Clinical study of preoperative skeletal muscle mass as a predictor of physical performance recovery following palliative surgery for spinal metastases.

BACKGROUND: Surgical treatment of spinal metastases has been associated with high morbidity and mortality in patients with sarcopenia based on low skeletal muscle mass. We assessed physical performance using the Eastern Cooperative Oncology Group performance status scale and the Barthel Index on the 30th day after palliative surgery for spinal metastases and investigated the effectiveness of surgery according to sarcopenia assessed by skeletal muscle mass. METHODS: We retrospectively analyzed 78 consecutive patients with thoracic and lumbar spinal metastases who underwent palliative surgery. The value of the area of the psoas major muscle at the L3 level normalized by the vertebral area was divided into first, middle, and third tertiles. Clinical variables were compared by tertile. Variables affecting the 30-day good performance status were investigated with univariate and multivariate analyses. RESULTS: The 30-day morbidity rates were 50%, 38.5%, and 15.4% by tertile. The 30-day mortality rate was 2%; all were in the first tertile. Good preoperative performance status scores were seen in 15.4% of first and 50% of third tertile patients. Postoperatively, the performance status improved in all groups, with 30.8%, 65.4%, and 92.3% by tertile. Multivariate regression analysis revealed that a good preoperative performance status (OR: 15.50, 95% CI: 1.610-149.00, P < 0.05) and the value of the area of the psoas major muscle at the L3 level normalized by the vertebral area not in the first tertile (OR: 0.22, 95% CI: 0.06-0.82, P < 0.05) were significant predictors of a good postoperative 30-day performance status. CONCLUSIONS: A good preoperative performance status and exclusion from the first tertile were clinical factors predicting a good postoperative 30-day performance status. In patients with large psoas muscle mass (third tertile), a good 30-day performance status can be expected after surgery, suggesting that surgery in this population should be pursued aggressively.

Tension Pneumocephalus Associated with Negative Pressure Wound Therapy with Instillation and Dwell Time for Methicillin-resistant Staphylococcus aureus Infection After Spinal Deformity Surgery.

PURPOSE: Surgical site infection (SSI) is a serious complication after spine surgery. Recently, it has become possible to perform negative pressure wound therapy with instillation and dwell time (NPWTi-d) for postoperative infected wounds. We report the first rare case of symptomatic pneumoencephalopathy following NPWTi-d for methicillin-resistant Staphylococcus aureus (MRSA) infection after spinal deformity surgery. METHODS: Retrospective review of a patient's medical record and imaging. RESULTS: A 77-year-old female patient underwent posterior corrective fixation with no intraoperative complications. On the 10th postoperative day, SSI was diagnosed, and debridement was performed. Since MRSA was detected in the wound culture, and a prolonged inflammatory reaction was observed, NPWTi-d was started to preserve the instrumentation. Gradually, good granulation was observed, and the extensive soft tissue defect decreased. On the 29th day after the start of NPWTi-d, the patient experienced sudden headache and neck pain while standing, and head computed tomography led to the diagnosis of symptomatic pneumoencephalopathy. NPWTi-d was discontinued, and when surgery was performed to close the wound, dural injury was found, which was not present at the time of the initial surgery, and dural repair was performed. After 2 weeks of bed rest, the patient's pneumoencephalopathy improved. Three years have passed since the surgery, and no recurrence of cerebrospinal fluid leakage or infection has been observed. CONCLUSIONS: Although NPWTi-d is a useful treatment for SSI, it is always necessary to pay attention to the development of pneumoencephalopathy and promptly diagnose and treat it because of the risk of life-threatening complications.

Sciatica Caused by Perineural Spread of Prostate Cancer.

An 81-year-old man with a history of prostate cancer developed sciatica and underwent L4/5 laminectomy followed by L5/S1 transforaminal lumbar interbody fusion. Postoperatively, pain improved temporarily, then deteriorated. Tumor resection was performed after enhanced magnetic resonance imaging showed a mass distal to the left greater sciatic foramen. Histopathological examination showed the perineural spread of prostate cancer to the sciatic nerve. Developments in diagnostic imaging have revealed that prostate cancer can undergo perineural spread. Imaging studies are essential when sciatica is diagnosed in patients with a history of prostate cancer.

Effect of particle size of intratracheally instilled crystalline silica on pulmonary inflammation.

Crystalline silica, known as a causal substance of silicosis, has been carefully evaluated for its carcinogenicity and fibrogenicity. In this study, we instilled crystalline silica of two different size (S(1.8) :1.80 microm (S.D. 2.0), S(0.7) :0.74 microm (S.D. 1.5)) into the trachea of rats to evaluate the size effects of the particles on pulmonary inflammation. S(1.8) and S(0.7) samples were administered to rats by a single intratracheal instillation (2 mg/ 0.4 ml saline). At three days, 1 wk and 1, 3 and 6 months after the instillation, the blood, bronchoalveolar lavage fluid (BALF), and pulmonary tissues were analyzed. Six images per HE-stained section were digitally captured and examined by the point counting method (PCM). Polymorphonuclear leukocyte (PMN)-in-blood specimens and cytospin specimens from BALF were stained immunohistochemically with BrdU. At six months after the instillation, the effects on inflammatory cells in the pulmonary tissues and BALF tended to be more marked in the rats instilled with S(1.8) than those instilled with S(0.7). Particularly, clear differences were observed in the number of inflammatory cells in BALF. Even if the particles are of the same chemical composition, the results suggest that, their biological effects vary depending on their particle size. Therefore, when such particles are used in workplaces, strict control systems should be established according to the risks present by different sizes of particles.

[Method for installing an effective smoking room and the effectiveness of real-time monitoring].

We investigated the methodology for installing effective smoking rooms in workplaces. It is absolutely necessary to install exhaust ventilation in smoking rooms. There are two bases for deciding the exhaust ventilation rate. The most important is to eliminate the leakage of environmental tobacco smoke (ETS) from the smoking room. An airflow rate of more than 0.2 m/s at the opening of the smoking room is required by the Guidelines for Smoking Control in Workplaces (Ministry of Labour, Welfare and Health) to eliminate the leakage. This ventilation rate is decided by multiplying the opening area by 0.2 m/s. The second important point is to keep the concentration of ETS in the smoking room less than control concentration (0.15 mg/m3). This ventilation rate is decided by dividing the rate of generation of ETS by the control concentration. It is confirmed that an effective smoking room can be installed by following these guidelines. We used real-time monitoring to evaluate the leakage of ETS from the smoking room and the ETS concentration in the smoking room before and after the improvement. It is concluded that real-time monitoring of ETS is a useful method for evaluating the effectiveness of the smoking room.

Patterns of histopathological change determined by the point counting method and its application for the hazard assessment of respirable dust.

We evaluate the morphometric point counting method (PCM) for qualitatively analyzing pulmonary inflammation and collagen deposits (i.e., fibrosis) in the assessment of the biological hazards of inhaled respirable particles at a realistic dose comparable to that of exposure in the work environment. Rats were exposed by intratracheal instillation to a 2-mg dose, which is close to the estimated overdose at which macrophage clearance is impared, of each of 3 kinds of particulate matter: crystalline silica, crocidolite asbestos, and titanium dioxide. The lung tissue was evaluated at 3 days, 1 wk, and 1, 3, and 6 mo after exposure. Digital images taken of the lung tissue after processing and staining of the lung sections were examined by the PCM under light microscopy. Evidence of inflammation along with progressive inflammatory changes occurred with crystalline silica and crocidolite, which are well-known hazardous particle types. In contrast, lung tissue from rats exposed to titanium dioxide particles demonstrated a decreasing pattern of histopathological change with increasing retention time. Differences in repair patterns of TiO(2) versus crocidolite and silica following the 2-mg dose exposure suggest that the PCM scoring system may be a useful and sensitive tool for qualitatively evaluating the biological hazards of new particle types, for which no toxicological information exists for low-dose exposure, by using the results from assessment of fibrogenic particle types (such as crocidolite and crystalline silica) as well as particle types with low toxicity (such as TiO(2)) as reference points.