) plication on AM geometries after surgery. The follow-up period ranged from 56 to 3283 days (median, 1073 days). RESULTS: All patients underwent mitral and tricuspid annuloplasty. Seventeen patients (29%) underwent additional LA plication. The AM angle was narrowed after surgery in patients with CVEs (115° ± 6.8° to 106° ± 4.2°, p = .00336), whereas it widened in patients without CVEs (115° ± 7.4° to 118° ± 8.4°, p = .0278). The postoperative AM angle was an independent predictor of postoperative CVEs (p = .000829). LA plication was not a predictor of CVEs; however, it was a predictor of the obtuse postoperative AM angle (p = .0071). CONCLUSIONS: Our results suggest that a narrow postoperative AM angle is an independent predictor of postoperative CVEs. Additional LA plication reduces the sharpening of the AM angle, which may prevent CVEs after mitral valve repair for atrial functional MR.

Morphological diversity of the tricuspid posterior leaflet affects surgical complexity for control of tricuspid regurgitation.

OBJECTIVE: We investigated the effect of morphological diversity of the tricuspid valve with multiple posterior leaflets on the technical outcomes of tricuspid valve repair. METHODS: From April 2016 to November 2020, 141 patients were diagnosed with secondary tricuspid regurgitation associated with left heart disease and underwent tricuspid valve repair. We retrospectively analyzed the clinical and echocardiographic data of patients who underwent both preoperative and postoperative transthoracic echocardiography. We divided the patients into two groups according to the surgical technique used to treat tricuspid regurgitation: ring annuloplasty alone (Group 1, n = 109) or additional approximation of leaflet edges (edge-to-edge repair) with ring annuloplasty (Group 2, n = 32). We measured the morphological diversity of the tricuspid valve during the operation in all patients. RESULTS: The preoperative tricuspid regurgitation score was higher in Group 2 than in Group 1 (2.1 ± 0.78 vs. 1.6 ± 0.7, respectively; p = 0.0046), and Group 2 contained more patients with two posterior leaflets than Group 1 [20 (63%) vs. 36 (33%), respectively; p = 0.003]. The univariate and multivariate logistic regression analyses showed that the presence of two posterior leaflets was an independent risk factor for additional procedures during tricuspid valve repair (odds ratio, 2.6; 95% confidence interval, 1.1-6.1; p = 0.033). CONCLUSIONS: Additional procedures to reduce tricuspid regurgitation were required more frequently in patients with two posterior leaflets of the tricuspid valve. The morphological diversity of two posterior leaflets is a potential risk factor for a more complicated tricuspid repair.

Left atrial volume index predicts future improvement of B-type natriuretic peptide levels after transcatheter aortic valve replacement.

In patients with symptomatic severe aortic stenosis (AS), those who experienced readmission due to heart failure after transcatheter aortic valve replacement (TAVR) showed poor prognosis. Furthermore, poor B-type natriuretic peptide (BNP) improvement is associated with increased morbidity and mortality. However, little is known about the clinical parameters related to the change in BNP levels after TAVR procedure. This study population consisted of 127 consecutive patients of symptomatic severe AS with preserved ejection fraction (EF) who underwent transfemoral TAVR (TF-TAVR). Comprehensive transthoracic echocardiography was performed prior to the day of TF-TAVR. BNP was measured serially before and 1 year after TF-TAVR. The median BNP level was significantly decreased from 252.5 pg/ml to 146.8 pg/ml in all 127 patients 1 year after TF-TAVR (P < 0.01). However, the patients could be divided into 2 groups according to decrease (72%) or increase (28%) in plasma BNP level. Multivariate logistic regression analysis revealed that Aortic valve (AV) peak velocity, pre-procedural BNP, and larger left atrial volume index (LAVI) were found to be an independent predictor of increased BNP level 1 year after TAVR (OR 0.55, 95% CI 0.38-0.77; P < 0.01). LAVI were negatively correlated with the change in BNP level before and 1 year after TAVR (r = 0.47, P < 0.01). The ROC analysis demonstrated that 52.9 ml/m2 was the optimal cut-off value of LAVI for decreasing BNP 1 year after TAVR (area under the curve 0.69) with 64% sensitivity and 70% specificity. In addition to AV peak velocity and pre-procedural BNP, LAVI independently predicts future improvement of BNP levels 1 year after TAVR. Our findings indicate an additive predictive value of assessment of LAVI before TAVR procedure for risk stratification.

Simple Height Reduction of the Posterior Leaflet in Robotic Mitral Annuloplasty.

Systolic anterior motion is occasionally encountered during mitral valve repair using neochordal reconstruction for mitral regurgitation owing to large posterior leaflet prolapse. In cases with a redundant posterior leaflet, the risk of systolic anterior motion increases if the redundant posterior leaflet is unresected to decrease the leaflet height. The posterior leaflet was fixed at the anterior annulus, cut near the posterior annulus, and resected into a spindle shape. The excised part of the posterior leaflet was subsequently closed with a continuous suture. Herein, we report our simple height reduction technique of the posterior leaflet, the "curtain technique," performed in robotic surgery.

Computed tomography to identify risk factors for left circumflex artery injury during mitral surgery.

OBJECTIVES: Cases in which the left circumflex coronary artery (LCX) runs close to the mitral annulus are considered high risk for LCX injury during mitral surgery. We investigated the anatomical relationship between the LCX and the mitral annulus using 3-dimensional (3D) computed tomography (CT). METHODS: We constructed 3D-CT images of the LCX and the mitral annulus before surgery in 122 patients with mitral regurgitation (MR). We classified coronary dominance by 3D-CT and MR aetiologies (degenerative, atrial functional MR, ventricular functional MR and Barlow's disease) using echocardiography. We detected the point on the mitral annulus closest to the LCX (X point) and measured the minimum distance from the LCX to the mitral annulus (mCAD). We judged whether atrioventricular disjunction existed using CT. We also investigated the factors affecting mCAD and examined how coronary dominance and MR aetiologies relate to the location of the X point. RESULTS: The median mCAD was 4.2 mm (range 0.9-11.4 mm). Considering coronary dominance and MR aetiologies, mCAD was shorter in patients with left coronary dominance and Barlow's disease. The X point mostly existed on the lateral side of the posterior annulus, but it sometimes existed on the medial side. Multiple regression revealed left dominance and mitral annular disjunction as significant factors affecting mCAD (P = 0.01). CONCLUSIONS: The anatomical relationship between the LCX and the mitral annulus can be recognized using superimposed 3D-CT images. This approach is useful to avoid LCX injury in mitral valve surgery since the X point varies between patients.