Yen Yao Li

Necrotizing soft-tissue infections and sepsis caused by Vibrio vulnificus compared with those caused by Aeromonas species

BACKGROUND Vibrio and Aeromonas species, which can cause necrotizing fasciitis and primary septicemia, are members of the Vibrionaceae family and thrive in aquatic environments. Because the clinical symptoms and signs of necrotizing fasciitis and sepsis caused by these two bacteria are similar, the purposes of this study were to describe the clinical characteristics of Vibrio vulnificus and Aeromonas infections, to analyze the risk factors for death, and to compare the effects of surgical treatment on the outcome. METHODS The cases of thirty-two patients with necrotizing soft-tissue infections and sepsis caused by Vibrio vulnificus (seventeen patients) and Aeromonas species (fifteen patients) were retrospectively reviewed over a four-year period. Surgical débridement or immediate limb amputation was initially performed in all patients. Demographic data, underlying diseases, laboratory results, and clinical outcome were analyzed for each patient in both groups. RESULTS Six patients in the Vibrio vulnificus group and four patients in the Aeromonas group died. The patients who died had significantly lower serum albumin levels than did the patients who survived (p < 0.05). The patients with a combination of hepatic dysfunction and diabetes mellitus had a higher mortality rate than those with either hepatic disease or diabetes mellitus alone (p < 0.05). The patients with Vibrio vulnificus infections had a significantly lower systolic blood pressure at presentation (p = 0.006). The patients with Aeromonas infections who died had significantly lower white blood-cell counts (p = 0.03) with significantly fewer numbers of segmented white blood cells than those who died in the Vibrio vulnificus group (p = 0.01). CONCLUSIONS The contact history of patients with a rapid onset of cellulitis can alert clinicians to a differential diagnosis of soft-tissue infection with Vibrio vulnificus (contact with seawater or raw seafood) or Aeromonas species (contact with fresh or brackish water, soil, or wood). Early fasciotomy and culture-directed antimicrobial therapy should be aggressively performed in those patients with hypotensive shock, leukopenia, severe hypoalbuminemia, and underlying chronic illness, especially a combination of hepatic dysfunction and diabetes mellitus.

Minimal access spinal surgery (MASS) in treating thoracic spine metastasis

Study Design. A retrospective study was conducted. Objective. This study aims to analyze the feasibility and efficacy of using minimal access spinal surgery (MASS) for managing thoracic spine metastasis. Summary of Background Data. Literature regarding minimally invasive surgical treatment for thoracic spine metastasis is sparse. In the past decade, the role of minimally invasive or endoscopic technique in managing metastatic thoracic disease has evolved. Methods. From February 1997 to March 2003, 46 patients with spine metastases, from T3–T12, were enrolled in this study. There were 29 patients undergoing MASS. Seventeen patients received standard thoracotomy (ST) in the early study period served as the control group. The indications for MASS include intractable back pain and/or neurologic deficits or neurologic deterioration during or after radiotherapy. Inclusion criteria for this study included tumor limited to one or two vertebral segments. Results. In the MASS and ST groups, no patient died as a result of an immediate intraoperative event. The mean operative blood loss was 1,110 versus 1,162 mL (P = 0.63), and the mean operative length was 179 versus 180 minutes (P = 0.54). Complication rates and 1-year, 2-year, and overall survival rates were comparable and the mean grade of neurologic recovery was 1.2 on the Frankel scale in both groups. Only 6.9% of MASS patients required a 2-day postoperative ICU stay compared with 88% of ST patients (P < 0.0001). Conclusions. The MASS technique is safe and effective and has proved to be an excellent alternative in managing thoracic spine metastasis. Surgeons may use progressively smaller incisions (5–6 cm in length) for the procedure. The learning curve for performing MASS procedures was not steep.

Management of giant pseudomeningoceles after spinal surgery

BackgroundPseudomeningoceles are a rare complication after spinal surgery, and studies on these complex formations are few.MethodsBetween October 2000 and March 2008, 11 patients who developed symptomatic pseudomeningoceles after spinal surgery were recruited. In this retrospective study, we reported our experiences in the management of these complex, symptomatic pseudomeningoceles after spinal surgery. A giant pseudomeningocele was defined as a pseudomeningocele >8 cm in length. We also evaluated the risk factors for the formation of giant pseudomeningoceles.ResultsAll patients were treated successfully with a combined treatment protocol of open revision surgery for extirpation of the pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage. Surgery-related complications were not observed. Recurrence of pseudomeningocele was not observed for any patient at a mean follow-up of 16.5 months. This result was confirmed by magnetic resonance imaging.ConclusionsWe conclude that a combined treatment protocol involving open revision surgery for extirpation of pseudomeningoceles, repair of dural tears, and implantation of a subarachnoid catheter for drainage is safe and effective to treat giant pseudomeningoceles.

Intraoperative computed tomography with integrated navigation in percutaneous iliosacral screwing

BACKGROUND Iliosacral screw fixation has generally been accepted as a treatment for unstable pelvic fractures with posterior sacroiliac joint disruption despite a 2-16% rate of screw malposition. The integration of an intraoperative computed tomography (iCT) with a navigation system was utilized in percutaneous sacroiliac screwing to provide an alternative. METHODS From October 2010 to November 2011, thirteen patients presented pelvic fractures with posterior ring disruption (lateral compression type 2-3 [n=12] and vertical shear type [n=1] by Young-Burgess Classification) and underwent percutaneous iliosacral screwing using an iCT integrated with navigation system. The perioperative data and radiographic outcomes of the patients were collected and analyzed. RESULTS Navigation times ranged from 10 to 45min (mean of 21.2±10.6min). Radiation exposure to the skin utilizing integrated navigation system ranged from 23.5 to 28.1mGy (mean of 26.4±1.5mGy), and the dose associated with examining the screw position ranged from 22.5 to 26.8mGy (mean of 25.5±1.1mGy). Effective dose of radiation ranged from 9.26 to 17.43mSv (mean of 13.16±2.52mSv). The iCT demonstrated iliosacral screws in adequate position (i.e., no penetration or encroachment of the neuroforamen or cord). No neurologic or vascular injury occurred in these cases. CONCLUSIONS An iCT with an integrated navigation system provided accuracy for percutaneous iliosacral screwing. In addition, the accumulated dose was minimized for surgeons. However, effective dose of radiation in iCT with an integrated navigation system group was higher than fluoroscopic-assisted iliosacral screwing in hands of the same group of surgeons. No neurologic complications occurred. The iCT with an integrated navigation system provided an alternative to percutaneous iliosacral screwing.

Comparing radiation exposure during percutaneous vertebroplasty using one- vs. two-fluoroscopic technique

BackgroundPercutaneous vertebroplasty (PV) requires relatively lengthy fluoroscopic guidance, which might lead to substantial radiation exposure to patients or operators. The two-fluoroscopic technique (two-plane radiographs obtained using two fluoroscopes) during PV can provide simultaneous two-planar projections with reducing operative time. However, the two-fluoroscopic technique may expose the operator or patient to increased radiation dose. The aim of this study was to quantify the amount of radiation exposure to the patient or operator that occurs during PV using one- vs. two-fluoroscopic technique.MethodsTwo radiation dosimeters were placed on the right flank of each patient and on the upper sternum of each operator during 26 single-level PV procedures by one senior surgeon. The use of two-fluoroscopic technique (13 patients) and one-fluoroscopic technique (13 patients) were allocated in a consecutive and alternative manner. The operative time and mean radiation dose to each patient and operator were monitored and compared between groups.ResultsMean radiation dose to the patient was 1.97 ± 1.20 mSv (95% CI, 0.71 to 3.23) for the one-fluoroscopic technique group vs. 0.95 ± 0.34 mSv (95% CI, 0.85 to 1.23) for the two-fluoroscopic technique group (P =0.031). Mean radiation dose to the operator was 0.27 ± 0.12 mSv (95% CI, 0.17–0.56) for the one-fluoroscopic technique group vs. 0.25 ± 0.14 mSv (95% CI, 0.06–0.44) for the two-fluoroscopic technique group (P = 0.653). The operative time was significantly different between groups: 47.15 ± 13.48 min (range, 20–75) for the one-fluoroscopic technique group vs. 36.62 ± 8.42 min (range, 21–50) for the two-fluoroscopic technique group (P =0.019).ConclusionCompared to the one-fluoroscopic technique, the two-fluoroscopic technique used during PV provides not only shorter operative times but also reduces the radiation exposure to the patient. There was no significant difference between the two techniques with regards to radiation exposure to the operator.

Role of the supine lateral radiograph of the spine in vertebroplasty for osteoporotic vertebral compression fracture: a prospective study

BackgroundSeverely collapsed vertebral compression fracture (VCF) is usually considered as a contraindication for vertebroplasty because of critically decreased vertebral height (less than one-third the original height). However, osteoporotic VCF can possess dynamic mobility with intravertebral cleft (IVC), which can be demonstrated on supine lateral radiographs (SuLR) and standing lateral radiographs (StLR). The purposes of this study were to: (1) evaluate the efficacy of SuLR to detect IVCs and assess the intravertebral mobility in VCFs, and (2) evaluate the short-term results of vertebroplasty in severely collapsed VCFs with IVCs.MethodsWe enrolled 37 patients with 40 symptomatic osteoporotic VCFs for vertebroplasty; 11 had severely collapsed VCFs with concurrent IVCs detected on the SuLR, the others had not-severely collapsed VCFs. A preoperative StLR, SuLR, magnetic resonance imaging (MRI), and postoperative StLR were taken from all patients. Radiographs were digitized to calculate vertebral body morphometrics including vertebral height ratio and Cobbs kyphotic angle. The intensity of the patients pain was assessed by the visual analogue scale (VAS) on the day before operation and 1 day, 1 month, and 4 months after operation. The patients VAS scores and image measurement results were assessed with the paired t-test and Pearson correlation tests; Mann-Whitney U test was used for VAS subgroup comparison. Significance was defined as p < 0.05.ResultsIVCs in patients with not-severely collapsed VCFs were detected in 21 vertebrae (72.4%) by MRI, in 15 vertebrae (51.7%) by preoperative SuLR, and in 7 vertebrae (24.1%) by preoperative StLR. Using the MRI as a gold standard to detect IVCs, SuLR exhibit a sensitivity of 0.71 as compared to StLR that yield a sensitivity of 0.33. In patients with VCFs with IVCs detected on SuLR, the average of the postoperative restoration in vertebral height ratio was significantly higher than that in those without IVCs (17.1% vs. 6.4%). There was no statistical difference in the VAS score between severely collapsed VCFs with IVCs detected on SuLR and not-severely collapsed VCFs at any follow-up time point.ConclusionsThe SuLR efficiently detects an IVC in VCF, which indicates a better vertebral height correction after vertebroplasty compared to VCF without IVC. Before performing a costly MRI, SuLR can identify more IVCs than StLR in patients with severely collapsed VCFs, whom may become the candidates for vertebroplasty.

Intraoperative computed tomography navigation for transpedicular screw fixation to treat unstable thoracic and lumbar spine fractures: clinical analysis of a case series (CARE-compliant).

AbstractTranspedicular screw (TPS) fixation in unstable thoracic and lumbar (TL) spine fractures remains technically difficult because of destroyed anatomical landmarks, unstable gross segments, and discrepancies in anatomic orientation using conventional anatomic landmarks, fluoroscopic guidance, or computed tomography (CT)-based navigation. In this study, we evaluated the safety and accuracy of TPS placement under intraoperative computed tomography (iCT) navigation in managing unstable TL spine fractures.From 2010 to 2013, we retrospectively reviewed the Spine Operation Registry records of patients who underwent posterior instrumented fusion to treat unstable TL spine fractures via the iCT navigation system. An unstable spine fracture was identified as AO/Magerl classification type B or type C.In all, 316 screws in 37 patients with unstable TL spine fractures were evaluated and involved 7 thoracic, 23 thoracolumbar junctional, and 7 lumbar fractures. The accuracy of TPS positioning in the pedicle without breach was 98% (310/316). The average number of iCT scans per patient was 2.1 (range 2–3). The average total radiation dose to patients was 15.8 mSv; the dose per single level exposure was 2.7 mSv. The TPS intraoperative revision rate was 0.6% (2/316) and no neurovascular sequela was observed. TPS fixation using the iCT navigation system obtained a 98% accuracy in stabilizing unstable TL spine fractures. A malplaced TPS could be revised during real-time confirmation of the TPS position, and no secondary operation was required to revise malplaced screws.The iCT navigation system provides accurate and safe management of unstable TL spine fractures. In addition, operating room personnel, including surgeons and nurses, did not need to wear heavy lead aprons as they were not exposed to radiation.

Video-Assisted Thoracoscopic Surgery and Minimal Access Spinal Surgery Compared in Anterior Thoracic or Thoracolumbar Junctional Spinal Reconstruction: A Case-Control Study and Review of the Literature

There are no published reports that compare the outcomes of video-assisted thoracoscopic surgery (VATS) and minimal access spinal surgery (MASS) in anterior spinal reconstruction. We conducted a retrospective case-control study in a single center and systematically reviewed the literature to compare the efficacy and safety of VATS and MASS in anterior thoracic (T) and thoracolumbar junctional (TLJ) spinal reconstruction. From 1995 to 2012, there were 111 VATS patients and 76 MASS patients treated at our hospital. VATS patients had significantly (p < 0.001) longer operating times and significantly (p < 0.022) higher thoracotomy conversion rates. We reviewed 6 VATS articles and 10 MASS articles, in which there were 625 VATS patients and 399 MASS patients. We recorded clinical complications and a thoracotomy conversion rate from our cases and the selected articles. The incidence of approach-related complications was significantly (p = 0.021) higher in VATS patients. The conversion rate was 2% in VATS patients and 0% in MASS patients (p = 0.001). In conclusion, MASS is associated with reduction in operating time, approach-related complications, and the thoracotomy conversion rate.

Application of Intraoperative CT-Guided Navigation in Simultaneous Minimally Invasive Anterior and Posterior Surgery for Infectious Spondylitis

This study was aimed at evaluating the safety and efficacy of using intraoperative computed tomography- (iCT-) guided navigation in simultaneous minimally invasive anterior and posterior surgery for infectious spondylitis. Nine patients with infectious spondylitis were enrolled in this study. The average operative time was 327.6 min (range, 210–490) and intraoperative blood loss was 407 cc (range, 50–1,200). The average duration of hospital stay was 48.9 days (range, 11–76). Out of a total of 54 pedicle screws employed, 53 screws (98.1%) were placed accurately. A reduced visual analog scale on back pain (from 8.2 to 2.2) and Oswestry disability index (from 67.1% to 25.6%) were found at the 2-year follow-up. All patients had achieved resolution of spinal infection with reduced average erythrocyte sedimentation rate (from 83.9 to 14.1 mm/hr) and average C-reactive protein (from 54.4 to 4.8 mg/dL). Average kyphotic angle correction was 10.5° (range, 8.4°–12.6°) postoperatively and 8.5° (range, 6.9°–10.1°) after 2 years. In conclusion, the current iCT-guided navigation approach has been demonstrated to be an alternative method during simultaneous minimally invasive anterior and posterior surgery for infectious spondylitis. It can provide a good intraoperative orientation and visualization of anatomic structures and also a high pedicle screw placement accuracy in patients lateral decubitus position.

Intraoperative computed tomography navigation for transpedicular screw placement in posterior instrumentation and correction of adolescent idiopathic scoliosis

Background: Intraoperative computed tomography (iCT) navigation produces high resolution real-time 3-dimensional images, which can be obtained after the well-prepared surgical field of posterior spinal elements is scanned by the iCT. There is a paucity of studies reporting the feasibility of the iCT navigation system integrated into posterior instrumentation and correction for adolescent idiopathic scoliosis (AIS). Purpose: This study is to evaluate the safety and accuracy of transpedicular screws (TPS) placement in AIS using the iCT navigation. Methods: We performed a retrospective review of records of the Spine Operation Registry at the authors’ institution to identify AIS patients who underwent correction with posterior pedicle screw instrumentation via the iCT navigation from year 2010 to 2014. Results: A total of 17 AIS patients underwent correction with posterior instrumentation via iCT navigation. A total of 245 screws including 175 thoracic screws and 70 lumbar screws were placed. The mean estimated blood loss was 718 ml (range, 350–1,500 ml) and the average operative time was 266 min (range, 150–420 min). The mean dose of patient radiation exposure was 20.1 mSv (range, 13.1–30 mSv) and the mean radiation dose per single level exposure was 1.9 mSv (range, 1.2–2.7 mSv). The average Cobb angles of major curve before surgery, in the immediate postoperative period, and at the most recent follow-up were 53.2 degrees, 16.5 degrees, and 17.7 degrees, respectively. The average correction rate was 67% (range, 50%–82%) with an average of 10.7 fused levels (range, 8–14 fused levels). A total of 236 screws (96%) were positioned in the pedicle without cortical breach, including 167 thoracic screws (95%) and 69 lumbar screws (99%). There were 90 wellpositioned screws (96%) on the concave side and 77 well-positioned screws (95%) on the convex side of the thoracic curves. There were 32 wellpositioned screws (100%) the concave side and 37 well-positioned screws (97%) on the convex side of the lumbar curves. Breach grade 1 occurred in one thoracic pedicle screw and one lumbar pedicle screw, and breach grade 2 occurred in seven thoracic pedicle screws. All screws with breach grade 2 were removed. The TPS removal rate was 3% (7/245) without any neurovascular sequela. Conclusion: TPS placement using the iCT navigation system resulted in 96% accuracy in posterior instrumentation and correction of AIS. A malpositioned pedicle screw could be immediately removed during real-time assessment of the TPS position, and no secondary operation was required.