Robotic excision of suture entrapment of the lumbosacral trunk. The authors have no financial disclosures. Nerve injuries are an uncommon but serious complication of sacrospinous ligament suspension. Surrounding structures include the lumbosacral trunk and its extension of the sciatic nerve, as well as the gluteal arteries and pudendal neurovascular bundle. We will demonstrate a minimally invasive approach to excision of a suture inadvertently placed in the lumbosacral plexus during sacrospinous ligament fixation. Our patient is a 44-year-old female who developed severe postoperative leg pain and gluteal pain with foot drop after a bilateral sacrospinous ligament fixation. She did not improve significantly with physical therapy. CT scan demonstrates significant asymmetric inflammation in the right hemipelvis, tracking inferiorly and medially to the vaginal apex on the right. Our excision begins with opening the pelvic peritoneum on the right. Brief bursts of energy causes pneumodissection to occur, which helps protect retroperitoneal structures. The stump of the right infundibulopelvic ligament is isolated and transected to create a large window into the retroperitoneum. We begin by opening the retroperitoneal space lateral to the external iliac vessels at the level of the pelvic brim. The ureter is clearly seen crossing the brim here. The lateral margin is the psoas muscle, over which lies the general femoral nerve. Careful push-spread technique reveals the obturator nerve crossing through the space. Once the nerve is identified, counter-traction with the left instrument permits the space to be safely and easily opened. Adipose and lymphatic tissue are dissected, revealing the obturator nerve, and medially, the internal iliac vessels can be seen. Posteriorly, the lumbosacral trunk is visible deep to these structures. Inspection of the lumbosacral trunk shows it is grossly inflamed, with significant encapsulation by scar and fibrous tissue. Traction-counter-traction combined with gentle wiping allows the encapsulated scar to be dissected free of the body of the nerve. Minimal energy is used here to avoid injury to delicate nerve fibers. Continued dissection reveals the superior gluteal artery surrounded by dense, fibrous scar tissue. Microbursts of low-voltage monopolar energy are delivered with high current density using the tip of the scissors. This millimeter-by-millimeter dissection allows the surgeon to minimize risk of injury to the artery. Here, an unidentified structure is seen emerging from the lumbosacral trunk at the level of the superior gluteal artery. Frozen-section pathology suggests fibrous scar, and neurosurgical consultation confirms no anatomic correlate in this region. Push-spread technique without energy is used to carefully dissect between the artery and the scar capsule in order to further isolate it from surrounding normal anatomy. The structure is explored further, and with posterior counter-traction of the right arm, an encapsulated braided permanent suture is clearly visualized. Further exploration reveals the suture traveling lateral to medial, consistent with the sacral spinous ligament suture. The extensive involvement of the lumbosacral trunk is clearly seen when traction is placed on the suture. As the sacral spinous sutures are placed in a loop, we undertake a posterior dissection to identify the remaining suture material. However, in our case, this lateral approach is ultimately unsuccessful. We return to the medial aspect of the lumbosacral trunk and continue dissecting along the fibrous encapsulation of the suture material using push-spread technique and millimeter-by-millimeter dissection. The posterior encapsulated suture is identified after continued dissection. It can be seen traversing posterior to the neural tissue and the superior gluteal artery. Traction upon this arm confirms its involvement with the body of the lumbosacral trunk. With the anterior, posterior, and lateral aspects of the suture loop identified, the location of the medial aspect is ascertained through palpation of the vagina and careful dissection medial to the superior gluteal artery. Suture material is easily identified. Again, tedious millimeter-by-millimeter dissection using push-spread technique, wiping, and minimal cautery are essential to protecting surrounding structures. Once enough of the medial aspect of the suture arm has been identified, the suture material is pulled into the abdomen with the knot intact. This confirms that the suture has penetrated not only the lumbosacral trunk, but has encircled the superior gluteal artery. We feel that this intermittent compression of the artery is the cause of the claudicative buttock pain felt by the patient when sitting. With the knot identified, the suture is cut and released without difficulty. Postoperatively, the patient notes daily improvement in her foot drop, sensation in the foot, and buttock pain. She has no evidence of postoperative infection or other complications. In conclusion, multiple neurovascular structures lay in close proximity to the sacrospinous ligament. New but persistent pain, neurologic deficits, and altered sensation should prompt consideration of suture removal when permanent suture is used for this procedure. We would like to thank the Mayo Clinic AV staff, in particular Tim Seelinger and Randy Reich for their assistance.

minimally invasive approach

suture excision

lumbosacral plexus

sacrospinous ligament fixation

neurologic deficits