Ventral Tumors Research Articles

The application of internal traction technique in retroperitoneal robot-assisted partial nephrectomy for renal ventral tumors

BackgroundFor patients with prior intra-abdominal surgery or multiple arteries, the retroperitoneal robot-assisted partial nephrectomy (rRAPN) is a better choice. The renal ventral tumor poses an additional challenge due to poor tumor exposure. This study is determined to assess the feasibility of an internal traction technique (ITT) in rRAPN for the management of renal ventral tumors.MethodsFrom November 2019 to March 2021, a total of 28 patients with renal ventral tumor underwent rRAPN. All patients had prior abdominal surgery or multiple arteries. The ITT group (20 patients), which improved the tumor exposure by traction of the kidney with suture, was compared with the traditional technique group (8 patients) in terms of warm ischemia time, estimated blood loss and postoperative hospital stay, retroperitoneal drainage, R.E.N.A.L. score, and serum creatinine. Differences were considered significant when P < 0.05.ResultsAll rRAPN surgeries were successful without conversion to radical nephrectomy or open partial nephrectomy. The warm ischemia time was lower in the ITT group (17.10 min vs. 24.63 min; P < 0.05). Estimated blood loss in the traditional technique group was 324.88 ± 79.42 mL, and in the ITT group, it was 117.45±35.25 mL (P < 0.05). No significant differences with regard to postoperative hospital stay, retroperitoneal drainage, R.E.N.A.L. score, and serum creatinine were observed between both groups. Surgical margins were negative and no intraoperative complications occurred in all the patients. After 10 months of follow-up, no recurrence or metastasis occurred in all cases.ConclusionITT is a feasible, safe, and valid procedure in rRAPN for renal ventral tumors. Application of ITT improved the exposure and reduces warm ischemic time in comparison with the conventional procedure.

Foramen Magnum Meningioma-The Attainment of the Intra-Arachnoidal Dissection: 2-Dimensional Operative Video.

Ventral foramen magnum meningiomas are a forbidding lesion. The stake is so high with a risk of devastating paralysis and respiratory failure. Careful preoperative clinical and radiological evaluation is necessary to implement the best treatment plan. Successful surgical intervention depends on paying high attention to minute details throughout the case, from intratracheal intubation to extubation. The neural head-on-neck position is critical to avoid further medullary compression at intubation and positioning.1 Extensive neurophysiological monitoring, including somatosensory, motor, brainstem evoked potential, and cranial nerves, during the positioning and throughout the case, is extremely helpful to detect early signs of dysfunction.1 To expose and access ventral tumors, partial condyle resection and vertebral artery transposition are invaluable techniques.2,3 Preservation and minute manipulation of the vital neurovascular structures at this junction that includes the medullar, anterior spinal artery, posterior inferior cerebellar artery, vertebral junction perforators, and lower cranial nerves are essential for good outcomes. This is achieved by microsurgical intra-arachnoidal dissection under high magnification and after debulking the tumor to establish that plane.1,3,4 The demonstration of this technique is the purpose of this article. We demonstrate these surgical tenets applied to the resection of a large ventral foramen magnum meningioma extending from the midclivus to the C3 vertebral body level in a 54-yr-old female presenting with swallowing difficulties. The patient consented to the surgical intervention and the publication of her images. Image at 1:38 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, © LWW, 1998.

Microsurgical Resection of an Intramedullary Spinal Cord Hemangioblastoma Through an Anterior Cervical Approach: 2-Dimensional Operative Video.

This video demonstrates the microsurgical removal of an intramedullary spinal cord hemangioblastoma through an anterior cervical approach. While most spinal hemangioblastomas arise from the dorsal or dorsolateral pial surface and can be safely resected through a posterior approach,1,2 ventral tumors can present a significant challenge to safe surgical removal.3-5 This patient presented with a progressively symptomatic ventral pial based hemangioblastoma at the C5-6 level with large polar cysts extending from C3 to T1. The tumor was approached through a standard anterior cervical exposure with a C5 and C6 corpectomy. Following midline durotomy, the tumor was identified and complete microsurgical resection was achieved. The principles and techniques of tumor resection are illustrated and described in the video. Following tumor resection and dural closure, a fibular allograft was inserted into the corpectomy defect and a C4-C7 fixation plate was placed. The patient was maintained in a supine position for 36 h. He was discharged home on postoperative day 3 in a cervical collar. The patient did well with near-complete recovery of neurological function. Postoperative magnetic resonance imaging at 6 wk showed a substantial resolution of the polar cysts and no evidence of residual tumor. The patient featured in this video consented to the procedure.

THE RESULTS OF SURGICAL TREATMENT IN PATIENTS WITH VERTEBRAL METASTASES

Study Objectives. The study was conducted to analyze and compare different types of surgical access in the treatment of patients with metastatic vertebral lesions to improve the outcome of surgery. Materials and Methods. The study included 108 patients with vertebral metastases who were operated on at the Romodanov Neurosurgery Institute of the National Academy of Medical Sciences of Ukraine in 2015–2019. Results. The choice of surgical access depended on a few factors such as tumor location relative to the dura mater, bones, and nerve structures and was as follows: posterior access was used to resect tumors located posteriorly and posterolaterally to the brain; lateral access was used for tumors located laterally to the brain; anterior access was used to resect tumors located in front of the spinal cord. In Group I (73 patients), posterior access was used in 49 cases (67%), anterior access – in 19 cases (26%), and lateral access – in 5 cases (7%). In Group II (35 patients), only posterior access was used. Discussion. Selection of adequate surgical access for vertebral tumor resection in order to minimize nerve structure injury significantly improved the results of surgical treatment. Anterior and lateral access for ventral and ventrolateral tumors operation made it possible to completely resect the tumor, reduce the traction of nerve structures, and obtain sufficient visual control of the operating field during the surgery, which in turn had a positive effect on regression of pain and conduction disorders. Conclusions. A differential approach to the choice of surgical access reduces the neurological deficit in the postoperative period and allows radical resection of the tumor, which in turn helps to significantly reduce the number of tumor recurrences in the long-term period.

Comparison of the efficacy and safety of the posterior and paramedian minimally invasive approaches to ventral and ventro-lateral intradural extramedullary tumors

Comparison of the efficacy and safety of the posterior and paramedian minimally invasive approaches to ventral and ventro-lateral intradural extramedullary tumors

Review of upper urinary modified minimal invasive surgical technology

Upper urinary surgery is an important area of urology surgery. Open surgery used to be the gold standard of upper urinary surgery. With the development of medical techniques, minimal invasive surgeries including laparoscopic and robot assisted-laparoscopic surgery have gradually replaced the open surgery. Because of the complexity and diversity of upper urinary diseases, surgeries sometimes are difficult, and minimal invasive surgeries require higher surgical abilities of urologists than open surgeries. In recent years, depending on our surgical experience and international reports, our team from three Chinese medical centers summarizes techniques of upper urinary minimal invasive surgeries. For malignant diseases, such as renal and ureteral carcinomas, it's important to totally remove the tumor first, and then to avoid the surgical injuries. We summarize surgical experience of retroperitoneal laparoscopic partial nephrectomy for moderately complex renal hilar tumors. Our team modified minimal invasive techniques for some complex tumors, including ring suture technique for renal hilar tumors, internal suspension technique for renal ventral tumors, and combination retroperitoneal laparoscopic surgery with mini-flank incision for complex renal tumors. While for begin diseases, urologists should focus on the resections and surgical injuries at the same time. We have reported the novel technique of laparoscopic aspiration for central renal angiomyolipoma, making the surgery simple and available. For reconstruction surgeries, operations should be based on several principals. We generalize it as "4TB principals", which include "tension-free", "water-tight", "thin suture", "no touch of the key area" and "protecting the blood supply". Depending on the localization, length, and etiology of the strictures, different techniques are required. Our team summarize the pyeloplasty, ureteral reimplantation and ileal ureter replacement based on our surgical experience. For infant upper urinary surgeries, our team has made invasive surgeries that can be used in complex diseases, such as duplex kidney. Based on years of surgical techniques, our modified surgeries achieve a better subjective cosmetic result than the traditional surgeries. In the future, the standardized, practical, simple and individual minimal invasive surgical technique will become the main direction in the future researches.

Anatomical study in exposed area and operating space of extended endonasal approach to the ventral region of cranio-cervical junction

Objective To explore the scope, feasibility and indications of extended neuroendoscopic endonasal approach to reveal the region of cranial-cervical junction. Methods Ten (20 sides) intact frozen adult cadaveric heads were used to simulate the extended neuroendoscopic endonasal approach to remove the anterior tubercle of atlas, part of the atlas anterior arch, odontoid and part of the slope. In the cranial-cervical junction area, we observed the exposed range and measured the distance from the nostril to the anterior tubercle of atlas, the height and width of the anterior arch of the atlas, the distance of bilateral medial margin of occipital condyle, the distance of bilateral medial margin of the foramen lacerum, the vertical distance from the occipital condyle to the homolateral foramen lacerum, and the height, anteroposterior diameter and transverse diameter of the odontoid. Results The exposed range of the extended neuroendoscopic endonasal approach was as follows: when the lesion was located at the foramen magnum, the medial margin of the occipital condyle was the boundary of both sides, the root of the odontoid was the lower boundary, and the lower edge of the occipital bone was the upper boundary. When the lesion was located at the region of cranial-cervical junction, the upper edge of the foramen lacerum on both sides was the upper boundary, and the foramen lacerum and the outer edge of the occipital condyle were the boundaries of both sides of the bone window. By measurement, the distance from the nostril to the anterior tubercle of atlas was 8.9-9.7 cm, with an average of 9.3±0.3 cm. The height of the anterior arch of the atlas was 2.3-3.0 cm, with an average of 2.7±0.3 cm; the width was 1.5-2.0 cm, with an average of 1.8±0.2 cm; the distance of bilateral medial margin of occipital condyle was 1.5-2.0 cm, with an average of 1.8±0.2 cm; the distance of bilateral medial margin of the foramen lacerum was 2.1-2.9 cm, with an average of 2.4 ±0.3 cm; the vertical distance from the occipital condyle to the homolateral foramen lacerum was 1.6-2.2 cm, with an average of 1.9±0.3 cm; the height of the odontoid was 0.9-1.3 cm, with an average of 1.1±0.2 cm, its length was 0.8-1.3 cm, with an average of 1.1±0.2 cm; the transverse diameter of the dentate was 0.9-1.2 cm, with an average of 1.0±0.1 cm.The maximum exposed area of cranio-cervical junction was 6.4-9.8 cm2, with an average of 8.6±1.6 cm2. Conclusion The extended neuroendoscopic endonasal approach with removal of the anterior tubercle of atlas and part of the atlas anterior arch could effectively reveal the cranial-cervical junction area which is suitable for the treatment of odontoid deformity, skull base depression and atlantoaxial joint dislocation as well as resection of epidural tumors in the cranial-cervical junction and ventral and ventral midline tumors. Key words: Natural orifice endoscopic surgery; Anatomy; Cranio-cervical junction; Extended endonasal approach

Benefits and Limitations of Indocyanine Green Fluorescent Image-Guided Surgery for Spinal Intramedullary Tumors.

Intraoperative image guidance using near-infrared indocyanine green videoangiography (ICG-VA) has been used to provide real-time angiographic images during vascular or brain tumor surgery, and it is also being used for spine surgery. To further investigate the benefits and limitations of ICG-VA image-guided surgery for spinal intramedullary tumors through retrospective study. ICG-VA was used in 48 cases that were treated surgically over the past 5 yr. The pathological diagnoses of the tumors included astrocytic tumor, ependymal tumor, cavernous malformation, and hemangioblastoma. Localization of normal spinal arteries and veins on the dorsal surface of the spinal cord helped the surgeons determine the length or point of myelotomy. Well-demarcated tumor stain was recognized in limited cases of anaplastic or highly vascularized tumors, whereas the location of cavernous malformation was recognized as an avascular area on the dorsal surface of the spinal cord. Feeding arteries and tumor stain were well differentiated from draining veins in dorsal hemangioblastomas, but not in intramedullary deep-seated or ventral tumors. The preservation of small perforating branches of the anterior spinal artery after successful resection of the tumor could be well visualized. ICG-VA can provide real-time information about vascular flow dynamics during the surgery of spinal intramedullary tumors, and it may help surgeons localize the normal circulation of the spinal cord, as well as the feeding arteries and draining veins, especially in highly vascular tumors. However, the benefits of intraoperative ICG-VA might be limited for intramedullary deep-seated or ventral tumors.

AB075. The application of internal suspension technique in retroperitoneal laparoscopic partial nephrectomy for renal ventral tumors

BackgroundTo evaluate the feasibility of our novel technique using natural suspension technique in retroperitoneal laparoscopic partial nephrectomy for the management of renal ventral tumors.MethodsBetween January 2013 and July 2016, a total of 145 patients underwent retroperitoneal laparoscopic partial nephrectomy with or without our natural suspension technique. For patients underwent natural suspension technique, surgeons preserved the external fat of the renal tumor as suspension traction measure when separating the kidney. The technique provided traction on the tumor that would stabilize the tumor and maintain the tension during tumor resection. Propensity-score matching was performed according to age, gender, tumor size, tumor location and R.E.N.A.L. nephrometry score, which resulted in 32 patients with natural suspension technique matched to 32 without the technique. Patient characteristics, intraoperative and postoperative outcomes were compared between the groups.ResultsBaseline characteristics including age, gender, tumor size, preoperative eGFR, ASA score and R.E.N.A.L score were statistically similar for the cohorts. The use of our new technique resulted in shorter WIT (15.0 vs. 19.0 minutes; P=0.002) and tumor resection time (4.0 vs. 7.5 minutes; P<0.001). The Trifecta outcomes were significantly improved (87.5% vs. 62.5%, P=0.021) with our technique. No statistic differences were observed in the operation time, estimated blood loss, margin status and overall surgical complications between the two groups.ConclusionsThis novel technique is a feasible and safe procedure in retroperitoneal laparoscopic partial nephrectomy for the management of renal ventral tumors. Prospective, larger studies are warranted for further evaluation.

The Application of "Renal Pedicle Rotation" Method in Retroperitoneal Laparoscopic Partial Nephrectomy for Renal Ventral Tumors.

To present preliminary experience of "renal pedicle rotation" method in retroperitoneal laparoscopic partial nephrectomy (RLPN) for renal ventral tumors. A retrospective analysis of renal surgery database about patients undergoing RLPN was conducted. We identified 14 consecutive cases of all the surgeries from December 2013 to October 2014 with renal ventral tumors. The 14 surgeries were all in the application of renal pedicle rotation method, an intraoperative skill in which surgeons rotates the kidney on renal pedicle axis after separating renal artery and vein for a better tumor exposure. A total of 14 patients underwent RLPN. All surgeries were successful without conversion to radical nephrectomy or open partial nephrectomy. The mean operative time was 171.1±47.2 min (range 83-246), the mean warm ischemia time was 15.9±9.8 min (range 7-35) and the mean estimated blood loss was 89.3±102.2 mL (range 10-300). Mean postoperative hospital stay was 6.2±1.9 days (range 4-10) and mean retroperitoneal drainage was 4.2±1.4 days (range 2-8). No intraoperative complications occurred. Postoperative complications developed in four patients. All patients had negative margins and pathological examination revealed 10 (71.4%) clear cell carcinomas, two (14.2%) epithelial renal angiomyolipoma, one (7.1%) papillary carcinoma and one (7.1%) nephrotuberculosis. The review of the early oncologic outcomes revealed no local recurrence and distant metastasis. The renal pedicle rotation method might be a feasible and safe procedure to get a better tumor exposure for incision and suture in renal ventral tumors RLPN surgeries with acceptable postoperative outcomes.

Biopsy of Brainstem Gliomas Using Flexible Endoscopes.

To describe our experience and the results obtained in performing transventricular brainstem biopsy with the use of flexible neuroendoscops. We identified patients who underwent a neuroendoscopic procedure with brainstem lesion biopsy to obtain histopathologic diagnosis and to treat obstructive hydrocephalus. All patients had follow-up examinations at months 1, 3, 6, and 12 postsurgery and then annually. Seven patients had a transventricular biopsy of the brainstem performed. Of those, five were pediatric patients. The median age was 10 years (range: 3-26 years). Five of them were female and two male. Four patients presented with secondary obstructive hydrocephalus. The main clinical presentations were intracranial hypertension syndrome in four patients, motor neuron disease in four patients, two with decreased state of alertness, two with gait ataxia, and one with Parinaud syndrome. The types of tumors found in the histopathology and their location were one ventral (pons) and one aqueductal anaplastic astrocytoma, two ventral, one aqueductal, and one attached to the floor of the fourth ventricle pilocytic astrocytoma and one ventral low-grade astrocytoma. The route taken to approach the ventral tumors was made through premammillary fenestration. The tumors of the aqueduct and floor of the fourth ventricle were approached transaqueductally. The use of flexible endoscops for biopsy of ventral, dorsal (tectum lamina quadrigemina), and diffuse brainstem tumors is a useful, effective, and safe procedure that also allows to treat obstructive hydrocephalus secondary to the tumors.

Application of intraoperative indocyanine green videoangiography for resection of spinal cord hemangioblastoma: Advantages and limitations

Hemangioblastomas constitute 2-15% of intramedullary spinal cord tumors. Identification of the feeding arteries and draining veins is crucial for an en bloc tumor resection and cure. We report our experience using intraoperative indocyanine green (ICG) videoangiography during the surgical resection of spinal cord hemangioblastomas (SH) and evaluate the advantages and limitations of this technique. Seven patients with an SH underwent resection with the assistance of intraoperative ICG videoangiography. The ICG videoangiography images were analyzed, and the preoperative, intraoperative, and postoperative images were compared. ICG videoangiography clearly revealed the feeding arteries and enlarged draining veins and assisted in defining the tumor borders in five of the seven patients (patients one, two, four, five, and seven). By contrast, patient three had a devascularized residual tumor located deep in the spinal cord parenchyma, which did not take up the fluorescent dye and therefore was not visualized by ICG videoangiography. In addition, in patient six, only the draining veins could be visualized in the ventrolateral tumor, because it was covered by the spinal cord parenchyma. Six tumors were completely removed, and one was partially removed. None of our patients had significant neurological deterioration after surgery. ICG videoangiography provided real-time information about the tumor vasculature during surgery for SH and aided in intraoperative decision-making. However, for deep tumors and ventral tumors, the benefits of this technique might be limited.

Basioccipital bone osteochondroma growing into the foramen magnum

Background:Osteochondroma is a common bone tumor and rarely affects the central nervous system. Although intraspinal osteochondromas are known to cause neurological deficits, intracranial osteochondromas with neurological compromise are very rare.Case Description:The authors report an exceptional case of a quadriparetic 73-year-old patient with a basioccipital bone osteochondroma growing into the foramen magnum. The embryology, differential diagnoses, and optimal management strategies are discussed.Conclusion:Although extremely rare, osteochondromas should be included in the differential diagnoses of tumors within the foramen magnum. For the tumors originating from the basioccipital bone, a simple medial suboccipital approach might suffice, while for ventral tumors, a far lateral transcondylar approach is necessary to avoid any neurovascular complications. Despite potentially catastrophic presenting symptoms, these tumors are pathologically benign and complete excision often results in long-term cure. To the best of our knowledge, this is the first report of an osteochondroma arising from the basiocciput.

Surgical Outcome of a Posterior Approach for Large Ventral Intradural Extramedullary Spinal Cord Tumors

Case series. The object of this study is to present surgical outcomes for treatment of large ventral intradural extramedullary (IDEM) spinal cord tumors with conventional laminectomy. Most IDEM spinal cord tumors are meningiomas and schwannomas, which are separated from the spinal cord by a discrete anatomical barrier (the arachnoid or pia membrane). As a result of this anatomical barrier, a tumor can be removed using the posterior approach with conventional laminectomy. Although many reports have demonstrated the feasibility of the posterior approach for ventral tumors, there have been no studies detailing large ventral IDEM tumors. From 2001 to 2008, we operated on 18 consecutive patients with a large ventral IDEM tumor using the posterior approach (8 cervical and 10 thoracic). Preoperatively, eight patients were classified as having Nurick grade 1 myelopathy, six patients had grade 2, and four had grade 3. Tumors were removed through a slit-like space between the dura and spinal cord without retraction of the spinal cord. Complete removal of the tumor was possible in 17 cases. The follow-up period was 39 ± 28 months (range = 10-97 months). There were 7 cases of meningiomas and 11 of schwannomas. One schwannoma was mixed with the cervical rootlets and the mass in the foramen was left behind. Clinical symptoms improved in 16 patients and stabilized in 2. The one residual mass was stable for 62 months. There were no cases of recurrence. Neither kyphotic change nor instability developed in any of the patients during the follow-up period. Large ventral IDEM spinal cord tumors can be completely removed using a posterior approach and conventional laminectomy. An understanding of the anatomical and growth characteristics of these tumors is extremely important for successful removal. However, this approach should be applied prudently and with a thorough understanding of its limitations.

Abstract 949: Different lineages of carcinogenesis in prostate lobes in the transgenic adenocarcinoma of mouse prostate (TRAMP) model in C57BL/6 background and their responses to chemopreventive selenium

Abstract The transgenic adenocarcinoma of the mouse prostate (TRAMP) model is based on probasin promoter-driven expression of SV40 T-antigen (Tag) to inactivate p53 and Rb tumor suppressor to propel proliferative lesions and aggressive cancers in the prostate. The genetic background of mice (FVB vs. C57BL/6) has been known to profoundly affect the pathogenesis profiles and disease severity. A recent study suggested prostate lobe specificity of neuro-endocrine (NE) carcinomas vs. glandular epithelial lesions, challenging the classical notion of single-lineage disease progression from early epithelial lesions to poorly differentiated carcinomas. Because of the increasing use of this model for chemoprevention studies, it is critical to further characterize the lobe-specificity of lesion lineages in the prostate and determine their responses to chemopreventive agents. To this end, we carefully dissected the dorsolateral (DLP) and ventral prostate (VP) and macroscopic tumors from 30 male C57BL/6 TRAMP mice at 24-weeks of age and fixed tissues in 10% formalin for pathology diagnosis. Our results show that macroscopic tumors were Tag+, synaptophysin (Syp)+, androgen-receptor (AR)− and E-cadherin− NE carcinomas (poorly differentiated carcinomas) and were dissected exclusively from VP, not DLP. Lesions identified in lymph node, liver or lung of such NE-carcinoma bearing mice showed concordant patterns of biomarkers with the primary prostate NE-carcinomas and represent their metastases. In the DLP, we found lesions ranging from mild (formerly as low grade PIN), moderate to atypical hyperplasia of Tag (formerly as moderately differentiated adenocarcinoma) with Tag+, AR+ and E-cadherin+ expression and no NE-carcinoma. For assessing the impact of selenium on the long term survival from different lineages of prostate lesions, we analyzed archival tissues from a survival study published recently (Wang et al, Cancer Prev Res 2009): TRAMP mice received a daily oral dose of 3 mg Se/kg body weight as methylseleninic acid (MSeA) beginning at 10 weeks (n=31) or 16 weeks of age (n=30), or water (n=31) until euthanasia or 50 weeks of age. MSeA supplementation significantly delayed death from NE-carcinomas (30% life-time incidence). MSeA also prolonged survival of mice with enlarged seminal vesicle containing epithelial-stromal tumors that were Tag+, Syp−, E-cadherin+ and AR+/low in the older TRAMP mice (&amp;gt;30 weeks). Interestingly, mice with enlarged seminal vesicle often had normal sized prostate. In summary, the C57BL/6 TRAMP mouse model represents two lineages of prostate carcinogenesis with an involvement of seminal vesicle tumorigenesis in older mice. Future chemoprevention studies should incorporate this new knowledge for efficacy assessment and for molecular target validations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 949.

Functional outcome after resection of spinal cord hemangioblastomas associated with von Hippel-Lindau disease

Spinal cord hemangioblastomas are a common protean manifestation of von Hippel-Lindau (VHL) disease and can be associated with significant morbidity. To better define expected outcome and optimal management of these tumors in the context of this neoplasia syndrome, the authors analyzed the findings from patients with VHL disease who underwent resection of spinal cord hemangioblastomas. Consecutive patients with VHL disease who underwent surgery for spinal cord hemangioblastomas with > 6 months follow-up were included in the study. Serial clinical examinations, functional scores, imaging findings, and operative records were analyzed. One hundred eight patients (57 male, 51 female) underwent 156 operations for resection of 218 spinal cord hemangioblastomas. One hundred forty-six operations (94%) were performed for symptom-producing tumors. The most common presenting symptoms included hypesthesia (64% of resections), hyperreflexia (57%), dysesthesia (43%), and weakness (36%). Mean follow-up was 7.0 +/- 5.0 years (range 0.5-20.9 years). Complete resection was achieved for 217 tumors (99.5%). At 6-months follow-up, patients were stable or improved after 149 operations (96%) and worse after 7 operations (4%). Ventral tumors (OR 15.66, 95% CI 2.54-96.45; p = 0.003) or completely intramedullary tumors (OR 10.74, 95% CI 2.07-55.66; p = 0.005) were associated with an increased risk of postoperative worsening. The proportion of patients remaining functionally stable at 2, 5, 10, and 15 years' follow-up was 93, 86, 78, and 78%. Long-term functional decline was caused by extensive VHL-associated CNS disease (6 patients), VHL-associated visceral disease (1 patient), or non-VHL disease (2 patients). Resection of symptomatic spinal cord hemangioblastomas is a safe and effective means of preserving neurological function in patients with VHL disease. Tumor location (ventral or completely intramedullary) can be used to assess functional risk associated with surgery. Long-term decline in neurological function is usually caused by VHL-associated disease progression.

Craniovertebral junction neoplasms in the pediatric population

The incidence of tumors at the craniovertebral junction in the pediatric population is low. Because of the variable pathology and the rarity of these tumors, ideal therapies are only now being defined. Thirty-eight children with tumors affecting the craniocervical junction were encountered between 1991 and 2006. These comprised neoplasms of osseous origin and neural extramedullary tumors. Chordomas of the clivus and foramen magnum were seen in eight, fibrous dysplasia in four, aneurysmal bone cysts in four, eosinophilic granuloma affecting the atlas and axis vertebra in four, Ewing's sarcoma involving the atlas in two, osteoblastoma in two, neurenteric cysts in four, meningioma in five, schwannoma in two, and plexiform neurofibromas in three. The location of these tumors was predominantly ventral, and a very small number had a lateral or dorsal location. The ventral tumors included chordoma, meningioma, fibrous dysplasia, aneurysmal bone cyst, and osteoblastoma. Plexiform neurofibroma affecting the craniocervical junction was ventral to the clivus and upper cervical spine causing severe kyphosis of the craniocervical region. Pain in the head and neck occurred in 70%. Paresthesias and dysesthesias in the hands were seen in 40% and spastic weakness of extremities in 22%. Cranial nerve palsies were seen in 33%. Twenty-eight percent of children showed dysphagia or dysarthria. The cranial nerves affected were the vagus followed by hypoglossal and glossopharyngeal nerves. This led to dysphagia, slurred speech, repeated aspiration pneumonia, and weight loss. The most common findings for chordomas at the craniocervical junction were isolated hypoglossal nerve palsy. All individuals underwent magnetic resonance imaging, computed tomography, and 3D computed tomography and angiography. Vertebral angiography was used to understand the dynamics of collateral circulation and tumor vascularity. Tumor embolization was performed in chordoma and aneurysmal bone cysts. Our experience and results are presented here.

Experience of a single institution treating foramen magnum meningiomas

Despite the introduction of skull base approaches, there is still controversy in the optimum surgical management of foramen magnum meningiomas. Between January 1990 and January 2003, 22 patients underwent 23 surgical procedures with a diagnosis of foramen magnum meningioma at Marmara University, Department of Neurosurgery. The suboccipital approach was used for 2 posteriorly located tumors with radiological total removal. The paramedian suboccipital approach was replaced by the far-lateral modification in the treatment of ventral meningiomas. 1 of the 20 ventral tumors was operated twice. The classical suboccipital approach was followed by the far-lateral modification. A gross-total removal was achieved in 21 patients. The overall morbidity was 32%. No specific and clinically significant complications attributable to the far-lateral modification were observed. The far-lateral approach has improved the success of surgery in ventrally located lesions. The posterior suboccipital approach is still indicated in the removal of lesions placed posterior to the dentate ligament.

Surgical treatment of solid brain stem tumors in adults: A report of 22 cases

Brain stem tumors in adults are infrequent. Most reports of surgical treatment for these tumors involve partial tumor removal in highly selected patients. A more aggressive approach for removing tumors, especially solid and intrinsic ones, has been controversial. Twenty-two adult patients with brain stem tumors were surgically treated. Surgical techniques, potential risks, and selection of appropriate treatment were evaluated. Tumors were totally or subtotally removed in 20 patients and only partially removed in two patients. Serious complications such as respiratory disturbances and circulatory dysfunction occurred in 10 patients. Eight patients with these complications recovered after appropriate treatments. Upon discharge, most signs and symptoms improved in 17 patients. Most brain stem tumors, except for malignant gliomas and small ventral tumors, are amenable to an aggressive surgical approach. Exophytic medullary tumors that present dorsally comprise the most benign subgroup of brain stem tumors. Total removal can enhance survival, improve the patient's quality of life, and offer a favorable long-term prognosis. Appropriate management of postoperative complications is essential for good results.

12-O-tetradecanoylphorbol-13-acetate-mediated systemic co-promotion in the murine skin multistage carcinogenesis protocol.

The systemic promoting and co-promoting activities of 12-O-tetradecanoylphorbol-13-acetate (TPA) were examined in a murine skin multistage carcinogenesis protocol. The dorsal skins of female inbred SENCAR (SSIN) mice were initiated with 25 nmol of 7,12-dimethylbenz[a]anthracene (DMBA). Topical treatment of initiated dorsal skin with 20 mg of benzoyl peroxide (BzP) promoted the eventual development of 8-15 dorsal papillomas per mouse. Repeated application of 2 micrograms of TPA to the ventral skins of dorsally initiated mice did not promote the formation of dorsal tumors. However, the latency of dorsal papilloma development was significantly decreased in initiated mice treated with 0.4 or 2 micrograms TPA (ventral application) and promoted with BzP (dorsal application). The co-promoting effects of topically applied TPA could not be mimicked by administering the promoter i.v. Only 6/23 initiated, BzP-promoted SSIN mice developed squamous cell carcinomas (SCC) during a 61 week promotion period. In contrast, during the same time-frame 12/24 and 11/24 BzP-promoted mice cotreated with 2 or 0.4 microgram of TPA developed SCC respectively. Repeated application of 2 micrograms of TPA to the ventral skins of dorsally initiated mice resulted in the development of ventral tumors. Ventral tumor incidence and multiplicities could be dramatically reduced by housing the mice individually, as opposed to collectively, for a day following initiation. Collectively these findings suggest that TPA can function as a co-promoter in the murine skin multistage carcinogenesis model through a systemic mechanism. The systemic co-promoting activity may be mediated by a factor(s) produced by the skin in response to TPA exposure. Furthermore, inter-mouse transfer of topically applied initiator from one cutaneous site to another occurs as a consequence of the huddling habits of mice.