Biomechanical evaluation of segmental instability in degenerative lumbar spondylolisthesis

Here we investigated the biomechanical properties of spinal segments in patients with degenerative lumbar spondylolisthesis (DLS) using a novel intraoperative measurement system. The measurement system comprised spinous process holders, a motion generator, a load cell, an optical displacement transducer, and a computer. Cyclic displacement of the holders produced flexion-extension of the segment with all ligamentous structures intact. Stiffness, absorption energy (AE), and neutral zone (NZ) were determined from the load-deformation data. Forty-one patients with DLS (M/F = 15/26, mean age 68.6 years; Group D) were studied. Adjacent segments with normal discs in six patients (M/F = 3/3, mean age 35 years) were included as a control group (Group N). Flexion stiffness was significantly lower in Group D than in Group N. The NZ, however, was significantly greater in Group D than in Group N. Thus, compared to normal segments, spinal segments with DLS had a lower flexion stiffness and a higher NZ. NZs in Group D were, however, widely distributed compared to those in Group N that showed NZ <2 mm/N in all cases, suggesting that the segment with DLS is not always unstable and that the segments with NZ >2 mm/N can be considered as unstable. A patent application for the intraoperative measurement system has been submitted.     

Successful video-thoracoscopic drainage for descending necrotizing mediastinitis

Descending necrotizing mediastinitis (DNM) is a rare but severe disease with a high mortality rate. We report a case of a 77-year-old woman with DNM who was treated using video-thoracoscopic drainage and a Blake drain. She was admitted to our hospital with a 3-day history of a sore throat. Computed tomography (CT) revealed a peritonsillar abscess descending into the anterior and posterior mediastinum below the carina. She was diagnosed with DNM, and emergency surgery was performed. The mediastinal abscess was drained via video-thoracoscopy, and a 24F Blake drain was inserted into the mediastinum. Following mediastinal drainage, cervical drainage was performed for treatment of the retropharyngeal abscess. The outcome of videothoracoscopic mediastinal drainage was satisfactory, and no further invasive treatment was required. We believe that video-thoracoscopic mediastinal drainage is an effective, minimally invasive treatment for DNM with subcarinal spread. Blake drains are useful for mediastinal drainage.     

Natural history of human prostate gland: Morphometric and histopathological analysis of Japanese men

BACKGROUND: To clarify the pathology of the development of prostatic disorders such as inflammation, cancer, and hyperplasia, we compared histopathological findings of the prostate according to age group. METHODS: Whole-mount sections of prostates were used to assess the relationship between age and prostate weight (n=962), prostate histological composition in the transition zone (TZ) and in the peripheral zone (PZ) (n=68), prostate histopathological findings by zone (n=102), and comparison of latent tumor development by age group (n=1,815). RESULTS: A rapid increase in prostate weight from birth to the 20s was followed by a slow rise thereafter. Volume increases (P<0.01) were observed in all components of glandular epithelium, glandular lumen, and stroma in the TZ from the 40s to 70s inclusive. In the PZ, the epithelial and stromal volumes tended to decrease in an age-dependent manner (P<0.05). Calculi and lymphocyte infiltration were detected at a relatively early age, with a tendency towards an age-dependent increase. Glandular dilation and nodular hyperplasia were noted first in the 30s group, also with a tendency towards age-dependent increase. Latent tumors were first detected in the 30s group (5.6%), and slowly increased thereafter. CONCLUSIONS: There was an age-dependent trend towards prostate glandular dilation and prostate enlargement with inflammation. It was demonstrated that tumor and hyperplasia have a long natural history, usually starting in the fourth decade of life, accompanied by dynamic changes with age in glandular tissue composition as well as cell proliferation activity.     

Fat-containing variant of solitary fibrous tumor (lipomatous hemangiopericytoma) arising on surface of kidney

Fat-containing variant of a solitary fibrous tumor is a recently recognized benign soft-tissue tumor that usually affects the thigh and retroperitoneum. We report a 51-year-old woman with a fat-containing variant of a solitary fibrous tumor that is the first reported case involving a visceral organ. The tumor was well delineated and seemed to arise from the renal capsule, radiographically and macroscopically. The tumor microscopically mimicked a solitary fibrous tumor but exhibited focal aggregates of fat cells. A fat-containing variant of a solitary fibrous tumor involving the kidney should be distinguished from spindle cell carcinoma, angiomyolipoma, gastrointestinal stromal tumor, and cellular schwannoma.     

Successful resection of cardiac metastatic liposarcoma extending into the SVC, right atrium, and right ventricle

Cardiac metastatic liposarcoma is a rare tumor. We report a case of successful resection of a cardiac metastatic liposarcoma extending into the superior vena cava (SVC), right atrium, and right ventricle. Using cardiopulmonary bypass (CPB) by venous cannulation of the upper portion of the SVC and inferior vena cava (IVC), the intracardiac tumor was completely resected. Surgical resection with the addition of radiotherapy prolonged the patient's life.     

Surgical device exchange provides improved clinical outcomes compared to medical therapy in treating continuous-flow left ventricular assist device thrombosis

The purpose of this study is to compare clinical outcomes of left ventricular assist device (LVAD) patients with device thrombosis who underwent device exchange (DE) or medical therapy (MT) alone. Consecutive patients undergoing LVAD implant between July 2008 and December 2017 were included. Device thrombosis was diagnosed with comprehensive assessments including ramp test, laboratory data, device parameters, and clinical presentations. First, MT was initiated in all patients. After MT, DE was considered if device thrombosis was refractory to initial MT, and it caused end-organ impairment and/or hemodynamic instability. Among 319 consecutive LVAD patients, 43 patients (13.5%) were diagnosed with device thrombosis. DE was performed in 28 patients (DE group); device explant was performed in 1 patient. MT was continued in 14 patients (MT group). In-hospital mortality was significantly lower in the DE group than the MT group (3.6% [1/28] vs. 28.6% [4/14], P = .0184). One-year survival was significantly better in the DE group (74.0% vs. 30.1%; log-rank = .001), and freedom from cerebrovascular accident (CVA) at 1 year was greater in the DE group (87.1% vs. 47.7%; log-rank = .004). DE was associated with improved 1-year survival and fewer CVAs. Surgical intervention, if feasible, is recommended for LVAD device thrombosis.     

Combination chemotherapy with ifosfamide, 5-fluorouracil, cisplatin for stage D2 prostatic cancer

Twelve patients with stage D2 adenocarcinoma of the prostate were treated with the combination chemotherapy of ifosfamide (2 g/body, i.v., day 1-3), 5-fluorouracil (250 mg/body, i.v., day 1-5) and cisplatin (20-30 mg/body, i.v., day 1-5). The averaged age was 62 years (from 52 to 73 years) with mean performance status of 70% (from 40 to 90%). Six patients were refractory to prior hormone therapy or chemotherapy and the other six had received no prior treatment for prostatic cancer. Based on criteria of National Prostatic Cancer Project, 4 patients achieved partial response (PR) which was maintained from 11 to 23 months with the mean of 17.8 months. Two patients achieved objectively stable stage (NC). Response rate (PR + NC) was 50%. Response rate of patients without prior therapy was 80%, whereas that of hormone-resistant group was 30%. There was a trend toward unfavorable response in patients with prior therapy. Adverse effects were mild to moderate gastric problems and myelosuppression except in one case Adverse effects were mild to moderate gastric problems and myelosuppression except in one case with low performance status under 60%. IFP combination chemotherapy achieved favorable responses and toxicities were tolerable. Therefore, it appears worth while to study whether IFP combination chemotherapy could extend the life of patients with advanced prostatic cancer.     

Bumetanide-induced enlargement of the intercellular space in the stria vascularis critically depends on Na+ transport

The intercellular space in the stria vascularis (intrastrial space) is a closed space and isolated from both the endolymph and the perilymph in normal tissue. Loop diuretics such as bumetanide and furosemide cause an acute enlargement of the intrastrial space in association with a decline in the endocochlear potential. It is known that bumetanide inhibits the Na+-K+-2Cl- cotransporter, which is expressed abundantly in the basolateral membrane of marginal cells. We studied ionic mechanisms underlying the bumetanide-induced enlargement of the intrastrial space using perilymphatic perfusion in guinea pigs. Perilymphatic perfusion with artificial perilymph containing 100 microM bumetanide caused marked enlargement of the intrastrial space, as reported previously. Removal of K+ from the perilymph did not affect the bumetanide-induced enlargement, whereas removal of Na+ from the perilymph inhibited it almost completely. Perilymph containing 1 mM amiloride also inhibited the enlargement of the intrastrial space almost completely. These results indicate that perilymphatic Na+, but not K+, and amiloride-sensitive pathways are essential to the bumetanide-induced enlargement of the intrastrial space. Two possible pathways could yield these results. Na+ in the perilymph could enter the endolymph via Reissner's membrane or the basilar membrane; Na+ in the endolymph would then be taken up by marginal cells via the apical membrane and secreted into the intrastrial space by Na+-K+-ATPase in the basolateral membrane of them. Another, less likely possibility is that Na+ in the perilymph is transported into basal cells or fibrocytes in the spiral ligament, then into intermediate cells via gap junctions, and finally secreted into the intrastrial space via Na+-K+-ATPase of intermediate cells.