Vafi Salmasi

Relationship between Intraoperative Hypotension, Defined by Either Reduction from Baseline or Absolute Thresholds, and Acute Kidney and Myocardial Injury after Noncardiac Surgery: A Retrospective Cohort Analysis.

Background: How best to characterize intraoperative hypotension remains unclear. Thus, the authors assessed the relationship between myocardial and kidney injury and intraoperative absolute (mean arterial pressure [MAP]) and relative (reduction from preoperative pressure) MAP thresholds. Methods: The authors characterized hypotension by the lowest MAP below various absolute and relative thresholds for cumulative 1, 3, 5, or 10 min and also time-weighted average below various absolute or relative MAP thresholds. The authors modeled each relationship using logistic regression. The authors further evaluated whether the relationships between intraoperative hypotension and either myocardial or kidney injury depended on baseline MAP. Finally, the authors compared the strength of associations between absolute and relative thresholds on myocardial and kidney injury using C statistics. Results: MAP below absolute thresholds of 65 mmHg or relative thresholds of 20% were progressively related to both myocardial and kidney injury. At any given threshold, prolonged exposure was associated with increased odds. There were no clinically important interactions between preoperative blood pressures and the relationship between hypotension and myocardial or kidney injury at intraoperative mean arterial blood pressures less than 65 mmHg. Absolute and relative thresholds had comparable ability to discriminate patients with myocardial or kidney injury from those without. Conclusions: The associations based on relative thresholds were no stronger than those based on absolute thresholds. Furthermore, there was no clinically important interaction with preoperative pressure. Anesthetic management can thus be based on intraoperative pressures without regard to preoperative pressure.

Intraoperative Core Temperature Patterns, Transfusion Requirement, and Hospital Duration in Patients Warmed with Forced Air

Background:Core temperature patterns in patients warmed with forced air remain poorly characterized. Also unknown is the extent to which transient and mild intraoperative hypothermia contributes to adverse outcomes in broad populations. Methods:We evaluated esophageal (core) temperatures in 58,814 adults having surgery lasting >60 min who were warmed with forced air. Independent associations between hypothermic exposure and transfusion requirement and duration of hospitalization were evaluated. Results:In every percentile subgroup, core temperature decreased during the first hour and subsequently increased. The mean lowest core temperature during the first hour was 35.7 ± 0.6°C. Sixty-four percent of the patients reached a core temperature threshold of <36°C 45 min after induction; 29% reached a core temperature threshold of <35.5°C. Nearly half the patients had continuous core temperatures <36°C for more than an hour, and 20% of the patients were <35.5°C for more than an hour. Twenty percent of patients had continuous core temperatures <36°C for more than 2 h, and 8% of the patients were below 35.5°C for more than 2 h. Hypothermia was independently associated with both transfusions and duration of hospitalization, although the prolongation of hospitalization was small. Conclusions:Even in actively warmed patients, hypothermia is routine during the first hour of anesthesia. Thereafter, average core temperatures progressively increase. Nonetheless, intraoperative hypothermia was common, and often prolonged. Hypothermia was associated with increased transfusion requirement, which is consistent with numerous randomized trials.

Establishment and characterization of a primary human chordoma xenograft model.

OBJECT Chordomas are rare tumors arising from remnants of the notochord. Because of the challenges in achieving a complete resection, the radioresistant nature of these tumors, and the lack of effective chemotherapeutics, the median survival for patients with chordomas is approximately 6 years. Reproducible preclinical model systems that closely mimic the original patients tumor are essential for the development and evaluation of effective therapeutics. Currently, there are only a few established chordoma cell lines and no primary xenograft model. In this study, the authors aimed to develop a primary chordoma xenograft model. METHODS The authors implanted independent tumor samples from 2 patients into athymic nude mice. The resulting xenograft line was characterized by histopathological analysis and immunohistochemical staining. The patients tumor and serial passages of the xenograft were genomically analyzed using a 660,000 single-nucleotide polymorphism array. RESULTS A serially transplantable xenograft was established from one of the 2 patient samples. Histopathological analysis and immunohistochemical staining for S100 protein, epithelial membrane antigen, and cytokeratin AE1/AE3 of the primary patient sample and the xenografts confirmed that the xenografts were identical to the original chordoma obtained from the patient. Immunohistochemical staining and western blot analysis confirmed the presence of brachyury, a recently described marker of chordomas, in the tumor from the patient and each of the xenografts. Genome-wide variation was assessed between the patients tumor and the xenografts and was found to be more than 99.9% concordant. CONCLUSIONS To the best of their knowledge, the authors have established the first primary chordoma xenograft that will provide a useful preclinical model for this disease and a platform for therapeutic development.

Expanded endonasal endoscopic approach for resection of a large skull base aneurysmal bone cyst in a pediatric patient with extensive cranial fibrous dysplasia

Aneurysmal bone cysts (ABCs) are uncommon non-neoplastic, hemorrhagic, and expansile osseous lesions. These lesions most commonly occur in the first two decades of life and affect the long bones and spinal column. Skull base involvement is rare. The authors report the case of a 16-year-old boy who presented with acute visual decline and was found to have a large skull base ABC centered in the sphenoid sinus. In addition, the patient had extensive cranial fibrous dysplasia. The patient underwent a staged expanded endonasal endoscopic approach for complete resection of this lesion with excellent return of his vision. This case adds to the growing body of evidence supporting a role for expanded endonasal endoscopic procedures in pediatric patients with skull base pathologies.

NY-ESO-1 Expression in Meningioma Suggests a Rationale for New Immunotherapeutic Approaches

Baia, Caballero, and colleagues found that NY-ESO-1 is the most frequently expressed cancer/testis antigen in meningioma tumors, and its expression positively correlates with higher-grade disease and worst prognosis. NY-ESO-1 proteins elicit spontaneous humoral immune responses; the authors propose that NY-ESO-1–based immunotherapy should be explored as a complement to standard therapy for patients with meningioma. Meningiomas are the most common primary intracranial tumors. Surgical resection remains the treatment of choice for these tumors. However, a significant number of tumors are not surgically accessible, recur, or become malignant, necessitating the repetition of surgery and sometimes radiation. Chemotherapy is rarely used and is generally not recognized as an effective treatment. Cancer/testis (CT) genes represent a unique class of genes, which are expressed by germ cells, normally silenced in somatic cells, but activated in various cancers. CT proteins can elicit spontaneous immune responses in patients with cancer and this feature makes them attractive targets for immunotherapy-based approaches. We analyzed mRNA expression of 37 testis-restricted CT genes in a discovery set of 18 meningiomas by reverse transcription PCR. The overall frequency of expression of CT genes ranged from 5.6% to 27.8%. The most frequently expressed was NY-ESO-1, in 5 patients (27.8%). We subsequently analyzed NY-ESO-1 protein expression in a larger set of meningiomas by immunohistochemistry and found expression in 108 of 110 cases. In some cases, NY-ESO-1 expression was diffused and homogenous, but in most instances it was heterogeneous. Importantly, NY-ESO-1 expression was positively correlated with higher grade and patients presenting with higher levels of NY-ESO-1 staining had significantly worse disease-free and overall survival. We have also shown that NY-ESO-1 expression may lead to humoral immune response in patients with meningioma. Considering the limited treatment options for patients with meningioma, the potential of NY-ESO-1–based immunotherapy should be explored. Cancer Immunol Res; 1(5); 296–302. ©2013 AACR.

Expanded endonasal endoscopic approach for resection of a growth hormone-secreting pituitary macroadenoma coexistent with a cavernous carotid artery aneurysm

The co-existence of pituitary adenomas (PA) and carotid artery aneurysms has been described and may be particularly frequent in acromegaly. The co-occurrence of an intracranial aneurysm in the setting of a PA presents significant risk to the patient, particularly when the aneurysm is within or near the operative field. We describe a 48-year-old, right-handed female patient with a large skull base lesion who had a left cavernous carotid artery aneurysm detected on her preoperative imaging studies. This patient was managed using a staged approach. She first underwent endovascular stent-assisted coiling of the aneurysm followed, six months later, by resection of the tumor via an expanded endonasal endoscopic approach. Histopathological analysis revealed a pituitary macroadenoma with neuronal metaplasia. Angiographic embolization followed by an expanded endonasal endoscopic approach is a safe and effective treatment for such lesions. Vascular imaging studies and a low index for suspicion are required for preoperative identification of such complex situations.

Clonidine Does Not Reduce Pain or Opioid Consumption After Noncardiac Surgery.

BACKGROUND: Clonidine is an &agr;2-adrenoceptor agonist, which has analgesic properties. However, the analgesic efficacy of perioperative clonidine remains unclear. We, therefore, tested the hypothesis that clonidine reduces both pain scores and cumulative opioid consumption during the initial 72 hours after noncardiac surgery. METHODS: Six hundred twenty-four patients undergoing elective noncardiac surgery under general and spinal anesthesia were included in this substudy of the PeriOperative ISchemia Evaluation-2 trial. Patients were randomly assigned to 0.2 mg oral clonidine or placebo 2 to 4 hours before surgery, followed by 0.2 mg/d transdermal clonidine patch or placebo patch, which was maintained until 72 hours after surgery. Postoperative pain scores and opioid consumption were assessed for 72 hours after surgery. RESULTS: Clonidine had no effect on opioid consumption compared with placebo, with an estimated ratio of means of 0.98 (95% confidence interval, 0.70–1.38); P = 0.92. Median (Q1, Q3) opioid consumption was 63 (30, 154) mg morphine equivalents in the clonidine group, which was similar to 60 (30, 128) mg morphine equivalents in the placebo group. Furthermore, there was no significant effect on pain scores, with an estimated difference in means of 0.12 (95% confidence interval, −0.02 to 0.26); 11-point scale; P = 0.10. Mean pain scores per patient were 3.6 ± 1.8 for clonidine patients and 3.6 ± 1.8 for placebo patients. CONCLUSIONS: Clonidine does not reduce opioid consumption or pain scores in patients recovering from noncardiac surgery.

Identification of location of nerve catheters using pumping maneuver and M-Mode—a novel technique☆☆☆★

BACKGROUND Optimum positioning of the nerve catheter is crucial for a successful nerve block. We present a novel technique for confirmation of catheter position. METHODS We are describing a novel technique for localization of the shaft and tip of the peripheral nerve catheter. After introduction of the catheter 3 to 5 cm beyond the needle tip and removal of the needle, the guide wire was reintroduced and was moved inward and outward rapidly. This movement produced the color Doppler effect along the track of the catheter and the catheter tip that helped us verify the proper positioning of the catheter. RESULTS We used our technique in a cadaveric study for bilateral supraclavicular brachial plexus block, followed by a series of 5 patients undergoing femoral, sciatic (anterior approach), popliteal (2 patients), and brachial plexus blocks. Catheters were also identified on M-Mode sonography during pumping maneuver and during the injection of medications. CONCLUSION Pumping maneuver and M-Mode can be additional tools in the array of modalities applied to verify proper positioning of a nerve catheter.

Intraoperative hypertensive crisis due to a catecholamine-secreting esthesioneuroblastoma

Although uncommon, esthesioneuroblastomas may produce clinically significant amounts of catecholamines.

Expanded endonasal endoscopic approach for resection of a skull base low-grade smooth muscle neoplasm.

Benign smooth muscle tumors rarely occur in the head and neck and, to the best of our knowledge, have not been reported in the pterygopalatine fossa. In this report, we describe a 15-year-old adolescent who presented with facial pain and was found to have a large skull base tumor centered in the pterygopalatine fossa. The patient underwent an expanded endonasal endoscopic approach for complete resection of this lesion with resolution of his symptoms. Pathology revealed a well-differentiated smooth muscle neoplasm consistent with a leiomyoma. This case adds to the growing body of literature supporting a role for endoscopic procedures in the treatment of skull base pathologies in pediatric patients.