Charles W. Kerber

A targeted supradose cisplatin chemoradiation protocol for advanced head and neck cancer

BACKGROUND Hypothesizing that cisplatin (DDP) drug resistance is dose dependent and the radiosensitizing effect of DDP is clinically beneficial, we conducted a chemoradiation protocol using extremely high doses of DDP delivered intra-arterially (IA) to locally advanced head and neck tumors. PATIENTS AND METHODS Twenty-nine patients with untreated stage IV disease received 4 weekly infusions of 150 mg/m2, simultaneous systemic DDP neutralization with intravenous (IV) bolus sodium thiosulfate, and concomitant radiotherapy (180 to 200 cGy/day x 35 fractions). RESULTS The complete response rate of the 24 evaluable patients as determined with repeat biopsies was 23/24 (96%). Of the 29 patients evaluable for toxicity, central nervous system complications related to the infusion technique occurred with 2/110 infusions, both of which were reversible. The rate of grade III to IV chemotoxicity was 13%. The median length of follow-up was 22 months. There have been 6 recurrences: 1 local; 3 regional; and 2 at distant sites. The projected overall and disease-free 3-year survival was 88% and 53%, respectively. CONCLUSION We conclude that the combination of rapid selective delivery of supradose DDP/IV thiosulfate neutralization and concomitant radiotherapy can be safely and effectively applied to patients with advanced head and neck cancer. Preliminary survival analysis indicates that this approach may improve the prognosis for patients with an otherwise devastating disease.

Balloon Catheter with a Calibrated Leak: A New System for Superselective Angiography and Occlusive Catheter Therapy

Problems with the use of the diagnostic angiography catheter as a therapeutic tool relate to difficulty in placing the catheter precisely in the desired area and controlling the infusion of the occluding agent. The author describes a soft microcatheter which has been developed to overcome these problems. The catheter ends in a balloon tip and thus can be flow-directed. To overcome the traditional difficulties of flow-guided catheters and the need for a double lumen, a calibrated leak in the balloon allows distal fluid delivery while the balloon remains inflated.

Transcatheter snare removal of acute middle cerebral artery thromboembolism: technical case report.

OBJECTIVE AND IMPORTANCE We describe the case of a patient in whom a snare designed for the removal of foreign bodies was successfully used to retrieve a thromboembolism from the middle cerebral artery. This technique can be used to reestablish blood flow when maximal pharmacological therapies have failed. CLINICAL PRESENTATION A 38-year-old man with scrotal squamous cell carcinoma presented with the abrupt onset of left hemiparesis and numbness. Computed tomography of the head showed no hemorrhage or hypodensity, and right middle cerebral artery thrombosis was suspected. INTERVENTION Cerebral angiography demonstrated a near-total occlusion of the right middle cerebral artery at the M1-M2 junction. The administration of intra-arterial urokinase, systemic heparin, and systemic abciximab, and mechanical maceration failed to lyse the clot. A 4-mm goose-neck snare was guided through a microcatheter, and the clot was snared and withdrawn. Immediate postoperative angiography demonstrated the reconstitution of normal flow. Pathological examination of the snared material was consistent with clot. By postoperative Day 5, the patient had regained full strength, except for the fingers of the left hand, which remained moderately weak. Computed tomography demonstrated a right insular and extreme capsular infarct. CONCLUSION To our knowledge, this is the first reported use of a snare to remove clot in the setting of thromboembolic stroke. As the use of intra-arterial thrombolysis increases, transcatheter snare removal of pharmacologically resistant clot may be considered as a salvage strategy.

Snare retrieval of intracranial thrombus in patients with acute stroke.

Intravenous or intraarterial thrombolysis of intracranial emboli is becoming an accepted clinical treatment modality for acute ischemic stroke, but not all emboli respond to the lytic drug regimens available today. If drug therapy fails, mechanical retrieval seems warranted. Four patients whose condition was resistant to intravenous and intraarterial thrombolytic drug treatment underwent at least partial clot removal with use of a snare, and almost immediate clinical improvement was noted. A fifth patients clot was removed before lytic drugs were administered. All five patients, who presented with a sudden onset of stroke, were evaluated by arterial angiography; then, after a failed trial of intraarterial fibrinolytic drugs, they were treated by passing a 2- or 4-mm snare through a microcatheter. The snare wire was guided around the thrombus, gently brought back toward the microcatheter-but not into it-and the entire microcatheter and snare assembly was then removed. In four of the five cases, follow-up angiography performed immediately after the retrieval showed wider distal branches than normal. Follow-up computed tomography results were abnormal in all cases, showing hyperdense material in the territory that was previously ischemic. This hyperdensity subsided within 48 hours in all but one patient who developed small parenchymal hemorrhages; however, he remained asymptomatic. The snare device offers an additional or alternative therapy until completely effective thrombolytic agents become available. Although use of a snare is not ideal, device improvements should make the retrieval less technically challenging and more effective. There is a need for improved mechanical extraction devices, especially in light of the patient improvement that occurred. This experience also suggests that immediate removal of a mature clot could reduce the total time of brain ischemia more quickly than administration of thrombolytic drugs.

Rapid prototyping to create vascular replicas from CT scan data: making tools to teach, rehearse, and choose treatment strategies.

Our goal was to develop and prove the accuracy of a system that would allow us to re‐create live patient arterial pathology. Anatomically accurate replicas of blood vessels could allow physicians to teach and practice dangerous interventional techniques and might also be used to gather basic physiologic information. The preparation of replicas has, until now, depended on acquisition of fresh cadaver material. Using rapid prototyping, it should be able to replicate vascular pathology in a live patient. We obtained CT angiographic scan data from two patients with known arterial abnormalities. We took such data and, using proprietary software, created a 3D replica using a commercially available rapid prototyping machine. From the prototypes, using a lost wax technique, we created vessel replicas, placed those replicas in the CT scanner, then compared those images with the original scans. Comparison of the images made directly from the patient and from the replica showed that with each step, the relationships were maintained, remaining within 3% of the original, but some smoothing occurred in the final computer manipulation. From routinely obtainable CT angiographic data, it is possible to create accurate replicas of human vascular pathology with the aid of commercially available stereolithography equipment. Visual analysis of the images appeared to be as important as the measurements. With 64 and 128 slice detector scanners becoming available, acquisition times fall enough that we should be able to model rapidly moving structures such as the aortic root.

A case of hemorrhagic pineal cyst: MR/CT correlation

SummaryA 30-year-old male had a headache for one month and was evaluated with both computed tomography (CT) and magnetic resonance (MR). These scans demonstrated an obstructing pineal cyst containing layered acute and subacute blood products by MR criteria. The concurrent scans allowed correlation between CT and MR findings in this rare complication of an unusual entity, explained his headache (and the development of later upward gaze paresis), provided a precise surgical/anatomic approach, and gave a good final clinical result. The report illustrates appropriate CT and MR images and pathological specimen.

A Parametric Model for Studies of Flow in Arterial Bifurcations

Regional differences in hemodynamic loads on arterial walls have been associated with localized vascular disease such as atherosclerosis and cerebral aneurysms. Due to their intrinsic geometric relevance, three-dimensional (3D) reconstructions of arterial segments are frequently used in hemodynamic studies of these diseases. However, it is not possible to use them to systematically vary geometric features for parametric studies. Idealized vascular models are inherently suited for parametric studies, but are limited by their tendency to oversimplify the vessel geometry. In this work, a hierarchy of three parametric bifurcation models is introduced. The models are relatively simple, yet capture all geometric features identified as common to cerebral bifurcations in the complex transition from parent to daughter branches. While these models were initially designed for parametric studies, we also evaluate the possibility of using them for 3D reconstruction of cerebral arteries, with the future goal of improving reconstruction of poor quality clinical data. The lumen surface and vessel hemodynamics are compared between two reconstructed cerebral bifurcations and matched parametric models. Good agreement is found. The average and maximum geometric differences are less than 3.1 and 10%, respectively for all three parametric models. The maximum difference in wall shear stress is less than 8% for the most complex parametric model.

Endovascular treatment of extensive cerebral sinus thrombosis

Cerebral venous and sinus thrombosis is an uncommon but potentially lethal event. Although thrombosis accounts for only 1% of all strokes, if it is left untreated patients suffer from continuing headaches, vague neurological complaints, and may even progress to coma and death. New endovascular techniques and technology allow the possibility of more aggressive thrombolysis and thrombectomy in the setting of acute thrombosis. The authors present a case of recanalization of an extensive cerebral thrombosis using a new endovascular retrieval device.

Observations on control of N2 and N3 neck disease in squamous cell carcinoma of the head and neck by intra-arterial chemoradiation

Patients with head and neck squamous cell cancer with N2 and N3 neck disease have a poor prognosis and are at risk to fail regionally despite combined surgery and radiation. Twenty‐two patients with N2 and N3 neck disease (and T3‐4 primaries) were treated with intra‐arterial, high‐dose cisplatin (CDDP), 150 mg/m2 per week for 4 weeks, and concurrent radiation. All patients were followed for at least 2 years or until death from any cause. Twenty patients had a complete response at the primary site. Two of the 20 with a complete response later had a neck recurrence and died. Five patients with palpable nodes after treatment underwent fine‐needle aspiration (FNA), one of which was positive and two suggestive of cancer. Six neck dissections were performed in this group, only two of which had positive nodes. This chemoradiation protocol may offer reasonable control of N2 and N3 neck disease in advanced head and neck squamous cell cancer. Neck dissection appeared to be necessary in only those patients with nodes 8 weeks after treatment in whom FNA was positive or suggestive of cancer. Because of the relatively small size of this series, additional accrual and monitoring of such patients is planned.

Multimodality treatment of deep periventricular cerebral arteriovenous malformations

The surgical treatment of arteriovenous malformations (AVMs) located in deep periventricular regions such as the basal ganglia is associated with marked morbidity and mortality. Approaches through critical brain regions afford limited exposure of the lesions, while surgical dissection is sometimes complicated by acute severe brain swelling and/or hemorrhage in the surrounding tissues. In our approach to deep AVMs, our regimen has evolved from direct staged microsurgical excision under routine fentanyl-N2O-relaxant anesthesia (first four patients) to the use of elective high-dose barbiturate anesthesia (subsequent 12 patients). In the first group of four patients, 11 operations were performed. Two patients improved, one of whom returned to normal neurologically. There were three episodes of acute brain swelling and/or hemorrhage. One patient died as a result, and another deteriorated. In the second group of 12 patients, all but two lesions were completely excised. Among the 10 patients in whom the AVM was completely excised, seven improved, six of whom achieved a good to excellent outcome, with two regaining full neurologic function. Three patients worsened (one as the result of acute brain swelling and/or hemorrhage). There was no death in this group. Only one incidence of acute brain swelling and/or hemorrhage occurred in 26 operations. Even though the number of patients is too small in the first group for meaningful statistical comparison, our intraoperative observations and postoperative results suggest that our evolved multimodality regimen, such as staged excision and the use of elective high-dose barbiturates, was likely to have contributed to the improved treatment results of these formidable lesions.