Giuseppe Esposito

Primary cerebral lymphomatoid granulomatosis: report of four cases and literature review

Background Lymphomatoid granulomatosis (LYG) is an angiocentric and angiodestructive lymphoreticular proliferation, which usually involves the lungs, but may also involve the central nervous system (CNS). Unique involvement of the CNS has been reported rarely. We report our experience with LYG confined to the brain and review the pertinent literature. Patients and Methods From January 1995 to September 2007, we identified patients with isolated brain LYG through a search of the histopathology database of the Catholic University of Rome; medical and radiological data were analyzed. Immunophenotype, in situ hybridization analysis of EBV-encoded small RNAs (EBER ISH) and immunoglobulin rearrangement studies were performed on the pathological specimens. Results Four patients with brain-LYG (male/female 1:1, mean age 44xa0years) underwent surgery in the study period. Subsequent therapy was tailored according to LYG grading. At the latest follow-up (range from 18 to 221xa0months), patient conditions had improved in all cases. EBER ISH was negative in all cases. Study of the IgH chain gene documented a monoclonal pattern in two cases. Conclusions CNS-LYG is a rare disease that should be considered in the differential diagnosis of both diffuse and space-occupying cerebral lesions. Primary cerebral LYG seems not to be associated with EBV and appears to have a better prognosis than systemic LYG with CNS localization, which is frequently EBV positive.

In vivo carotid artery closure by laser activation of hyaluronan-embedded gold nanorods

We prove the first application of near-infrared-absorbing gold nanorods (GNRs) for in vivo laser closure of a rabbit carotid artery. GNRs are first functionalized with a biopolymeric shell and then embedded in hyaluronan, which gives a stabilized and handy laser-activable formulation. Four rabbits undergo closure of a 3-mm longitudinal incision performed on the carotid artery by means of a 810-nm diode laser in conjunction with the topical application of the GNRs composite. An effective surgery is obtained by using a 40-W/cm(2) laser power density. The histological and electron microscopy evaluation after a 30-day follow-up demonstrates complete healing of the treated arteries with full re-endothelization at the site of GNRs application. The absence of microgranuloma formation and/or dystrophic calcification is evidence that no host reaction to nanoparticles interspersed through the vascular tissue occurred. The observation of a reshaping and associated blue shift of the NIR absorption band of GNRs after laser treatment supports the occurrence of a self-terminating process, and thus of additional safety of the minimally invasive laser procedure. This study underlines the feasibility of using GNRs for in vivo laser soldering applications, which represents a step forward toward the introduction of nanotechnology-based therapies in minimally invasive clinical practices.

Endoscope-assisted microsurgical transoral approach to the anterior craniovertebral junction compressive pathologies

At the present time, an update to the classical microsurgical transoral decompression is strongly provided by the most recent literature dealing with the introduction of the endoscopy in spine surgery. In this paper, we present our experience on the endoscope-assisted microsurgical transoral approach to anterior craniovertebral junction (CVJ) compressive pathology. We analysed seven patients (3 paediatrics and 4 adults ranging from 6 to 78xa0years) operated on for CVJ decompressive procedures using an open access, microsurgical technique, neuronavigation and endoscopy. All techniques mentioned were simultaneously employed. Among the endoscopic routes described in the literature, we have preferred the transoral using 30° endoscopes. In all the cases endoscopy allowed a radical decompression compared to the microsurgical technique alone, as confirmed intraoperatively with contrast medium fluoroscopy. In conclusion, endoscopy represents a useful complement to the standard microsurgical approach to the anterior CVJ; it provides information for a better decompression with no need for soft palate splitting, hard palate resection, or extended maxillotomy. Moreover, intraoperative fluoroscopy helps to recognize residual compression. Virtually, in normal anatomic conditions, no surgical limitations exist for endoscopically assisted transoral approach, compared with the pure endonasal and transcervical endoscopic approaches. In our opinion, the endoscope deserves a role as “support” to the standard transoral microsurgical approach since 30° angulated endoscopy significantly increases the surgical area exposed at the level of the anterior CVJ.

Selective-targeted extra-intracranial bypass surgery in complex middle cerebral artery aneurysms: correctly identifying the recipient artery using indocyanine green videoangiography.

BACKGROUND: Treatment of complex middle cerebral artery (MCA) aneurysms often requires vessel sacrifice or prolonged temporary occlusion with extra- to intracranial (EC-IC) bypass to preserve perfusion. A crucial surgical step is the identification of the bypass recipient artery matching the distal territory of the involved vessel. OBJECTIVE: To report about the feasibility and efficiency of an indocyanine green videoangiography (ICG-VA) assisted technique for identification of cortical recipient vessels to perform selective-targeted EC-IC bypass. METHODS: The proposed technique is based on the analysis of differences in the timing of filling of M4 vessels seen on serial ICG-VAs. A delayed fluorescence can be visualized either primarily on a baseline ICG-VA or secondarily on an ICG-VA performed during temporary occlusion of the involved MCA branch. M4 branches presenting delayed fluorescence represent suitable bypass recipient arteries. We report 7 consecutive patients treated for complex MCA aneurysms with selective-targeted EC-IC bypass. RESULTS: Application of the proposed technique permitted the correct identification of recipient arteries (cortical branches of the involved MCA segment) in all patients. The cortex distal to the occlusion filled concomitantly on ICG-VA at the end of surgery. All patients underwent successful treatment of the aneurysm, including a cortical bypass. There were no ischemic complications, and a favorable clinical outcome was achieved in all patients (modified Rankin Scale at follow-up ⩽ modified Rankin Scale preoperative). CONCLUSION: The proposed ICG-VA-based technique enables reliable and accurate identification of the cortical recipient artery and eliminates the risk of erroneous revascularization of noninvolved territories. ABBREVIATIONS: CT-A, computed tomography angiography DSA, digital subtraction angiography EC-IC, extra- to intracranial GSA, giant serpentine aneurysm ICG, indocyanine green ICG-VA, indocyanine green videoangiography MCA, middle cerebral artery mRS, modified Rankin Scale STA-MCA, superficial temporal artery to middle cerebral artery

Indocyanine green video-angiography in neurosurgery: A glance beyond vascular applications

OBJECTIVEnIndocyanine green video angiography (ICG-VA) is a non invasive, easy to use and a very useful tool for various neurosurgical procedures. Initially introduced in vascular neurosurgery since 2003, its applications have broadened over time, both in vascular applications and in other neurosurgical fields. The objective of our study is to review all published literature about ICG-VA, cataloguing its different applications.nnnMETHODSnA systematic review of all pertinent literature articles published from January 2003 to May 2014 using Pubmed access was performed using pertinent keywords; cross check of references of selected articles was performed in order to complete bibliographical research. Results of research were grouped by pathology.nnnRESULTS AND CONCLUSIONSnThe paper systematically analyses ICG-VA different applications in neurosurgery, from vascular neurosurgery to tumor resection and endoscopic applications, focusing on reported advantages and disadvantages, and discussing future perspectives.

Minimally occlusive laser vascular anastomosis (MOLVA): experimental study

BackgroundTemporary occlusion of an intracranial artery during microvascular anastomosis is a major risk factor in cerebrovascular surgery. A new laser vascular welding technique that minimizes the occlusion time of the recipient vessel has been developed and is described in this report.MethodA new minimally occlusive technique of end-to-side microvascular anastomosis was developed employing a diode laser in association with the application of a chromophore in our experimental model of double end-to-side anastomosis. The implantation of a vein graft on the patent carotid artery was obtained through the application of three interrupted sutures at each anastomotic site; the carotid was then clamped, two arteriotomies were performed, followed by the application of a fourth suture and of the laser welding procedure on each anastomosis. Monitoring of the temperature at the site of the anastomosis was introduced in order to control the welding technique.FindingsThe time of the clamping of the carotid artery was 12xa0min to perform two end-to-side anastomoses (i.e., 6xa0min for each anastomosis). All bypasses were patent after a follow-up of 90xa0days and histological study confirmed good preservation of the vascular wall.ConclusionsOur laser-assisted technique of vascular anastomosis reduces the duration of the clamping of the recipient artery down to 6xa0min. This technique can minimize the risk of cerebral ischemia associated with occlusion of a recipient artery in intracranial bypass procedures, promoting an improved vascular healing process with a lower risk of thrombosis and occlusion.

In vivo laser assisted microvascular repair and end-to-end anastomosis by means of indocyanine green-infused chitosan patches: a pilot study

Laser‐based repairing techniques offer several advantages respect to standard suturing in microsurgery. In this work we evaluate the applicability and feasibility of two innovative laser‐based approaches for microvascular repair and anastomoses: (1) laser‐assisted vascular repair (LAVR); (2) laser‐assisted end‐to‐end vascular anastomosis (LAVA). All these procedures have been executed by the use of diode laser irradiation and chitosan‐patches infused with Indocyanine Green (ICG).

Diode laser-assisted carotid bypass surgery: an experimental study with morphological and immunohistochemical evaluations.

OBJECTIVEConventional suturing methods of microvascular anastomosis are associated with various degrees of vascular wall damage that can lead to thrombosis and bypass occlusion. An experimental model of double end-to-side venous graft anastomosis on the common carotid artery was set up to compare conventional suturing methods with a low-power diode laser vascular welding technique. METHODSThe experiments were performed on 40 rabbits that underwent implantation of a 15-mm segment of jugular vein on the common carotid artery. The proximal end-to-side suture was performed by eight interrupted stitches; the distal suture, which was done using a laser welding technique, was supported by four stay sutures. The animals were evaluated after 2 days (n = 15), 9 days (n = 15), and 30 days (n = 10). The vascular segments were excised and subjected to histological, immunohistochemical, and ultrastructural evaluation. RESULTSThe average clamping time to perform both anastomoses was 35 minutes. At the end of the follow-up period, one case of complete occlusion was observed after 9 days and one case was observed after 30 days. Surgical observations and pathological evaluation indicated that adoption of the laser welding technique reduced operative time and bleeding. Histologically, a reduction of thrombosis, inflammation, myointimal hyperplasia, and dystrophic calcification was observed in laser-assisted anastomoses. A better preservation of the endothelium was also evident in laser-treated anastomoses. The observed differences were deemed statistically significant (P < 0.05). CONCLUSIONOur study demonstrated the efficacy of diode laser welding in improving surgical techniques of high-flow bypass and in reducing the vascular wall damage observed with conventional methods.

A comment on "Contralateral cerebral hemodynamic changes after unilateral direct revascularization in patients with moyamoya disease".

Direct revascularization has been used successfully to prevent strokes by improving regional cerebral blood flow (rCBF) to the affected hemisphere faster in patients with moyamoya disease (MMD). Since most literatures have focused on the rCBF changes of operative hemisphere, we evaluated the hemodynamics of nonoperative side by xenon-enhanced computed tomography (Xe-CT) and acetazolamide challenge test in patients with MMD during a short time follow-up. Fifteen MMD patients with unilateral ischemic presentations who received direct revascularization on the symptomatic hemispheres with complete hemodynamic evaluations by Xe-CT and acetazolamide challenge test were enrolled. Hemodynamic evaluations were performed 1, 3, and 6 months, postoperatively. The postoperative rCBF and cerebral vascular reserve (CVR) were recorded and correlated with clinical outcome. Angiography was performed if the patient had neurological deterioration or deficits. The average follow-up time was 8.5 ± 3.5 months. Three months after the ipsilateral direct revascularization, the CVR of nonoperative hemispheres (25.8 ± 8.1%) began to decrease significantly (P = 0.003). Six months later, the rCBF showed a downward trend in nonoperative hemispheres (47.4 ± 8.0 ml·100 g−1 min−1) than the preoperative status, but the difference was not significant (P = 0.053). Three patients presented with decreased rCBF and impaired CVR in the nonoperative hemispheres. Among them, two patients were symptomatic. Unilateral direct revascularization in symptomatic hemisphere for MMD patient could induce CVR impaired in primary asymptomatic hemisphere during the short term after the surgery. Therefore, critical follow-up, especially the hemodynamic follow-up in the asymptomatic hemispheres should be performed in patients with MMD.

Pituitary surgery and volumetric assessment of extent of resection: a paradigm shift in the use of intraoperative magnetic resonance imaging

OBJECTIVEnThe aim of this study was to quantitatively assess the role of intraoperative high-field 3-T MRI (3T-iMRI) in improving the gross-total resection (GTR) rate and the extent of resection (EOR) in endoscopic transsphenoidal surgery (TSS) for pituitary adenomas.nnnMETHODSnRadiological and clinical data from a prospective database were retrospectively analyzed. Volumetric measurements of adenoma volumes pre-, intraoperatively, and 3 months postoperatively were performed in a consecutive series of patients who had undergone endoscopic TSS. The quantitative contribution of 3T-iMRI was measured as a percentage of the additional rate of GTR and of the EOR achieved after 3T-iMRI.nnnRESULTSnThe cohort consisted of 50 patients (51 operations) harboring 33 nonfunctioning and 18 functioning pituitary adenomas. Mean adenoma diameter and volume were 21.1 mm (range 5-47 mm) and 5.23 cm(3) (range 0.09-22.14 cm(3)), respectively. According to Knosps classification, 10 cases were Grade 0; 8, Grade 1; 17, Grade 2; 12, Grade 3; and 4, Grade 4. Gross-total resection was the surgical goal (targeted [t]GTR) in 34 of 51 operations and was initially achieved in 16 (47%) of 34 at 3T-iMRI and in 30 (88%) of 34 cases after further resection. In this subgroup, the EOR increased from 91% at 3T-iMRI to 99% at the 3-month MRI (p < 0.05). In the 17 cases in which subtotal resection (STR) had been planned (tSTR), the EOR increased from 79% to 86% (p < 0.05) and GTR could be achieved in 1 case. Intrasellar remnants were present in 20 of 51 procedures at 3T-iMRI and in only 5 (10%) of 51 procedures after further resection (median volume 0.15 cm(3)). Overall, the use of 3T-iMRI led to further resection in 27 (53%) of 51 procedures and permitted GTR in 15 (56%) of these 27 procedures; thus, the GTR rate in the entire cohort increased from 31% (16 of 51) to 61% (31 of 51) and the EOR increased from 87% to 95% (p < 0.05).nnnCONCLUSIONSnThe use of high-definition 3T-iMRI allowed precise visualization and quantification of adenoma remnant volume. It helped to increase GTR and EOR rates in both tGTR and tSTR patient groups. Moreover, it helped to achieve low rates of intrasellar remnants. These data support the use of 3T-iMRI to achieve maximal, safe adenoma resection.