A New Treatment Algorithm That Incorporates Minimally Invasive Surgery for Pyogenic Spondylodiscitis in the Thoracic and Lumbar Spines: The Results of Its Clinical Application to a Series of 34 Patients.

Background and Objectives: Spinal minimally invasive surgery (MIS) experts at the university hospital worked as a team to develop a new treatment algorithm for pyogenic spondylodiscitis in lumbar and thoracic spines. They modified a flow chart introduced for this condition in a pre-MIS era to incorporate MIS techniques based on their extensive experiences accumulated over the years, both in MIS for degenerative lumbar diseases and in the treatment of spine infections. The MIS procedures incorporated in this algorithm consisted of percutaneous pedicle screw (PPS)-rod fixation and transpsoas lateral lumbar interbody fusion (LLIF). The current study analyzed a series of 34 patients treated with prospective selection of the methods according to this new algorithm. Materials and Methods: The algorithm first divided the patients into those who had escaped complicated disease conditions, such as neurologic impairment, extensive bone destruction, and the need to be mobilized without delay (Group 1) (19), and those with complicated pyogenic spondylodiscitis (Group 2) (15). Group 1 had image-guided needle biopsy followed by conservative treatment alone with antibiotics and a spinal brace (12) (Group 1-A) or a subsequent addition of non-fused PPS-rod fixation (7) (Group 1-B). Group 2 underwent an immediate single-stage MIS with non-fused PPS-rod fixation followed by posterior exposure for decompression and debridement through a small midline incision (12) (Group 2-A) or an additional LLIF procedure after an interval of 3 weeks (3) (Group 2-B). Results: All patients, except four, who either died from causes unrelated to the spondylodiscitis (2) or became lost to follow up (2), were cured of infection with normalized CRP at an average follow up of 606 days (105-1522 days). A solid interbody fusion occurred at the affected vertebrae in 15 patients (50%). Of the patients in Group 2, all but two regained a nearly normal function. Despite concerns about non-fused PPS-rod instrumentation, only seven patients (21%) required implant removal or replacement. Conclusions: Non-fused PPS-rod placements into infection-free vertebrae alone or in combination with posterior debridement through a small incision worked effectively in providing local stabilization without contamination of the metal implant from the infected tissue. MIS LLIF allowed for direct access to the infected focus for bone grafting in cases of extensive vertebral body destruction.

Threshold-based Monitoring of Compound Muscle Action Potentials for Percutaneous Pedicle Screw Placement in the Lumbosacral Spine: Can We Rely on Stimulation of the Uninsulated Screw to Provide a Valid Safety Warning?

STUDY DESIGN: A prospective analysis. OBJECTIVE: To test if threshold-based monitoring of compound muscle action potentials (CMAPs) by stimulating the screw loaded to uninsulated extender sleeve provides a valid safety warning for percutaneous pedicle screw (PPS) placements in the lumbosacral spine. SUMMARY OF BACKGROUND DATA: Utility of the CMAP monitoring to PPS procedures remains controversial. METHODS: A series of 202 patients underwent a total of 1664 lumbosacral PPS placements under CMAP monitoring without fluoroscopic guidance. The monitoring consisted of stimulating the PPS assembled to uninsulated extender sleeve and recording CMAPs from the vastus medialis, biceps femoris, tibialis anterior, and medial gastrocnemius. Automated steps of a threshold hunting algorithm using 0.2-ms duration pulses of increasing intensities delivered at 2/s allowed quick determination of a minimum stimulation current to evoke >100-µV amplitude CMAPs. RESULTS: At L2 through S1 spines, postoperative CT scans identified 51 medial or inferior pedicle wall breaches of 1536 screws (3.3%) without neurologic complications. The receiver operating characteristic curve analysis determined the critical cutoff threshold value of 27 mA (74% sensitivity and 95% specificity) for predicting 35 breaches of 627 screws (5.6%) at L2 and L3, and of 17 mA (100% sensitivity and 98% specificity) for 16 of 909 (1.8%) at L4 through S1. While advancing the screw, three breaches (5.9%) showed a particularly low threshold of ≤6-mA, allowing the surgeon to immediately redirect the screw and retest the new trajectory as safe. CONCLUSION: Screw stimulation with threshold hunting algorithm has a distinct advantage over the time-consuming insulated pilot hole stimulation, allowing an uninterrupted flow of the surgery. The present findings have documented practical usefulness and reliability of CMAP monitoring using direct stimulation of the PPS assembled to uninsulated extender sleeve.

A new technique useful for lumbosacral percutaneous pedicle screw placement without fluoroscopy or computer-aided navigation systems.

BACKGROUND: Percutaneous pedicle screw (PPS) placements in the lumbosacral spine generally rely on fluoroscopy at the expense of radiation exposure. Our accumulated experience in open PS placements without fluoroscopic guidance realized a consistent shift toward PPS insertion with newly developed devices, which require neither fluoroscopy nor navigation. We wish to report our new technique and evaluations of its accuracy. METHODS: Our equipment consisted of a pedicle targeting tool to identify and escort the cannulated awl to the correct starting point for cortical bone perforation and a cannulated awl-probe system with a guidewire to maintain the optimal position throughout the subsequent surgical steps. The surgeon could advance the blunt-tipped probe searching for the cancellous bone track using tactile feedback as experienced in open techniques. A 2-year period of transition from a free-hand (1169 screws in 286 patients) to the new PPS technique (1933 screws in 413 patients) allowed accuracy comparison between the two procedures using postoperative CT scans. RESULTS: Compared with the open-group, the PPS-group showed a lower rate of fully contained intrapedicular PS placements at L1 through S1, as a whole (90.7% vs 85.4%), but not at L4 through S1 (89.9% vs 90.2%). Less-accurate PPS placements at upper than lower lumbar spines in part reflect intended pedicle perforations laterally as a trade-off for avoiding facet violation immediately above the most cephalad screw. The PPS-group also had a higher incidence of PS-related transient nerve root complications (0% vs 1.7%). These values for the PPS-group, however, fell within those previously reported for free-hand or fluoroscopy techniques. CONCLUSIONS: Our new PPS technique, although useful for eliminating the potential risk of repeated radiation exposure, fell short of reaching the accuracy of the free-hand technique. Nerve integrity monitoring with PS stimulation, which we currently use, will help further improve the technical precision. STUDY DESIGN: Original Article. The study was approved by our institutional review boad (2,019,231).

Minimally invasive endoscopic aortic valve replacement for alkaptonuria-associated severe aortic stenosis: a case report and literature review.

Alkaptonuria is an inherited metabolic disease caused by a genetic deficiency of homogentisate 1,2-dioxygenase and characterized by dark-brown connective tissue related to the deposition of oxidized homogentisic acid. Pigment deposition is also observed in the cardiovascular system, such as in the coronary arteries, cardiac valves, and aorta. Because aortic stenosis may develop secondary to pigment deposition-related calcification at the aortic valve, aortic valve replacement may be necessary for severe aortic valve disease. We report the case of a 75 year-old man with alkaptonuria-associated severe aortic stenosis who was successfully treated with minimally invasive endoscopic aortic valve replacement via right anterior minithoracotomy. The tricuspid aortic valve was severely calcified and both the valve and the aortic intima were ochronotic. No perioperative complications were observed and the postoperative course was uneventful.

[Successful Treatment of Ascending Aortic Graft Infection with a Rifampicin-soaked Vascular Prosthesis and Continuous Irrigation].

A 68-year-old woman underwent replacement of the ascending aorta for acute type A aortic dissection. She was then diagnosed with postoperative methicillin-resistant Staphylococcus aureus (MRSA) infection, and the infected aortic graft was replaced with a rifampicin-soaked vascular prosthesis, which was followed by continuous irrigation using a 0.1% povidone-iodine solution. The postoperative course was uneventful, and she has been doing well for 5 years with no recurrence of infection. Prosthetic graft replacement using a rifampicin-soaked graft followed by continuous irrigation with povidone-iodine is useful for treatment of an MRSA-infected prosthetic vascular graft.

[Native Valve Endocarditis due to Corynebacterium Striatum; Report of a Case].

We recently encountered a case of native valve endocarditis caused by Corynebacterium striatum (C. striatum) in the absence of immunosuppression and a prosthetic valve. A 49-year-old woman was urgently admitted for disturbance of consciousness and nosebleeds. Careful clinical examination revealed infective endocarditis caused by C. striatum, for which replacement of aortic and mitral valves was performed. The postoperative course was favorable, and we were able to save the patient with no postoperative complications. Detection of C. striatum may be recognized as contamination because this organism is a rare pathogen. However, elderly patients and patients with immunosuppression are rapidly increasing, and it is important to keep C. striatum in mind when Gram-positive bacilli are detected in the clinical examination.

Influence of tibial trancutaneous repetitive electrical nerve stimulation on neurogenic claudication and F-wave in lumbar spinal stenosis.

OBJECTIVES: To determine whether repetitive tibial nerve stimulation (RTNS) affects neurogenic claudication and F-wave conduction in lumbar spinal stenosis. DESIGN: An intervention study: before/after trial. SUBJECTS: Data for 12 central lumbar spinal stenosis patients were compared with 13 age- and sex-matched healthy volunteers. METHODS: A conditioning RTNS at the ankle, 0.3-ms duration square-wave pulses with an intensity 20% higher than the motor threshold, was applied at a rate of 5/s for 5 min. We assessed the effects of RTNS on the claudication distance at which the lumbar spinal stenosis patients can no longer continue walking due to increasing leg symptoms, and on tibial F-wave measurements. RESULTS: A comparison between mean pre-RTNS and post-RTNS revealed a significant difference in claudication distance (66 m (standard deviation (SD) 19) vs 133 m (SD 37); p = 0.003), mean F-wave minimal latency (48.3 ms (SD 1.7) vs 44.8 ms (SD 1.0); p = 0.007) and mean F-wave conduction velocity (53.3 m/s (SD 2.0) vs 55.5 m/s (SD 1.9); p = 0.009) in the lumbar spinal stenosis group, but not in the control group. CONCLUSION: RTNS has beneficial effects on neurogenic claudication and F-wave conduction in central lumbar spinal stenosis patients. This phenomenon may have practical value in providing a new therapeutic modality for lumbar spinal stenosis.

Circumaortic left renal vein associated with juxtarenal abdominal aortic aneurysm.

The patient was an 82-year-old man who was found to have a juxtarenal abdominal aortic aneurysm accompanied by a circumaortic left renal vein (CLRV). During dissection of the proximal anastomosis site the CLRV was injured, but was successfully repaired. A graft implantation was performed below the renal arteries. The incidence of CLRV is thought to be rare, however it is found in 7% of cadavers donated for anatomy. CLRV may cause unexpected bleeding by inadvertent dissection of the abdominal aorta. To prevent unexpected bleeding, surgeons should always keep in mind this potential risk when performing surgery.

Pharmacokinetics of linezolid in the mediastinum and pleural space.

The purpose of this study was to investigate the penetration of linezolid into the mediastinum and pleural space by comparing its concentration in the serum, mediastinum, and pleural space. The linezolid area under the concentration-versus-time curve from zero to 12h (AUC)(mediastinum fluid/serum) and AUC(pleural fluid/serum) ratio were 1.32 and 1.64, respectively. The results suggest that the linezolid concentration in the mediastinum varies as in the serum, and that the concentration in the mediastinum is the same as or greater than that in the serum.

Usefulness of multi-channels in intraoperative spinal cord monitoring: multi-center study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

OBJECT: The purpose of this study is to analyze the data in terms of the number of channels employed to examine the usefulness of multi-channels in intraoperative spinal cord monitoring. METHODS: The prerequisites for inclusion in the baseline data were as follows: (1) cases in which only CMAP monitoring was conducted; (2) cases in which monitoring was conducted under the same stimulation condition and the recording condition. Cases where inhalation anesthesia was used or muscle relaxants were used as maintenance anesthesia was excluded from the baseline data. Of the 6,887 cases, 884 cases met the criteria. The items examined for each of the different numbers of channels were the sensitivity and specificity, the false positive rate, the false negative rate, and the coverage rate of postoperative motor deficit muscles. RESULT: To examine these two items in terms of the number of channels, the 4-channel group had lower sensitivity and specificity scores compared with the 8- and 16-channel groups (4 channels 73/93 %, 8 channels 100/97 %, 16 channels 100/95 %). Only four channels were derived for these cases and the coverage of postoperative motor deficit muscles was 38 % with only 30 out of the 80 postoperative motor deficit muscles in total being monitored. In the 8-channel group, it was 60 % with 12 of the 20 postoperative motor deficit muscles being monitored. The 16-channel group had 100 % coverage rate of postoperative motor deficit muscles. CONCLUSION: We suggest that multi-channel monitoring of at least eight channels is desirable for intraoperative spinal cord monitoring.

Toward the rational use of standardized infection ratios to benchmark surgical site infections.

BACKGROUND: The National Healthcare Safety Network transitioned from surgical site infection (SSI) rates to the standardized infection ratio (SIR) calculated by statistical models that included perioperative factors (surgical approach and surgery duration). Rationally, however, only patient-related variables should be included in the SIR model. METHODS: Logistic regression was performed to predict expected SSI rate in 2 models that included or excluded perioperative factors. Observed and expected SSI rates were used to calculate the SIR for each participating hospital. The difference of SIR in each model was then evaluated. RESULTS: Surveillance data were collected from a total of 1,530 colon surgery patients and 185 SSIs. C-index in the model with perioperative factors was statistically greater than that in the model including patient-related factors only (0.701 vs 0.621, respectively, P < .001). At one particular hospital, for which the percentage of open surgery was lowest (33.2%), SIR estimates changed considerably from 0.92 (95% confidence interval: 0.84-1.00) for the model with perioperative variables to 0.79 (0.75-0.85) for the model without perioperative variables. In another hospital with a high percentage of open surgery (88.6%), the estimate of SIR was decreased by 12.1% in the model without perioperative variables. CONCLUSION: Because surgical approach and duration of surgery each serve as a partial proxy of the operative process or the competence of surgical teams, these factors should not be considered predictive variables.

Surgical experience with chronic constrictive pericarditis.

OBJECTIVE: Constrictive pericarditis is a disease characterized by marked thickening of the pericardium which causes restriction of diastolic cardiac function. The purpose of this report is to review the outcome of pericardiectomy for constrictive pericarditis and to discuss its problems. METHODS: Sixteen consecutive patients who underwent pericardiectomy for constrictive pericarditis in our institution between March 2000 and June 2011 were reviewed. All patients underwent decortication including at least the anterior surface from the right atrium to the left phrenic nerve and the diaphragmatic surface of the heart. The epicardium was concomitantly resectioned because it was usually sclerotic and constrictive. RESULTS: Postoperatively, mean central venous pressure decreased to 8.8 ± 3.1 mmHg and was significantly lower than the preoperative value 15.3 ± 3.7 mmHg (p < 0.001). The mean postoperative duration of hospitalization was 25.6 ± 13.5 days. There were 2 in-hospital deaths and early mortality rate was 12.5 %; however, excluding hospital deaths, there were no significant postoperative complications and all survivors recovered and maintained good cardiac function during the mean follow-up period of 3.7 ± 2.8 years. CONCLUSION: For an acceptable outcome, surgical intervention should be performed at an appropriate time and the pericardiectomy should have proper scope and depth to prevent irreversible changes in the heart, liver, and other organs.

Twelve years of experience with the ATS mechanical heart valve prostheses.

OBJECTIVE: The ATS Open Pivot mechanical heart valve has been implanted routinely at our institution since 1999. The objective of this study is to retrospectively analyze our 12-year clinical results with ATS prostheses. METHODS: ATS Open Pivot mechanical valves were implanted in 268 adult patients between May 1999 and August 2010. We selected 259 subjects who could be adequately followed (follow-up rate 96.6 %). Aortic valve replacement was performed in 157 patients, mitral valve replacement (MVR) in 71, and double (aortic and mitral) valve replacements (DVR) in 31. Mean age at the time of implant was 58.8 ± 10.6 years. The gender ratio was 128 males/131 females. Mean follow-up was 4.4 ± 7.8 years, and the cumulative follow-up was 1144 patient-years (pt-yr). RESULTS: Early death within 30 days after the operation occurred in 5 (2.5 %) patients. Late death occurred in 27 patients including valve-related deaths in 13. The 10-year survival rate after the operation was 82.7 ± 2.9 %. The rate of freedom from valve-related death was 92.2 ± 2.2 %. The incidence of valve-related complications was 2.19 %/pt-yr. Of these, the incidence of thromboembolic events and that of bleeding complications were 1.22 and that 0.87 %/pt-yr. The incidence of valve thrombosis was 0.09 %/pt-yr. No structural valve deterioration was observed in any of the three operative procedure groups. CONCLUSIONS: Our 12-year experience with aortic and MVR using the ATS mechanical heart valve demonstrated low incidences of thromboembolic events, bleeding complications, and valve thrombosis.

Survival and quality of life of octogenarians who underwent mechanical valve replacement at a younger age.

PURPOSE: Mechanical valve replacement is associated with complications, however, there is little information on the quality of life (QOL) of octogenarians who had undergone mechanical valve replacement at a relatively younger age. We examined survival, valve-related events, and the QOL of octogenarians who had undergone mechanical valve replacement. METHODS: A total of 56 octogenarians who underwent mechanical valve replacement between 1969 and 1997 (age at the time of surgery, 65.6 ± 6.7 years), completed a questionnaire on survival, valve-related events, and QOL (basic activities of daily living, instrumental activities of daily living, mental health). RESULTS: The mean follow-up was 12.4 ± 6.6 years, and the cumulative follow-up period was 642.4 patient-years. Six valve-related deaths (0.9%/patient-year) were registered during the follow-up. Furthermore, 11 valve-related events (1.8%/patient-year) were recorded. The mean age of the 21 survivors was 82.9 ± 1.8 years, and 19 of the survivors lived at home. Their QOL was excellent. CONCLUSION: The valve-related deaths and events in octogenarians who had previously undergone mechanical valve replacement at a younger age were within acceptable limits. The QOL was similar to that of octogenarians described in previous studies.

Systolic anterior motion after mitral valve repair: predicting factors and management.

PURPOSE: The aim of this study was to determine the mechanism of systolic anterior motion (SAM) after mitral valve (MV) repair by analyzing the clinical data of patients with MV repair. METHODS: A total of 104 MV repairs were performed for patients with isolated degenerative posterior leaflet prolapse. Eight patients (7.7%) developed SAM with severe mitral regurgitation. We compared the preoperative and intraoperative findings of the two groups (8 patients in the SAM group, 96 in the non-SAM group) and reported the clinical courses of the SAM patients. RESULTS: Preoperative left ventricular end-diastolic and end-systolic diameters were significantly smaller and the preoperative left ventricular ejection fraction was significantly greater in the SAM group than in the non-SAM group. The number of patients with a sigmoid septum and the number with anterior leaflet-septal contact (LSC) during diastole were significantly larger in the SAM group. Incidence of billowing posterior leaflet, prolapsed segments, and operative techniques were comparable for the two groups. SAM improved with correction of hemodynamic status in four patients. In four other patients secondary cardiopulmonary bypass was required to resolve SAM. SAM resolved with additional repairs in two patients, whereas the other two required MV replacement. Of the six patients in whom conservative treatment or re-repair was successful, one had recurrent SAM 3 months after surgery. CONCLUSION: The sigmoid septum and LSC may predict SAM after MV repair. A strict follow-up is imperative for patients with persistent or recurrent SAM.

A case of pulmonary infective endarteritis associated with patent ductus arteriosus: surgical closure under circulatory arrest.

A 35-year-old man was admitted to the hospital with prolonged high-grade fever. Chest computed tomography revealed multiple pulmonary infiltrations in both lungs, suggesting septic emboli. Echocardiography revealed patent ductus arteriosus and mobile large vegetations in the pulmonary artery. Because of uncontrollable infection and the imminent possibility of massive pulmonary embolism, he underwent transpulmonary surgical closure of the ductus and resection of the vegetations under hypothermic circulatory arrest using cardiopulmonary bypass. We report a rare case of open heart surgery in a patient with pulmonary infective endarteritis associated with patent ductus arteriosus.

Primary cardiac osteosarcoma with imaging that revealed no calcification.

Osteosarcoma is a rare primary cardiac malignancy. Calcification on imaging is crucial to differentiating osteosarcoma, but we encountered a case that was difficult to diagnose because imaging revealed no calcification. A 67-year-old man was admitted for heart failure. Echocardiography demonstrated mitral regurgitation and a mass in the left atrium. A cardiac malignancy was suspected. Computed tomography revealed no calcification. Operation was performed, and histopathological examination identified the tumor as an osteosarcoma.

Surgical treatment for chronic type A aortic dissection and aortic regurgitation in a patient with a tracheostoma.

We successfully performed aortic root replacement and partial aortic arch replacement by a T-shaped sternotomy at the second intercostal space in a patient who had undergone tracheotomy for respiratory insufficiency and cardiac failure caused by methicillin-resistant Staphylococcus aureus pneumonia during preservation treatment of chronic type A aortic dissection and aortic regurgitation.

Neurological complications of cervical laminoplasty for patients with ossification of the posterior longitudinal ligament-a multi-institutional retrospective study.

STUDY DESIGN: Retrospective multi-institutional study. OBJECTIVE: To investigate the incidence of neurological deficits after cervical laminoplasty for ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: According to analysis of long-term results, laminoplasty for cervical OPLL has been reported as a safe and effective alternative procedure with few complications. However, perioperative neurological complication rates of laminoplasty for cervical OPLL have not been well described. METHODS: Subjects comprised 581 patients (458 men and 123 women; mean age: 62 ± 10 years; range: 30-86 years) who had undergone laminoplasty for cervical OPLL at 27 institutions between 2005 and 2008. Continuous-type OPLL was seen in 114, segmental-type in 146, mixed-type in 265, local-type in 24, and not judged in 32 patients. Postoperative neurological complications within 2 weeks after laminoplasty were analyzed in detail. Cobb angle between C2 and C7 (C2/C7 angle), maximal thickness, and occupying rate of OPLL were investigated. Pre- and postoperative magnetic resonance imaging was performed on patients with postoperative neurological complications. RESULTS: Open-door laminoplasty was conducted in 237, double-door laminoplasty in 311, and other types of laminoplasty in 33 patients. Deterioration of lower-extremity function occurred after laminoplasty in 18 patients (3.1%). Causes of deterioration were epidural hematoma in 3, spinal cord herniation through injured dura mater in 1, incomplete laminoplasty due to vertebral artery injury while making a trough in 1, and unidentified in 13 patients. Prevalence of unsatisfactory recovery not reaching preoperative level by 6-month follow-up was 7/581 (1.2%). Mean occupying rate of OPLL for patients with deteriorated lower-extremity function was 51.2 ± 13.6% (range, 21.0%-73.3%), significantly higher than the 42.3 ± 13.0% for patients without deterioration. OPLL thickness was also higher in patients with deterioration (mean, 6.6 ± 2.2 mm) than in those without deterioration (mean, 5.7 ± 2.0 mm). No significant difference in C2/C7 lordotic angle was seen between groups. CONCLUSION: Although most neurological deterioration can be expected to recover to some extent, the frequency of short-term neurological complications was higher than the authors expected.

Ruptured thoracic descending aortic aneurysm coexisting with DeBakey type IIIb aortic dissection.

We have encountered a rare case of ruptured true thoracic aortic aneurysm coexisting with DeBakey type IIIb aortic dissection. The patient was a 67-year-old woman who had a past history of hypertension and cerebral infarction. She experienced DeBakey type IIIb acute aortic dissection, and initially conservative medical treatment was carried out. However, the patient suddenly went into shock, and emergency contrast-enhanced computed tomography revealed the presence of a ruptured true thoracic aortic aneurysm coexisting with the type IIIb dissection. Replacement of the descending aorta was performed through a left thoracotomy using circulatory arrest and deep hypothermia. The rupture site and intimal tear were located in the middle of the aneurysm. Open proximal and distal anastomoses were carried out using a 22 × 10 mm gelatin-covered Dacron graft. The patient was discharged from our hospital uneventfully on the 33rd postoperative day.