Self-Expandable nitinol stent for cardiovascular applications: canine and human experience

The initial experimental and clinical experience with the cardiovascular self-expandable Nitinol stent (vascular and coronary versions) is described. The stent is designed as a helical coil with two terminal balls that are used for restraining it on the delivery catheter. Upon release, the stent self-expands immediately. A temporary stent version continues with a long wire that can be removed by pulling it as a straight wire through a small profile catheter. The stent uncoils in its own groove upon removal, a relatively atraumatic procedure. The stents have been studied in dogs and in peripheral arteries in patients. The results show a transient nonocclusive proliferative response to the stent that is maximal at 3–6 mo. The removability of the permanent stent has been proven in dogs. The preliminary results in patients are encouraging and demonstrate its feasibility for permanent and potentially temporary arterial support. © 1994 Wiley-Liss,Inc..     

Detection of abnormal proliferation in histologically 'normal' colonic biopsies using FTIR-microspectroscopy

BACKGROUND: Abnormal crypt proliferation and development in the colon has been associated with premalignant stages of colon cancer. Conventionally, molecular markers are used to detect abnormal crypt proliferation. METHODS: In the present work, feasibility studies of FTIR-MSP to distinguish between normal and abnormal crypts from colon biopsies that show normal histopathological features have been undertaken. RESULTS: The results indicate that abnormal crypts show deviations in the pattern of absorbance in the Mid IR region along the crypt height when compared with the normal crypts. The crypts could be empirically classified into three groups such as crypts having a normal absorbance pattern for all biochemical components, crypts with abnormal absorbance pattern for some biochemical components and crypts with completely abnormal absorbance pattern along the height for all or most biochemical components studied by FTIR. The utilization of FTIR-MSP is proposed for diagnosis of abnormal metabolism at the molecular level of histologically completely normal-looking crypts, especially from those biopsies that are taken from sites far away from cancer. CONCLUSIONS: This method could give rise to a reduction in false-negative results during examination of biopsies using the conventional histopathological methods. The present method may be complementary to existing methods for precise demarcation of the zone of colostomy prior to colon cancer surgery.     

Three-dimensional imaging improves surgical skill performance in a laparoscopic test model for both experienced and novice laparoscopic surgeons

Study objective

The objective of this study was to evaluate and compare the impact of three-dimensional (3D) imaging system on the performance of basic laparoscopic tasks in a test model by novice and experienced surgeons.

Design

Three tasks were performed in a test model by 30 surgeons, 15 experienced surgeons, and 15 with minimal laparoscopic experience. The tasks were performed using 2D and 3D vision systems.

Design classification

Canadian Task Force II-1.

Subjects

Fifteen experienced laparoscopic surgeons and fifteen novices with minimal laparoscopic experience.

Measurements

Performance times were recorded using both two-dimensional and 3D imaging system for each task.

Main results

Performance time for all skills was significantly (P < 0.02) shorter when using 3D imaging system. Performance times were reduced by 18–31 % using 3D imaging for all participants. Experienced surgeons performed the tasks faster and showed similar improvement while using 3D imaging system.

Conclusion

3D vision systems allow for significant improvement in performance times of basic laparoscopic tasks in a test model for both inexperienced and advanced laparoscopic surgeons. Experienced surgeons benefit as much as novices from 3D imaging system. This benefit should be weighed against the disadvantages of the 3D vision systems, mainly cost, decreased light, eye strain, headaches, and shorter focal lengths.     

Intrascleral implantation of glass beads during evisceration

BACKGROUND AND OBJECTIVE: To review the results after small glass bead implantation in the scleral cavity during evisceration. MATERIALS AND METHODS: In this retrospective study, we retrieved the follow-up data of 17 patients who underwent evisceration with glass bead implantation from 1993 to 1996. RESULTS: All patients achieved good cosmetic results with good motility of the prosthesis. Complications included transient chemosis at the early postoperative period in 3 patients (17.6%), 1 patient (5.9%) with local dehiscence of the wound, 1 patient developed a cyst in the socket (5.9%), and 1 patient was afflicted with thinning of the conjunctiva over the surgical wound. CONCLUSION: The use of glass beads to fill the scleral cavity during evisceration has the advantage of an excellent fit in accordance with the scleral cavity volume, as well as ease of treatment in case of extrusion. The prosthesis movement is good because of its engagement with the scleral bulges caused by the glass beads.     

Short-term treatment of post-traumatic stress disorder with naltrexone: an open-label preliminary study

Eight patients (6 men and 2 women) with chronic post-traumatic stress disorder (PTSD) were treated with naltrexone 100-200 mg/day. Seven patients completed 2 weeks of treatment. A subtle and clinically insignificant improvement was noted in intrusive and hyperarousal symptoms (p < 0.05 for both), but not in avoidance symptoms. All patients demonstrated side effects which limited the targeted dose. It is suggested that the subtle positive effect of naltrexone and the hypersensitivity of these patients to its side effects do not encourage the use of naltrexone in the treatment of PTSD patients.     

Late whiplash syndrome: correlation of brain SPECT with neuropsychological tests and P300 event-related potential

BACKGROUND: The acceleration forces infringing the cervical spine in whiplash injury are frequently associated with multiple cerebral symptoms. The purpose of this study was to determine whether there is a correlation between cerebral perfusion findings, P300 recording (an electrophysiologic marker of cognitive ability), and neuropsychological tests in patients with whiplash injury. METHODS: Twenty patients with chronic whiplash injury underwent extensive clinical evaluation and neuropsychological testing. A brain single-photon emission computed tomography (SPECT) study using 99mTc-HMPAO was performed in all patients within 24 hours of neuropsychological evaluation. P300 event-related potentials were performed in 15 patients and in 9 normal volunteers. RESULTS: Thirteen of 20 patients had brain perfusion abnormalities on the SPECT studies, in one or more regions. Eight of 15 patients had abnormal P300 studies. Seven of eight patients with abnormal P300 had also an abnormal SPECT study. Seven of 15 patients had normal P300 results, 6 of them with a normal SPECT and 1 with SPECT abnormalities. There was no significant correlation between the SPECT findings or the P300 results and the scores of attention and working memory. There was, however, close agreement between the SPECT and P300. CONCLUSION: SPECT perfusion abnormalities in patients with chronic whiplash syndrome correlate well with P300 recording. The combination of these studies with neurocognitive and neurobehavioral tests may be useful in identifying a subgroup of patients having organic brain lesions.