[Constrictive Pericarditis with Intractable Ascites after Aortic Valve Replacement;Report of a Case].

We report a 68-year-old man, who developed refractory ascites of unknown cause after aortic valve replacement. He was diagnosed with constrictive pericarditis because of "dip-and-plateau" waveform findings via cardiac catheterization and operated with cardiopulmonary bypass. Following waffle procedure, we incised pericardium for decompression, so that pericardial mobility and diastolic dysfunction was improved. Postoperative computed tomography (CT) image also showed decrease of ascites fluid. We concluded that pericardiotomy is an established surgical procedure and is excellent indication to constrictive pericarditis.

What Did Endovascular Aortic Repair Bring for the Treatment Strategy of Abdominal Aortic Aneurysm?

Objective: We examined the effects of the introduction of endovascular aortic repair (EVAR) on treatment for abdominal aortic aneurysms (AAAs). Subjects: We compared patients in the following three periods: period I (January 2002-December 2006, 105 patients), period II (January 2007-December 2011, 242 patients, duration of 5 years after the introduction of EVAR), and period III (January 2012-December 2016, 237 patients, duration of 5 years after period II). We used the American Society of Anesthesiologists (ASA) classification for risk assessment. Results: In the Open repair (OR) group, the incidences of ASA class 2 increased and classes 3 and 4 decreased significantly in periods II and III compared with period I. In all periods, there were no in-hospital deaths. Suprarenal aortic cross-clamping was required in 18 patients (19.1%) in period III and 5 patients (6.3) in period I, and the difference was significant (P<0.05). In the EVAR group, no differences in age, sex, or ASA classification class were observed between periods II and III. In period II, one patient died due to aneurysm rupture during surgery. Significant differences were observed when comparing both groups in periods II and III: patients in the EVAR group were older (P<0.01) and the OR group had a higher proportion of ASA class 2 patients and the EVAR group had a higher proportion of ASA class 3 or 4 patients (P<0.01). Among all AAA surgeries, rupture occurred in 25 patients (23.8%) in period I, 18 patients (7.4) in period II, and 16 patients (6.8) in period III. The number of ruptures was significantly lower in periods II and III than in period I (P<0.01). Conclusions: The findings of this study suggest that EVAR should be indicated for high-risk patients and had the good outcome of AAA treatment. (This is a translation of Jpn J Vasc Surg 2018; 27: 27-32.).

Morphological study of abdominal aortic aneurysm: optimal stent-graft size for Japanese patients.

PURPOSE: We report on the optimal stent-graft (SG) size for Japanese patients with abdominal aortic aneurysm (AAA). MATERIALS AND METHODS: Ninety three Japanese patients undergoing elective AAA repair were selected for this study. The parameters measured were the proximal neck (PN) diameter (D1), the diameter of the right and left common iliac arteries (D2 and D3, respectively), the diameter of the right and left external iliac arteries (D4 and D5, respectively), the distance between the lowest renal artery and the common iliac arterial bifurcation (L1), and the distance between the right and left common iliac arterial bifurcations and the internal iliac arterial bifurcation (L2 and L3, respectively). RESULTS: The following results were obtained: D1: 20.7+/-3.9 mm (14 to 28 mm); D2: 14.0+/-3.0 mm (9.5 to 20 mm); D3: 13.8+/-3.1 mm (9 to 19.5 mm); D4: 7.5+/-1.0 mm (6 to 10 mm); D5: 7.4+/-0.9 mm (6 to 10 mm); L1: 107.7+/-13.4 mm (80 to 130 mm); L2: 40.0+/-10.1 mm (20 to 61 mm); L3: 39.7+/-9.6 mm (20 to 60 mm). CONCLUSION: The results indicate the necessity of exercising adequate care when selecting a device for Japanese patients.

Valve-on-valve technique for replacement of degenerated tricuspid bioprosthetic valve without explantation.

A 73-year-old woman admitted to our hospital with shortness of breath and edema of the lower extremities was diagnosed with right ventricular failure stemming from tricuspid valve regurgitation. She had undergone mitral valve replacement (MVR) with a mechanical valve at the age of 51, and reoperative MVR with mechanical valve, tricuspid valve replacement (TVR) with bioprosthetic valve, and pacemaker implantation at the age of 63. Reoperative TVR was performed when the patient failed to respond to drug therapy. A beating heart cardiopulmonary bypass procedure was performed in which only the bioprosthetic valve leaflet was excised, and reoperative TVR was performed with a 27-mm OptiForm mechanical mitral valve (Sulzer Carbomedics Inc., Austin, TX, USA) by the valve-on-valve technique. The operative course was uneventful. The technique used here appears to be an effective approach to reoperative TVR, in this instance making it possible to avoid the risks associated with excision of the old prosthesis.

Long-term results of endoluminal grafting for descending thoracic aortic aneurysms.

OBJECTIVE: This paper describes the long-term results of endoluminal grafting (EG) for the treatment of descending thoracic aortic aneurysms (dTAA). METHODS: Until July 2004, EG for dTAA has been applied in 45 cases (male/female, 29/16, 49-86 years old, mean age 67 years old). Locations included the proximal dTAA in 24 cases, and middle or distal dTAA in 21 cases. The stent-grafts (SGs) were constructed of Gianturco Z-stents covered with woven polyester grafts. RESULTS: Deployment of the SGs was successful in 43 of 45 cases (96%) and complete thrombosis of the aneurysm was achieved in 39 cases (87%). Six minor endoleaks (13%), one migration (2%) and one conversion to surgery (2%) occurred. There was no instance of paraplegia nor hospital death. Over a mean 48 month follow-up (range 3 to 90), there were three persistent endoleaks (6%), four secondary endoleaks (8%), one breakage of wire frame (2%). Four cases were converted to open surgery due to secondary endoleak. There were two aneurysmal ruptures at the site where EG was not performed. The cumulative survival rate was 95.6 +/- 4.4% at 12 months, 85.7 +/- 5.4% at 24 months, and 82.4 +/- 6.1% at 36 and 60 months. CONCLUSION: These results demonstrated that EG is safe and effective in selected dTAA patients. Improvements in patients selection, surgical techniques and equipment will reduce EG related complications and conversion to open repair over the course of the evaluation.

Long-term results of open stent-grafting using a Matsui-Kitamura stent to treat thoracic aortic aneurysm.

PURPOSE: We describe a retrospective study of initial and long-term outcomes with an open stent grafting (OSG) with a Matsui-Kitamura stent for treating thoracic aortic aneurysm. METHODS: Between August 2005 and September 2013, 50 patients with aortic arch disease extending to the descending aorta underwent OSG. Circulatory arrest with total cardiopulmonary bypass and selective cerebral perfusion were used, and the aorta was transected between the brachiocephalic and left subclavian artery. The stent-graft was inserted, sutured to a transected aortic edge, and anastomosed to a four-branched arch graft. Preoperative, operative, and short- and long-term postoperative data were obtained from the patients' medical records. RESULTS: The perioperative (within 30 days) mortality rate was 8%. Two patients (4%) had a stroke and 5 patients (10%) had a spinal cord injury resulting in paraplegia or paraparesis (1 patient each) or transient paraplegia (3 patients). Actuarial survival rates at 1, 3, 5, and 7 years postoperatively were 87.8%, 78.3%, 70.7%, and 65.3%, respectively; the rates of freedom from an aortic event were 100%, 89.1%, 82.2%, and 74.7%. There were no complications related to use of the stent-graft. CONCLUSION: Our OSG method provided durable results in patients treated for thoracic aortic aneurysm, with few adverse events.

[Examination of dose verification in intensity modulated radiation therapy (IMRT) treatment planning using averaging dose in chamber volume].

Since the year 2000, our hospital has been equipped with an intensity modulated radiation therapy (IMRT) facility. Before IMRT is administered, the absorbed dose is measured by the ionization chamber to provide verification for the IMRT procedure. In utilizing the current point dose evaluation, large discrepancies have been experienced when the measured dose is compared with the calculated dose. This discrepancy is due to the lack of uniformity in IMRT irradiation in comparison with that of the present method of dose distribution. In order to reduce the margin of error, the average dose of the ionization chamber calculated on a dose-volume histogram was compared with the measured dose. As a result, the margin of error was minimized to <2% in uniform areas and <4% in non-uniform areas.

[Usefulness of intensity-modulated radiation therapy for breast conserving radiation therapy: a three-dimensional treatment planning system comparison of irradiation methods].

Until recently, conservative radiation therapy of breast cancer using a wedge-filter combined with rectangular tangential irradiation was widely carried out. This method of irradiation creates uniform dose distribution in the target, minimizing the radiation dose to the lung. However, this method of irradiation results in many cases in which the amount of dose in the irradiated area differs as a result of the shape and size of the breast. It is necessary to prevent excessive doses from reaching the lung. IMRT ensures a uniform dose to the target. Therefore, IMRT was examined because of the possibility that the normal tissue dose can be effectively utilized in cases of conservative radiation therapy of breast cancer by providing a minimum dose. To compare the irradiation of each method of rectangular tangential irradiation, an electronic compensator (ELC), and IMRT, which uses Dynamic MLC, we evaluated target dose uniformity, standard deviation, and target differential DVH in 13 examples. We evaluated the lung dose of the irradiated side (V(30), 30 Gy volume) of the lung to the volume of the lung on the irradiated side based on the report of Hernando.(6)) With this method of irradiation, irrespective of the difference in the shape and size of the target, dose uniformity with ELC was very good. IMRT can reduce the lung dose in comparison with the other irradiation methods. However, it is apt to cause a high-dose area in the irradiation field. In addition, it affects the target and the skin-extracting contour, and the dose to the skin surface declines. Although ELC cannot offer lung doses that are as low as those of IMRT, most of the 13 examples planned for cure with ELC showed rates of 22% of V(30) and below. In conservative radiation therapy of breast cancer, ELC is more effective than the rectangular tangential irradiation method and IMRT.

[Usefulness of 3D-VIBE method in breast dynamic MRI: imaging parameters and contrasting effects].

MR imaging (MRI) has been reported to be a useful modality to characterize breast tumors and to evaluate disease extent. Contrast-enhanced dynamic MRI, in particular, allows breast lesions to be characterized with high sensitivity and specificity. Our study was designed to develop three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) techniques for the evaluation of breast tumors. First, agarose/Gd-DTPA phantoms with various concentrations of Gd-DTPA were imaged using 3D-VIBE and turbo spin echo (TSE). Second, one of the phantoms was imaged with 3D-VIBE using different flip angles. Finally, water excitation (WE) and a chemical shift-selective (CHESS) pulse were applied to the images. Each image was analyzed for signal intensity, signal-to-noise ratio (1.25*Ms/Mb) (SNR), and contrast ratio [(Ms1-Ms2)/[(Ms1+Ms2)/2]]. The results showed that 3D-VIBE provided better contrast ratios with a linear fit than TSE, although 3D-VIBE showed a lower SNR. To reach the best contrast ratio, the optimized flip angle was found to be 30 degrees for contrast-enhanced dynamic study. Both WE and CHESS pulses were reliable for obtaining fat-suppressed images. In conclusion, the 3D-VIBE technique can image the entire breast area with high resolution and provide better contrast than TSE. Our phantom study suggests that optimized 3D-VIBE may be useful for the assessment of breast tumors.

[Fundamental study of the relation between flow velocity and signal intensity in the TrueFISP sequence].

The purpose of this study was to evaluate the effect of inflow phenomenon on TrueFISP. We created a phantom using a vinyl tube and distilled water, and applied a pump-oxygenator to the phantom to obtain stationary flow. First, to evaluate the effect of inflow and the dephase phenomenon on signal intensity, the phantom was measured for the signal intensity of variable flow velocity. Second, the relation of TR/TE with signal intensity was analyzed. The results showed that a flow velocity of less than 15 cm/sec did not participate in signal reduction; however, signal intensity was reduced when flow velocity was more than 30 cm/sec. Moreover, the reduction of signal intensity was remarkable with a flow velocity of 50-100 cm/sec, which corresponds with arterial flow velocity. In the analysis of TR/TE, signal intensity was increased when TR of less than 5 ms was applied to the slow velocity of 15 cm/sec. Signal intensity was decreased when the same TR was applied to the high velocity of 50-100 cm/sec. When TR was 6-9 ms, peak signal intensity was recognized at the high velocity of 50-100 cm/sec. This peak, however, might correspond only to the inflow phenomenon, and steady state might have already collapsed. Based on these results, we concluded that TrueFISP is suitable for the imaging of slow flow velocity. A short TR of less than 5 ms was effective for obtaining high signal intensity. Our next goal will be to apply TrueFISP to MR venography, although further investigation will be necessary.

Abundance, transcription levels and phylogeny of bacteria capable of nitrous oxide reduction in a municipal wastewater treatment plant.

Nitrous oxide (N2O) production and expression of genes capable of its reduction were investigated in two full-scale parallel plug-flow activated sludge systems. These two systems continuously received wastewater with the same constituents, but operated under distinct nitrification efficiencies due to mixed liquor suspended solid (MLSS) concentration and the different hydraulic retention times (HRTs). A shorter HRT in system 2 resulted in a lower nitrification efficiency (40-60%) in conjunction with a high N2O emission (50.6 mg-N/L/day), whereas there was a higher nitrification efficiency (>99%) in system 1 with low N2O emission (22.6 mg-N/L/day). The DNA abundance of functional genes responsible for nitrification and denitrification were comparable in both systems, but transcription of nosZ mRNA in the lower N2O emission system (system 1) was one order of magnitude higher than that in the higher N2O emission system (system 2). The diversity and evenness of the nosZ gene were nearly identical; however, the predominant N2O reducing bacteria were phylogenetically distinct. Phylogenetic analysis indicated that N2O-reducing strains only retrieved in system 1 were close to the genera Rhodobacter, Oligotropha and Shinella, whereas they were close to the genera Mesorhizobium only in system 2. The distinct predominant N2O reducers may directly or indirectly influence N2O emissions.

Emergency endovascular repair of a ruptured descending thoracic aortic aneurysm in an octogenarian: report of a case.

Emergency conventional surgical repair of the descending thoracic aorta remains a therapeutic challenge and is associated with a high risk of mortality. We describe a case of ruptured descending thoracic aortic aneurysm in an 87-year-old man who presented with chest and back pain. The patient underwent successful endovascular repair of the lesion with the use of Gore TAG thoracic endoprosthesis. Post-procedure computed tomography showed complete exclusion of the aneurysm without endoleaks. Endovascular repair is feasible and can be effective in such cases.

Simultaneous open abdominal aortic replacement and thoracic stent-graft placement: report of a case.

A 77-year-old man with severe chronic obstructive pulmonary disease was admitted to our hospital for surgical treatment of a proximal descending thoracic aortic aneurysm (dTAA) and an infrarenal abdominal aortic aneurysm (AAA). The patient had poor respiratory function; however, a simultaneous abdominal aortic replacement and thoracic stent-graft placement were successfully performed without any complications. This case report demonstrates that simultaneous abdominal aortic replacement and thoracic stent-graft placement for multiple aneurysms may be feasible and can safely be performed in selected high-risk patients, despite the many problems associated with the treatment of aortic aneurysms using stent grafts.

Clinical results of open stent grafting applied using an improved endotracheal tube in the treatment of high-risk patients with distal arch aneurysms.

Whereas the operative results for thoracic aortic aneurysms (TAA) have improved in recent years, the results for distal arch aneurysms (DAA) remain unsatisfactory. We report herein the initial results of open stent grafting (OSG) applied using an improved endotracheal tube for surgical treatment of high-risk DAA. OSG was used to treat DAA in five men aged 69-80 years (mean, 77 years). Four cases involved chronic obstructive pulmonary disease, and the remaining case involved both ischemic heart disease and chronic renal failure. Previous surgical repairs of an abdominal aortic aneurysm had been performed in four patients, and thoracoplasty and reconstruction of the lower extremities had been performed in the remaining patient. Under selective cerebral perfusion, OSG with revascularization of two cerebral branches was performed in two patients, whereas OSG with total arch replacement was performed in three patients. The procedure was successful in all cases. There were no complications related to cerebrospinal disorders, and complete thrombosis of the aneurismal sac was achieved in all cases. The new deployment method using an endotracheal tube offers numerous advantages, including reduced aortic wall injury and accurate placement of the stent graft in the operative field. These initial results suggest that this specific approach makes OSG a useful surgical procedure in the treatment of high-risk DAA.