Pterygopalatine Fossa Anatomy for a Surgical Approach to Sphenopalatine Ganglion.

The sphenopalatine ganglion is an extracranial neural structure within the pterygopalatine fossa. Modulation of this region via implantation of a neuromodulatory device presents a novel therapy for the treatment of facial and head pain. Yet sex, race, and genetic factors contribute to morphological variations between individuals. This study defines the standards and variations of the bony landmarks surrounding the pterygopalatine fossa. One hundred dry skulls were analyzed from the Hamann-Todd osteological collection. Ten anatomical dimensions were measured on each side of the face for each specimen (vidian foramen, zygomatic buttress, zygomatic maxillary suture, pyriform rim, infraorbital rim, pterygoid maxillary suture, greater palatine foramen, auditory canal, and pterygoid fossa). A statistical analysis was performed for both sides of the face based on sex and race. When stratified by sex, 7 of the 10 measurements revealed a statistically significant difference bilaterally. When stratified by race, 5 of the 10 measurements demonstrated a statistically significant difference bilaterally. Both male and African American skulls showed greater hemifacial values bilaterally when compared with their respective counterparts. The only statistically significant measurement on both the left and right sides of all skulls was the length from the vidian foramen to the infraorbital rim. Defining the anatomical mean distance between skull landmarks and highlighting differences between sex and race not only provides further insight into relative skull anatomy, but also sets the stage for device innovation.

Electrical stimulation of sphenopalatine ganglion for acute treatment of cluster headaches.

INTRODUCTION: Cluster headaches (CH) are primary headaches marked by repeated short-lasting attacks of severe, unilateral head pain and associated autonomic symptoms. Despite aggressive management with medications, oxygen therapy, nerve blocks, as well as various lesioning and neurostimulation therapies, a number of patients are incapacitated and suffering. The sphenopalatine ganglion (SPG) has been implicated in the pathophysiology of CH and has been a target for blocks, lesioning, and other surgical approaches. For this reason, it was selected as a target for an acute neurostimulation study. METHODS: Six patients with refractory chronic CH were treated with short-term (up to 1 hour) electrical stimulation of the SPG during an acute CH. Headaches were spontaneously present at the time of stimulation or were triggered with agents known to trigger clusters headache in each patient. A standard percutaneous infrazygomatic approach was used to place a needle at the ipsilateral SPG in the pterygopalatine fossa under fluoroscopic guidance. Electrical stimulation was performed using a temporary stimulating electrode. Stimulation was performed at various settings during maximal headache intensity. RESULTS: Five patients had CH during the initial evaluation. Three returned 3 months later for a second evaluation. There were 18 acute and distinct CH attacks with clinically maximal visual analog scale (VAS) intensity of 8 (out of 10) and above. SPG stimulation resulted in complete resolution of the headache in 11 attacks, partial resolution (>50% VAS reduction) in 3, and minimal to no relief in 4 attacks. Associated autonomic features of CH were resolved in each responder. Pain relief was noted within several minutes of stimulation. CONCLUSION: Sphenopalatine ganglion stimulation can be effective in relieving acute severe CH pain and associated autonomic features. Chronic long-term outcome studies are needed to determine the utility of SPG stimulation for management and prevention of CH.

3-D microfabricated electrodes for targeted deep brain stimulation.

This work presents a novel 4-sided, 16-channel deep brain stimulation electrode with a custom flexible high-density lead for connectivity with pulse generation electronics. The 3-dimensional electrode enables steering the current field circumferentially. The electrode is fabricated in pieces by micromachining and microfabrication techniques; the pieces are then assembled mechanically to form the electrode, after which the lead is connected. The electrode is modeled by finite element analysis and tested in vitro to validate the design concept, i.e., targeted stimulation. Simulation and experimental results for a targeted stimulation show close agreement. With a symmetric bipolar stimulation configuration, within a 3 mm radius, the electric potential in front of the activated side is at least 3.6 times larger than that on the corresponding two adjacent, not-activated sides, and 9 times larger than the corresponding opposite, not-activated side.

Robotically assisted gynaecological surgery.

Industry has used robots successfully for fine, delicate, repetitive tasks for decades. Recently, robots have been introduced into clinical medicine and specifically into the surgical suite. Voice algorithms have been developed that allow voice activation of some types of equipment in the operating room, such as the laparoscope or the light source. Advances in computer software have allowed a computer controller to translate a surgeon's movements from the handles located in a console to the robotic arms that hold the surgical instruments. This console is placed away from the surgical table. Clinical experience is limited and there are few published clinical trials. The initial trials have focused on laparoscopic microsuturing such as that performed during coronary bypass surgery or tubal anastomosis. Preliminary results have demonstrated that laparoscopic coronary bypass surgery with the internal mammary artery can be achieved. In gynaecological surgery, laparoscopic tubal reanastomosis can be performed using the same technique that has been used traditionally at laparotomy. Future clinical trials will assess whether other gynaecological procedures can be performed with robotic assistance.