Initial experience using middle meningeal artery embolisation for patients with recurrent and high-recurrence-risk chronic subdural haematoma.

Recurrence rates following surgical management of chronic subdural haematoma (CSDH) range from 5 to 33 %. There is growing evidence which suggests middle meningeal artery embolisation (MMAe) may reduce recurrence rates when used as surgical adjunct or standalone treatment. In this study we described our experience of this new procedure in the our UK institution. Patients with recurrent CSDH or CSDH at high risk of recurrence were selected for MMAe on a case-by-case basis following MDT discussion. A departmental database was used to identify patients treated. 26 CSDH were embolised in 20 patients; 9 CSDH were de-novo and 17 were recurrent. 10/26 CSDH were treated with MMAe only. No procedural mortality, access site or thrombo-embolic complications occurred. One patient experienced symptomatic collection growth 12 h following MMAe and required surgical drainage. 15 (75 %) of patients were living at home at follow-up (mean 14 months). On imaging follow-up 15/18 showed CSDH volume reduction or resolution, 1/18 remained stable requiring no further treatment, 2/18 patients suffered recurrent CSDH requiring treatment. In both recurrent cases incomplete embolisation was noted on procedural imaging (posterior division of MMA not embolised). Persistent posterior MMA division filling was significantly associated with collection recurrence (p = 0.002). Our results suggest MMAe as a stand-alone or adjuvant therapy can be performed safely in a UK neuroscience setting and is associated with high rates of symptomatic CSDH size reduction or resolution in problematic CSDH that have either recurred or are prone to recurrence.

Subtherapeutic ganciclovir (GCV) levels and GCV-resistant cytomegalovirus in lung transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) infection results in significant morbidity and mortality in lung transplant recipients. Ganciclovir (GCV) has dramatically reduced complications caused by CMV infections. Unfortunately, GCV resistance is identified in 5-10% of CMV-infected patients. Mismatched CMV status and ongoing replication due to immunosuppression are risk factors for drug resistance. Whether subtherapeutic GCV levels contribute to resistance remains unknown. METHODS: A retrospective review was conducted in all 51 patients who underwent lung transplantation between March 2007 and June 2008 at Loyola University Medical Center. GCV resistance and outcome data of CMV-infected patients were analyzed to identify variables that may contribute to suboptimal response to CMV infection. RESULTS: During the 16-month period, CMV infection was identified in 21 of 51 lung transplant recipients. Ten of 21 patients (47.6%) had CMV infection with early response to GCV, and 11 patients (52.4%) had CMV infection with suboptimal response to GCV. GCV levels were obtained in the 11 CMV-infected patients with suboptimal response. In 6 patients, GCV levels were therapeutic; all 6 had delayed response to GCV. In 5 patients, GCV levels were subtherapeutic; each had persistent suboptimal response to GCV. Genotyping documented GCV-resistant (GCV-R) CMV in all 5 patients. Cystic fibrosis as the diagnosis requiring lung transplantation was associated with GCV-R CMV infection (P = 0.01). CONCLUSION: In our lung transplant recipient cohort, GCV levels were subtherapeutic in all patients with persistent suboptimal response to GCV, each of whom had GCV-R CMV infection. In contrast, GCV levels were therapeutic in CMV-infected patients with delayed GCV response.

Successful emergent lung transplantation after remote ex vivo perfusion optimization and transportation of donor lungs.

A recent clinical trial provided evidence that ex vivo lung perfusion (EVLP) results in optimized human donor lungs for transplantation. Excellent recipient outcomes were documented after 4 h of normothermic perfusion. We report a clinical case utilizing remote EVLP to assess and improve function of initially otherwise unacceptable injured donor lungs followed by transportation and subsequent bilateral lung transplantation in a patient with virally induced refractory respiratory failure supported with extracorporeal membrane oxygenation. This is the first lung transplantation with the application of remote EVLP, wherein the donor lungs were transported from the donor hospital to a center for EVLP and then transported to another hospital for transplantation. It is also the first case of lung transplantation in the United States utilizing EVLP for functional optimization leading to successful transplantation. Organ procurement data, EVLP assessment, and the pre- and postoperative course of the recipient are presented. The available evidence supporting EVLP, the humanitarian and cooperative utilization of lungs otherwise discarded, are discussed.

Morgagni hernia presenting with bowel obstruction in a lung transplant recipient: case report.

Morgagni hernias are uncommon congenital diaphragmatic deficiencies that may remain asymptomatic till adulthood. We report a case of Morgagni hernia presenting with subacute bowel obstruction in a bilateral lung transplant recipient. This diaphragmatic deficiency was not evident during bilateral lung transplantation surgery via clamshell incision. To our knowledge this is the first report of a congenital defect evident after lung transplantation.

Mitral valve dysfunction and repair following orthotopic heart transplantation: a case report.

Mitral valve dysfunction after orthotopic heart transplantation may cause symptoms refractory to medical therapy. In this report, we present a patient who underwent mitral annuloplasty for severe symptomatic mitral valve insufficiency 9 years after heart transplantation, and we critically appraise the literature available for mitral valve dysfunction in this setting. Mitral valve repair, when feasible, should be considered for mitral insufficiency after transplantation to improve functional status and reduce the risk of retransplantation--this is particularly prudent in view of chronic donor shortage.

Early hemodynamic injury during donor brain death determines the severity of primary graft dysfunction after lung transplantation.

Sympathetic discharge and hypertensive crisis often accompany brain death, causing neurogenic pulmonary edema. Progressive systemic inflammatory response develops, which can injure the lung further. We investigated whether (a) early hemodynamic injury during donor brain death increases reperfusion injury after lung transplantation and (b) delaying lung recovery would augment reperfusion injury further, because of the progressive systemic inflammatory response in the donor. Brain death was induced by intracranial balloon inflation in rats, with or without alpha-adrenergic blockade pretreatment to prevent the hypertensive crisis. Another group of rats had a sham procedure. Lungs were retrieved 15 min after brain death or sham procedure and reperfused using recipient rats. In a fourth group, brain death was induced and the lungs were retrieved 5 h after brain death and reperfused. Postreperfusion, lungs retrieved early from untreated brain-dead donors developed more severe reperfusion injury, as assessed by functional parameters and inflammatory markers, than those from sham or alpha-blockade-treated donors. Lungs retrieved late from brain-dead donors had similar inflammatory markers after reperfusion to those retrieved early, but significantly lower pulmonary vascular resistance. Early hemodynamic damage during donor brain death increases reperfusion injury after lung transplantation. Delaying retrieval may allow the lung to recover from the hemodynamic injury.

Impact of donor and recipient factors on allograft survival in lung transplantation: A single-center analysis.

BACKGROUND: It remains unclear which donor and recipient factors influence long-term allograft function in lung transplantation (LTx). METHODS: From October 1988 to February 2005, a total of 280 recipients underwent LTx at our center. Donor data and cause of death (CoD) were analyzed. The CoD was categorized according to rate of increase in intracranial pressure at the time of death. Each donor and recipient factor was correlated with long-term graft function. Recipient details, type of transplant, indication for transplant, and time on waiting list were analyzed. Recipients were stratified based on allograft ischemia time (AIT): 0 to 6, 6 to 8, 8 to 10, and >10 hours. RESULTS: Mean donor age was 30.9 years (36.7% male); 49.8% were cytomegalovirus (CMV) positive. Donor CoD was characterized by a slow rise in intracranial pressure (ICP) in 34.4%, rapid ICP in 18.7%, an intermediate ICP in 44.3%, and with no rise in 2.6%. A graft survival benefit was seen with female donors (P = .048); 34.4% of recipients ultimately developed graft failure at long term follow-up. Mean recipient age was 48 years; 63% were male and mean body-mass index (BMI) was 23.6; 60.2% had single lung transplantation, and mean wait list time was 323 days. Mean AIT totaled 421 minutes. Graft survival was longer with AIT of 8 to 10 hours compared to 6 to 8 hours (P = .03). CONCLUSIONS: Donor factor analysis implied only female donor status conferred a long-term graft survival advantage. Intracranial pressure rise differences appear clinically unimportant. Prolonged cold ischemic time (>10 hours) or low recipient BMI did not adversely affect allograft function in our review.

Clinical experience with porous tantalum cervical interbody implants in a prospective randomized controlled trial.

A prospective randomized study was undertaken to evaluate the radiological appearance and clinical effectiveness of two porous tantalum (Hedrocel) implants in achieving a stable cervical interbody fusion. A prerandomization protocol was used to allocate patients to the three arms of the study: a ring implant containing autologous cancellous bone graft, a solid block implant or autologous tricortical iliac crest bone graft. Patients were followed for 2 years with plain radiological studies, SF-36, and Neck Disability Index questionnaires and neurological assessment. Early in the study the postoperative radiographs of four patients receiving Hedrocel implants showed inferior end-plate lucency raising concerns about delayed or non-fusion. Recruitment to the study was halted by the investigators to allow longer-term follow-up of the implanted patients when only 24 patients had been recruited to the study. Although fusion was subsequently noted in all patients at 12 months there was no further enrolment to the study. At 2 years the radiological and clinical outcomes of the three groups appeared comparable, but the study numbers were too small for any statistical analysis. This study highlights the difficulties that can arise when clinical caution takes precedence over objective measures of clinical progress during a study. In the absence of an independent safety monitoring committee, the investigators were under an ethical obligation to suspend recruitment to this study, until it was clear that the radiological features were not associated with poor clinical outcomes. The use of safety monitoring committees and the clarification of stopping criteria in relation to outcome measures should be considered in open randomized trials of spinal surgical techniques and implants.

Metastatic adenocarcinoma masquerading as a solitary nerve sheath tumour.

We present a case of a solitary metastasis of an adenocarcinoma to a dorsal root ganglion (DRG) following a disease free interval of 12 years after resection of a Duke's C carcinoma. The presentation of this unusually placed metastasis was associated with a 3-year complex pain syndrome and radiological appearances consistent with benign disease. The case highlights the importance of not dismissing unusual lesions as innocent in the presence of a history of malignant disease.

A technique for frameless stereotaxy and placement of transarticular screws for atlanto-axial instability in rheumatoid arthritis.

The aim of the present study was to outline a new surgical technique and describe how, in a clinical setting, computer-generated image-guidance can assist in the planning and accurate placement of transarticular C1/C2 screws inserted using a minimally invasive exposure. Forty-six patients with atlanto-axial instability due to rheumatoid arthritis underwent posterior stabilisation with transarticular screws. This was achieved with a minimal posterior exposure limited to C1 and C2 and percutaneous screw insertions via minor stab incisions. The Stealth Station (Medtronic Sofamor Danek, Memphis, Tenn., USA) was used for image guidance to navigate safely through C2. Reconstructed computed tomographic (CT) scans of the atlanto-axial complex were used for image guidance. It was possible to perform preoperative planning of the screw trajectory taking into account the position of the intraosseous portion of the vertebral arteries, the size of the pars interarticularis and the quality of bone in C2. Screws could be inserted percutaneously over K-wires using a drill guide linked to the image-guidance system. Preoperative planning was performed in all 46 patients and accurate registration allowed proposed screw trajectories to be identified. Thirty-eight patients had bilateral screws inserted and eight had a unilateral screw. A total of 84 screws were inserted using the Stealth Station. There were no neurovascular injuries. This technique for placing transarticular screws is accurate and safe. It allows a minimally invasive approach to be followed. Image guidance is a useful adjunct for the surgeon undertaking complex spinal procedures.

Nonautologous interbody fusion materials in cervical spine surgery: how strong is the evidence to justify their use?

STUDY DESIGN: A review of the literature concerning the use of interbody fusion devices and materials in anterior cervical surgery. OBJECTIVES: To examine the evidence supporting the use of interbody fusion devices as an alternative to autologous bone after anterior cervical discectomy. SUMMARY OF BACKGROUND DATA: Concerns over the morbidity associated with harvesting autologous bone and the risk of transmissible infectious from allografts and xenografts have prompted the search for alternative methods of achieving interbody fusion. Several of these methods have been associated with an unacceptable rate of complications. The clinical and health economic implications of the widespread introduction of interbody fusion devices in the absence of sound evidence cannot be ignored. METHODS: A systematic review of the literature relating to cervical interbody fusion was undertaken. Studies were assessed critically with respect to their methodology, results, and conclusions. RESULTS: Thirty-two clinical studies and 10 laboratory studies were analyzed. Methodologic weaknesses were identified in the majority. Only four clinical reports were either randomized or blinded or involved independent assessment of their outcomes. Fewer than half of the studies included a valid statistical analysis. Radiologic evidence of fusion was limited in many cases. There was little evidence that nonautologous fusion devices offered a reduction in the length of hospital stay. Autologous bone was as effective as, or superior to, many other fusion devices. The early results of some new fusion techniques used alone or in combination showed promise. CONCLUSIONS: There is limited evidence supporting the use of a cervical interbody fusion device in place of autologous bone. There is a need to standardize the testing of implants with good quality laboratory work preceding clinical use. Certain devices including cages, some forms of hydroxyapatite, and bone morphogenic proteins merit further study.

Image-guided surgery: applications to the cervical and thoracic spine and a review of the first 120 procedures.

OBJECT: The authors undertook a study to demonstrate that frameless stereotaxy can be applied safely to the cervical and thoracic spine to minimize complications and associated morbidity. METHODS: A retrospective review of cases was conducted involving the use of an image-guidance system for the accurate placement of surgical implants or for resection of lesions within the cervical and thoracic spine. The outcome measures considered were neural injury, vascular injury, wound infection, surgical revision, and death. CONCLUSIONS: Image-guidance systems are useful intraoperative tools that can be applied accurately to spinal surgery. In addition, such systems can be of great use in the preoperative planning of complex spinal surgery.

Frameless stereotaxy and anterior cervical surgery.

OBJECTIVE: The role of a frameless image guidance system for anterior cervical surgery was evaluated in 40 patients with cervical spondylosis. An assessment was made of the challenges posed in achieving accurate three-dimensional image registration in the absence of multiple fixed anatomical landmarks, and a solution to this problem is outlined using a novel registration tracking device. MATERIALS AND METHODS: Patients underwent preoperative CT scanning of the surgical field of interest, and the image data was reconstructed on a StealthStation (Sofamor Danek, Memphis, Tennessee, USA). An image guidance tracking device was attached to a modified Caspar retractor. Point matching and surface mapping were used for registration. RESULTS: It was not possible to achieve accurate registration in the first 7 patients. In the next 5 patients, the time taken to achieve registration was prolonged. For 28 patients, registration was achieved in an acceptable time with an accuracy of 0.74 +/- 0.4 mm. Anatomical resection margins were accurately identified and 36 anterior cervical screws were precisely placed. CONCLUSIONS: Frameless stereotaxy can now be applied to procedures involving the anterior cervical spine. Potential benefits include accurate definition of the anatomy, demonstration of resection margins, and intraoperative guidance. The technique may prove particularly useful in cases of complex or disrupted anatomy.

The influence of the ventrolateral medulla on thermoregulatory circulations in the rat.

The rostral ventrolateral medulla (RVLM) was stimulated electrically and chemically (0.1-0.2 microliter, 0.4 M DL-homocysteic acid) in urethane-anaesthetised rats. Changes in the vasomotor tone of the cutaneous circulation of the tail, front and hind feet, the nose and the fur covered areas of the back, proximal hind leg and neck were assessed indirectly by measurement of skin temperatures. Electrical stimulation of the RVLM at 25 Hz (2-5 min) produced sustained decreases in skin temperatures and differed from the effect induced by stimulation at 100 Hz or chemical stimulation, in that the concomitant increases in blood pressure and respiration, as well as the accompanying bradycardia or tachycardia, were minimal and within 10-15% of basal control levels. In the hyperthermic animal changes in the skin temperatures of the tail and feet were observed on stimulation of sites lateral to the rostral third of the inferior olive (IO) and which extended through the nuc. paragigantocellularis lateralis to an area medial to the caudal half of the facial nucleus (FN). There was some degree of topographical organisation with the front and hind feet areas overlying the more extensive tail area in a rostro-caudal orientation. The representation of the other areas of the body was more limited. Neck and nose temperatures changed on stimulation of a small area of the RVLM adjacent to the caudal pole of FN, while the skin of the back and upper hind limb responded to stimulation of a limited area lateral to the rostral pole of IO. The unequal representation of the cutaneous surface probably reflects the degree of vascularisation and the importance of the tail and plantar foot surfaces in thermoregulatory responses.

Changes in the tail surface temperature of the rat following injection of 5-hydroxytryptamine into the ventrolateral medulla.

5-Hydroxytryptamine (5-HT) was injected into the rostral ventrolateral medulla (RVLM) in urethane-anaesthetized rats and its effect assessed on thermoregulatory and non-thermoregulatory cutaneous circulations by the measurement of skin surface temperatures. 5-Hydroxytryptamine (5-50 nmol) produced a dose-related fall in blood pressure (5-20 mmHg) and an increase in tail and plantar foot surface temperatures, indicative of dilatation in the underlying cutaneous circulations. If heat was not applied to the animal, the body temperature fell by 1-2 degrees C within 15-25 min. The decrease in tail and foot temperatures, produced by low frequency (25 Hz, 5 min) electrical stimulation, was antagonized by the injection of 5-HT at the site of stimulation. 5-Carboxyamidotryptamine (2.5-20 nmol) and flesinoxan (5-25 nmol) produced responses similar to 5-HT. The 5-HT2 receptor agonist, alpha-methyl 5-hydroxytryptamine (alpha-methyl 5-HT, 5.5-100 nmol) was only effective in increasing tail and plantar foot temperatures, at dose levels above 25 nmol. However, in a few sites restricted to the anterior region of the RVLM, alpha-methyl 5-HT (11 nmol) evoked a small decrease in tail and foot temperatures, indicative of a constrictor effect, without influencing resting cardiovascular parameters. The results are discussed in relation to the central mechanisms which underly the hypothermia and hyperthermia produced by 5-HT1A and 5-HT2 receptor agonists.