Cavitron Ultrasonic Aspirator Research Articles

IMMU-53. MONITOR THE IMMUNE MICROENVIRONMENT AND SYSTEMIC IMMUNE EFFECTS IN PEDIATRIC BRAIN TUMORS – THE MIMIC PROGRAM

Abstract INTRODUCTION Dismal outcomes of pediatric high-grade CNS tumors demand new therapeutic strategies. A better understanding of the immune system may contribute to designing better immunotherapies for these children. The MIMIC program (Dutch Trial Registry NL8967) is a prospective observational longitudinal cohort study, conducted in patients with newly diagnosed or relapsed high-grade CNS tumors with the aim of characterizing and quantifying changes in immune parameters at diagnosis and during treatment. METHODS All patients with a newly diagnosed or relapsed high-grade CNS tumor are included after obtaining informed consent. Patient study material is collected longitudinally and includes tumor tissue (TT), Cavitron Ultra Sonic Aspirator (CUSA) material and optional bone marrow aspiration (BM) at diagnosis and relapse. Cerebrospinal fluid (CSF), peripheral blood (PB) and fecal samples (FS) at diagnosis, 3 months, 6 months, 12 months, relapse and additionally collection of CSF and FS at 14 days. Furthermore, FS is collected from patient siblings as a reference. RESULTS The MIMIC program has opened in June 2021 in the Princess Máxima Center, the national pediatric oncology center in the Netherlands, including so far 47 patients (out of ~60 eligible patients annually). More than 400 samples, out of which 46 TT, 34 CUSA, 65 CSF, 14 BM, 143 PB, and 105 FS have been collected. All samples are subject to extensive immunological profiling using 70+ markers flow cytometry panels (PB, TT, CUSA, CSF, BM), (spatial single cell) RNA and protein profiling (TT, CUSA, BM), immunohistochemistry (TT), proteomics (CSF and PB), and 16S rRNA or shotgun metagenomic sequencing (FS). CONCLUSION The MIMIC program demonstrates the feasibility of obtaining various samples for pediatric high-grade CNS tumors. By incorporating multiple technologies in longitudinal samples, the MIMIC program provides insight into the different immune compartments and their relation to the tumor, forming the base for future clinical trials with immunotherapy.

IMMU-46. MONITORING T-CELL DYNAMICS AND CHECKPOINT EXPRESSION IN THE IMMUNE MICROENVIRONMENT OF PEDIATRIC HIGH GRADE BRAIN TUMORS: THE MIMIC PROGRAM

Abstract BACKGROUND Pediatric high grade brain tumors (pHGBT) pose a significant challenge due to limited treatment options and poor prognosis. Understanding the immune landscape, in particular T cell profiles and functionality, is of high interest as numerous immunotherapeutic approaches focus on or utilize T-cells. This study aimed to characterize T-cell phenotypes and their potential for immunotherapeutic interventions in tumor fragments (obtained from cavitron ultrasonic surgical aspiration (CUSA)) and tumor tissue (biopsy), in comparison with peripheral blood, collected from pHGBT patients. METHODS Spectral flow cytometry was employed to characterize the presence of T-cell subsets and their functional phenotype. RESULTS T cells were detected in all materials with similar CD8/CD4 ratios. At diagnosis, T-cells in the tumor microenvironment exhibited significantly increased expression of PD1, LAG3 and TIM3 checkpoint receptors compared to peripheral blood. This difference was more pronounced in biopsy samples compared to CUSA fragments. T-cell composition and phenotype in peripheral blood were similar to healthy adult controls at diagnosis. However, during therapy, the T-cell compartment showed a shift towards a higher CD8/CD4 ratio, accompanied by increased activation markers (CD25, CD69) and checkpoint receptor expression . Notably, CD8+ T-cells in both peripheral blood and tumor microenvironment showed high production of Granzyme B. CONCLUSION Our findings demonstrate that despite the high expression of checkpoint receptors on CD8+ T-cells, these cells retain the capability to produce significant amounts of Granzyme B, indicating their potential for cytotoxic activity. Furthermore, variations in checkpoint receptor expression on T-cells were observed when comparing CUSA fragments to biopsy material. Functional assays will further validate these findings and elucidate the functional status of these cells. Understanding the function of T-cells within the tumor microenvironment is essential for designing novel combination therapies to enhance T-cell cytotoxicity against pHGBT.

IMMU-58. CHARACTERIZATION OF MYELOID CELL POPULATIONS IN PEDIATRIC HIGH-GRADE BRAIN TUMORS: THE MIMIC PROGRAM

Abstract BACKGROUND Pediatric high-grade brain tumors (pHGBT) pose treatment challenges with limited options. Myeloid cells, particularly tumor-associated macrophages (TAMs) in the tumor-microenvironment (TME), exhibit potent immunosuppressive features inhibiting effective anti-tumor T-cell responses. Targeting these cells holds promise to improve outcomes, however the underlying mechanisms of myeloid cell dysfunction remain poorly understood. This study aimed to comprehensively characterize myeloid cell populations in pHGBT and investigate their functional phenotype. METHODS Spectral flow cytometry was performed on tumor tissue (biopsies or resections) and tumor fragments obtained by cavitron ultrasonic surgical aspiration (CUSA) in pHGBT patients (High-grade glioma n=2, Ependymoma n=1, Medulloblastoma n=6, Pilocytic Astrocytoma n=2) enrolled in the MIMIC program. This allowed quantification and comprehensive characterization of myeloid cell populations within the TME. RESULTS The pHGBT TME showed a low abundance of immune cells across different entities, with myeloid cells comprising the predominant proportion. CD49d was used to identify invading cells derived from bone marrow (CD49+) and resident microglia (CD49-). The total TAMs/microglia population was detected in both tumor tissue and CUSA tumor fragments in similar proportions, however resident CD49d- microglia were notably increased in CUSA tumor fragments. Additionally, invading TAMs displayed a mixed "M1" and "M2" polarization phenotype and exhibited higher expression of the chemokine receptor CCR2 and HLA-DR, and of the immune-checkpoint receptors SIRP1A/B, CD33, and TIM3, compared to resident microglia. CONCLUSIONS TAMs play a multifaceted role in pHGBT. The high expression of immune-checkpoint receptors by invading TAMs suggests an immunosuppressive phenotype, potentially facilitating tumor growth, infiltration and (immune)therapy escape. Although, differences between disease entities could not yet be analyzed, disparities were observed in the TME between tumor and CUSA samples, likely related to spatial cellular organization. Understanding TAM dynamics and functional differences between invading and resident subsets, as well as their underlying mechanisms, is crucial for advancing therapeutic efficacy in pHGBT.

Incidental Long Makuuchi ligament and its surgical relevance in pediatric hepatic resection

The surgical relevance of Makuuchi ligament (inferior vena cava ligament) has been less explored, especially in pediatric population. With the advent of major hepatectomies and liver transplantation indicated for various malignancies and metabolic conditions in children, knowledge about IVC ligament seems essential, in terms of its draining vessels, contained hepatic tissue and close relation with caudate lobe. Herein, we present a 2 years old female child diagnosed with hepatoblastoma (PRE-Treatment-EXTent of tumor II and POST-Treatment EXTent of tumor II) (PRETEXT II, and POSTTEXT II), with tumor involving right hepatic vein, who underwent right hepatectomy. Intraoperatively, after liver mobilization, we encountered a long IVC ligament, in the form of a broad membranous ligament bridging the left and right sides of caval groove encircling IVC completely. With the help of Cavitron Ultrasonic Aspirator (CUSA) and fine Ligaclips, the IVC ligament was meticulously ligated before tumor handling, preventing any major intraoperative bleeding, bile leak and possible tumor spread. Segments V-VIII were resected out to complete a formal anatomical right hepatectomy. The child was shifted to intensive care unit (ICU) on ventilator for postoperative recovery and care. Postoperatively, we did not encounter any signs of hepatic failure and the subhepatic drain output was persistently minimal without any bleed or bile leak.

Totally laparoscopic central bisectionectomy for colorectal cancer liver metastasis using indocyanine green fluorescence imaging

Laparoscopic central bisectionectomy is still an area of great challenge and technically requiring surgery due to high incidence of surgical complication and poor intraoperative outcomes. We report our experience totally laparoscopic central bisectionectomy for colorectal cancer liver metastasis (CRLM) using indocyanine green (ICG) fluorescence imaging. The patient was 77-years-old man and was performed laparoscopic low anterior resection with ileostomy, cholecystectomy for rectal cancer 3 years before admission. He diagnosed metachronous CRLM and on magnetic resonance imaging, 5 cm sized hepatic mass was shown between segment 4 and 8 with middle hepatic vein (MHV) involvement. During operation, the Cavitron Ultra Sonic Aspirator® and Sonicision™ (Medtronic) was applied for hepatic parenchyma dissection. For resection of major glissonian pedicle and MHV, Signia™ staple (Medtronic) was used. After right anterior glissonian pedicle was isolated and temporary clamping, 2.5 mg ICG was injected intravenously. The ICG stained area could be recognized, and subsequent parenchyma dissection was completed successfully under Pringled maneuver. Specimen was retieved via extended umbilical port site. The operation time was 205 minutes and the estimated blood loss was 300 mL. No transfusion was done intraoperatively and postoperatively. There was no significant complication after surgery. Computed tomography was checked on postoperative day 5, showed no abnormal pathologic findings. On pathologic findings, metastatic adenocarcinoma sized 5.4 cm with clear resection margin was diagnosed. The patient discharged on postoperative day 7. Laparoscopic central bisectionectomy is safe and feasible compared with conventional open surgery. ICG imaging system is effective and helpful for safe hepatic resection.

Acquisition of Basic Micro-Neurosurgical Skills Using Cavitron Ultrasonic Aspirator in Low-Cost Readily Available Models: The Egg Model

Attainment of micro-neurosurgical skills is a challenge in teaching hospitals throughout training. Models that mimic the workflow as well as haptics are time-consuming, expensive, and unsuitable to serve as a routine platform. Our objective was to present a model and a set of tasks, based on a hard-boiled egg, microscope, and a Cavitron ultrasonic aspirator (CUSA; Integra Lifesciences Corp., Tullamore, Ireland), which is cheap, easy to setup and can be used for training microsurgery and CUSA skills, required for removal of deep-seated tumors. The goal was to remove the egg yolk from within a hard-boiled egg, representing an intrinsic brain tumor, surrounded by the egg's white, representing adjacent brain tissue, while preserving it. Assessment was based on the yolk's exposure, completeness of removal, and collateral damage and task completion duration, with repeated trials (n= 4), for validation purposes, for 6 operators with different experience levels. Improvement in overall score (mean of 47.5 ± 19 in the first trial vs. 80.0 ± 12 in the fourth trial, P < 0.01), and task duration completion (mean initial duration of 21:25 ± 4:52 minutes to 15:30 ± 5:17 minutes, P < 0.01) was observed. Parameters gradually improved on repeated attempts, and experience level of the operators correlated with scores. The egg model is an easy-to-handle, cheap model that enables the acquisition of basic micro-neurosurgical skills and basic workflow required for removing of intrinsic brain tumors. This study has validated and defined reproducible tasks that can be scored, correlated with performance. This model can be incorporated into a resident's routine and potentially provide an accessible training platform for neurosurgical trainees.

Dynamic mapping using an electrified ultrasonic aspirator in lipomyelomeningocele and spinal cord detethering surgery-a feasibility study.

Intraoperative neurophysiologic monitoring (IONM) is an established technique and adjunct of brain and spinal lesion resection surgery. In spina bifida syndrome surgery, mapping of the surgical wound is a common and accepted method in determining the position and functionality of nerve roots of the cauda equina (CE), especially when the anatomy is not straightforward and roots are splayed across or entangled within the lesion. Here, we describe a novel technique of continuous CE mapping using an electrified cavitron ultrasonic aspirator (eCUSA) in children with lipomyelomeningocele (LMMC) lesions. We assessed a method of dynamic CE mapping using an eCUSA as a stimulation probe. Twenty children (0.5-18 years) were included in this study, diagnosed with occult spina bifida LMMC in which the eCUSA stimulator was applied. IONM data and 2-weeks post-operative data were collected. LMMC lesions were located in the lumbar, sacral, and lumbosacral spine. eCUSA stimulation at 0.3-3.0 mA intensities elicited positive lower extremity muscle responses in 12 of the 20 patients included in the study. These responses allowed the surgeon real-time identification of the nerve roots tangent at the LMMC-cauda equina structure and intensive removal of the fat tissue in the area non-responding to the eCUSA stimulation. Continuous eCUSA-based stimulation of the cauda equina during LMMC resection is a feasible mapping technique with potential added value improving safety of untethering. Future studies evaluating extension of untethering, as well as the rates of retethering and long-term neurological and urological outcomes, are warranted.

A New Technique to Avoid Sternotomy in Retrosternal Thyroid Surgery

Sternotomy along with the cervical incision for management of a retrosternal goiter increases the pain, morbidity, and length of hospital stay of the patient. The need for sternotomy increases when the retrosternal component reaches up to or below the concavity of the aortic arch and especially if the retrosternal component is broader than the thyroid girth at the thoracic inlet. We have tried a new method using the Cavitron Ultrasonic Aspirator to debulk the retrosternal component, thus facilitating its easy delivery into the neck, and avoided sternotomy in 3 patients. In all the three patients sternotomy was contemplated based on the preoperative contrast-enhanced computed tomography picture.

Application of 3D-Printed Craniocerebral Model in Simulated Surgery for Complex Intracranial Lesions

To demonstrate the use of 3-dimensional (3D)-printed intracranial lesion models for complex neurosurgery to increase the success rate of clinical surgeries via practice in simulated surgeries. We collected computed tomographic, magnetic resonance (MR), and computed tomographic images from patients with intracranial tumor or aneurysm, conducted multimodal image reconstruction, and then constructed a 3D-printed model with the skull base, cerebral arteries, and brain tumor or aneurysm. Forty-nine simulated surgeries were carried out on the model under a microscope, and actual surgery was carried out after validation and accumulation of experience. The 3D-printed brain tumor models were used to design the surgical route, to simulate piecemeal resection of tumors through keyhole approach, and to verify the extent of tumor resection. A drill was used for bone flap removal and milling of bony structures such as the anterior clinoid process, tuberculum sellae, petrous apex, and internal acoustic meatus. The tumors were removed by laser knife and cavitron ultrasonic aspiration. The 3D-printed aneurysm models were used to assess the feasibility of different keyhole approaches and to select the aneurysm clip. Actual surgery was based on the results of the simulated surgery. Postoperative MR image review showed that 84% (21/25) of patients had total tumor resection and 16% (4/25) subtotal resection. Digital subtraction angiography confirmed complete clipping of all aneurysms (24 cases/39 aneurysms). 3D-printed craniocerebral models provide effective simulated surgery conditions for keyhole surgeries of complex brain tumors or aneurysms and aid in preoperative surgical design, accumulation of surgical experience, and validation of surgical outcomes.

Laparoscopic Isolated Total Caudate Lobectomy for Hepatocellular Carcinoma Located in the Paracaval Portion of the Cirrhotic Liver

Despite the widespread use of laparoscopic hepatectomies in past decades, laparoscopic isolated total caudate lobectomy for hepatocellular carcinoma (HCC) remains challenging,1,2 especially for patients with cirrhosis. Moreover, a laparoscopic isolated total caudate lobectomy for HCC originating in the paracaval portion of the caudate lobe is very rare. We herein present a video showing laparoscopic total caudate lobectomy for a cirrhotic patient with HCC located in the paracaval portion of the caudate lobe. A 58-year-old woman who suffered from hepatitis C virus-related cirrhosis was admitted to our institution. The preoperative computed tomography showed a 2.5 × 2.0cm liver mass located in segment I that was very close to the right hepatic pedicle. Although her liver function was Child-Pugh A, the indocyanine green (ICG)-15 test was high at 10.9%. Right hepatectomy plus caudate lobectomy was not adopted because of the severe cirrhosis and the elevated ICG-15. Thus, laparoscopic isolated total caudate lobectomy was contemplated. The patient was placed in the supine position. After full mobilization, the caudate lobe was exposed. The third porta of the liver was then dissected and the short hepatic veins were controlled with clips and LigaSure. The dissection was finished when the whole third porta of the liver was freed. Subsequently, the portal branches to the caudate lobe were ligated and cut. The combination between the left- and right-sided laparoscopic approaches was used to transect liver parenchyma. The superficial parenchyma was divided using an harmonic scalpel, while the deeper tissue was divided using a Cavitron ultrasonic aspirator (CUSA). The Pringle maneuver was used intermittently during the parenchymal transection as necessary. In the left-sided approach, the caudate lobe was resected along the left and middle hepatic vein toward the right side, to expose the dorsal semicircle of the right hepatic vein. In the right-sided approach, the resection started from the right border of the process portion to the root of the right hepatic vein in the cranial direction. Finally, the whole caudate lobe was resected and the three main hepatic veins were exposed on the cutting plane. The specimen was removed from suprapubic incision. The operative time was 300min and the total Pringle time was 50min. The postoperative course was uneventful. A laparoscopic isolated total caudate lobectomy for HCC located in the paracaval portion of the cirrhotic liver seems to be feasible and safe in selected patients.

Meningioma Consistency: Correlation Between Magnetic Resonance Imaging Characteristics, Operative Findings, and Histopathological Features.

Introduction:Intracranial meningiomas account for 30% of all primary intracranial tumors. Surgical resection remains the mainstay of the treatment for meningiomas. The magnetic resonance of intracranial meningiomas has been largely discussed in many reports of the radiological and neurosurgical literature. To date, a few studies have been attempted to differentiate the tumor characteristics of meningiomas based on magnetic resonance imaging (MRI) studies.Objective:The objective of the study is to evaluate the relationship between MRI signal characteristics of intracranial meningiomas and consistency of tumor using objective measures.Materials and Methods:A prospective study included all the patients who were admitted for surgery with an MRI finding suggestive of meningioma. All patients were subjected to routine radiological investigations. Surgical resection was performed for patients eligible for surgery using cavitron ultrasonic aspirator (CUSA). The relationship and correlation between the radiological, intraoperative measurements and the histopathological diagnosis were studied. The tumor consistency was measured using mean CUSA level. Intensity on T2, fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted imaging (DWI) was measured using circular regions of interest (ROI) on the MRI. Multiple ROIs were placed initially on the lesions avoiding the obvious blood vessels, if any, then on the brain cortex to avoid the vasogenic edema. The mean ROI (mROI) results from the lesion were subtracted from the mean ROI from the brain cortex for each lesion to achieve normalized ratio. The results of lesion mROI-cortex mROI were compared to the operative and histopathology results using Pearson's correlation test and linear regression test.Results:The total number of patients was seventy. The mean age of the patients was 51 ± 14.8, with 72% of them being females and 28% males. There was a strong statistically significant (P = 0.046) and (P = 0.003) correlation between mean CUSA and FLAIR mROI difference or T2 mROI difference, respectively. On the other hand, there was an inversely proportional relationship between mean CUSA and FLAIR mROI difference and mean CUSA and T2 mROI difference. The value of the regression test (r) shows that there was a slight linear relationship between FLAIR mROI difference or T2 mROI difference and mean CUSA values, in which the mean CUSA value = 50.1 + (−0.088) × FLAIR mROI difference (r = −0.273, P = 0.046) or mean CUSA value = 50.8 + (−0.055) × T2 mROI difference (r = 0.4, P = 0.003). There was no statistical significance in the relation between CUSA values and tumor histological subtypes, DWI values, age, or gender.Conclusion:This study presents a new objective method to measure the consistency of intracranial meningiomas based on a simple algorithmic formula. Such information will aid in planning surgery and assessing the resectability of the tumor. To date, this is the first objective measurement of meningioma consistency based on MRI studies and objective intraoperative evaluation.

Laparoscopic Anatomical Combined Segment 3 and Segment 4 Liver Resection

Background: In 1992, Kawasaki et al. reported the first combined segments 3 and 4 liver resection through an open procedure.1 As opposed to a major hepatectomy, this type of liver resection reduces the risk of postoperative hepatic insufficiency, especially in cirrhotic patients. Presently, various types of laparoscopic liver resections are performed in numerous surgical centers. To our knowledge, a combined segments 3 and 4 liver resection through a laparoscopic procedure has not been reported.2–9 This video describes the technical aspects of a totally laparoscopic anatomical combined segments 3 and 4 liver resection using the Glissonian approach. Methods: A 63-year-old woman was referred for a 2.1 cm tumor in segment 4. The tumor was suspected to be a hepatocellular carcinoma and was located deep in segment 4 and adjacent to the Glissonian pedicle of segment 3. The patient had viral hepatitis C, and based on her liver enzymes she was a Child–Pugh class A. Although a left hemihepatectomy could be performed in this case, an anatomical combined segments 3 and 4 liver resection was planned to preserve segment 2 to maximize the remnant liver volume. Technically, the most important aspects of this case included an oncologic resection while preserving the vascular structures to the remnant liver to avoid ischemia in segment 2. Operatively, Glissonian pedicles to segments 2, 3, and 4 (G2, G3, and G4) were dissected proximally. To avoid damaging G2 pedicle, G3 and G4 pedicles were ligated separately with a laparoscopic stapler. A flexible endoscope was used to maximize visualization intra-operatively. After ligating the pedicles, a line of parenchymal demarcation was established along segment 3. Meticulous dissection along the precise ischemic line was performed to prevent injury to the vascular structure of the remnant liver. Ultrasonic shears was used to transect the superficial liver parenchyma, and the deep portion was transected using both laparoscopic cavitron ultrasonic aspirator and electrocautery. After transecting segment 3, segment 4 was dissected along the middle hepatic vein. After ligating the left medial vein from the left hepatic vein, segments 3 and 4 were resected. The specimen was inserted into a vinyl bag and the operative field was irrigated and fibrin glue was applied along the parenchyma. Results: The operation took ~290 minutes and the estimated intraoperative blood loss was 400 mL. No intraoperative transfusion was necessary. On postoperative day 5, a postoperative computed tomogram scan showed no evidence of complications, and the patient recovered with no problems. The final pathology analysis confirmed a cholangiocarcinoma, with a negative resection margin. The patient is alive without adjuvant treatment at 1 year. Conclusion: Laparoscopic anatomical combined segments 3 and 4 liver resection is a feasible operative procedure in patients at risk of hepatic insufficiency. A laparoscopic resection of these segments may be performed without sacrificing large amounts of hepatic parenchyma. No competing financial interests exist. Runtime of video: 6 mins 39 secs This video was presented at the SAGES 2016 annual meeting, held at the Hynes Veterans Memorial Convention Center in Boston, MA.

Subcortical Mapping Using an Electrified Cavitron UltraSonic Aspirator in Pediatric Supratentorial Surgery.

Intraoperative electrophysiology is increasingly used for various lesion resections, both in adult and pediatric brain surgery. Subcortical mapping is often used in adult surgery when lesions lie in proximity to the corticospinal tract (CST). We describe a novel technique of continuous subcortical mapping using an electrified Cavitron UltraSonic Aspirator (CUSA) in children with supratentorial lesions. We evaluated the method of subcortical mapping using a CUSA as a stimulation probe. Included in this study were children (<18 years of age) with supratentorial lesions in proximity to the CST in which the CUSA stimulator was applied. Data were collected retrospectively. Eleven children were included. Lesions were located in the thalamus (3), basal-ganglia (2), lateral ventricle (1), and convexity (5). Lesions included low-grade gliomas (6), arteriovenous malformation (1), cavernoma (1), cortical dysplasia (1), ependymoma grade II (1), and high-grade glioma (1). Seven patients had positive mapping responses to CUSA-based stimulation at various stimulation intensities. These responses led to a more limited resection in 5 cases. There were no complications related to the mapping technique. Continuous CUSA-based subcortical stimulation is a feasible mapping technique for assessing proximity to the CST during resection of supratentorial lesions in children. Future studies should be performed to better correlate the current threshold for eliciting a motor response with the distance from the CST, as well as the effect of age on this technique.

Liver parenchymal transection techniques

While liver surgery has become safer with improvements in peri-operative management, parenchymal resection is the part of the procedure which is associated with major loss of blood and damage to important structures if not performed carefully. The ideal technique for hepatic parenchymal transection should be quick, easy to perform, reduce intra-operative blood loss and transfusion requirement, reduce post-operative bile leakage, and cause minimal damage to the surrounding hepatic parenchyma-- preferably at the lowest cost possible. This paper is a review of commonly used techniques for liver parenchymal transection during liver resections. According to the literature, there is little benefit of using the complicated and expensive devices over the simpler clamp crushing technique. We in our institution, who perform a large number of liver resections and living donor transplants, prefer to use the clamp crushing technique with a bipolar cautery for most resections and cavitron ultrasonic aspirator(CUSA) with a bipolar cautery for removal of part of the liver from a living donor.

Medical and surgical interventions for the treatment of usual-type vulval intraepithelial neoplasia.

Medical and surgical interventions for the treatment of usual-type vulval intraepithelial neoplasia.

Which Strategy for Petroclival Tumors?

Access to the petroclival region has always been challenging owing to the surrounding neurovascular structures. The ideal approach to the region depends not only on the specific tumor characteristics, but also on surgeon preference. In this video article, we have highlighted the use of the modified Dolenc-Kawase approach to expand the standard anterior petrosectomy corridor for challenging tumors that need additional exposure.1, 2, 3, 4, 5 A 60-year-old woman presented with facial sensory loss and occasional diplopia. On radiological investigation, a densely calcified petroclival lesion was identified (Video 1). A temporal craniotomy with zygomatic osteotomy was performed followed by deroofing of the superior orbital fissure, saucerization of the foramen spinosum, and coagulation and division of the middle meningeal artery. The temporal dura propria was then dissected off the lateral wall of cavernous sinus using a combination of sharp and blunt dissection to expose the modified Dolenc-Kawase rhomboid. A T-shaped dural incision was made along with tentorial sectioning and division of the superior petrosal sinus. Owing to dense calcification in the tumor, a bone Cavitron ultrasonic aspirator (CUSA; Integra LifeSciences, Princeton, New Jersey, USA) was used for debulking of the tumor. Tumor was removed piecemeal alternately using the bone CUSA and scissors. Tumor was dissected from above and below the trigeminal nerve that forms the center of the corridor followed by dissection off the sixth cranial nerve as it enters the Dorello canal. An endoscope may be used at the end to ensure complete removal of the tumor.

Posterior fossa syndrome following brain tumour resection: review of pathophysiology and a new hypothesis on its pathogenesis.

Posterior fossa syndrome (PFS), also known as cerebellar mutism syndrome (CMS), is a severe complication affecting children following surgery for posterior fossa brain tumours. Its incidence varies between 8 and 31 %, and its exact pathogenesis remains unclear. In this article, we aim to review the existing theories on its pathogenesis and propose a new hypothesis. There is varying level of evidence on existing theories on the pathogenesis of PFS following surgery. These include cerebellar perfusion deficits due to vasospasm, oedema or axonal injury due to direct surgical injury and neuronal dysfunction. There is emerging evidence that interruption of the dentato-thalamo-cortical (DTC) pathway is responsible for PFS. Based on our experience with intraoperative MRI, radiological and pathological evidence on heat-related brain injury, we propose a new hypothesis implicating thermal injury resulting from the use of the Cavitron Ultrasonic Aspirator (CUSA) as an important mechanism in the pathogenesis of PFS. The pathogenesis of PFS is likely to be multifactorial with direct injury from surgery being a major factor. We believe that thermal injury in addition to mechanical injury to the proximal segment of the DTC plays an important role in the pathogenesis of PFS and should be considered in future research related to the aetiology, prevention and management of PFS.

Treatment developments and the unfolding of the quality of life discussion in childhood medulloblastoma: a review

To describe how the quality of life (QOL) discussion in childhood medulloblastoma (MB) relates to treatment developments, survival and sequelae from 1920 to 2014. Articles containing "childhood medulloblastoma" and "quality of life" were identified in PubMed. Those containing phrases pertaining to psychological, emotional, behavioral or social adjustment in the title, abstract or keywords were selected. Inclusion of relevant older publications was assured by cross-checking references. 1920-1930s: suction, electro-surgery, kilovolt (KV) irradiation. Survival = months. Focus on operative mortality, symptoms and survival. 1940s: radiotherapy improved. 1950s: chemotherapy and intubation. Survival = years. Opinions oscillated between optimism/awareness of physical sequelae of radiotherapy. 1960s: magnified vision, ventriculo-peritoneal (VP) shunts, megavolt (MV) irradiation. Long-term survival shifted the attention towards neurological problems, disability and carcinogenesis of radiotherapy. 1970s: CT, microscope, bipolar coagulation, shunt filters, neuroanesthesia, chemotherapy trials and staging studies. Operative mortality decreased and many patients (re)entered school; emphasis on neuropsychological sequelae, IQ and academic performance. 1980s: magnetic resonance imaging (MRI), Cavitron ultrasonic aspiration (CUSA), laser surgery, hyper-fractionated radiotherapy (HFRT). Cerebellar mutism, psychological and social issues. 1990s: pediatric neurosurgery, proton beams, stem cell rescue. Reflections on QOL as such. 21st century: molecular genetics. Premature aging, patterns of decline, risk- and resilience factors. QOL is a critical outcome measure. Focus depends on survival and sequelae, determined after years of follow-up. Detailed measurements are limited by time, money and human resources, and self-reporting questionnaires represent a crude measure limited by subjectivity. Therapeutic improvements raise the question of QOL versus cure. QOL is a potential primary research endpoint; multicenter international studies are needed, as are web-based tools that work across cultures.

State of the art of surgery in advanced epithelial ovarian cancer

State of the art of surgery in advanced epithelial ovarian cancer

A review of paediatric liver resections in Johannesburg: Experiences and preferred technique

Liver resections are widely performed in paediatric surgery. Many techniques exist to achieve vascular control, minimise bleeding and complete the parenchymal division. We retrospectively reviewed all liver resections performed in the Department of Paediatric Surgery at our institution between January 2005 and June 2012. Data pertaining to basic demographics, indications for surgery, parenchymal transection techniques, morbidity, mortality and histology were collated. Twenty-one resections were performed in children aged 6 weeks - 11 years; 18 for malignant liver disease (including 9 hepatoblastomas), and 3 for benign disease. We describe 1 peri-operative mortality secondary to torsion of the liver remnant, and no surgical morbidity. Three cases underwent total hepatic vascular exclusion with sharp parenchymal transection. The remaining patients underwent selective vascular inflow and outflow control using the Cavitron Ultra Sonic Aspirator and Harmonic Scalpel to divide the parenchyma. Care for these patients should be multidisciplinary. High-volume units and access to liver transplantation offer optimal results. No technique is proven superior to the 'clamp crush' technique of parenchymal transection. Knowledge of hepatic anatomy is key to minimising morbidity, and surgeons should be familiar with and have the flexibility to use all techniques of vascular control.