Delayed persistent hyperthermia after resection of a craniopharyngioma

Challenges of transsphenoidal pituitary surgery in severe brachycephalic dogs

Introduction

Transsphenoidal hypophysectomy is the standard surgical technique for the excision of pituitary neoplasms. Anatomy may be more obscured in brachycephalic skull types due to the crowding of soft tissue and osseous structures. We describe the unique challenges to approach the sphenoid bone and localize the correct burr hole site in severe brachycephalic dogs.

Materials and methods

A single institution retrospective case series of brachycephalic dogs with pituitary-dependent hypercortisolism (PDH). Preoperative computed tomography enabled 3D-, and cross-sectional reconstruction to plan and dry-practice the position of the ideal burr hole in relation to the sella turcica, pterygoid hamular processes, and hard palate. Rostral burring of the caudal hard palate obscuring the direct sphenoid approach necessitated adaptations to the original transsphenoidal hypophysectomy procedure. Postoperative outcomes and complications with respect to those seen in mesocephalic dogs are described.

Results

Ten brachycephalic dogs including French Bulldogs (n = 9) and a single Dogue de Bordeaux were included. All dogs were diagnosed with PDH and had preoperative advanced imaging performed on the skull. All but one dog had an enlarged pituitary gland, with a median pituitary/brain value of 0.5 (range 0.21-0.9). A total of 11 transsphenoidal hypophysectomy procedures were performed in these 10 dogs. Rostral extension of the soft palate incision into the hard palate was performed to access the burr hole site on the sphenoid bone. Major complications included aspiration pneumonia (n = 1), severe gastroesophageal reflux (n = 1), and central nervous signs (=1). All dogs survived until discharge, with a median time to follow-up of 618 days (range 79-1,669 days). Seven dogs experienced long-term remission of PDH.

Conclusion

Brachycephalic dogs undergoing transsphenoid al hypophysectomy benefit from meticulous presurgical planning and extension of the approach into the caudal hard palate. Advanced surgical skills can render a good outcome in a technically challenging environment.

The effect of postoperative early lumbar drainage on delayed fever after cerebellopontine angle tumour surgery: study protocol for a randomized controlled trial

BACKGROUND

Postoperative fever is one of the common complications in neurosurgery, and intracranial aseptic inflammation and infection are important risk factors. Continuous drainage of cerebrospinal fluid (CSF) via lumbar drainage (LD) is often used in the treatment of postoperative intracranial infection or aseptic inflammation. Compared with the previously reported placement of LD after the onset of meningitis symptoms, we designed this randomized controlled trial (RCT) to evaluate the effectiveness and safety of early drainage (1st day postoperation) of CSF using the preset lumbar cistern to prevent delayed fever (fever occurred after the third day postoperation) or reduce its treatment time after cerebellopontine angle (CPA) tumour surgery.

METHODS

Patients suffering from CPA tumours and who underwent resection of the tumour with an intraoperative dura opening time > 4 h are recruited for this study. The study is a 2-arm RCT to compare the early LD group and the no early LD group. Postoperative duration and rate of delayed fever and postoperative length of stay (LOS), as the main outcomes, will be compared in the two groups.

DISCUSSION

Here, we present the study design of a prospective RCT to evaluate the safety and efficacy of using preoperative preset LD to treat or reduce postoperative delayed fever.

TRIAL REGISTRATION

China Clinical Trial Registry ChiCTR2100049057. Registered on July 20, 2021.

Predicting the location of the preoptic and anterior hypothalamic region by visualizing the thermoregulatory center on fMRI in craniopharyngioma using cold and warm stimuli

Hypothalamic nuclei in the preoptic and anterior hypothalamic region (POAH) are critically involved in thermoregulation and neuroendocrine regulation and can be displaced by craniopharyngiomas (CPs). We aimed to locate the POAH by visualizing hypothalamic thermoregulation through task-related functional magnetic resonance imaging (fMRI) to guide hypothalamus protection intraoperatively. Nine adult healthy volunteers (HVs) and thirty-two adult primary CP patients underwent task-related fMRI for POAH localization by warm (60° C) and cold (0° C) cutaneous thermoreceptor stimulation. Approach selection and intraoperative POAH protection were performed based on preoperative POAH localization. In all HVs and patients, significant single positive blood oxygen level-dependent (BOLD) signal changes were located in the POAH. The BOLD activity was significantly greater for cold (P=0.03) and warm (P=0.03) stimuli in patients than in HVs. Gross total resection and near-total resection were achieved in 28 (87.5%) and 4 (12.5%) patients, respectively. New-onset diabetes insipidus and new-onset hypopituitarism occurred in 6 patients (18.8%) and 10 patients (31.3%), respectively. Our findings suggest that cutaneous thermoreceptor stimulation could accurately activate the hypothalamic thermoregulatory center and allow POAH localization through task-related fMRI. Preoperative POAH localization could help neurosurgeons protect hypothalamic function intraoperatively. The CP patients were more sensitive to thermal stimulation.

Severe hyperthermia, hypernatremia, and early postoperative death after transethmoidal cavitron ultrasonic surgical aspirator (CUSA)-assisted diencephalic mass removal in 4 dogs and 2 cats

OBJECTIVE

To report clinical findings including severe hyperthermia and hypernatremia after transethmoidal Cavitron ultrasonic surgical aspirator (CUSA)-assisted diencephalic mass removal.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 4) and 2 cats.

METHODS

Medical records (1997-2003) of dogs and cats that had transethmoidal CUSA-assisted diencephalic mass removal were reviewed. Retrieved data were: history, signalment, blood work, neurologic examination findings, MRI results, histopathology, postoperative complications, pre- and postoperative medical therapy, and outcome.

RESULTS

Tumor types included: meningioma (n = 3), choroid plexus papilloma (1), astrocytoma (1), and pituitary macroadenoma (1). Median onset of hyperthermia was 3.5 hours (range: 1-6 hours) after extubation; median high temperature at onset was 40.3°C, (range: 39.6-41.7°C). Median onset of hypernatremia (median, 172 mmol/L; range: 168-196 mmol/L) was 4.5 hours (range: 1-9 hours) after extubation. Median time of death after hyperthermia was 10.5 hours (range: 6-13 hours) and after extubation was 13.5 hours (range: 11-15 hours).

CONCLUSIONS

Transethmoidal CUSA-assisted diencephalic mass removal is associated with early postoperative hyperthermia, hypernatremia, and death, and cannot be recommended.

Central hyperthermia, brain hyperthermia and low hypothalamus temperature

INTRODUCTION, PATIENTS AND METHODS: We measured brain temperature in a case of central hyperthermia.

RESULTS

Brain temperature was increased except for hypothalamus that was colder.

CONCLUSION

We suppose that central hyperthermia is driven by cold hypothalamus.

Characterization of neuromedin U effects in canine smooth muscle

Two endogenous receptors for the potent smooth muscle-stimulating peptide neuromedin U (NmU) have recently been identified and cloned. Pharmacological, binding, and expression studies were conducted in an attempt to determine the receptor(s) involved in the smooth muscle-stimulating effects of NmU. The NmU peptides caused a concentration-dependent contraction of canine isolated urinary bladder. NmU did not have this same effect in the urinary bladder from rat, guinea pig, rabbit, mouse, or ferret. Although NmU had no effect on canine uterus it did cause contraction of canine stomach, ileum, and colon. As well as causing contraction of canine bladder in vitro, NmU administered systemically resulted in a significant increase in urinary bladder pressure in vivo. High-affinity binding sites for NmU were identified in canine bladder. The four NmU peptides porcine NmU-8, rat NmU-23, human NmU-25, and porcine NmU-25 displaced (125)I-NmU-25 binding with similar K(i) values (0.08-0.24 nM). A different binding profile was revealed in human embryonic kidney-293 cells transiently expressed with the canine NmU-2 receptor where porcine NmU-8 (K(i) = 147.06 nM) was much less potent than the other NmU peptides. Using TaqMan, expression of NmU-1 was detected in human urinary bladder, small intestine, colon, and uterus. Expression of NmU-2 was much lower or absent in these human tissues and undetectable in canine bladder and stomach. The results of this study reveal significant species differences in the activity of NmU. The contractile activity in human and canine smooth muscle seems to be mediated by the recently cloned NmU-1 receptor.