Patient reported outcomes after navigated minimally invasive hybrid lumbar interbody fusion (nMIS-HLIF) using cortical bone trajectory screws.

Prospective observational study. To evaluate patient-reported outcomes after navigation-guided minimally invasive hybrid lumbar interbody fusion (nMIS-HLIF) for decompression and fusion in degenerative spondylolisthesis (Meyerding grade I-II). Posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) are well-known standard procedures for lumbar spinal fusion. nMIS-HLIF is a navigation-guided combined percutaneous and open procedure that combines the advantages of PLIF and TLIF procedures for the preparation of a single-port endoscopic approach. 33 patients underwent nMIS-HLIF. Core outcome measure index (COMI), oswestry disability index (ODI), numeric rating scale (NRS) back, NRS leg, and short form health-36 (SF-36) were collected preoperatively and at follow-up of 6 weeks, 3 months, 6 months, and 1 year. The impact of body mass index (BMI) was also analyzed. Computed tomography reconstruction was used to assess realignment and verify fused facet joints and vertebral bodies at the 1-year follow-up. 28 (85%) completed the 1-year follow-up. The median BMI was 27.6 kg/m2, age 69 yrs. The mean reduction in listhesis was 8.4% (P < .01). BMI was negatively correlated with listhesis reduction (P = .032). The improvements in the NRS back, NRS leg, ODI, and COMI scores were significant at all times (P < .001-P < .01). The SF-36 parameters of bodily pain, physical functioning, physical component summary, role functioning/physical functioning, and social functioning improved (P < .003). The complication rate was 15.2% (n = 5), with durotomy (n = 3) being the most frequent. To reduce the complication rate and allow transitioning to a fully endoscopic approach, expandable devices have been developed. The outcomes of nMIS-HLIF are comparable to the current standard open and minimally invasive techniques. A high BMI hinders this reduction. The nMIS-HLIF procedure is appropriate for learning minimally invasive dorsal lumbar stabilization. The presented modifications will enable single-port endoscopic lumbar stabilization in the future.

Prospective surgical solutions in degenerative spine: spinal simulation for optimal choice of implant and targeted device development.

OBJECTIVES: The most important goal of surgical treatment for spinal degeneration, in addition to eliminating the underlying pathology, is to preserve the biomechanically relevant structures. If degeneration destroys biomechanics, the single segment must either be surgically stabilized or functionally replaced by prosthetic restoration. This study examines how software-based presurgical simulation affects device selection and device development. METHODS: Based on videofluoroscopic motion recordings and pixel-precise processing of the segmental motion patterns, a software-based surrogate functional model was validated. It characterizes the individual movement of spinal segments relative to corresponding cervical or lumbar spine sections. The single segment-based motion of cervical or lumbar spine of individual patients can be simulated, if size-calibrated functional X-rays of the relevant spine section are available. The software plug-in "biokinemetric triangle" has been then integrated into this software to perform comparative segmental motion analyses before and after treatment in two cervical device studies: the correlation of implant-induced changes in the movement geometry and patient-related outcome was examined to investigate, whether this surrogate model could provide a guideline for implant selection and future implant development. RESULTS: For its validation in 253 randomly selected patients requiring single-level cervical (n=122) or lumbar (n=131) implant-supported restoration, the biokinemetric triangle provided significant pattern recognition in comparable investigations (p<0.05) and the software detected device-specific changes after implant-treatment (p<0.01). Subsequently, 104 patients, who underwent cervical discectomy, showed a correlation of the neck disability index with implant-specific changes in their segmental movement geometry: the preoperative simulation supported the best choice of surgical implants, since the best outcome resulted from restricting the extent of the movement of adjacent segments influenced by the technical mechanism of the respective device (p<0.05). CONCLUSIONS: The implant restoration resulted in best outcome which modified intersegmental communication in a way that the segments adjacent to the implanted segment undergo less change in their own movement geometry. Based on our software-surrogate, individualized devices could be created that slow down further degeneration of adjacent segments by influencing the intersegmental communication of the motion segments.

Do statins reduce the rate of revision surgery after chronic subdural hematoma drain?

BACKGROUND: With chronic subdural hematoma (CSDH), surgery is the therapeutic mainstay for large or symptomatic cases. Statins are reported to be effective as the primary therapy of CSDH to obviate the need for surgery. However, the effect of statins on the postoperative course of CSDH is largely unclear. We therefore sought to determine whether statins reduce the rate of repeat surgery after CSDH drain. METHODS: We performed an analysis of all patients who underwent surgery for CSDH at our institution between 2012 and 2018. The patients were separated into those who received statins as part of their previous medication (statin group) and those who did not (control group). The medical records were reviewed for repeat surgeries and complications. Additionally, patients or their relatives were contacted via phone to obtain missing data and inquire about possible repeat surgeries at other institutions. RESULTS: We identified 407 patients who received CSDH evacuation via burr hole craniotomy. In total, 123 patients were treated with statins as part of their daily medication. Repeat surgery was performed in 26 patients in the statin group (21.1%) and 57 patients in the non-statin group (20.1%, p = 0.81). Upon multivariate logistic regression analysis, neither of the variables statins, age, antithrombotic medication, Charlson comorbidity index, or Markwalder grading score yielded a statistically significant effect upon the revision rate. CONCLUSIONS: We found no evidence for the protective effect of statins in patients who underwent surgery for CSDH. We thus conclude that statin therapy is not warranted for CSDH perioperatively.

Olfactory bulb volume changes associated with trans-sphenoidal pituitary surgery.

OBJECTIVE: The trans-sphenoidal approach is most frequently used for pituitary adenoma (PA) enucleation. However, effects of this surgery on neighboring structures have received little attention so far. In particular, no investigations on olfactory bulb (OB) anatomy after trans-sphenoidal surgery have been reported. Because impairment of olfaction has been shown in small groups following trans-sphenoidal surgery we hypothesized that the transnasal approach is likely to alter OB volume which is associated with changes of olfactory function. METHODS: The study comprised 33 patients with pituitary adenoma (14 women and 19 men, mean age 50 years). Comprehensive assessment of olfactory function was conducted with the "Sniffin' Sticks" test kit. Based on magnetic resonance imaging scans OBs were measured before and approximately one year after trans-sphenoidal PA enucleation. RESULTS: Owing to postoperative non-compliance and MRI artifacts partly due to drill friction complete evaluation of "Sniffin' Sticks" in term of obtaining the TDI score was possible pre- and postoperatively in 21 patients whereas OB volumes were available in 32 patients. Approximately one year after surgery olfactory function was not significantly different from baseline. However, left- and right-sided OB volume in patients treated via trans-sphenoidal surgery decreased (p = 0.001). The side of the surgical approach did not affect OB volume in a side-specific manner. Changes in odor threshold were significantly correlated to changes in right-sided OB volume (r = 0.45, p = 0.024). CONCLUSION: Overall olfactory performance one year after surgery was not significantly different from baseline. However, changes in OB volume are associated with changes in olfactory performance and OB volumes decreased in patients.

Endoscopic and Microscopic Segmental Decompression via Translaminar Crossover Spinal Approach in Elderly Patients.

OBJECTIVE: For effective minimally invasive lumbar decompression, we changed the routine of segmental decompression. Using a high-speed drill or an ultrasound knife, we created a working channel, starting at the base of the spinous process of the upper vertebra slightly above the disc level, to target and decompress the contralateral recess, and termed it the translaminar crossover decompression (TCD). We evaluated the feasibility and compared the outcomes of a navigation-guided endoscopic translaminar crossover approach for segmental decompression (eTCD) in elderly patients with microscopic decompression using the same approach (mTCD). METHODS: A total of 740 elderly patients were enrolled in a prospective cohort study. Of the 740 patients, 297, who had undergone mTCD, and 253, who had undergone eTCD, completed a 1-year follow-up visit. In addition to the surgical data, numerical rating scales (NRSs) for back and leg pain, the Core Outcome Measures Index and Oswestry Disability Index were recorded preoperatively and 3, 6, and 12 months after surgery. The MacNab criteria were supplemented by qualitative assessment of the patients' postoperative pain-free walking distance. RESULTS: A comparison of the preoperative and postoperative clinical scores showed significant improvement after TCD in both cohorts (P < 0.01): Oswestry Disability Index, from 50.3% ± 12.6% to 15.5% ± 7.43%; NRS (back), from 6.9 ± 1.9 to 2.5 ± 1.3; NRS (leg), from 8.0 ± 0.85 to 1.6 ± 0.33; Core Outcome Measures Index (back), from 7.8 ± 2.0 to 2.7 ± 1.5. No statistically significant differences were found in the outcomes between the 2 cohorts. CONCLUSIONS: TCD inherently eliminated central stenosis and facilitated decompression of both recesses via mutual undercutting, with preservation of facet joint integrity.

Adjustable Polyurethane Foam as Filling Material for a Novel Spondyloplasty: Biomechanics and Biocompatibility.

OBJECTIVE: To investigate the biomechanics and biocompatibility of polyurethane (PU) foam with adjustable stiffness as a filling material for a novel spondyloplasty that is designed to reduce the risk of postoperative adjacent level fractures. METHODS: Sixty individual porcine lumbar vertebrae were randomly split into 4 groups: A, B, C, and D. Group A served as unmodified vertebral body controls. Groups B, C, and D consisted of hollowed vertebral bodies. Vertebrae of groups C and D were filled with adjustable PU foams of different stiffness. The compressive strength and stiffness of vertebrae from groups A-D were recorded and analyzed. 3T3 mouse fibroblasts were cultured with preformed PU foams for 4 days to test biocompatibility. RESULTS: The strength and stiffness of the hollowed groups were lower than in group A. However, the differences were not statistically significant between group A and group C (P > 0.05), and were obviously different between group A and group B or group D (P < 0.01 and <0.05, respectively). Moreover, the strength and stiffness after filling foams in group C or group D were significantly greater than in group B (P < 0.01 and <0.05, respectively). Live/dead staining of 3T3 cells confirmed the biocompatibility of the PU foam. CONCLUSIONS: The new PU foam shows adaptability regarding its stiffness and excellent cytocompatibility in vitro. The results support the clinical translation of the new PU foams as augmentation material in the development of a novel spondyloplasty.

ActiGait implantable drop foot stimulator in multiple sclerosis: a new indication.

OBJECTIVE Direct stimulation of the peroneal nerve by the ActiGait implantable drop foot stimulator is a potent therapy that was described previously for stroke-related drop foot. The authors report here successful long-term application of the ActiGait implantable drop foot stimulator in patients with multiple sclerosis (MS). METHODS Six patients with MS and 2 years of persisting central leg paresis received an implantable ActiGait drop foot stimulator after successful surface test stimulation. Ten weeks and 1 year after surgery, their gait speed, endurance, and safety were evaluated. Patient satisfaction was assessed with a questionnaire. RESULTS In the 20-m gait test, stimulation with the ActiGait stimulator significantly reduced the time needed, on average, by approximately 23.6% 10 weeks after surgery, and the time improved further by 36.3% after 1 year. The median distance covered by patients with the stimulator after 6 minutes of walking increased significantly from 217 m to 321 m and remained stable for 1 year; the distance covered by patients after surface stimulation was 264 m. Patients with an implanted ActiGait stimulator noticed pronounced improvement in their mobility, social participation, and quality of life. CONCLUSIONS The ActiGait implantable drop foot stimulator improved gait speed, endurance, and quality of life in all patients over a period of 1 year. It may serve as a new therapeutic option for patients with MS-related drop foot.

Intratumoral heterogeneity and TERT promoter mutations in progressive/higher-grade meningiomas.

BACKGROUND: Recent studies have reported mutations in the telomerase reverse transcriptase promoter (TERTp) in meningiomas. We sought to determine the frequency, clonality and clinical significance of telomere gene alterations in a cohort of patients with progressive/higher-grade meningiomas. METHODS: We characterized 64 temporally- and regionally-distinct specimens from 26 WHO grade III meningioma patients. On initial diagnoses, the meningiomas spanned all WHO grades (3 grade I, 13 grade II and 10 grade III). The tumor samples were screened for TERTp and ATRX/DAXX mutations, and TERT rearrangements. Additionally, TERTp was sequenced in a separate cohort of 19 patients with radiation-associated meningiomas. We examined the impact of mutational status on patients' progression and overall survival. RESULTS: Somatic TERTp mutations were detected in six patients (6/26 = 23%). Regional intratumoral heterogeneity in TERTp mutation status was noted. In 4 patients, TERTp mutations were detected in recurrent specimens but not in the available specimens of the first surgery. Additionally, a TERT gene fusion (LPCAT1-TERT) was found in one sample. In contrary, none of the investigated samples harbored an ATRX or DAXX mutation. In the cohort of radiation-induced meningiomas, TERTp mutation was detected in two patients (10.5%). Importantly, we found that patients with emergence of TERTp mutations had a substantially shorter OS than their TERTp wild-type counterparts (2.7 years, 95% CI 0.9 - 4.5 years versus 10.8 years, 95% CI 7.8 -12.8 years, p=0.003). CONCLUSIONS: In progressive/higher-grade meningiomas,TERTp mutations are associated with poor survival, supporting a model in which selection of this alteration is a harbinger of aggressive tumor development. In addition, we observe spatial intratumoral heterogeneity of TERTp mutation status, consistent with this model of late emergence in tumor evolution. Thus, early detection of TERTp mutations may define patients with more aggressive meningiomas. Stratification for TERT alterations should be adopted in future clinical trials of progressive/higher-grade meningiomas.

Restoration of ankle movements with the ActiGait implantable drop foot stimulator: a safe and reliable treatment option for permanent central leg palsy.

OBJECT The ActiGait drop foot stimulator is a promising technique for restoration of lost ankle function by an implantable hybrid stimulation system. It allows ankle dorsiflexion by active peroneal nerve stimulation during the swing phase of gait. In this paper the authors report the outcome of the first prospective study on a large number of patients with stroke-related drop foot. METHODS Twenty-seven patients who experienced a stroke and with persisting spastic leg paresis received an implantable ActiGait drop foot stimulator for restoration of ankle movement after successful surface test stimulation. After 3 to 5 weeks, the stimulator was activated, and gait speed, gait endurance, and activation time of the system were evaluated and compared with preoperative gait tests. In addition, patient satisfaction was assessed using a questionnaire. RESULTS Postoperative gait speed significantly improved from 33.9 seconds per 20 meters to 17.9 seconds per 20 meters (p < 0.0001), gait endurance from 196 meters in 6 minutes to 401 meters in 6 minutes (p < 0.0001), and activation time from 20.5 seconds to 10.6 seconds on average (p < 0.0001). In 2 patients with nerve injury, surgical repositioning of the electrode cuff became necessary. One patient showed a delayed wound healing, and in another patient the system had to be removed because of a wound infection. Marked improvement in mobility, social participation, and quality of life was confirmed by 89% to 96% of patients. CONCLUSIONS The ActiGait implantable drop foot stimulator improves gait speed, endurance, and quality of life in patients with stroke-related drop foot. Regarding gait speed, the ActiGait system appears to be advantageous compared with foot orthosis or surface stimulation devices. Randomized trials with more patients and longer observation periods are needed to prove the long-term benefit of this device.

Radio-chemotherapy improves survival in IDH-mutant, 1p/19q non-codeleted secondary high-grade astrocytoma patients.

Isocitrate dehydrogenase (IDH) mutations are beginning to drive decisions on therapy for glioma patients. Here we sought to determine the impact of adjuvant treatment in patients with IDH-mutant, 1p/19q non-codeleted secondary high-grade astrocytoma (sHGA) WHO grades III/IV. Clinical data of 109 sHGA patients grades III/IV, in addition to IDH mutation-, 1p/19q-codeletion- and MGMT-promoter methylation status-were retrospectively analyzed. Survival analysis in relation to adjuvant treatment modalities and molecular profiling were performed. Out of 109 patients, 88 patients (80.7 %) harbored IDH mutations, 30 patients had a 1p/19q-codeletion (27.5 %) and 69 patients (63.3 %) exhibited a methylated MGMT-promoter status. At a median follow-up of 9.8 years, 62 patients (57 %) died. The postsurgical treatment included: radio-chemotherapy (RT-CT; 54.5 %), RT alone (19.3 %), and CT alone (22.7 %). The median overall survival (OS) in the entire group was 3.4 years (1.9-6.7 years). Patients who received RT-CT had a significantly longer OS compared with those who underwent RT alone (6.5 vs. 1.2 years, HR 0.35, CI 0.32-0.51, p = 0.011). In the IDH-mutant 1p/19q non-codeleted sHGA subgroup the RT-CT cohort had a significantly longer OS in comparison to the RT cohort (6.4 vs. 1.2 years, HR 2.7, CI 1.1-6.5, p = 0.022). In the stepwise multivariable Cox model for OS of all 88 IDH-mutant sHGA patients, survival was strongly associated with only one factor, namely, adjuvant RT-CT at diagnosis of a sHGA. This retrospective long-term study demonstrates that RT and CT (mostly PCV) significantly improves progression-free and overall survival in IDH-mutant secondary high-grade astrocytoma patients, regardless of 1p/19q-codeletion status.

A five year-old child with clear cell petro-clival meningioma: case report with clinical and histopathological long-term follow-up.

BACKGROUND: Only a few cases have been previously published about clear cell meningiomas in children, the majority of them in the location of the spine. We describe an unusual case of clear cell meningioma occurring at the petro-clival region in a 5-year-old child. We further seek to determine the impact of several growth factors as well as the AKT1 mutation on the tumor growth pattern. CASE PRESENTATION: A five-year-old girl was presented with a one-week history of cephalgia, ataxia, and left sided torticollis. Magnetic resonance imaging (MRI) revealed a dumbbell-shaped homogeneously petro-clival gadolinium-enhancing mass. A staged operative approach was chosen, and a complete removal of the tumor was achieved. Due to recurrent tumor progression, the child underwent several tumor surgeries and two cranial radiations. None of the treatments were able to stop tumor progression. Consequently, the child died at the age of 14 after further extensive intracranial and extracranial tumor progression. The initial histological examination revealed a clear cell meningioma WHO grade II with an MIB-1 labeling index of <1%, which gradually increased with every recurrence up to 10% by the last progression at the age of 13 years. Analogically, an increasing overexpression of epidermal growth factor receptor (EGFR), the platelet-derived growth factor receptor (PDGFR), and the vascular endothelial growth factor receptor (VEGFR) was observed with each recurrence. The AKT1 (E17K) mutation in the tumor was not detectable in all investigated specimens. CONCLUSION: Pediatric clear cell meningiomas WHO grade II are very rare. Our data demonstrate the progressive overexpression of EGF-, PDGF-, and VEGF-receptors in each recurrence, providing one of these receptors as targeted therapy in such cases. Further evaluation of these growth factors in clear cell meningioma is required to establish the optimal treatment of these aggressive tumors.

Hemicraniectomy in older patients with extensive middle-cerebral-artery stroke.

BACKGROUND: Early decompressive hemicraniectomy reduces mortality without increasing the risk of very severe disability among patients 60 years of age or younger with complete or subtotal space-occupying middle-cerebral-artery infarction. Its benefit in older patients is uncertain. METHODS: We randomly assigned 112 patients 61 years of age or older (median, 70 years; range, 61 to 82) with malignant middle-cerebral-artery infarction to either conservative treatment in the intensive care unit (the control group) or hemicraniectomy (the hemicraniectomy group); assignments were made within 48 hours after the onset of symptoms. The primary end point was survival without severe disability (defined by a score of 0 to 4 on the modified Rankin scale, which ranges from 0 [no symptoms] to 6 [death]) 6 months after randomization. RESULTS: Hemicraniectomy improved the primary outcome; the proportion of patients who survived without severe disability was 38% in the hemicraniectomy group, as compared with 18% in the control group (odds ratio, 2.91; 95% confidence interval, 1.06 to 7.49; P=0.04). This difference resulted from lower mortality in the surgery group (33% vs. 70%). No patients had a modified Rankin scale score of 0 to 2 (survival with no disability or slight disability); 7% of patients in the surgery group and 3% of patients in the control group had a score of 3 (moderate disability); 32% and 15%, respectively, had a score of 4 (moderately severe disability [requirement for assistance with most bodily needs]); and 28% and 13%, respectively, had a score of 5 (severe disability). Infections were more frequent in the hemicraniectomy group, and herniation was more frequent in the control group. CONCLUSIONS: Hemicraniectomy increased survival without severe disability among patients 61 years of age or older with a malignant middle-cerebral-artery infarction. The majority of survivors required assistance with most bodily needs. (Funded by the Deutsche Forschungsgemeinschaft; DESTINY II Current Controlled Trials number, ISRCTN21702227.).

Retractor-endoscopic nerve decompression in carpal and cubital tunnel syndromes: outcomes in a small series.

OBJECTIVE: To present midterm to long-term results obtained in carpal tunnel release, in situ decompression, and anterior transposition of the ulnar nerve using the retractor integrated endoscope. METHODS: During the period 2000-2010, 145 patients underwent endoscopic carpal tunnel releases (n = 47), endoscopic in situ decompression of the ulnar nerve (n = 55), and endoscopic anterior transposition of the ulnar nerve (n = 52). Bilateral surgery was performed in 9 patients. Independent examinations at 24 months after surgery were used for objective results (Bishop score). Subjective results were procured using a questionnaire. RESULTS: After endoscopic carpal tunnel release, 59.6% of patients showed excellent results, 21.2% showed good results, 12.8% showed fair results, and 6.4% showed poor results according to objective scoring. In 85% of patients, subjective improvement was noted after surgery; symptoms were the same as before surgery in 12.8% of patients and were worse in 2.1% of patients after surgery. After endoscopic in situ decompression, 56.4% of patients showed excellent results on objective scoring, 32.7% showed good results, 9.1% showed fair results, and 1.8% showed poor results. On subjective questioning, 72.7% of patients reported improvement, 20% reported no change in symptoms, and 7.3% reported worse symptoms. After endoscopic anterior transposition of the ulnar nerve, 48.1% of patients showed excellent results on objective scoring, 26.9% showed good results, 23.1% showed fair results, and 1.9% showed poor results. Subjectively, 65.4% of patients reported improvement, 26.9% reported no change in symptoms, and 7.7% reported worse symptoms. Patients with symptom duration of <9 months before surgery showed better results than patients with symptom duration of >9 months. CONCLUSIONS: The retractor-endoscopic technique provides good long-term results after carpal tunnel release, in situ decompression, and anterior subcutaneous transposition of the ulnar nerve. Outcomes showed some correlation to the duration of preoperative symptoms.

Label-free differentiation of human pituitary adenomas by FT-IR spectroscopic imaging.

Fourier transform infrared (FT-IR) spectroscopic imaging has been used to characterize different types of pituitary gland tumors and normal pituitary tissue. Freshly resected tumor tissue from surgery was prepared as thin cryosections and examined by FT-IR spectroscopic imaging. Tissue types were discriminated via k-means cluster analysis and a supervised classification algorithm based on linear discriminant analysis. Spectral classification allowed us to discriminate between tumor and non-tumor cells, as well as between tumor cells that produce human growth hormone (hGH+) and tumor cells that do not produce that hormone (hGH-). The spectral classification was compared and contrasted with a histological PAS and orange G stained image. It was further shown that hGH+ pituitary tumor cells show stronger amide bands than tumor cells that do not produce hGH. This study demonstrates that FT-IR spectroscopic imaging can not only potentially serve as a fast and objective approach for discriminating pituitary gland tumors from normal tissue, but that it can also detect hGH-producing tumor cells.

Frequent loss of the CDKN2C (p18INK4c) gene product in pituitary adenomas.

Genomic alterations of cyclin-dependent kinase inhibitors have been demonstrated in a variety of tumor types including brain tumors. Among them, the cyclin-dependent kinase inhibitor 2A (CDKN2A or p16(INK4a)) gene has been shown to be frequently deleted or inactivated in astrocytic tumors. The CDKN2C (p18(INK4c)) gene is functionally related to CDKN2A. Moreover, mice with targeted disruption of CDKN2C alone or combined CDKN2C and cyclin-dependent kinase inhibitor 1B (CDKN1B or p27(Kip1)), or CDKN2C and TP53 gene disruption develop pituitary adenomas (PA) at high frequencies. The purpose of our study was to investigate genetic alterations of the CDKN2C gene by analysis of loss of heterozygosity (LOH), screening for mutations, analysis of promoter methylation, and protein expression in 38 PAs. In addition, genomic alterations and protein expression of the cell cycle genes CDKN2A and its alternatively spliced form, p14(ARF), as well as the retinoblastoma RB1 gene were investigated. LOH at the CDKN2C gene locus was detected in 25% of pituitary adenomas, whereas the RB1 and CDKN2A loci were altered in only 10%. No mutations were detected within the coding regions of the CDKN2C gene. However, 39.5% of adenomas displayed CDKN2C promoter methylation. The absence of CDKN2C protein was correlated with LOH of the CDKN2C locus on chromosome 1 and with methylation of the CDKN2C promoter. This is the first report to describe that the tumor suppressor gene CDKN2C is frequently targeted by genomic alterations in pituitary adenoma. The most common genetic alteration was promoter methylation suggesting that inactivation of CDKN2C by this mechanism may play an important role in pituitary adenoma development. Additional Supporting Information may be found in the online version of this article.

A novel minimally occlusive microvascular anastomosis technique using a temporary intraluminal shunt: a prospective technique to minimize brain ischemia time during superficial temporal artery-to-middle cerebral artery bypass.

OBJECTIVE: To describe a new technique of suturing microvessels with persistent perfusion via a temporary intraluminal microshunt. METHODS: Experiments were conducted in Wistar rats. Abdominal aorta grafts were explanted from donor rats. A soft silicon microcatheter was introduced into the lumen of this graft. The abdominal aorta of a recipient rat was prepared for end-to-side microvascular anastomosis. Acland clamps (S&T AG, Neuhausen, Switzerland) were applied, and a linear arteriotomy was made. One end of the graft-clad microcatheter was introduced into the lumen and occluded with a fenestrated Acland clamp. At a more distal part, a similar arteriotomy was performed, and the other end of the microcatheter was introduced into the lumen and clamped with a fenestrated Acland clip. This created a temporary shunt through the graft-clad microcatheter. Then, the graft was anastomosed to the arteriotomies at both ends, over the microcatheter, in an end-to-side manner. The microcatheter was explanted from the vessel lumen through an arteriotomy in the middle of the graft. The graft was clipped short to close this arteriotomy. The mean total occlusion time before perfusion was reestablished amounted to 3.7 minutes. This experiment was repeated in 12 animals (6 with and 6 without heparin) without technical complications. As controls, conventional anastomoses were made in 2 animals. RESULTS: Suturing microvessels mandates their occlusion during the period of anastomosis. Although ischemia is well tolerated by other tissue types, the brain is quite sensitive to even short windows of ischemia. Nonocclusive anastomotic techniques have been developed recently. These are confined to vessels with luminal diameters greater than 3 mm. We have evolved a novel technique that can be used with microvessels, as pertinent to superficial temporal artery-to-middle cerebral artery bypass. CONCLUSION: We have described a new technique for performing microvascular anastomoses over a temporary intraluminal microcatheter shunt.