Distinguish reasons for the variety of intraoperative transcranial magnetic motor evoked potential: the anaesthesia or the operative injury / 中华外科杂志

<p><b>OBJECTIVE</b>To find a way to discriminate operative reason from anaesthesia reason for the changes of intraoperative transcranial magnetic motor evoked potentials (MEPs).</p><p><b>METHODS</b>In 26 patients under Etomidate/Fentanyl anesthesia from February 2001 to June 2004, MEPs elicited by transcranial magnetic stimulation were recorded from tibialis anterior muscles, simultaneously bispectral index (BIS) and train-of-four stimulation (TOF) were used to monitor the anesthesia depth and neuromuscular blockade respectively. MEP, BIS and measurements of TOF at different anesthesia depth and muscular relaxation were recorded synchronously, statistical analysis of this data set was done in order to find the inherent relationship between these variables.</p><p><b>RESULTS</b>Under anesthesia, MEP amplitude was always positively correlated with the corresponding BIS and TOF value. A regression equation could be built, with which the MEP amplitude could be reckoned based on realtime BIS and T(1)/T(c). In case of spinal cord injury, the measured amplitude value would significantly deviate from predicted one, which suggested that the change of MEP was because of the operation, but not the anaesthesia or neuromuscular blockade. Each patient had his or her own regression equation, which was different from each other.</p><p><b>CONCLUSIONS</b>The establishment of regression equation from MEPs, BIS and TOF is very useful to distinguish reasons of the changes of transcranial magnetic MEPs during surgery, and with this technique, the intraoperative MEP monitoring should be more reliable and practicable.</p>

The utility of neuronavigation in the microsurgery for cerebral cavernous malformations / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the utility of neuronavigation in the microsurgery for cerebral cavernous malformations.</p><p><b>METHODS</b>In a retrospective study, 47 patients with cavernous malformations were involved from January 1995 to December 2010. Fourteen cases admitted into hospital from January 1995 to December 2002 were treated without neuronavigation (conventional group), the focus localization was based on magnetic resonance imaging (MRI) images, anatomic landmarks, and the experiences of the neurosurgeon. In the other 33 cases admitted after February 2002 to December 2010, surgeries were performed with neuronavigation using the Medtronic Stealth Station TREON or TRIA system (neuronavigation group). Excision of the cavernomas were all performed microsurgically, surrounding gliotic rim and hemosiderin stained tissue were resected in the case of epilepsy, and a few patients underwent extended hippocampal resection or multiple subpial transection.</p><p><b>RESULTS</b>With the use of neuronavigation, the extent of craniotomy reduced from 5.2 cm to 3.6 cm (P < 0.01), and deeper cavernoma focuses could be treated surgically. There were no changes with regard to the mean size of the cavernomas, the mean time of surgery and hospital stay (P > 0.05), but the mean time of anaesthesia was prolonged from 164 min to 197 min (P < 0.01). Cavernomas were resected completely in all 47 cases, which was confirmed by postoperative MRI recheck. The conditions of all patients were improved or remain unchanged, and no significant differences in the clinical outcome could be evaluated between the two groups.</p><p><b>CONCLUSIONS</b>Application of neuronavigation-assisted microsurgery of intracranial cavernous malformations surgery, helps reduce the surgical trauma, and has security and reliability.</p>

The utility of transcranial magnetic motor evoked potential monitoring during spinal surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the practicability and validity of transcranial magnetic motor evoked potential monitoring (TMS-MEP) during spinal surgery.</p><p><b>METHODS</b>From February 2001 to June 2004, 37 patients undergoing spinal surgery were involved, anaesthesia was maintained with volatile anesthetics in 11 operations and etomidate in 26. Analgesia was provided with fentanyl, and non-depolarizing muscle relaxant was given intermittently. MEPs elicited with transcranial magnetic stimulations were recorded from tibialis anterior muscles, simultaneously bispectral index (BIS) and train-of-four stimulation (TOF) were used to monitor the anesthesia depth and neuromuscular blockade respectively. The variety of MEP and its effect on surgical operation at different anesthesia depth and muscular relaxation were observed, and the muscle strength of the patients before and after operation were compared.</p><p><b>RESULTS</b>The 11 cases anesthetized with isoflurane or enflurane gave no response to TMS, the other 26 cases in which anaesthesia was maintained with etomidate and fentanyl gave satisfactory TMS-MEPs, but with significantly attenuated amplitudes and prolonged latencies (P < 0.05). Intraoperative MEP showed a grossly unchanged waveform, and its amplitude and latency had little fluctuation when anaesthesia and neuromuscular blockade maintained stable. When T(1) value of TOF at 40% - 60%, a steady MEP could be acquired and the muscular contraction after TMS should not interfere the operation.Seven of 26 cases had a MEP amplitude drop up to 50% or more during the operation, the surgical team was notified to avoid further spinal injury, at last only 1 case had a worsen muscle power after operation.</p><p><b>CONCLUSIONS</b>Myogenic TMS-MEP is a valid and practicable technique for intraoperative monitoring, and the etomidate + fentanyl technique is adequate for its anesthesia. BIS and TOF monitoring are helpful to maintain the steadiness of the anesthesia and MEPs, which is very important for monitoring the changes of the MEPs.</p>

Effects of gap junction blocking on the oxygen partial pressure in acupoints of the bladder meridian / 中国针灸

<p><b>OBJECTIVE</b>To explore the relation between gap junction and meridian phenomenon.</p><p><b>METHODS</b>The oxygen partial pressure in acupoints [see text for formula] and in their corresponding non-acupoints of the Bladder Meridian was observed with the needle-type tissue oxygen tension sensor in the gap junction blocking goats by 1-Heptanol injection and the Connexin 43 (Cx43) gene knockout mice.</p><p><b>RESULTS</b>(1) The oxygen partial pressure in acupoints of Bladder Meridian on goats was higher than that in non-acupoints after 1-Heptanol injection with significant differences between them (both P < 0.01). (2) The oxygen partial pressure in acupoints of Bladder Meridian on goats increased significantly after injecting 1-Heptanol as compare with that either injecting normal saline or injecting nothing with significant differences between them (all P < 0.01). (3) The oxygen partial pressure in acupoints of the Bladder Meridian was significantly higher than that in the non-acupoint controls in Cx43 wild type (WT) mice (all P < 0.01). In Cx43 heterozygote (HT) mice, the oxygen partial pressure between acupoints and non-acupoint controls showed no significant differences (all P > 0.05). (4) In acupoints, the oxygen partial pressure in Cx43 WT mice was significantly higher than that in Cx43 HT mice (all P < 0.05), while in the corresponding non-acupoints, this difference had no statistically significant (all P > 0.05).</p><p><b>CONCLUSION</b>Gap junction maybe the essential factor in signal transduction of acupuncture.</p>

Treatment of multisegmental intramedullary cervical spinal cord ependymomas / 中华外科杂志

<p><b>OBJECTIVE</b>To discuss the possibility of microneurosurgery techniques in the treatment of multisegmental intramedullary cervical spinal cord ependymomas.</p><p><b>METHODS</b>The clinical data of 26 cases of multisegmental intramedullary cervical spinal cord ependymomas patients was reviewed and analyzed.</p><p><b>RESULTS</b>There were 14 cases of cervical spinal cord ependymomas, 12 cases of cervical and thoracic spinal cord ependymomas. 4.5 spinal cord segments were involved in average. Incompletely inferior paraplegia was in 18 cases, incompletely high paraplegia in 8 cases, dyspnea in 6 cases, sphincter dysfunction in 10 cases. MRI detected syringomyelia formation in 24 cases. Vertebral lamina reposition were done in 20 cases. Muscle strength recovered in 21 cases, no change in 4 cases, aggravated in 1 case. All cases had total resection and 1 cases vertebral had instability in MRI.</p><p><b>CONCLUSIONS</b>Total resection of intramedullary cervical spinal cord ependymomas can be achieved by microneurosurgery. Most of the symptoms can be released after microsurgical treatment. After multisegmental laminotomy, the vertebral plate reposition should be done to ensure the stability.</p>

Management of elderly patients with symptomatic vertebrobasilar insufficiency / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility, safety and short-term efficacy of stent-assisted angioplasty and/or drug therapy for elderly patients with symptomatic vertebrobasilar insufficiency.</p><p><b>METHODS</b>Elderly patients (> or = 60 years old) with symptomatic vertebrobasilar stenosis (> or = 50%) demonstrated by cerebral angiography were treated with drug therapy and some with endovascular stenting further from April 2001 to June 2006. The clinical, imaging, intervention and follow-up data were collected and analyzed.</p><p><b>RESULTS</b>Eighty-one elderly patients were chosen for study, including 68 males and 13 females. The mean age is 70 years (60 - 87 years); stroke rate of 4.9% (4/81) and stroke-related mortality rate of 2.5% (2/81) were found in this group during hospitalization and follow-up (mean 28.1 months), and symptoms resolved or improved clinically in 66 (81.5%). Fifty-two balloon expandable stents were placed in 48 (59.3%) patients of this group with a technical success rate of 98.1% and the mean degree of stenosis was reduced from (82.4 +/- 13.1)% to (6.4 +/- 3.2)% (t = 22.4, P = 0.00).</p><p><b>CONCLUSIONS</b>Appropriate management including endovascular stenting and/or drug therapy may improve short-term outcomes of elderly patients with symptomatic vertebrobasilar insufficiency; meanwhile, stent-assisted angioplasty is technically feasible and relatively safe.</p>

Effect of acupuncture on pH values of acupoints in the goat / 中国针灸

<p><b>OBJECTIVE</b>To study effect of acupuncture on pH values of acupoints and non-acupoints.</p><p><b>METHODS</b>The pH values of acupoints and non-acupoints were determined with pH sense needles at the same time and separately in the goat.</p><p><b>RESULTS</b>(1) The pH value of the acupoints and non-acupoints decreased when acupuncture was separately at acupoints and non-acupoints with the pH value of the acupoint decreased more significantly; (2) there was no significant difference in decreasing amplitudes of the pH values between the acupoint and non-acupoint when acupuncture was simultaneously given at acupoints and non-acupoints.</p><p><b>CONCLUSION</b>Acupuncture can more significantly strengthen metabolism of acupoints; when acupuncture was simultaneously given at acupoints and non-acupoints, local metabolism is influenced each other.</p>