Modifications of the paraspinous muscle flap: anatomy and clinical application

Single Surgeon Comparison of Midline Versus Overlapping Locoregional Flap Closure Following Spinal Instrumentation

BACKGROUND

Two techniques for paraspinous muscle flap closure of spine surgeries have been described: one with tension-free mobilization of the muscle flaps approximated at the midline and one with perforators more aggressively dissected to allow for overlapping of the flaps. We seek to compare the surgical outcomes in patients who underwent either type of complex spinal closure as no investigation has yet evaluated a superior technique.

METHODS

An institutional review board (IRB)-approved retrospective analysis was conducted on all patients who underwent spine surgery followed by locoregional muscle flap complex closure performed by a single plastic surgeon between January 2016 and July 2021. Patients were divided into 2 groups based on which closure method was employed. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed by multivariable logistic regression with Firth's correction.

RESULTS

One hundred and 10 patients with similar baseline demographics were included. There were significantly more smokers (15% vs. 0%, P = 0.02) and a significantly greater rate of postoperative radiation (40% vs. 17%, P = 0.009) in the overlapping group. After controlling for smoking and postoperative radiation, the incidence of surgical site infection, skin necrosis, dehiscence, hematoma, and seroma did not differ between the groups. The procedure length per centimeter of closure was shorter in the midline approximation group, although this data fell just short of significance (3.2 vs. 3.8 minutes/cm, P = 0.08).

CONCLUSIONS

The present study demonstrates that both the overlapping and midline approximation of muscle flaps are equally safe and effective strategies for locoregional closure of spinal wounds.

Paraspinous muscle flap for the treatment of an empyema cavity: three case reports

A surgical option is commonly chosen when conservative medical therapy for empyema is impossible. The muscles used include the latissimus dorsi, trapezius, and pectoris major, based on the size and location of the empyema cavity. However, these volumes are decreased in patients suffering from malnutrition, and flap dissection and elevation are sometimes invasive. Therefore, we developed an alternative method, and present three successful cases in which we used a pedicled paraspinous muscle flap to fill the dead space caused by empyema fenestration in the medial region of the back. The paraspinous muscle flap remains an important tool in reconstruction. However, such flaps should be created only in selected cases, such as those with empyema in the posterior region. Also, if the pleural space is large, additional muscle flaps will be required.

Paraspinous muscle flap for the treatment of an empyema cavity

For the reconstruction of defects localised near the midline region of the back, there have been occasional reports of reconstruction using a paraspinous muscle flap; however, to the best of our knowledge, there have been no reports of empyema space reconstruction using a paraspinous muscle flap. A patient who developed empyema after a pulmonary lobectomy and in whom a paraspinous muscle flap was used to reconstruct a dead space in the medial region of the upper back created by fenestration is presented. The dead space was filled sufficiently, and the patient had a favourable course without complications. Although the rotation arc of the paraspinous muscle flap is limited, the flap's blood flow is stable, and flap elevation is easy and less invasive. The paraspinous muscle flap is useful for filling and closing a defect near the midline region of the back.

Salvage of Infected Spinal Hardware With Paraspinous Muscle Flaps

PURPOSE

Infected spinal stabilization devices represent a significant reconstructive challenge by threatening spinal stability and increasing the risk of neurologic complications. This study provides an anatomic and clinical investigation of posterior midline trunk reconstruction using paraspinous muscle flaps as the primary method of repair.

METHODS

We retrospectively analyzed a series of 25 consecutive patients (mean age, 57.2 years; range, 32-78 years) with complex spinal wounds, reconstructed with paraspinous muscle flaps, at a single university healthcare system. To help define the versatility of these muscle flaps, we also performed cadaveric dissections with lead oxide injections in 10 specimens, with an emphasis on regional blood supply, flap width, and arc of rotation.

RESULTS

From 1994 to 2000, we successfully reconstructed 25 patients with complex spinal wounds, using 49 paraspinous muscle flaps as the primary method of reconstruction. Hardware present in 22 patients was replaced or retained in 17 cases. Long-term spinal fusion with preservation of neurologic status was observed in all patients, with no cases of dehiscence or reinfection. Wound complications included cerebrospinal fluid leak (1), skin necrosis (1), sinus tracts (3), and seroma (2). Mean length of stay was 24 days (range, 8-57 days). One postoperative death occurred. Paraspinous dissections and injections confirmed a segmental type IV blood supply with medial and lateral perforators, arising from intercostal vessels superiorly and lumbar and sacral vessels inferiorly. Flap width was 8 cm at the sacral base, 5 cm at the level of the inferior scapular angle, and 2.5 cm at the first thoracic vertebra.

CONCLUSIONS

Paraspinous muscle flaps can be used as the primary reconstructive option to cover and preserve spinal hardware, control local infection, and enable long-term spinal stabilization. Cadaveric dissections confirmed the usefulness of paraspinous flaps, which can be based upon lateral or medial perforators and can be safely mobilized to reliably reconstruct complex spinal wounds.

The Bipedicled and Bipartite Latissimus Dorsi Free and Perforator Flap: An Anatomic Study

BACKGROUND

The purpose of this study was to search for an enhanced blood supply in the distal one third of the latissimus dorsi and, thus, to have a closer look at the muscular branches of the intercostal vessels.

METHODS

The muscle branches to the latissimus dorsi muscle arising in the "costal groove" segment of the three lowermost intercostal vessels (ninth to eleventh interspaces) were identified bilaterally in 28 fixed hemithoraces (84 interspaces). In the interspaces, the perforators 0.5 mm or greater were localized and dissected free to their junction with the intercostal source vessels. The number of branches was recorded and external diameters of branches and source vessels were measured.

RESULTS

At least one big muscular branch to the latissimus dorsi was found in every hemithorax. In the tenth and eleventh interspaces, at least one branch was found in all cases; in the ninth interspaces, one branch was found in 93 percent of cases. A second big branch was found in approximately half of the ninth and tenth interspaces, and in one fourth of the eleventh interspaces. The external mean diameter of the muscular branches at their branching point from the source vessel was 1.5 mm for the artery and 1.8 mm for the vein.

CONCLUSIONS

The versatility of the latissimus dorsi muscle can be enhanced by including intercostal vascular branches of the intercostal groove segment into the flap design. The latissimus dorsi can be harvested as a bipedicled free flap; thus, it allows the harvest of two separate bipartite, independent muscle, musculocutaneous, or perforator flaps.

Paraspinous muscle flaps for the treatment and prevention of cerebrospinal fluid fistulas in neurosurgery

STUDY DESIGN

A prospective clinical study was conducted to evaluate the efficacy of paraspinous muscle flaps in preventing and managing cerebrospinal fluid fistulas in high-risk neurosurgery patients.

OBJECTIVES

To evaluate the efficacy of paraspinous muscle flap coverage using a "vest-over-pants" closure in the prevention and treatment of cerebrospinal fluid fistulas.

SUMMARY OF BACKGROUND DATA

Previous studies have described paraspinous muscle flaps for the closure of complex spinal wounds, but none has addressed their use for the prevention and treatment of cerebrospinal fluid fistulas.

METHODS

This prospective clinical study evaluated nine consecutive patients with either refractory cerebrospinal fluid fistulas or high risk for cerebrospinal fluid leaks after spinal surgery. Bilateral paraspinous muscle flaps were used as primary flaps and closed using an overlapping vest-over-pants technique in eight of nine cases. The latissimus dorsi and trapezius muscles were recruited as additional muscle flaps for closure of thoracolumbar and high thoracic deficits, respectively.

RESULTS

Paraspinous muscle flaps provided immediate wound coverage in seven high-risk patients undergoing spinal surgery and two patients with recurrent cerebrospinal fluid fistulas. Postoperative hospitalization averaged 14.4 days. There was no evidence of a cerebrospinal fluid fistula after an average follow-up of 176.7 days. No wound infections occurred. The only complications were a superficial hematoma, which was drained percutaneously on postoperative day 6, and a seroma, which was drained during the follow-up period and eventually resolved.

CONCLUSIONS

Paraspinous muscle flaps allow effective treatment and prevention of cerebrospinal fluid fistulas in selected high-risk patients and provide simple durable coverage of complex spinal wounds with minimal morbidity.