Search Results

You are looking at 1 - 10 of 60 items for

  • Author or Editor: Peter Kan x
  • Refine by Access: all x
Clear All Modify Search
Full access

James K. Liu, Peter Kan, and Meic H. Schmidt

Primary lymphomas of the sacrum are rare tumors, reported only in a few cases in the literature. The authors describe two patients with diffuse large B-cell lymphomas presenting as a sacral tumor.

In the first case a 52-year-old man presented with progressive back pain, bilateral radicular pain, and saddle block anesthesia secondary to a lytic, expansile soft-tissue mass. The mass arose from the sacrum and eroded through the right S-1 to S-4 foramina and extended into the epidural space of the spinal canal. On magnetic resonance imaging, the sacral mass enhanced homogeneously with Gd. In the second case a 64-year-old man presented with left-sided radicular pain, paresthesias, and progressive weakness due to a lytic soft-tissue mass in the left sacral ala extending into the left L-5 and S-1 foramina. Metastatic workup in each patient demonstrated unremarkable findings. In both cases, an open biopsy procedure was performed after nondiagnostic examination of needle biopsy samples. Histopathological examination showed evidence consistent with diffuse large B-cell lymphoma in both patients. In the first case the disease was classified as Stage IAE, and the patient subsequently underwent four cycles of cyclophosphamide/doxorubicin/vincristine/prednisone (CHOP)– and rituximab-based chemotherapy followed by consolidation radiotherapy. In the second case the disease was also classified as Stage IAE, and the patient underwent CHOP-based chemotherapy and consolidation radiotherapy. In both cases radiography demonstrated a decrease in size of the sacral lymphomas.

The authors review the clinical, radiological, and histological features of sacral lymphomas. Lymphoma should be considered in the differential diagnosis of sacral tumors.

Free access

Visish M. Srinivasan, Anish N. Sen, and Peter Kan

The authors present a case of a patient with a Barrow Type B carotid-cavernous fistula (CCF) who presented with severe symptoms of eye redness, diplopia, and proptosis. Due to the tortuosity and size of her angular vein and the lack of good flow/access via the inferior petrosal sinus, she was treated with a transvenous approach via a large, dilated superior ophthalmic vein for coil embolization of the CCF. The patient had a full angiographic and symptomatic cure. The authors present the treatment plan and strategy and the fluoroscopic recording of the treatment. Nuances of the technique are discussed.

The video can be found here:

Free access

Visish M. Srinivasan, Frederick F. Lang, and Peter Kan

Oncolytic viruses (OVs) have been used in the treatment of cancer, in a focused manner, since the 1990s. These OVs have become popular in the treatment of several cancers but are only now gaining interest in the treatment of glioblastoma (GBM) in recent clinical trials. In this review, the authors discuss the unique applications of intraarterial (IA) delivery of OVs, starting with concepts of OV, how they apply to IA delivery, and concluding with discussion of the current ongoing trials. Several OVs have been used in the treatment of GBM, including specifically several modified adenoviruses. IA delivery of OVs has been performed in the hepatic circulation and is now being studied in the cerebral circulation to help enhance delivery and specificity. There are some interesting synergies with immunotherapy and IA delivery of OVs. Some of the shortcomings are discussed, specifically the systemic response to OVs and feasibility of treatment. Future studies can be performed in the preclinical setting to identify the ideal candidates for translation into clinical trials, as well as the nuances of this novel delivery method.

Free access

Visish M. Srinivasan, Aditya Vedantam, and Peter Kan

We present a case of a patient with an anterior communicating artery aneurysm treated by PulseRider-assisted coil embolization. PulseRider is a new device, FDA approved for treatment of broad-necked aneurysms of the basilar apex or internal carotid artery terminus. The aneurysm was broad-necked and involved the anterior communicating artery and was considered for traditional stent-assisted coiling as well as PulseRider-assisted coiling. The authors present the treatment plan and strategy and then fluoroscopic recording of the PulseRider delivery and subsequent coiling phase. Nuances of technique for this new device used in a challenging setting are discussed.

The video can be found here:

Full access

William T. Couldwell, Peter Kan, and Martin H. Weiss

✓ The most common nonendocrine complication after transsphenoidal surgery is cerebrospinal fluid (CSF) leak. Many neurosurgeons have advocated the routine reconstruction of the floor of the sella turcica using autologous fat, muscle, fascia, and either cartilage or bone after transsphenoidal surgery to prevent postoperative CSF fistulas. However, the use of autologous grafting requires a second incision, prolongs operative time, and adds to the patient's postoperative discomfort. In addition, the presence of sellar packing may interfere with the interpretation of postoperative images. To avoid these disadvantages, the authors suggest that routine sellar reconstruction or closure after transsphenoidal surgery is unnecessary unless an intraoperative CSF leak is encountered. The incidence of postoperative CSF leakage in the patients reported on in this series is no higher than that reported by others, and no other complications such as pneu-matocele have been encountered in approximately 2700 patients in whom no intraoperative CSF leak was encountered. The authors conclude that routine closure of the floor of the sella turcica or sphenoid is unnecessary in the absence of intraoperative CSF leak.

Full access

Peter Kan and Meic H. Schmidt


The choices available in the management of metastatic spine disease are complex, and the role of surgical therapy is increasing. Recent studies have indicated that patients treated with direct surgical decompression and stabilization before radiation have better functional outcomes than those treated with radiation alone. The most common anterior surgical approach for direct spinal cord decompression and stabilization in the thoracic spine is open thoracotomy; however, thoracotomy for spinal access is associated with morbidity that can be avoided with minimally invasive techniques like thoracoscopy.


A minimally invasive thoracoscopic approach was used for the surgical treatment of thoracic and thoracolumbar metastatic spinal cord compression. This technique allows ventral decompression via corpectomy, inter-body reconstruction with expandable cages, and stabilization with an anterolateral plating system designed specifically for minimally invasive implantation. This technique was performed in 5 patients with metastatic disease of the thoracic spine, including the thoracolumbar junction.


All patients had improvement in preoperative symptoms and neurological deficits. No complications occurred in this small series.


The minimally invasive thoracoscopic approach can be applied to the treatment of thoracic and thoracolumbar metastatic spine disease in an effort to reduce access morbidity. Preliminary results have indicated that adequate decompression, reconstruction, and stabilization can be achieved with this technique.

Restricted access

John D. Nerva, Peter S. Amenta, and Aaron S. Dumont

Restricted access

John D. Nerva, Peter S. Amenta, and Aaron S. Dumont

Full access

Visish M. Srinivasan, Gouthami Chintalapani, Edward A. M. Duckworth, and Peter Kan


The evaluation of the venous neurovasculature, especially the dural venous sinuses, is most often performed using MR or CT venography. For further assessment, diagnostic cerebral angiography may be performed. Three-dimensional rotational angiography (3D-RA) can be applied to the venous system, producing 3D rotational venography (3D-RV) and cross-sectional reconstructions, which function as an adjunct to traditional 2D digital subtraction angiography.


After querying the database of Baylor St. Luke’s Medical Center in Houston, Texas, the authors reviewed the radiological and clinical data of patients who underwent 3D-RV. This modality was performed based on standard techniques for 3D-RA, with the catheter placed in the internal carotid artery and a longer x-ray delay calculated based on time difference between the early arterial phase and the venous phase.


Of the 12 cases reviewed, 5 patients had neoplasms invading a venous sinus, 4 patients with idiopathic intracranial hypertension required evaluation of venous sinus stenosis, 2 patients had venous diverticula, and 1 patient had a posterior fossa arachnoid cyst. The x-ray delay ranged from 7 to 10 seconds. The 3D-RV was used both for diagnosis and in treatment planning.


Three-dimensional RV and associated cross-sectional reconstructions can be used to assess the cerebral venous vasculature in a manner distinct from established modalities. Three-dimensional RV can be performed with relative ease on widely available biplane equipment, and data can be processed using standard software packages. The authors present the protocol and technique used along with potential applications to venous sinus stenosis, venous diverticula, and tumors invading the venous sinuses.