Management of Failed Cranioplasty

AIM

Failed cranioplasty attempts may lead to numerous complications in a broad spectrum including cosmetic problems, infection, neurological deterioration and even death. Selection of the most appropriate surgical technique for second and further surgical attempts for these patients still remains a debate. We aimed to share our experience and technical pitfalls on management of failed cranioplasty, particularly for patients with large cranial defects.

MATERIAL AND METHODS

A retrospective data analysis of cranioplasty cases in our series was performed including the time period between 2002 and 2012. Patients required recurrent cranioplasty were analyzed in detail.

RESULTS

Totally, 101 patients underwent cranioplasty for bony defect. Of 101 patients, eleven required a revision surgery due to infection or spontaneous resorption of the bone flap. All patients underwent revision cranioplasty with pre-surgical plaster cast mold technique modified from previous studies and/or tissue expansion technique. Polymethyl-metacrylate (PMMA) was used as substitute for reconstructions. Mean follow-up was 36 months. Two out of eleven cases (18.1%) developed major complications, which led to further revision. At the end, a satisfactory reconstruction was achieved for all patients.

CONCLUSION

Our modified molded plaster cast technique is a safe and cost-effective approach for the revision of failed cranioplasty. We believe that the tissue expanding techniques have also great contribution to achieve successful results.

MGMT gene variants, temozolomide myelotoxicity and glioma risk. A concise literature survey including an illustrative case

Temozolomide may cause thrombocytopenia or neutropenia in 3-4% of glioblastoma patients, respectively. However, pancytopenia is rarely reported. MGMT (O6-methylguanine-DNA-methyltransferase) enzyme repairs temozolomide-induced DNA mutations and associates both with antitumour efficacy and myelosuppression. Many studies on the effects of MGMT gene-methylation on temozolomide's effects exist, but much fewer publications concerning MGMT variants were documented. A full sequencing of the MGMT gene was performed in a female glioblastoma patient, who developed pancytopenia following temozolomide treatment. Results indicated the presence of all the rs2308321 (I143 V), rs2308327 (K178R) and rs12917 (L84F) MGMT-variants, which were previously associated with temozolomide myelotoxicity. rs12917 (L84F) variant was reported as associating with lesser risk of gallbladder tumours, yet with higher risk of non-Hodgkin lymphomas related with exposure to chlorinated solvents or hair dyes. DNA repair proteins may exert diverging effects on DNA injuries caused by different chemicals and therefore exerting complex effects on myelotoxicity, antitumour activity and carcinogenesis.

LOW O6-METHYLGUANINE-DNA METHYTRANSFERASE (MGMT) AND PAN-CYTOKERATIN (PAN-CK) EXPRESSION VIA IMMUNOHISTOCHEMISTRY IN PITUITARY ADENOMAS

Introduction

Pituitary adenomas (PA) are the third most common intracranial tumors, with an incidence rate of 10-15%. More than half are invasive, infiltrating adjacent structures. The primary objective of this project was to determine whether MGMT expression is associated with the invasiveness of PA.

Material and Method

All patients who underwent surgical decompression consecutively between 2007-2012 were included. All data were obtained from the case records. Formalin-fixed paraffin-embedded (FFPE) tissue specimens were stained with hematoxylin and eosin (HE) and then examined via light microscope. Paraffin blocks that lacked necrosis and hemorrhage were chosen for histologic examination. In addition to an immunoprofile battery that consisted of Ki-67 and p53, MGMT, S-100 and Pan-CK were evaluated as well.

Results

The subjects included 25 women and 15 men. The mean age was 48.9 ± 14.5 years. Of these, 63% of cases involved the invasion of adjacent structures. Of the PA, 17 (42%) were non-functioning pituitary adenomas (NFPA). There was a statistically significant relationship between the invasiveness and Ki-67, p53, MGMT expression, and prolactinoma. Gonodotropinomas were mostly non-invasive. FPAs presented invasive features more frequently than NFPAs. Pan-CK was positive in GH-secreting adenomas but negative in FSH- and LH-secreting adenomas.

Conclusion

Ki-67 and p53 in lower expression level can be used for evaluating invasiveness but not for recurrence. MGMT expression can be a useful IHC indicator for invasiveness. However, Pan-CK cannot be used for invasiveness or aggressiveness.

Relation of apparent diffusion coefficient with Ki-67 proliferation index in meningiomas

OBJECTIVE

The purpose of this study was to investigate the relationship between Ki-67 proliferation indexes and apparent diffusion coefficient (ADC) values of low-grade and atypical/anaplastic (high-grade) meningiomas.

METHODS

Pre-operative diffusion-weighted imaging and histopathological evaluation of 44 patients with meningiomas were performed retrospectively. Regions of interest (ROIs) were manually drawn on the ADC images. In total six ROI measurements were taken in three consecutive slices, and the average of the mean ADC value was used. The relationship between the ADC and Ki-67 values was investigated, and the ADC values of the low-grade and high-grade meningiomas were compared.

RESULTS

31 (70%) patients had low-grade the meningiomas. 10 (23%) patients had atypical and 3 (7%) had anaplastic meningiomas. ADC values of the low-grade and high-grade meningiomas were 0.81 ± 0.12 × 10(-3) and 0.66 ± 0.08 × 10(-3) mm(2) s(-1), respectively. Ki-67 proliferation indexes were 2.19% ± 1.14% for low-grade and 11.20% ± 9.80% for high-grade meningiomas. A statistically significant negative correlation between Ki-67 proliferation index and ADC values of the low-grade and high-grade meningiomas was detected (r(2) = 0.326, p < 0.001). High-grade meningiomas had lower ADC values than that of low-grade meningiomas. There was statistically significant difference between the ADC values of the low-grade and high-grade meningiomas (p < 0.001).

CONCLUSION

Our data provide an inverse correlation between the ADC and Ki-67 proliferation index values of meningiomas. ADC values can be used for histopathological characterization of the meningiomas and pre-surgical planning.

ADVANCES IN KNOWLEDGE

The purpose of this study was to investigate the relationship between Ki-67 proliferation indexes and ADC values of low-grade and atypical/anaplastic (high-grade) meningiomas. In addition, we compared the ADC and Ki-67 proliferative index values of the low-grade and atypical/anaplastic (high-grade) meningiomas. We concluded that there was an inverse correlation between the ADC and Ki-67 proliferation index values in meningiomas, and we have found statistically significant difference between the ADC values of the low-grade and high-grade meningiomas. ADC values can be used for histopathological characterization of the meningiomas and pre-surgical planning.

Diagnostic approach to reveal retroperitoneal injury during lumbar discectomy

For decades, lumbar discectomy has been one of the most common surgical practices performed by neurosurgeons. Although it has proved to be an effective and safe surgical procedure, life threatening complications may occur in rare cases, including iliac artery and/or vein injuries, superior rectal artery injury, common iliac artery aneurysms, iliac arteriovenous fistula, intestinal injuries, and ureteral injuries. Ureteral damage during the lumbar L4-5 microdiscectomy was reported in a slim 50 year-old male patient. Because of a small amount of bleeding occurred during the surgery as soon as the patient came out of anesthesia, an angio-computed tomography (CT) of the abdomen was performed. It showed no hematoma and no major vascular injury, but air bubbles were seen in the retroperitoneal region, indicating that perforation had occurred. The patient was then monitored carefully for immediate and possible subsequent injuries, in this way; ureteral damage was found and repaired. This is perhaps the first such case report in the literature of the early detection of ureteral damage using an angio CT scan. If there is a suspicion of perforation of the anterior annulus fibrosus and anterior longitudinal ligaments but no indication for an emergency laparotomy, an abdominal angio CT done immediately after the surgery and an abdominal non-contrast CT 4 hours later will give sufficient information concerning the potential occurrence of nearly all the major complications associated with lumbar discectomy.