Validity of a model using routinely collected data for identifying infections following gastric, colon, and liver cancer surgeries.

PURPOSE: Validating outcome measures is a prerequisite for using administrative databases for comparative effectiveness research. Although the Japanese Diagnosis Procedure Combination database is widely used in surgical studies, the outcome measure for postsurgical infection has not been validated. We developed a model to identify postsurgical infections using the routinely collected Diagnosis Procedure Combination data. METHODS: We retrospectively identified inpatients who underwent surgery for gastric, colon, or liver cancer between April 2016 and March 2018 at four hospitals. Chart reviews were conducted to identify postsurgical infections. We used bootstrap analysis with backwards variable elimination to select independent variables from routinely collected diagnosis and procedure data. Selected variables were used to create a score predicting the chart review-identified infections, and the performance of the score was tested. RESULTS: Among the 746 eligible patients, 96 patients (13%) had postoperative infections. Three variables were identified as predictors: diagnosis of infectious disease recorded as a complication arising after admission, addition of an intravenous antibiotic, and bacterial microscopy or culture. The prediction model had a C-statistic of 0.885 and pseudo-R2 of 0.358. A cut-off of one point of the score showed a sensitivity of 92% and specificity of 72%, and a cut-off of two points showed a sensitivity of 75% and specificity of 91%. CONCLUSIONS: Our model using routinely collected administrative data accurately identified postoperative infections. Further external validation would lead to the application of the model for research using administrative databases.

Histological effects of intraputaminal infusion of glial cell line-derived neurotrophic factor in Parkinson disease model macaque monkeys.

Glial cell line-derived neurotrophic factor (GDNF) is a potent neuroprotection and regeneration molecule for dopamine neurons in the substantia nigra. A recent clinical study showed that intraputaminal infusions of GDNF restored the striatal dopaminergic function, resulting in improvement in patients with Parkinson disease. To investigate the efficacy and the safety of this treatment, the histological changes associated with intraputaminal GDNF infusions were investigated in non-human primate models of Parkinson disease. Two types of Parkinson disease model were constructed: unilateral infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin (MPTP) into the internal carotid artery to induce hemiparkinsonism and intermittent systemic injection to induce Parkinson disease. GDNF (50 microg) was infused into the putamen on the day of the first MPTP treatment and 4 weeks later. The monkey brains were examined by immunohistochemistry 2-4 weeks after the second GDNF infusion. Losses of the nigral dopamine neurons were mild (30-50% loss) on the side of GDNF infusion, and moderate (approximately 70% loss) on the side of vehicle infusion in the Parkinson disease model. The dopamine fibers were thick and dense in the striatum around the GDNF infusion sites. Both GDNF- and vehicle-treated monkeys of the hemiparkinsonian model showed severe decrease of dopamine neurons to 10% of the intact side. Although reactive astrocytes proliferated around the GDNF infusion sites, the densities of striatal neurons involving GABAergic and cholinergic neurons were not affected. Intraputaminal infusions of GDNF have beneficial effects in parkinsonian monkeys, but dose control is required according to the severity of the disease. The specificity for dopamine neurons is quite high and there are no serious histological changes.

Patency of perforating arteries after stent placement? A study using an in vivo experimental atherosclerosis-induced model.

BACKGROUND AND PURPOSE: The recent advent of flexible stents has enabled their application in intracranial atherosclerotic disease. However, it is unclear whether perforating artery occlusion occurs after stent placement in atherosclerotic stenotic vessels. We investigated this issue by using experimental atherosclerosis-induced rabbits. METHODS: A stainless steel balloon-expandable stent was deployed into the atherosclerosis-induced abdominal aorta across the lumbar artery in six New Zealand white rabbits. This model system is suitable because the diameter of the abdominal aorta is similar to that of human intracranial arteries. We evaluated the patency of the lumbar artery by using angiography and scanning electron microscopy (SEM) 3 months after stent placement. Histopathologic evaluation also was performed in one rabbit. RESULTS: The lumbar artery was patent in five of six rabbits per angiography. The lumbar artery was occluded with an intraluminal thrombus in one rabbit. However, SEM findings demonstrated that the stent struts were covered completely with a thick neointima and the ostium of the lumbar artery became narrowed in all cases. In the one lumbar artery that was occluded at angiography, histopathologic findings confirmed that intraluminal thrombus surrounded the stent struts crossing the ostium. CONCLUSION: We observed luminal narrowing after stent placement in an atherosclerotic stenotic vessel, although patency of the perforating arteries was generally maintained.

Microvascular decompression of cranial nerves using sheets of a dural substitute--technical note.

Several types of prosthesis are used for microvascular decompression (MVD) surgery for neurovascular compression syndrome. However, most prostheses adhere to the surrounding neuronal structures and occasionally cause granulomas. The present study evaluated a dural substitute made of expanded polytetrafluoroethylene, the Gore-Tex EPTFE patch, as a prosthesis for MVD. Twelve patients with trigeminal neuralgia, 19 patients with hemifacial spasm (HFS), and two patients with glossopharyngeal neuralgia underwent MVD using the dural substitute. In most cases, one or two sheets of the dural substitute were inserted between the offending artery and the compression site covering the cranial nerve and the brainstem. Thirty of the 33 patients experienced complete relief of the symptoms that lasted for at least 10-75 months after the surgery. HFS recurred one month post-surgery in a patient who underwent MVD using two small sheets. Varied grades of hearing disturbance were observed in three patients with HFS. MVD using dural substitute is an easy and efficient method because it is not necessary to move the offending arteries away from the compression site. Large sheets should be positioned over the compression site for sufficient decompression. However, this technique needs to be improved so that the prosthesis does not affect cranial nerve VIII, as three of 19 patients with HFS showed hearing disturbances despite intraoperative monitoring of the auditory brainstem response.

Distant metastasis of dermatofibrosarcoma protuberans of the scalp--case report.

A 49-year-old man presented with a rare dermatofibrosarcoma protuberans (DFSP) of the scalp associated with local recurrence and distant metastasis to the lung and abdomen. An elastic-hard small mass on the right occipital scalp was initially treated by simple resection in another clinic. Ten years later, recurrent tumor was associated with infiltration to the calvarium, and resection was performed again also in another clinic. Approximately 1.5 years later, the patient was transferred to our clinic because of recurrence with intracranial involvement. Repeated relapses and metastasis to the lung were recognized despite surgery, chemotherapy, and local radiation. Eventually, the patient died of distant metastasis to the abdomen 17 years after the initial diagnosis. Scalp DFSP is very uncommon but is an aggressive scalp tumor, so initial wide local resection and local radiation therapy after surgery are important to prevent local recurrence and distant metastasis.

Intraoperative hemorrhage in medulloblastoma: a case report and review of the literature.

OBJECT: We present the first case of intraoperative hemorrhage in a medulloblastoma. CASE REPORT: A 10-year-old girl presented with a 4-week history of headache, nausea, and vomiting. Radiological examination showed a space-occupying mass in the cerebellar vermis. Surgical removal was performed via a midline suboccipital approach. When the dura was incised and the occipital sinus was ligated after suboccipital craniectomy, bleeding occurred in the tumor. Macroscopically, hematoma was found only in the left part of the tumor and not in the right part. Microscopically, different architectures of tumor vessels, thin-walled and thick-walled, were found between the left part and the right part, respectively. The tumoral contents and hematoma were totally removed. Histological examination revealed a medulloblastoma. CONCLUSION: We experienced a very rare case of medulloblastoma in which intratumoral hemorrhage occurred during operation. We speculate that ligation of the occipital sinus and thin-walled vessels within the tumor might have caused the hemorrhage in our case.

Dopaminergic neuroprotection and regeneration by neurturin assessed by using behavioral, biochemical and histochemical measurements in a model of progressive Parkinson's disease.

Trophic effects of neurturin, a member of the glial cell line-derived neurotrophic factor-family, have been demonstrated on mesencephalic dopaminergic neurons, suggesting its therapeutic potential for Parkinson's disease. This study was designed to test the neuroprotective and regenerative effects of an intrastriatal injection of neurturin based on behavioral, neurochemical and histochemical changes in a rat model of progressive Parkinson's disease. An extensive and progressive dopaminergic lesion was unilaterally made by intrastriatal convection-enhanced delivery of 6-hydroxydopamine (6-OHDA), in which 20 microg of 6-OHDA dissolved in 20 microl of vehicle was infused at a rate of 0.2 microl/min. For neuroprotection study, recombinant human neurturin (5 microg in 5 microl of vehicle) was stereotaxically injected into the unilateral striatum. The 6-OHDA lesion was made on the ipsilateral side 3 days after the neurturin treatment. Tyrosine hydroxylase (TH)-immunoreactive neurons of the substantia nigra were protected from progressive degeneration in the neurturin-treated animals compared with the vehicle-treated animals 2 and 8 weeks after the 6-OHDA lesion. Eight weeks after the 6-OHDA lesion, dopamine concentration significantly increased in the striatum of neurturin-treated animals with improvement of methamphetamine-induced rotation behavior. For neuroregeneration study, 5 microg of neurturin was injected into the striatum 12 weeks after the 6-OHDA lesion. Four weeks after neurturin or vehicle injection, there were no significant differences in the survival of nigral TH-immunoreactive neurons between the groups. However, TH-immunoreactive fibers were thicker and more abundant in the striatum of the neurturin-treated rats compared to those of the control group, suggesting neurturin-induced growth of the dopaminergic axons. Striatal dopamine levels also significantly increased in the neurturin-treated rats compared with those in the control group of rats, accompanied by the recovery of methamphetamine-induced rotation in the neurturin-treated rats. In conclusion, an intrastriatal injection of neurturin is a useful method to protect nigral dopaminergic neurons from extensive cell death in a model of progressive Parkinson's disease, as well as to promote the axonal regeneration and dopaminergic function.

Study of the patency of small arterial branches after stent placement with an experimental in vivo model.

BACKGROUND AND PURPOSE: The patency of intracranial perforating arteries after stent placement is unknown despite the general clinical use of intracranial arterial stenting. METHODS: We deployed stainless steel stents in the abdominal aorta across the lumbar artery in eight normal rabbits in which the diameters of the abdominal arterial vessels were similar to those of human intracranial arteries. We evaluated the patency via angiographic and scanning electron microscopic methods 3 months after stent placement. Histopathologic evaluation was also performed for one rabbit. RESULTS: The lumbar arteries were patent, even when stent struts crossed the ostium, except in one rabbit in which intimal dissection occurred intraoperatively. The scanning electron microscopy showed that the regenerative endothelium had grown onto the strut at the ostium of the lumbar artery. CONCLUSION: We confirmed the patency of the lumbar arteries in this study by using normal rabbits. Thus, intracranial stenting may not pose a risk of occluding perforating arteries of the same diameter of the lumbar artery, even if stent struts cover the ostium.

Presigmoid approach for cavernous angioma in the pons--technical note.

Surgical treatment of brainstem lesions has been encouraged after the development of magnetic resonance imaging. However, direct approaches to intra-axial lesions in the brainstem still carry a high risk of morbidity because the neuronal structures can be injured along the entry routes. We present two patients whose pontine cavernous angiomas were removed via incision of the lateral aspect of the pons with presigmoid approach. The first case, a 41-year-old woman, presented with paresis of the cranial nerves VI, VII, and VIII, and left hemiparesis progressing over 2 weeks caused by a cavernous angioma ventrally located in the lower pons. The second case, a 50-year-old woman, developed dizziness over 2 months due to a large cavernous angioma in the center of the pons. These lesions were totally removed through the presigmoid approach and no additional neurological deficits were observed. An image-guided navigation system was used for the craniotomy and removal of the lesion in the second patient. The presigmoid approach provides a safe route to intra-axial lesions in the pons. A technique for presigmoid craniotomy with one-piece bone flap under the image-guided navigation is also described.