Pedicled omental flaps for complex wound reconstruction following surgery for primary spine tumors of the mobile spine and sacrum.

OBJECTIVE: Surgery for primary tumors of the mobile spine and sacrum often requires complex reconstruction techniques to cover soft-tissue defects and to treat wound and CSF-related complications. The anatomical, vascular, and immunoregulatory characteristics of the omentum make it an excellent local substrate for the management of radiation soft-tissue injury, infection, and extensive wound defects. This study describes the authors' experience in complex wound reconstruction using pedicled omental flaps to cover defects in surgery for mobile spine and sacral primary tumors. METHODS: A retrospective cohort analysis was conducted on 34 patients who underwent pedicled omental flap reconstruction after en bloc resection of primary sacral and mobile spine tumors between 2010 and 2020. The study focused on assessing the indications for omental flap usage, including soft-tissue coverage, protection against postoperative radiation therapy, infection management, vascular supply for bone grafts, and dural defect and CSF leak repair. Patient demographic characteristics, tumor characteristics, surgical outcomes, and follow-up data were analyzed to determine the procedure's efficacy and complication rates. RESULTS: From 2010 to 2020, 34 patients underwent pedicled omental flap reconstruction after en bloc resection of sacral (24 of 34 [71%]) and mobile spine (10 of 34 [29%]) primary tumors, mostly chordomas. The patient cohort included 21 men and 13 women with a median (range) age of 60 (32-89) years. The most common indication for omental flap was soft-tissue coverage (20 of 34 [59%]). Other indications included protecting abdominopelvic organs for postoperative radiation therapy (6 of 34 [18%]), treating infections (5 of 34 [15%]), providing vascular supply for free fibular bone graft (1 of 34 [3%]), and repairing large dural defects and CSF leak (2 of 34 [6%]). The median (range) follow-up was 24 (0-132) months, during which 71% (24 of 34) of patients did not require additional surgery for wound-related complications. At last follow-up, 59% (20 of 34) had stable disease and 32% (11 of 34) had recurrence, had progression of disease, or had been discharged to hospice after treatment. CONCLUSIONS: The pedicled omentum is an effective local tissue graft that can be used for complex wound reconstruction and management of high-risk closures in primary spine tumors. This technique may have a lower rate of complications than other approaches and may influence surgical planning and flap selection in challenging cases.

Supinator to Posterior Interosseous Nerve Transfer for Recovery of Hand Opening in the Tetraplegic Patient: A Case Series.

BACKGROUND AND OBJECTIVES: Cervical spinal cord injury results in devastating loss of function. Nerve transfers can restore functional use of the hand, the highest priority function in this population to gain independence. Transfer of radial nerve branches innervating the supinator to the posterior interosseous nerve (SUP-PIN) has become a primary intervention for the recovery of hand opening, but few outcome reports exist to date. We report single-surgeon outcomes for this procedure. METHODS: The SUP-PIN transfer was performed on adults with traumatic spinal cord injury resulting in hand paralysis. Outcome measures include Medical Research Council strength grade for extension of each digit, and angles representing critical apertures: the first web space opening of the thumb, and metacarpophalangeal angle of the remaining fingers. Factors affecting these measurements, including preserved tone and spasticity of related muscles, were also assessed. RESULTS: Twenty-three adult patients with a C5-7 motor level underwent SUP-PIN transfers on 36 limbs (median age 31 years, interquartile range [21.5, 41]). The median interval from injury to surgery was 10.5 (8.2, 6.5) months, with 9 (7.5, 11) months for the acute injuries and 50 (32, 66) months for the chronic (>18 months) injuries. Outcomes were observed at a mean follow-up of 22 (14, 32.5) months. 30 (83.3%) hands recovered at least antigravity extension of the thumb and 34 (94.4%) demonstrated successful antigravity strength for the finger extensors, providing adequate opening for a functional grasp. Chronic patients (>18 months after injury) showed similar outcomes to those who had earlier surgery. Supination remained strong (at least M4) in all but a single patient and no complications were observed. CONCLUSION: SUP-PIN is a reliable procedure for recovery of finger extension. Chronic patients remain good candidates, provided innervation of target muscles is preserved. Higher C5 injuries were more likely to have poor outcomes.

Emergence of nanoscale viscoelasticity from single cancer cells to established tumors.

Tumors are complex materials whose physical properties dictate growth and treatment outcomes. Recent evidence suggests time-dependent physical properties, such as viscoelasticity, are crucial, distinct mechanical regulators of cancer progression and malignancy, yet the genesis and consequences of tumor viscoelasticity are poorly understood. Here, using Wide-bandwidth AFM-based ViscoElastic Spectroscopy (WAVES) coupled with mathematical modeling, we probe the origins of tumor viscoelasticity. From single carcinoma cells to increasingly sized carcinoma spheroids to established tumors, we describe a stepwise evolution of dynamic mechanical properties that create a nanorheological signature of established tumors: increased stiffness, decreased rate-dependent stiffening, and reduced energy dissipation. We dissect this evolution of viscoelasticity by scale, and show established tumors use fluid-solid interactions as the dominant mechanism of mechanical energy dissipation as opposed to fluid-independent intrinsic viscoelasticity. Additionally, we demonstrate the energy dissipation mechanism in spheroids and established tumors is negatively correlated with the cellular density, and this relationship strongly depends on an intact actin cytoskeleton. These findings define an emergent and targetable signature of the physical tumor microenvironment, with potential for deeper understanding of tumor pathophysiology and treatment strategies.

Blood pressure cuff-induced radial nerve palsy following minimally invasive lateral microdiscectomy: illustrative case.

BACKGROUND: The authors describe a rare case of transient postoperative wrist and finger drop following a prone position minimally invasive surgery (MIS) lateral microdiscectomy. OBSERVATIONS: Hand and wrist drop is an unusual complication following spine surgery, especially in prone positioning. The authors' multidisciplinary team assessed a patient with this complication following MIS lateral microdiscectomy. The broad differential diagnosis included radial nerve palsy, C7 radiculopathy, stroke, and spinal cord injury. Given the patient's supinator weakness, intact pronation and wrist flexion, and transient recovery within 4 weeks, the most likely diagnosis was radial nerve neuropraxia secondary to ischemic compression. After careful consideration of the operative environment and anatomical constraints, the patient's blood pressure cuff was found to be the most probable source of compression. LESSONS: Blood pressure cuff-induced peripheral nerve injury may be a source of postoperative radial nerve neuropraxia in patients undergoing spine surgery. Careful considerations must be given to the blood pressure cuff location, which should not be placed at the distal end of the humerus due to higher susceptibility of peripheral nerve compression. Spine surgeons should be aware of and appropriately localize postoperative deficits along the neuroaxis, including central versus proximal or distal peripheral injuries, in order to guide appropriate postoperative management.

Selective Tibial Neurotomy for Spastic Equinovarus Foot: Operative Technique.

BACKGROUND AND OBJECTIVES: Spastic equinovarus foot (SEF) is a common complication of stroke and other upper motor neuron injuries. It is characterized by a plantigrade and inverted foot, often with toe curling, causing significant disability from pain, gait, and balance difficulties. Management includes physical therapy, antispasticity drugs, orthoses, chemical neurolysis, or botulinum toxin, all of which may be insufficient, sedating, or transient. Selective tibial neurotomy (STN) provides a surgical option that is effective and long-lasting. Our goal is to provide a concise description of our technique for performing the STN for treatment of SEF. We discuss the standard posterior approach with surgical variations used by other groups and a medial approach, should the posterior approach be insufficient. METHODS: A posterior leg approach allows access to the tibial nerve and its branches to the bilateral gastrocnemius muscles, soleus, posterior tibialis, and extrinsic toe flexors. A medial approach is used if the toe flexors cannot be accessed sufficiently from the posterior approach. Nerve branch targets identified by preoperative functional assessment are carefully exposed and fully neurolysed distally to identify all terminal branches to each muscle of interest before neurotomy. RESULTS: The STN is a powerful tool for treating SEF, with an immediate and lasting effect. Approximately 80% of the target muscle should be denervated to ensure long-term efficacy while maintaining adequate function of the muscle through collateral innervation. CONCLUSION: The STN is a safe and effective outpatient procedure that can be performed by an experienced nerve surgeon to improve balance and ambulation and reduce pain for patients with SEF. Large clinical trials are necessary to further establish this underutilized procedure in the United States.

Axillary to Radial Nerve Transfer for Recovery of Elbow Extension After Spinal Cord Injury.

BACKGROUND AND OBJECTIVES: Cervical spinal cord injuries (SCI) result in severe loss of function and independence. Nerve transfers have become a powerful method for restoring upper extremity function, the most critical missing function desired by this patient population. Recovery of active elbow extension allows for expansion of one's workspace to reach for objects and stabilizes control at the elbow joint. Without triceps function, a patient with a cervical SCI is rendered entirely helpless when in the supine position. Our objective was to provide a concise description of the transfer of branches of the axillary nerve (AN) to the long head of the triceps branch of the radial nerve (RN) for restoration of elbow extension after cervical SCI. METHODS: An anterior, axillary approach is used for the transfer of the nerve branches of the AN (which may include branches to the teres minor, posterior deltoid, or even middle deltoid) to the long head of the triceps branch of the RN. Preoperative assessment and intraoperative stimulation are demonstrated to direct optimal selection of axillary branch donors. RESULTS: The axillary approach provides full access to all branches of the AN in optimal proximity to triceps branches of the RN and allows for tension-free coaptation to achieve successful recovery of elbow extension. Final outcomes may not be achieved for 18 months. Of our last 20 patients with greater than 12-month follow-up, 13 have achieved antigravity strength in elbow extension, 4 are demonstrating ongoing progression, and 3 are definitive failures by 18 months. CONCLUSION: The axillary to RN transfer is an important intervention for recovery of elbow extension after cervical SCI, which significantly improves quality of life in this patient population. Further large population outcomes studies are necessary to further establish efficacy and increase awareness of these procedures.

Restoring bladder function using motor and sensory nerve transfers: a cadaveric feasibility study.

OBJECTIVE: Bladder dysfunction after nerve injury has a variable presentation, and extent of injury determines whether the bladder is spastic or atonic. The authors have proposed a series of 3 nerve transfers for functional innervation of the detrusor muscle and external urethral sphincter, along with sensory innervation to the genital dermatome. These transfers are applicable to only cases with low spinal segment injuries (sacral nerve root function is lost) and largely preserved lumbar function. Transfer of the posterior branch of the obturator nerve to the vesical branch of the pelvic nerve provides a feasible mechanism for patients to initiate detrusor contraction by thigh adduction. External urethra innervation (motor and sensory) may be accomplished by transfer of the vastus medialis nerve to the pudendal nerve. The sensory component of the pudendal nerve to the genitalia may be further enhanced by transfer of the saphenous nerve (sensory) to the pudendal nerve. The main limitations of coapting the nerve donors to their intrapelvic targets are the bifurcation or arborization points of the parent nerve. To ensure that the donor nerves had sufficient length and diameter, the authors sought to measure these parameters. METHODS: Twenty-six pelvic and anterior thigh regions were dissected in 13 female cadavers. After the graft and donor sites were clearly exposed and the branches identified, the donor nerves were cut at suitable distal sites and then moved into the pelvis for tensionless anastomosis. Diameters were measured with calipers. RESULTS: The obturator nerve was bifurcated a mean ± SD (range) of 5.5 ± 1.7 (2.0-9.0) cm proximal to the entrance of the obturator foramen. In every cadaver, the authors were able to bring the posterior division of the obturator nerve to the vesical branch of the pelvic nerve (located internal to the ischial spine) in a tensionless manner with an excess obturator nerve length of 2.0 ± 1.2 (0.0-5.0) cm. The distance between the femoral nerve arborization and the anterior superior iliac spine was 9.3 ± 1.8 (6.5-15.0) cm, and the distance from the femoral arborization to the ischial spine was 12.9 ± 1.4 (10.0-16.0) cm. Diameters were similar between donor and recipient nerves. CONCLUSIONS: The chosen donor nerves were long enough and of sufficient caliber for the proposed nerve transfers and tensionless anastomosis.

Spinal motor neuron transplantation to enhance nerve reconstruction strategies: Towards a cell therapy.

Nerve transfers have become a powerful intervention to restore function following devastating paralyzing injuries. A major limitation to peripheral nerve repair and reconstructive strategies is the progressive, fibrotic degeneration of the distal nerve and denervated muscle, eventually precluding recovery of these targets and thus defining a time window within which reinnervation must occur. One proven strategy in the clinic has been the sacrifice and transfer of an adjacent distal motor nerve to provide axons to occupy, and thus preserve (or "babysit"), the target muscle. However, available nearby nerves are limited in severe brachial plexus or spinal cord injury. An alternative and novel proposition is the transplantation of spinal motor neurons (SMNs) derived from human induced pluripotent stem cells (iPSCs) into the target nerve to extend their axons to occupy and preserve the targets. These cells could potentially be delivered through minimally invasive or percutaneous techniques. Several reports have demonstrated survival, functional innervation, and muscular preservation following transplantation of SMNs into rodent nerves. Advances in the generation, culture, and differentiation of human iPSCs now offer the possibility for an unlimited supply of clinical grade SMNs. This review will discuss the previous reports of peripheral SMN transplantation, outline key considerations, and propose next steps towards advancing this approach to clinic. Stem cells have garnered great enthusiasm for their potential to revolutionize medicine. However, this excitement has often led to premature clinical studies with ill-defined cell products and mechanisms of action, particularly in spinal cord injury. We believe the peripheral transplantation of a defined SMN population to address neuromuscular degeneration will be transformative in augmenting current reconstructive strategies. By thus removing the current barriers of time and distance, this strategy would dramatically enhance the potential for reconstruction and functional recovery in otherwise hopeless paralyzing injuries. Furthermore, this strategy may be used as a permanent axon replacement following destruction of lower motor neurons and would enable exogenous stimulation options, such as pacing of transplanted SMN axons in the phrenic nerve to avoid mechanical ventilation in high cervical cord injury or amyotrophic lateral sclerosis.

Supinator to Posterior Interosseous Nerve Transfer for Restoration of Finger Extension.

BACKGROUND: Cervical spinal cord injuries result in a severe loss of function and independence. The primary goal for these patients is the restoration of hand function. Nerve transfers have recently become a powerful intervention to restore the ability to grasp and release objects. The supinator muscle, although a suboptimal tendon transfer donor, serves as an ideal distal nerve donor for reconstructive strategies of the hand. This transfer is also applicable to lower brachial plexus injuries. OBJECTIVE: To describe the supinator to posterior interosseous nerve transfer with the goal of restoring finger extension following spinal cord or lower brachial plexus injury. METHODS: Nerve branches to the supinator muscle are transferred to the posterior interosseous nerve supplying the finger extensor muscles in the forearm. RESULTS: The supinator to posterior interosseous nerve transfer is effective in restoring finger extension following spinal cord or lower brachial plexus injury. CONCLUSION: This procedure represents an optimal nerve transfer as the donor nerve is adjacent to the target nerve and its associated muscles. The supinator muscle is innervated by the C5-6 nerve roots and is often available in cases of cervical SCI and injuries of the lower brachial plexus. Additionally, supination function is retained by supination action of the biceps muscle.

Total Laparoscopic Hysterectomy: Making It Safe and Successful for Obese Patients.

OBJECTIVE: To investigate outcomes and ascertain the safety and efficacy on patients having total laparoscopic hysterectomy (TLH), stratified by body mass index (BMI), focusing on high-BMI patients. METHODS: This was a retrospective cohort study that reviewed 2,266 patients with benign gynecologic diagnoses, early cervical, endometrial, and ovarian carcinoma from September 1996 to October 2017. BMI was from 14.5 to 74.2 and were classified as normal or underweight (<24.9); overweight (25.0-29.9); class I obese (>30.0-34.9); class II obese (35-39.9); or class III obese (>40.0). All patients underwent TLH. RESULTS: Patients' characteristics were similar across all BMI classes except for age, postoperative pathological diagnoses, and whether a cystoscopy was performed. Surgical duration, and estimated blood loss were similar across BMI classes. Overweight and obese class III patients had lower odds of staying >1 day compared to patients of normal BMI (OR = 0.65, P = .015). Obese class II patients had fewer complications compared to normal BMI patients (OR = 0.27, P = .013), but patients from other high BMI categories did not show any difference compared to patients with normal BMI. The rate of unplanned laparotomy was statistically, but not clinically, higher in obese class III patients (1.8% versus .7%, P = 0.011), most often due to large fibroids. The mean reoperation rate was 2.7%, with the lowest rate (.5%) among obese class II patients, and the highest rate (3.9%) among the normal BMI patients. CONCLUSION: TLH is feasible and safe for obese women, regardless of BMI. Obesity is not a contraindication to good outcomes from laparoscopic surgery.

Comprehensive laparoscopic lymphadenectomy from the deep circumflex iliac vein to the renal veins: Impact on quality of life.

OBJECTIVE: Compare quality of life metrics for consecutive patients having total laparoscopic hysterectomy, bilateral salpingo-oophorectomy (TLHBSO) with and without comprehensive pelvic/aortic lymphadenectomy (CPALND) from proximal to the distal circumflex iliac nodes and vessels to the renal vessels. METHODS: Analysis of mailed survey responses with 25 validated questions regarding musculoskeletal/lower extremity, gastro-intestinal, abdominal, urological, and energetic/activities of daily living. Data analyzed with Chi-Square tests of Association, Mann-Whitney U tests and follow up regression analysis. RESULTS: Of 533 surveys mailed, 197 (37%) responded; 57 (28.9%) received CPALND. Age and parity were not different between groups, but the TLHBSO group had a higher BMI (31.4 v. 25.8, p<0.001), and were less likely to receive chemotherapy (CT), radiotherapy (RT), or both (CT+RT). In the CPALND cohort, a mean of 47 nodes were removed, of which 26% were positive: 21% pelvic, 11% inframesenteric, 11% infrarenal. Both groups had similar total quality of life total scores of 86/92. Those having CPALND did not report more swelling but they did report more tingling/numbness (2.8 v. 3.5, p<0.001). A series of hierarchical regressions confirmed that CPALND, per se, did not significantly reduce lower extremity scores apart from CT (p=0.402) and CT+RT (p=0.108). However, CPALND did predict for lower extremity swelling after receipt of CT, RT, or CT+RT. Node count, in total, or from each basin, did not correlate with any QOL decrement. CONCLUSIONS: CPALND did not cause lymphedema or a reduction in overall quality of life. Only after controlling for BMI, and receipt of radiation and/or chemotherapy were QOL scores mildly reduced. Routine omission of the distal circumflex nodes from the dissection may account for the low risk of lymphedema from the dissection. Larger prospective studies are needed to determine the optimal staging protocols that address all the likely sites of metastasis and recurrence, and optimize survival, while maintaining our patients' quality of life.

Analysis of a Standardized Technique for Laparoscopic Cuff Closure following 1924 Total Laparoscopic Hysterectomies.

Objective. To review the vaginal cuff complications from a large series of total laparoscopic hysterectomies in which the laparoscopic culdotomy closure was highly standardized. Methods. Retrospective cohort study (Canadian Task Force Classification II-3) of consecutive total and radical laparoscopic hysterectomy patients with all culdotomy closures performed laparoscopically was conducted using three guidelines: placement of all sutures 5 mm deep from the vaginal edge with a 5 mm interval, incorporation of the uterosacral ligaments with the pubocervical fascia at each angle, and, whenever possible, suturing the bladder peritoneum over the vaginal cuff edge utilizing two suture types of comparable tensile strength. Four outcomes are reviewed: dehiscence, bleeding, infection, and adhesions. Results. Of 1924 patients undergoing total laparoscopic hysterectomy, 44 patients (2.29%) experienced a vaginal cuff complication, with 19 (0.99%) requiring reoperation. Five patients (0.26%) had dehiscence after sexual penetration on days 30-83, with 3 requiring reoperation. Thirteen patients (0.68%) developed bleeding, with 9 (0.47%) requiring reoperation. Twenty-three (1.20%) patients developed infections, with 4 (0.21%) requiring reoperation. Three patients (0.16%) developed obstructive small bowel adhesions to the cuff requiring laparoscopic lysis. Conclusion. A running 5 mm deep × 5 mm apart culdotomy closure that incorporates the uterosacral ligaments with the pubocervical fascia, with reperitonealization when possible, appears to be associated with few postoperative vaginal cuff complications.

Infrarenal lymphadenectomy for gynecological malignancies: two laparoscopic approaches.

OBJECTIVE: Compare two approaches for laparoscopic infrarenal lymphadenectomy. METHODS: Retrospective chart review. Statistical analyses with SPSS. PATIENTS: 4 stage II/III cervical carcinoma, 75 clinical stage I/II endometrial carcinoma, 36 clinically stage I/II tubal/ovarian cancer. 36 transperitoneal approaches; 79 extraperitoneal approaches. Both groups had similar age, 58years (range 29-80), BMI of 25 (range 18-41), blood loss, 150cm(3) (range 25-1500), and hospital stay, 1day (range 1-6). The extraperitoneal surgery took longer (240 v 202min; p=.001); yielded more nodes (50 v 41; p=.004). Extraperitoneal approach yielded more inframesenteric (14 v 10; p=.036), and infrarenal nodes (14 v 9; p=.001). 25% of cervical, 19% of endometrial and 14% of ovarian cancer patients had metastases in radiographically negative infrarenal nodes. 50% of cervical, 33% of endometrial and 17% of ovarian cancer patients had therapy altered by aortic lymphadenectomy. When the inframesenteric nodes were positive, 63% of endometrial and 80% of ovarian cancer patients had infrarenal metastases. More metastases were identified with increasing aortic node count. Extraperitoneal lymphadenectomy had no learning curve (p=0.320), while transperitoneal lymphadenectomy did (p=0.016). Higher BMI patients had lower aortic node yields by transperitoneal (p=.057) but not extraperitoneal approach (p=.578). Among the 14 patients whose BMI was 35-41, mean extraperitoneal total aortic nodal yield was 30; transperitoneal yield was 6. CONCLUSIONS: Infrarenal aortic lymphadenectomy may offer higher aortic nodal yields, even in patients with BMI's of 45. Larger prospective studies are needed to confirm whether this dissection in high-risk patients ensures more accurate therapy, and possibly improves cure rates.