Comparison of Bacterial Inoculation and Transcutaneous Oxygen Tension in the Rabbit S1Perforator and Latissimus Dorsi Musculocutaneous Flaps

Challenging the Dogma of Dead Space Obliteration With Muscle Flaps in Deep Spinal Surgical Site Infections

Background

A deep surgical site infection (SSI) after spinal surgery is a serious complication. The defect formed is often a complex 3-dimensional dead space due to tissue loss, frequently containing spinal hardware. Traditionally, obliteration of that dead space is performed with the use of muscle flaps. We challenge this dogma in reconstructive surgery by using the medial dorsal intercostal artery perforator (MDICAP) flap as an alternative in the reconstruction. It adheres to the concept of replacing "like with like," as there are no muscles at the posterior midline.

Methods

A retrospective study was performed of a cohort of 18 patients with deep SSI and a posterior midline defect after spinal surgery who received reconstruction with the MDICAP flap. A review of postoperative imaging with focus on dead space was performed.

Results

All patients had satisfactory functional and aesthetic outcomes. No patients had a recurrent deep SSI during follow-up (average 64 mo, range 3-384 mo). In the 16 patients who had postoperative imaging performed, dead space was not present at the flaps' recipient site.

Conclusions

The MDICAP flap is a good alternative to muscle flaps in reconstructive surgery for complex posterior midline defects caused by a deep SSI after spinal surgery. Postoperative imaging showed no dead space with the use of MDICAP flaps. All patients had an uneventful postoperative course with no recurrent infections. This challenges the dogmata of (1) the need for muscle flaps in such reconstruction and (2) the obligate need for dead space obliteration at the time of operation.

Muscle vs. Fasciocutaneous Microvascular Free Flaps for Lower Limb Reconstruction: A Meta-Analysis of Comparative Studies

(1) Background: Lower extremity microvascular reconstruction aims at restoring function and preventing infection while ensuring optimal cosmetic outcomes. Muscle (M) or fasciocutaneous (FC) free flaps are alternatively used to treat similar conditions. However, it is unclear whether one option might be considered superior in terms of clinical outcomes. We performed a meta-analysis of studies comparing M and FC flaps to evaluate this issue. (2) Methods: The PRISMA guidelines were followed to perform a systematic search of the English literature. We included all articles comparing M and FC flap reconstructions for lower limb soft tissue defects following trauma, infection, or tumor resection. We considered flap loss, postoperative infection, and donor site morbidity as primary outcomes. Secondary outcomes included minor recipient site complications and the need for revision surgery. (3) Results: A total of 10 articles involving 1340 patients receiving 1346 flaps were retrieved, corresponding to 782 M flaps and 564 FC flaps. The sizes of the studies ranged from 39 to 518 patients. We observed statistically significant differences (p < 0.05) in terms of donor site morbidity and total flap loss with better outcomes for FC free flaps. Moreover, the majority of authors preferred FC flaps because of the greater aesthetic satisfaction and lesser rates of postoperative infection. (4) Conclusion: Our data suggest that both M and FC free flaps are safe and effective options for lower limb reconstruction following trauma, infection, or tumor resection, although FC flaps tend to provide stronger clinical benefits. Further research should include larger randomized studies to confirm these data.

Exenatide improves random-pattern skin flap survival via TFE3 mediated autophagy augment

Random-pattern skin flaps are widely applied to rebuild and restore soft-tissue damage in reconstructive surgery; however, ischemia and subsequent ischemia-reperfusion injury lead to flap necrosis and are major complications. Exenatide, a glucagon-like peptide-1 analog, exerts therapeutic benefits for diabetic wounds, cardiac injury, and nonalcoholic fatty liver disease. Furthermore, Exenatide is a known activator of autophagy, which is a complex process of subcellular degradation that may enhance the viability of random skin flaps. In this study, we explored whether exenatide can improve skin flap survival. Our results showed that exenatide augments autophagy, increases flap viability, enhances angiogenesis, reduces oxidative stress, and alleviates pyroptosis. Coadministration of exenatide with 3-methyladenine and chloroquine, potent inhibitors of autophagy, reversed the beneficial effects, suggesting that the therapeutic benefits of exenatide for skin flaps are due largely to autophagy activation. Mechanistically, we identified that exenatide enhanced activation and nuclear translocation of TFE3, which leads to autophagy activation. Furthermore, we found that exenatide activates the AMPK-SKP2-CARM1 and AMPK-mTOR signaling pathways, which likely lead to exenatide's effects on activating TFE3. Overall, our findings suggest that exenatide may be a potent therapy to prevent flap necrosis, and we also reveal novel mechanistic insight into exenatide's effect on flap survival.

[Flap design and preliminary clinical experience of the lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle]

Objective

To explore the reliability and effectiveness of soft tissue defect reconstruction using the lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle.

Methods

Between December 2014 and December 2019, 13 patients underwent the reconstruction of soft tissue defects in various sites using the lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle. There were 10 males and 3 females, with an average age of 52.1 years (range, 29-83 years). Twelve wounds were resulted from resection of various malignant tumor, including 6 cases of head and neck tumors, 5 cases of shoulder and back tumors, 1 case of chest and back tumors. Among the 12 cases, 4 cases were complicated with wound infection and bone exposure, 1 case with skull defect and cerebral dura exposure, and 1 case with wound infection, skull necrosis, and cerebrospinal fluid leakage. One case was injured in a traffic accident, which resulted in infection wound in the back and shoulder and bone exposure. The sizes of the defect and musculocutaneous flap ranged from 11 cm×7 cm to 23 cm×15 cm and 25 cm×8 cm to 40 cm×14 cm, respectively. According to the spatial relationship between the donor and recipient sites, propeller flaps (8 cases) or percutaneous tunnel island flaps (5 cases) were used to transfer the myocutaneous flap to the recipient area to repair the wound. The donor site was directly closed and sutured in 9 cases, and those with excessive tension were repaired with free skin grafts in 2 cases or transferred flaps in 2 cases.

Results

After the operation, necrosis of the distal 4-cm of the musculocutaneous flap occurred in 2 cases. After debridement, the resultant wounds were reconstructed using a local flap and a posterior intercostal artery perforator flap, respectively. The remaining 11 myocutaneous flaps survived completely without arteries and veins crisis. The wounds in the donor and recipient areas healed by first intention. All the patients were followed up 1 to 48 months (mean, 7.4 months). The color and texture of the flap were good. During the follow-up, 1 patient underwent tumor resection again due to tumor recurrence, and 1 patient with a scalp hemangiosarcoma died due to unexplained thoracic hemorrhage. Tumor recurrence was not found in the remaining patients. The musculocutaneous flap coverage was stable and the infection was controlled.

Conclusion

The lower trapezius musculocutaneous flap carrying a portion of the latissimus dorsi muscle can be an alternation option to reconstruct refractory wounds with exposure of vital structures and organs and infection.

Lumbar Perforator Flaps for Coverage of Extensive Defects With Osteomyelitis

INTRODUCTION

Lumbar osteomyelitis is a rare, although serious condition if not appropriately treated, potentially leading to neurologic complications, such as radiculopathy. Traditionally, studies have suggested the preferred use of muscle or myocutaneous flaps to prevent recurrent infections. However, late evidence suggests that radical debridement and dead space obliteration are more important than the type of flap. The lumbar perforator flap is a reliable local option with low donor site morbidity. It is a powerful tool for local trunk reconstruction, but its use in case of osteomyelitis is scarcely described. We aimed to report long-term outcomes of lumbar perforator flaps to cover lumbar soft tissue defects with chronic osteomyelitis.

MATERIAL AND METHODS

This retrospective investigation was performed on a prospectively maintained database including 7 consecutive patients (10 flaps), all presenting extensive defects of the posterior midline at L2-S1 level (defect size 287 ± 136 cm [average ± SD]). Four patients presented defects after recurrent tumor resection, whereas in 2 patients, the defect was due to vascular jeopardy of internal iliac arteries with consequent necrosis. Last defect derived from debridement of a neglected wound in a paraplegic patient. All patients had concomitant bone infection. Infectious details and postoperative complications were recorded.

RESULTS

Patients were in general poor medical condition (including peripheral arterial disease, hypertension, diabetes, or a combination of these). Eight flaps were raised as propeller perforator, whereas 2 as V-Y perforator. One propelled flap had venous congestion on postoperative day 1 and required a revision surgery to be converted to V-Y. Subsequent partial flap necrosis was treated conservatively. One patient presented a wound dehiscence that required surgical revision. All flaps were closed primarily except for 1 patient whose flap presented a mild intraoperative congestion, which was treated by delayed closure on postoperative day 6, with uneventful outcome. Time to complete healing was 29 ± 17 days (mean ± SD). No flap loss occurred, and all patients benefited from effective coverage at a mean follow-up of 20 months.

CONCLUSIONS

Lumbar perforator flap is a reliable option to cover large soft tissue defects in the lumbar area despite chronic osteomyelitis, with low morbidity and acceptable cosmetic outcome.

Reconstruction of Spinal Soft Tissue Defects With Perforator Flaps From the Paraspinal Region

BACKGROUND/AIM

Reconstruction of spinal soft tissue defects is challenging, especially when neural structures or prosthetic material are exposed. They should be covered with well-vascularized tissue such as paraspinal perforator flaps.

MATERIALS AND METHODS

This is a retrospective study of soft tissue reconstructions with paraspinal perforator flaps from 2011 to 2018. The technique is described and risk factors for poor wound healing were assessed. Postoperative complications are reported.

RESULTS

Twenty patients with a mean age of 63.65 years were included. Defects had an average size of 47 cm² and were mainly located in the lumbosacral region (9 patients). Twelve patients suffered from infection following spinal stabilization, seven of whom were diagnosed with osteomyelitis, two patients presented with pressure sore and one patient experienced wound dehiscence. One partial flap necrosis with a lumbar defect occurred, which required revision surgery. No total flap loss occurred. Stable, closed wounds were achieved at their final follow-up.

CONCLUSION

Perforator paraspinal flaps are suitable for immediate reconstruction of spinal defects.

Free tissue transfer to the lower extremity: a paradigm shift in flap selection for soft tissue reconstruction

INTRODUCTION

The free anterolateral thigh (ALT) skin perforator flap has gained enormous popularity as a free skin perforator flap. Currently being used for various reconstructions primarily in Asia, its routine application for soft-tissue reconstruction of the lower extremity remains unknown in the United States. The purpose of the present study was to review the current trend of flap selection for soft tissue reconstruction of the lower extremity.

METHODS

We performed a retrospective review of a single-surgeon case log between 2007 and 2011 in a tertiary academic medical center. Inclusion criteria were patients who underwent free tissue transfer for lower extremity reconstruction regardless of sex or age. Exclusion criteria were limited to patients with a body mass index greater than 35 kg/m. A total of 20 patients underwent reconstruction with a free tissue transfer for soft tissue coverage of the lower extremity wound were identified.

RESULTS

Fourteen free ALT and 6 free muscle flap reconstructions were performed over a 4-year period. Good reconstructive outcomes resulting in reliable soft tissue coverage were achieved in all patients. It was noted that more ALT flaps were used in the last 2 years and less muscle flaps (0/8 vs 6/12, P = 0.042) when compared with the years prior.

CONCLUSIONS

Although technically more challenging to perform, the free ALT flap has recently been used significantly more for lower extremity reconstruction because of its minimal donor-site morbidity, reliable coverage, and improved contour. This represents a paradigm shift in flap selection that is being highlighted as surgical proficiency in flap dissection technique improves.

Closure of Complex Posterior Midline Defects After Spinal Surgery With Sensate Midline-based Perforator Flaps and the Long-term Results

STUDY DESIGN

Prospective study.

OBJECTIVE

Evaluating the use of a midline-based perforator flap for closure of complex midline defects after spine surgery complicated with implant exposure and deep subfascial infection.

SUMMARY OF BACKGROUND DATA

Traditionally, muscle flaps are used to close complex defects after spine surgery complicated by exposed spinal implants and deep subfascial infections. There are no reports on the long-term results on the use of perforator flaps to close these defects.

METHODS

Information was prospectively registered of all patients in whom a medial dorsal intercostal artery perforator (MDICAP) flap was used for closure of a complex midline defect with exposed spinal implant and deep subfascial infection after spine surgery.

RESULTS

In 9 patients, 10 MDICAP flaps were used. All flaps survived with only 1 flap experiencing marginal flap necrosis. The flaps provided stable coverage of all defects and spinal instrumentation could be retained in all patients. The perforator flaps provided in all patients, except in the patient with a meningomyelocele, protective sensibility in the reconstructed areas. The mean postoperative hospital stay after closure of the defects was 10 days (range 4-21). During follow-up (mean 65 mo, range 7-106) only 1 patient developed an infection in the operated area which occurred 81 months postoperatively. None of the patients had any functional loss at the donor site of the flap.

CONCLUSION

The medial dorsal intercostal artery perforator flap seems to be a reliable alternative for treatment of complex midline defects with exposed spinal implants and deep subfascial surgical site infections. Protective sensibility may be obtained in the reconstructed area with this flap. Donor site morbidity is minimal. In case of recurrence, complex reconstructive procedures using muscle flaps are still possible. The use of this perforator flap may contribute to shorter hospital stays and reduction of costs.

LEVEL OF EVIDENCE

4.

Functional outcomes of posttraumatic lower limb salvage: a pilot study of anterolateral thigh perforator flaps versus muscle flaps

BACKGROUND

Functional outcomes of lower extremity reconstruction compared with amputation have been evaluated. However, there are little comparative data among the different reconstructive options. With the recent increase in perforator flaps, we compared the functional outcomes of muscle and perforator flaps.

METHODS

We conducted a retrospective review of 136 lower extremity trauma patients who underwent reconstruction with either a free muscle or perforator flap during a 7-year period. Forty-two of these patients completed the study. Patients answered the short musculoskeletal functional assessment form and supplemental questions. A physical therapist evaluated performance of physical tasks. Donor site sensation was measured with the pressure specified sensing device. Radiographic fracture union was evaluated by an orthopedic surgeon.

RESULTS

Of the 42 patients enrolled, 20 had coverage with perforator flaps and 22 with muscle flaps. Quality of life and functional outcomes demonstrate no difference (p > 0.05). Ninety-three percent of patients would go through the limb salvage process to avoid amputation. Sensation at the donor site was diminished in all patients; however, the perforator flap donor site had more significant sensory loss (p = 0.005). Time to bony union (p = 0.51), union in the presence of infection (p = 0.85), and infection after flap (p = 0.87) was not related to flap type.

CONCLUSION

Both muscle and perforator flaps provide vascularized coverage, which nourishes the fracture but muscle flaps pilfer a functional unit which may not be inconsequential in a patient trauma. This pilot study suggests that functional outcomes of perforator skin flaps are equal to muscle flaps and a larger prospective study is warranted.

Perforator-Sparing Transposition Flaps for Lower Limb Defects

The local fasciocutaneous flap has the advantage of low donor-site morbidity when used for the coverage of lower limb defects. However, flap reliability remains a major problem with its use. The purpose of this study was to determine the feasibility of preserving perforators to the tip of conventional local fasciocutaneous flaps to improve its vascularity. The technical considerations of raising these flaps were examined in cadaveric specimens. Twenty-one local perforator-sparing transposition flaps were raised in 12 specimens. The leg was divided into knee/proximal-third, middle-third, and lower-third/ankle regions. We raised 7 flaps in each region. Success was defined as ability to transpose flaps to cover defects without tension on the perforators. In the knee/upper-third and middle-third regions of the leg, all wounds were successfully closed. However in the lower-third and ankle region, we were unable to close wounds in 3 of 7 cases. The reasons for this were the inadequate length of the perforator and the presence of tendons in the distal leg that interfered with perforator transposition. We successfully employed this flap in 6 clinical cases. This flap represents a technical advancement over conventional lower limb skin flaps because of its improved vascularity. It can safely be performed in the knee and upper and middle-thirds of the leg and can potentially be a valuable alternative to local muscle flaps for wounds in these areas.

Soft-Tissue Coverage of the Elbow: An Outcome Analysis and Reconstructive Algorithm

BACKGROUND

Soft-tissue defects surrounding the elbow can be a challenging problem for the reconstructive surgeon. Multiple reconstructive options are available, but there are few published outcome studies. The authors performed an outcome analysis of soft-tissue coverage for elbow defects to determine the benefits and limitations of various reconstructive options in this problematic area.

METHODS

A retrospective review was performed of all elbow defects requiring flap coverage from 1988 to 2005. Patient demographics, defect characteristics, type of flaps used, complications, and long-term outcomes were analyzed. The t test was used for statistical comparison.

RESULTS

A total of 99 flaps were performed in 96 patients. Forty-seven percent of the defects were secondary to trauma. Sixty-six percent of the flaps used were pedicled flaps and 19 percent were free flaps. The most common pedicled flap used was the radial forearm flap, whereas the most commonly used free flap was the latissimus dorsi muscle flap. Reconstructive failures occurred in 10 percent of patients; these 10 patients required a second flap for limb salvage. The pedicled latissimus dorsi muscle flap had the highest complication rate (57 percent), with distal necrosis being the most frequent complication. The pedicled latissimus dorsi flap was associated with a higher complication rate when compared with the radial forearm flap (p = 0.01).

CONCLUSIONS

The pedicled latissimus was associated with a high rate of distal necrosis when it was used to cover defects distal to the olecranon. The authors recommend the use of the radial forearm flap or a free flap for soft-tissue coverage of defects lying over the proximal ulna.

Is there evidence-based guidance for timing of soft tissue coverage of grade III B tibia fractures?

The treatment of soft tissue damage associated with severe complicated tibia fractures is a clinical challenge. A recent study of grade III B/C open tibia fractures treated by delayed soft tissue coverage resulted in 20% of patients having osteomyelitis, with a mean follow-up of only 10 months. This study prompted us to review the literature on the association of timing of soft tissue closure in complicated grade III B tibia fractures and the incidence of infections and bone union. A Medline literature search was performed focusing on evidence-based medicine with regard to the timing of soft tissue closure and patients developing bony union and complications such as osteomyelitis. It was difficult to analyze publications with rigor. It appears that the time of surgery has little influence on free-flap failure but that early aggressive debridement followed by soft tissue cover within 3 to 5 days reduces osteomyelitis and delayed bone union. A need for better designed studies is also indicated.