A Low‐Cost,Small Volume Circuit for Autologous Blood Normothermic Perfusion of Rabbit Organs

We have designed a laboratory extracorporeal normothermic blood perfusion system for whole organs (e.g., kidney) that achieves pulsatile flow, low levels of hemolysis, and a blood priming volume of 60 mL or less. Using this uniquely designed extracorporeal circuit, we have achieved perfusion of two isolated ex vivo constructs. In the first experiment, we successfully perfused a rabbit epigastric flap based on the femoral vessels. In the second experiment, we were able to perfuse the isolated rabbit kidney for 48 h (range for all kidneys was 12–48 h) with excellent urine output, normal arterial blood gasses at 24 h, and normal ex vivo kidney histology at the conclusion of the experiments. These parameters have not been achieved before with any known or previously published laboratory extracorporeal circuits. The study has implications for prolonged organ perfusion prior to transplantation and for tissue engineering of vascularized tissues, such as by the perfusion of decellularized organs.     

Sleep apnea and cervical spine pathology

Purpose

Sleep apnea is a multi-factorial disease with a variety of identified causes. With its close proximity to the upper airway, the cervical spine and its associated pathologies can produce sleep apnea symptoms in select populations. The aim of this article was to summarize the literature discussing how cervical spine pathologies may cause sleep apnea.

Methods

A search of the PubMed database for English-language literature concerning the cervical spine and its relationship with sleep apnea was conducted. Seventeen published papers were selected and reviewed.

Results

Single-lesion pathologies of the cervical spine causing sleep apnea include osteochondromas, osteophytes, and other rare pathologies. Multifocal lesions include rheumatoid arthritis of the cervical spine and endogenous cervical fusions. Furthermore, occipital–cervical misalignment pre- and post-cervical fusion surgery may predispose patients to sleep apnea.

Conclusions

Pathologies of the cervical spine present significant additional etiologies for producing obstructive sleep apnea in select patient populations. Knowledge of these entities and their pathophysiologic mechanisms is informative for the clinician in diagnosing and managing sleep apnea in certain populations.     

Five-level cervical corpectomy for neurofibromatosis-associated spinal deformity: case report

Purpose

To describe a successful five-level cervical corpectomy and circumferential reconstruction in a patient with a plexiform neurofibroma causing a severe kyphotic deformity.

Methods

Case report.

Results

43-year-old man with history of Neurofibromatosis presented with signs and symptoms of myelopathy with spastic lower extremities and gait difficulties. Imaging studies demonstrated a severe kyphotic deformity of the cervical spine with associated cord compression secondary to an anteriorly positioned plexiform neurofibroma. Two-stage surgical procedure was designed to treat this lesion. Stage I consisted of tracheostomy placement, transmandibular, circumglossal approach to the anterior cervical spine, C2–C6 corpectomies, and C1–C7 reconstruction with a custom titanium cage/plate. Stage II consisted of suboccipital craniectomy, C1–C2 laminectomies, and occipital-cervical thoracic instrumented fusion (O-T8). There were no operative complications, but the patient did develop a small pulmonary embolism post-operatively treated with anticoagulation. Patient required two-weeks of inpatient rehabilitation following surgery. Gastrostomy tube and tracheostomy were successfully discontinued with preserved swallowing and respiratory function. Patient-reported outcome measurements revealed significant and sustained improvement post-operatively.

Conclusions

Five-level cervical corpectomy including C2 can be safely and successfully performed via a transmandibular, circumglossal approach. Circumferential reconstruction utilizing a custom anterior titanium cage and plate system manufactured from a pre-operative CT scan was utilized in this case. Long segment occipital-cervical-thoracic reconstruction is recommended in such a case. Using such a technique, improvement in myelopathy, correction of deformity, and improved quality of life can be achieved.

     

Association Between Symptom Dimensions and Categorical Diagnoses of Psychosis: A Cross-sectional and Longitudinal Investigation

Context:

Cross-sectional studies of the signs and symptoms of psychosis yield dimensional phenotypes. However, the validity and clinical utility of such dimensions remain debated. This study investigated the structure of psychotic symptomatology, the stability of the structure over time, and the concordance between symptom dimensions and categorical diagnoses.

Methods:

Sample consisted of 500 first-episode psychotic patients. A cross-sectional study (N = 500) investigated the organizational structure of symptom dimensions at the onset of psychosis and its concordance with categorical diagnoses; next, a nested longitudinal study (N = 100) examined the stability of the symptom dimensions structure after 5–10 years of follow-up.

Results:

Factor analyses identified 6 first-order factors (mania, negative, disorganization, depression, hallucinations, and delusions) and 2 high-order factors (affective and nonaffective psychoses). Cumulative variance accounted for by the first and high-order factors was 63%: 31% by the first-order factors and 32% by the high-order factors. The factorial structure of psychotic symptoms during first episode remained stable after 5–10 years of follow-up. The overall concordance between 4 categorical diagnostic groups (schizophrenia, mania with psychosis, psychotic depression and schizoaffective disorder) and dimensional symptom ranged from 62.2% to 73.1% (when the schizoaffective group was excluded).

Conclusions:

Symptoms of psychosis assume a multidimensional hierarchical structure. This hierarchical model was stable over time and showed good concordance with categorical diagnoses. The combined use of dimensional and categorical approach to psychotic disorders would be of clinical and research utility.Key words: symptom dimensions, diagnostic classification, psychosis, DSM-5, longitudinal study