Manraj K.S. Heran

Venous Malformations: Classification, Development, Diagnosis, and Interventional Radiologic Management

Venous malformations are categorized as low-flow vascular malformations within the domain of vascular anomalies and are the most common vascular malformation encountered clinically. Venous malformations are by definition present at birth, undergo pari passu growth, and present clinically because of symptoms related to mass effect or stasis. Although diagnosis can usually be made by clinical history and examination, differentiation from other vascular and nonvascular entities often requires an imaging work-up that includes ultrasound, CT, MR imaging, and diagnostic phlebography. All decisions regarding imaging work-up and decision to treat must be coordinated though referral and discussions with a multidisciplinary team and be based on clearly defined clinical indications. Percutaneous image-guided sclerotherapy has become the mainstay of treatment for venous malformations and involves the introduction of any one of a number of endothelial-cidal sclerosants into the vascular spaces of the lesion, with each sclerosant possessing its own unique spectrum of advantages and disadvantages.

Whole brain radiotherapy with hippocampal avoidance and simultaneous integrated boost for 1-3 brain metastases: a feasibility study using volumetric modulated arc therapy.

PURPOSE To evaluate the feasibility of using volumetric modulated arc therapy (VMAT) to deliver whole brain radiotherapy (WBRT) with hippocampal avoidance and a simultaneous integrated boost (SIB) for one to three brain metastases. METHODS AND MATERIALS Ten patients previously treated with stereotactic radiosurgery for one to three brain metastases underwent repeat planning using VMAT. The whole brain prescription dose was 32.25 Gy in 15 fractions, and SIB doses to brain metastases were 63 Gy to lesions >or=2.0 cm and 70.8 Gy to lesions <2.0 cm in diameter. The mean dose to the hippocampus was kept at <6 Gy(2). Plans were optimized for conformity and target coverage while minimizing hippocampal and ocular doses. Plans were evaluated on target coverage, prescription isodose to target volume ratio, conformity number, homogeneity index, and maximum dose to prescription dose ratio. RESULTS Ten patients had 18 metastases. Mean values for the brain metastases were as follows: conformity number = 0.73 +/- 0.10, target coverage = 0.98 +/- 0.01, prescription isodose to target volume = 1.34 +/- 0.19, maximum dose to prescription dose ratio = 1.09 +/- 0.02, and homogeneity index = 0.07 +/- 0.02. For the whole brain, the mean target coverage and homogeneity index were 0.960 +/- 0.002 and 0.39 +/- 0.06, respectively. The mean hippocampal dose was 5.23 +/- 0.39 Gy(2). The mean treatment delivery time was 3.6 min (range, 3.3-4.1 min). CONCLUSIONS VMAT was able to achieve adequate whole brain coverage with conformal hippocampal avoidance and radiosurgical quality dose distributions for one to three brain metastases. The mean delivery time was under 4 min.

Combined Cementoplasty and Radiofrequency Ablation in the Treatment of Painful Neoplastic Lesions of Bone

PURPOSE To assess the safety and effectiveness of combined radiofrequency (RF) ablation and cementoplasty in the treatment of painful neoplastic lesions of bone. MATERIALS AND METHODS The authors performed a retrospective analysis of 25 combined treatments comprising RF ablation followed by injection of polymethylmethacrylate cement performed in 19 patients during a 22-month period. Patients ranged in age from 42 to 82 years (mean, 58.9 years) and included five women and 14 men. Eleven vertebrae (eight lumbar and three thoracic), nine acetabulae, three sacra, one pubis, and one humerus were treated with a total of 36 RF ablations (in several instances, overlapping ablations were used). The location of the primary neoplasm, lesion size, pain before and after the procedure (as determined with a 10-point visual analog scale [VAS]), number of RF treatments, type of device used for cementoplasty, RF time, cement volume, and extravasation were documented. RESULTS A total of 25 combined RF ablations and cementoplasties were performed. The technical success rate was 100% (25 of 25 treatments). There were seven minor complications: six limited cement extravasations and a transient thermal nerve injury. The mean RF time was 9.1 minutes (range, 6-12 minutes). The mean cement volume injected was 6.1 mL (range, 0.8-16 mL). The mean preprocedure pain (as measured with a VAS) was 7.9 (range, 7.0-9.0) and the mean posttreatment pain was 4.2 (range, 0-6); the difference was statistically significant (mean score, 4.08; 95% confidence interval: 3.92, 4.87; P < .0001) using a paired t test. CONCLUSIONS Combined RF ablation and cementoplasty appears to be safe and effective in the treatment of painful neoplastic lesions of bone.

Diffusion Tensor Imaging Findings Are Not Strongly Associated With Postconcussional Disorder 2 Months Following Mild Traumatic Brain Injury

Objective:To examine the relation between diffusion tensor imaging (DTI) of the corpus callosum and postconcussion symptom reporting following mild traumatic brain injury (MTBI). Participants:Sixty patients with MTBI and 34 patients with orthopedic/soft-tissue injuries (Trauma Controls) prospectively enrolled from consecutive admissions to a level 1 trauma center. Procedure:Diffusion tensor imaging of the corpus callosum was undertaken using a Phillips 3T scanner at 6 to 8 weeks postinjury. Participants also completed a postconcussion symptom checklist. The MTBI group was divided into 2 subgroups based on the International Classification of Diseases, Tenth Revision symptom criteria for postconcussion disorder (PCD): PCD Present (n = 21), PCD Absent (n = 39). Main Outcome Measures:Measures of fractional anisotropy and mean diffusivity for the genu, body, and splenium of the corpus callosum. Participants also completed the British Columbia Post-Concussion Symptom Inventory. Results:The MTBI group reported more postconcussion symptoms than the trauma controls. There were no significant differences between MTBI and trauma control groups on all DTI measures. In the MTBI sample, there were no significant differences on all DTI measures between those who did and did not meet the International Classification of Diseases, Tenth Revision research criteria for postconcussion disorder. Conclusions:These data do not support an association between white matter integrity in the corpus callosum and self-reported postconcussion syndrome 6 to 8 weeks post-MTBI.

A review of ancillary tests in evaluating brain death.

The neurological determination of death (NDD) is primarily considered to be clinical. However, situations may arise where confounding factors make this clinical assessment difficult or impossible. As a result, ancillary tests have been developed in order to aid in the confirmation of brain death. As assessment of neuronal electrical activity; electroencephalography (EEG) is no longer recommended in this determination, tools assessing cerebral perfusion, as reflected by the presence or absence of cerebral blood flow (CBF), are the mainstay of NDD. The preferred ancillary test currently is Hexamethylpropylene amine oxime-single photon emission computed tomography (HMPAO SPECT) radionuclide angiography. When this is not available, or is equivocal, 4-vessel cerebral angiography can be used to determine the presence or absence of intracranial blood flow. However, as cerebral angiography has its own limitations, other techniques are sought by physicians in the Intensive Care and Neuro-intensive Care settings to replace cerebral angiography. In this article, we briefly review the history of diagnosis of brain death, pathophysiologic issues in making this determination, and currently available CBF imaging techniques, discussing each in turn with respect to their utility in the diagnosis of brain death.

Radiographic evaluation of scoliosis: review.

Despite enormous advances in cross-sectional imaging over the past few decades, radiography remains the main-stay of diagnosis and evaluation of scoliosis. Knowledge of technical factors, measurement error, and measurement techniques is important in the comparison of serial radiographs and affects surgical decision making. This article focuses on adolescent idiopathic scoliosis as a framework for understanding the general concepts in the radiographic evaluation of the scoliotic spine.

Treatment of cystic lymphatic vascular malformations with OK-432 sclerotherapy.

Background: Cystic lymphatic vascular malformations are benign lesions that can cause disfigurement and functional impairment. Complete surgical resection is often difficult, and clinical recurrence is common. Sclerotherapy has been used as an alternative to excision. OK-432 is a lyophilized mixture of Streptococcus pyogenes and benzylpenicillin which, when injected into a lesion, has shown significant ability to reduce its size or obliterate it completely. Methods: The authors report a series of 12 patients treated in this fashion at the Vascular Anomalies Clinic, British Columbia Childrens Hospital, between 1999 and 2004. All patients underwent imaging of the lesion: 10 had magnetic resonance imaging, one had a computed tomographic scan, and one had ultrasound examination. Six patients had macrocystic malformations (cysts ≥ 2 cm) and six had microcystic or combined lymphaticovenous malformations. Patients were treated with intralesional injection of OK-432. The position of the injection was confirmed by angiography and/or ultrasound in 10 cases. Response to treatment was assessed clinically. Results: All patients with macrocystic malformations had complete resolution or good response to treatment. None required any additional treatment. In contrast, those with microcystic or combined malformations responded poorly. All of these patients underwent subsequent excision without adverse consequences. The size and location of the lesion did not correlate with response to treatment. Seventy-five percent of patients experienced pyrexia. Local swelling is an expected phenomenon and must be anticipated, particularly for lesions near the airway. Conclusions: OK-432 is an excellent treatment for patients with macrocystic lymphatic malformations. However, it is ineffective for microcystic lesions.

A Step-by-Step Practical Approach to Imaging Diagnosis and Interventional Radiologic Therapy in Vascular Malformations

Within vascular anomalies, vascular malformations are those present at birth that grow with the patient and exhibit abnormal dilated vascular channels lined by mature endothelium. Vascular tumors, the other group of vascular anomalies, demonstrate endothelial hypercellularity. Vascular malformations are further divided into low-flow varieties (capillary, venous, and lymphatic malformations) and high-flow varieties (arteriovenous malformation and fistula). All malformations exhibit a predictable group of clinical patterns that vary in severity and rate of progression. The interventional radiologist must incorporate this clinical data with characteristic ultrasound and magnetic resonance findings to arrive at a diagnosis. One must then decide in a multidisciplinary fashion, based on objective clinical criteria and image-based morphology, if the patent is a candidate for intervention. Sclerotherapy is a technique used to treat vascular malformations whereby an endothelial-cidal agent is introduced into the endoluminal compartment to initiate vascular closure. The high flow rate of an arteriovenous malformation requires the incorporation of superselective transarterial, direct, and transvenous access with flow reduction techniques to deliver adequate dose of sclerosant and embolic to the nidus. Satisfactory outcomes are seen in over half of all malformations patients. Similar treatment-related complications are seen between malformations but are lowest in lymphatic and highest in arteriovenous malformations.

Topical mitomycin-C for recalcitrant esophageal strictures: a novel endoscopic/fluoroscopic technique for safe endoluminal delivery

BACKGROUND Nonsurgical treatment of recalcitrant pediatric esophageal strictures is challenging. The chemotherapy drug mitomycin-C, which reduces collagen synthesis and scar formation, shows anecdotal promise in the topical treatment of these strictures. Mitomycin-C is cytotoxic, and a safe endoluminal delivery system that avoids inadvertent application to adjacent mucosa has not yet been described. DISCUSSION We have treated 2 patients with a combined endoscopic/fluoroscopic technique that ensures protected delivery of a mitomycin-soaked pledget directly to the targeted site. Following pneumatic balloon dilation of the stricture under fluoroscopy, flexible esophagoscopy is performed to the disrupted stricture. Through the gastrostomy tract, a 12F to 16F semirigid sheath is introduced over a guide wire and passed retrograde up the esophagus to the stricture. A grasping forceps introduced through the instrument channel of the esophagoscope is advanced through the sheath and grasps a mitomycin-C-soaked pledget. The pledget is drawn back through the sheath up to the stricture where timed, serial radial applications to the stricture are performed without any contamination of the rest of the esophagus or stomach. CONCLUSION We describe a novel technique of endoluminal delivery and focused application of mitomycin-C to an esophageal stricture that avoids inadvertent topical application to adjacent mucosa.

Percutaneous thrombin embolization of a post-traumatic superficial temporal artery pseudoaneurysm

Pseudoaneurysm of the superficial temporal artery is rare in children and is frequently a result of direct facial trauma. Conventional management has included surgical ligation and resection and more recently endovascular embolization to prevent complications including local pain, headache, facial disfigurement and bleeding. We report a unique case of a US-guided percutaneous thrombin injection for the treatment of a post-traumatic superficial temporal artery pseudoaneurysm in a child.