Carsten Kohlmeier

Technical and surgical aspects of the sphenopalatine ganglion (SPG) microstimulator insertion procedure

Cluster headache (CH) is a debilitating, severe form of headache. A novel non-systemic therapy has been developed that produces therapeutic electrical stimulation to the sphenopalatine ganglion (SPG). A transoral surgical technique for inserting the Pulsante SPG Microstimulator into the pterygopalatine fossa (PPF) is presented herein. Technical aspects include detailed descriptions of the preoperative planning using computed tomography or cone beam computed tomography scans for presurgical digital microstimulator insertion into the patient-specific anatomy and intraoperative verification of microstimulator placement. Surgical aspects include techniques to insert the microstimulator into the proper midface location atraumatically. During the Pathway CH-1 and Pathway R-1 studies, 99 CH patients received an SPG microstimulator. Ninety-six had a microstimulator placed within the PPF during their initial procedure. Perioperative surgical sequelae included sensory disturbances, pain, and swelling. Follow-up procedures included placement of a second microstimulator on the opposite side (n=2), adjustment of the microstimulator lead location (n=13), re-placement after initial unsuccessful placement (n=1), and removal (n=5). This SPG microstimulator insertion procedure has sequelae comparable to other oral cavity procedures including tooth extractions, sinus surgery, and dental implant placement. Twenty-five of 29 subjects (86%) completing a self-assessment questionnaire indicated that the surgical effects were tolerable and 90% would make the same decision again.

Long-term biomechanical analysis of donor site morbidity after radial forearm free flap.

BACKGROUND Although the radial forearm free flap (RFF) is a commonly used microvascular graft for head and neck reconstruction, long-term biomechanical results regarding donor site morbidity are rare. PATIENTS AND METHODS In a prospective panel study, 32 patients were included. Biomechanical assessment was performed preoperatively, three months postoperatively and two years postoperatively. The primary endpoint of the study was grip strength. In addition, the Mayo wrist score, DASH score (disabilities of the arm, shoulder and hand score), fine motor skill strengths (tip pinch, key pinch, palmar pinch) and the range of motion were analysed. Primary defects were closed with local full-thickness skin grafts (FTSG) from the donor site forearm avoiding a secondary defect site. RESULTS In the long-term analysis, grip strength was reduced in both arms. A significant improvement over time was found only for the donor arm. A persistent deficit of tip pinch strength and dorsal extension was recorded. Persistent sensory limitations occurred in four cases. Patient contentment after two years of follow-up was high and daily life routine was not restricted. CONCLUSION Gross and fine motor skill limitations are reversible short-term effects after RFF harvesting and do not restrict daily routine in the long term. These findings substantiate the value of the RFF as a workhorse in reconstructive surgery.

Value of intra- and post-operative cone beam computed tomography (CBCT) for positioning control of a sphenopalatine ganglion neurostimulator in patients with chronic cluster headache

INTRODUCTION The objective of this study was to determine whether postoperative control of the neurostimulator placement within the pterygopalatine fossa (PPF) by means of 3-dimensional (3D) cone beam computed tomography (CBCT) was of therapeutic relevance compared to intraoperative CBCT imaging alone. MATERIAL AND METHODS Immediately after implantation of the sphenopalatine ganglion (SPG) neurostimulator, intraoperative CBCT datasets were generated in order to visualize the position of the probe within the PPF. Postoperatively, all patients received a CBCT for comparison with intraoperatively acquired radiographs. RESULTS Twenty-four patients with cluster headache (CH) received an SPG neurostimulator. In 4 patients, postoperative CBCT images detected misplacement not found in intraoperative CBCT. In 3 cases, electrode tips were misplaced into the maxillary sinus and in 1 case into the apex of the PPF superior to the suspected location of the SPG. Immediate revision with successful repositioning within 3 days was done in 2 patients and a deferred reimplantation in 1 patient within 6 months. One patient declined revision. CONCLUSION We were able to demonstrate the clinical value of postoperative dental CBCT imaging with a wide region of interest (ROI) due to a superior image quality compared with that achieved with intraoperative medical CBCT. Although intraoperative 3D CBCT imaging of electrode placement is helpful in the acute surgical setting, resolution is, at present, too low to safely exclude misplacement, especially in the maxillary sinus. High-resolution postoperative dental CBCT allows rapid detection and revision of electrode misplacement, thereby avoiding readmission and recurrent tissue trauma.

Prospective biomechanical evaluation of donor site morbidity after radial forearm free flap.

Although the radial forearm free flap (RFF) is a commonly-used microvascular flap for orofacial reconstruction, we are aware of few prospective biomechanical studies of the donor site. We have therefore evaluated the donor site morbidity biomechanically of 30 consecutive RFF for orofacial reconstruction preoperatively and three months postoperatively. This included the Mayo wrist score, the Disabilities of the Arm, Shoulder and Hand (DASH) score, grip strength, followed by tip pinch, key pinch, palmar pinch, and range of movement of the wrist. Primary defects were all closed with local full-thickness skin grafts from the donor site forearm, thereby circumventing the need for a second defect. Postoperative functional results showed that there was a reduction in hand strength measured by (grip strength: -24.1%, in tip pinch: -23.3%, in key pinch: -16.5, and in palmar pinch: -19.3%); and wrist movement measured by extension (active=14.3% / passive= -11.5%) and flexion = -14.8% / -8.9%), and radial (-9.8% / -9.8%) and ulnar (-11.0% / -9.3%) abduction. The Mayo wrist score was reduced by 9.4 points (-12.9%) and the DASH score increased by 16.1 points (+35.5%) compared with the same forearm preoperatively. The local skin graft resulted in a robust wound cover with a good functional result. Our results show that the reduction in hand strength and wrist movement after harvest of a RFF is objectively evaluable, and did not reflect the subjectively noticed extent and restrictions in activities of daily living. Use of a local skin graft avoids a second donor site and the disadvantages of a split-thickness skin graft.

Functional donor site morbidity longer than one year after fibula free flap: A prospective biomechanical analysis

The fibula free flap is the workhorse procedure for osseous reconstruction. The objective of this study was to investigate long‐term functional outcomes of the harvesting site.

Evaluation of long-term functional donor-site morbidity after deep circumflex iliac crest artery bone flap harvest

Free flap surgery can be associated with donor‐site morbidity. The purpose of this study was to analyze long‐term functional outcomes at the donor site after deep circumflex iliac artery (DCIA) bone flap harvesting.