Biomedical subjects

David F Kallmes

Publications and source records attributed to David F Kallmes.

59 records · Page 4Linked to original sources

PubMedDate not supplied

Transradial cerebral angiography: technique and outcomes.

BACKGROUND AND PURPOSE: The transradial approach is routinely used for coronary angiography, but only limited data exist regarding transradial cerebral angiography. The purpose of this report was to offer detailed procedural methods for transradial cerebral angiography to facilitate adoption of the technique. METHODS: We reviewed 60 consecutive cases of transradial access used for neuroangiography and catalogued the indications for angiography, the sheath size, the catheter type, the length of the procedure, the number of cases in which radial artery access was unsuccessful, and the complications. We also noted procedural details regarding adjunctive medications, preprocedural patient assessment, and postprocedural care. RESULTS: Transradial angiography was successfully applied in 57 of 60 cases (51 diagnostic, six interventional, three failed accesses). Sheaths were used in all cases and ranged in size from 4F to 6F. Mean procedural time for diagnostic cases was 40 minutes +/- 19 [SD]. Access-site complications included one forearm hematoma. CONCLUSION: Transradial angiography is a useful tool for diagnostic and interventional neuroangiographic procedures. All relevant vessels can be accessed from the radial artery for diagnostic studies. Interventions in the right vertebral and carotid systems are facilitated by the transradial approach.

Carotid Arteries↗

PubMedDate not supplied

Radiation dose to the operator during vertebroplasty: prospective comparison of the use of 1-cc syringes versus an injection device.

BACKGROUND AND PURPOSE: Percutaneous vertebroplasty procedures require relatively long durations of fluoroscopic guidance, which might lead to substantial radiation dose to operators. Specialized injection devices have been proposed to limit operator exposure. Our purpose was to compare the radiation dose to the operator's hands during vertebroplasty when using 1-cc syringes versus that when using an injection device. METHODS: Radiation dosimeters were worn on the left wrist during 39 vertebroplasty injection procedures in 25 patients. Cases were alternated between the use of 1-cc syringes (19 procedures) and the use of an injection device (20 procedures). For each procedure, one dosimeter was worn throughout the procedure, both during needle placement and injection, and a second dosimeter was worn during the injection phase only. Mean doses for the whole case and mean doses for the injection procedure alone were compared between groups. RESULTS: Mean whole case dose was 128 +/- 161 mrem (range, 0-660 mrem) for the 1-cc syringe group versus 98 +/- 90 mrem (range, 0-340 mrem) for the injection device group (P =.23). Mean dose during injection was 100 +/- 145 mrem (range, 0-660 mrem) for the 1-cc syringe group versus 55 +/- 43 mrem (range, 0-130 mrem) for the injection device group (P =.09). Three of 19 1-cc syringe cases yielded zero dose, compared with four of 20 injection device cases. Duration of injection was markedly different between groups, with mean injection times of 4.2 and 7.5 min for 1-cc syringe and injection device cases, respectively (P <.00002). Mean injection dose per minute of lateral fluoroscopy was 23.6 and 7.3 mrem for the 1-cc syringe and injection device groups, respectively (P =.002). CONCLUSION: The use of an injection device significantly decreased the radiation dose to the operator's extremity per unit time of injection. However, total dose per injection was equivalent between groups because of significantly longer injection duration for the injection device cohort.

Bone Cements↗

PubMedDate not supplied

MRI findings after successful vertebroplasty.

BACKGROUND AND PURPOSE: Recurrent or residual back pain after vertebroplasty (VP) is common, and many patients with these symptoms are evaluated by MRI. The purpose of this report is to describe post-treatment MRI findings after successful VP. METHODS: We identified all patients who underwent VP at our institution and later presented with back pain and had a spine MRI. From these patients, we identified a cohort with uncomplicated procedures, in whom back pain at the site of the VP was not the dominant pain source at follow-up. Using the pre- and postoperative MRIs and the VP conventional radiographs, we assessed such features as interval height loss and changes in marrow edema in treated vertebrae. RESULTS: Thirty patients (51 treated vertebrae) met our clinical criteria for uncomplicated VP. Nine (18%) of 51 vertebrae lost additional height after the procedure. Neither patient demographics nor variables associated with the procedure itself, including volume of cement injected, correlated with additional height loss after VP. Moderate or severe marrow edema was demonstrated in 62% of vertebrae on preoperative MRI and in 33% of vertebrae on follow-up MRI. Twenty-one percent of vertebrae had new areas of marrow edema on follow-up. Twenty-two percent of vertebrae imaged >6 months after VP had moderate or severe edema. CONCLUSION: Progressive and persistent edema and interval height loss after successful VP are common and should not be interpreted as sufficient evidence of ongoing pathology at the treated vertebral level.

Adult↗

PubMedDate not supplied

Histopathologic and immunohistochemical comparison of human, rabbit, and swine aneurysms embolized with platinum coils.

BACKGROUND AND PURPOSE: The purpose of this study was to clarify the cellular mechanisms of aneurysmal healing by comparing histologic and immunohistochemical findings in experimental rabbit and swine aneurysms to a human aneurysm embolized with platinum coils. METHODS: Swine sidewall aneurysms (n = 5, harvested at 12 weeks) and elastase-induced rabbit aneurysms (n = 6, harvested at 24 weeks) were created and embolized. A single human aneurysm, embolized 6 years before death, was harvested following autopsy. All specimens were processed by using a modified paraffin embedding technique. Tissue was sectioned and stained with hematoxylin and eosin and Masson trichrome. Immunohistochemistry and immunofluorescence were performed with multiple antibodies, including alpha smooth muscle actin, myosin heavy chain, desmin, vimentin, and CD31. RESULTS: The human aneurysm's dome was filled with loose, hypocellular, amorphous tissue. The aneurysm's neck was completely covered with a thin layer of hypocellular tissue. Collagen and myofibroblasts were sparse in both the dome and neck. Rabbit aneurysms' domes were also filled with a loose, hypocellular tissue, amorphous matrix. In 5 of 6 aneurysms, a thin layer of hypocellular tissue ran along the neck. Collagen and myofibroblasts were sparse in the dome. Swine aneurysms were filled with densely infiltrated tissue, including chronic inflammatory tissue and extensive, attenuated collagen fiber bundles associated with myofibroblasts. Thick layers of myofibroblasts entirely bridged the necks. CONCLUSIONS: Absence of collagen deposition and scant myofibroblastic reaction to platinum coil embolization are seen in the rabbit model but not in swine aneurysms. The elastase-induced aneurysm model in rabbits is more suitable than sidewall swine aneurysms for testing of modified devices aimed at improving intra-aneurysmal fibrosis.

Actins↗

PubMedDate not supplied

Evaluation of vertebroplasty with a validated outcome measure: the Roland-Morris Disability Questionnaire.

BACKGROUND AND PURPOSE: Vertebroplasty is rapidly disseminating as a treatment for vertebral compression fractures, but its efficacy has not been assessed with a well-validated, back pain-specific instrument. We report the use of the Roland-Morris Disability Questionnaire (RDQ) in patients undergoing vertebroplasty for painful osteoporotic compression fractures. METHODS: Retrospective review of patients treated with vertebroplasty who completed the RDQ and 2 verbal pain scales (0-10) for pain at rest and pain with activity at baseline, 1 week, 1 month, 6 months, and 1 year post-vertebroplasty. Changes in outcome measures were analyzed by using a paired t test and correlations were assessed with Spearman rho. Multiple linear regression was used to analyze the relationship between baseline scores and independent variables. RESULTS: One hundred thirteen patients were treated at 164 vertebral levels. At baseline, RDQ scores were associated with rest and activity pain (P < .001 and P = .002, respectively) but were not associated with other independent variables. All 3 outcome scores decreased by 1 week and remained improved through maximal follow-up (P < .001). RDQ scores improved by a mean of 7.0 points at 1 week and remained improved at 1 year (P = .02). RDQ scores correlated with both rest and activity pain, but the absolute correlation was slightly better (+0.15 on average) with activity pain. CONCLUSIONS: Patients who underwent vertebroplasty experienced relief of back pain and symptoms, as shown by improvement in verbal pain and RDQ scores. The RDQ correlates well with measures of pain, shows clinically significant improvement and is responsive to changes across time. More important, the RDQ provides an easily administered, well-validated, back pain-specific outcome measure that could be adopted to assess vertebroplasty outcomes.

Adult↗