Introduction – Paraspinous Flap

• A flap we commonly use for posterior spine coverage, specifically in patients with complex spinal wounds from multiple reoperations, infection, etc. 

• A great option for a complex problem – Quick, straightforward dissection, but shown to significantly improve wound complication rates in spinal closures
• Several variations to this flap which can improve its utility 

• Posterior Trunk Anatomy: 
• Layers from superficial to deep – skin, subcutaneous tissues, superficial fascia 
• “Superficial Muscular Envelope” – Trapezius (upper back) and latissimus (lower back), as well as rhomboids, and serratus posterior 
• DEEP to this we have our paraspinous muscles 
• From medial to lateral – Spinalis, Longissimus, Iliocostalis 
• Originate from sacrum, iliac crest, and spinous and transverse process of lower vertebral levels and insert on the superior spinous and transverse processes of the upper vertebrae, skull base, and ribs 

• Vascular Anatomy: 

• Mathes and Nahai Type 4 muscle flap: 

• Pedicle Dorsal branch of intercostal vessels from the aorta 
• TWO parallel lines of perforators (one medial and one lateral) 

• Muscle can survive on individual perforating vessels from either row, and the medial row is often sacrificed by the spine surgeons especially if laminectomy is preformed  

• Several variations/additions to this flap that can improve its utility 
• Superficial dissection: 
• Trapezius and Latissimus overly these muscle, when mobilizing this flap you can opt to either elevate these muscles off of the paraspinous in continuity with the skin of subcutaneous tissue, or elevate these layers separately – this may allow for an additional layer of closure 
• Fascial Scoring: 
• The paraspinous muscles are covered by a layer of investing fascia that can be “scored” approximately 3cm from the midline to allow for “unfurling” of the muscle, opens like an accordion 
• Closure options 
• Figure of 8 sutures 
• Lambert sutures 
• “Tacking” sutures 

• Postoperative Care 
• Prevena Vac dressing 
• Drains 

 
Questions: 

1. Big picture – Why do you love the paraspinous flap and what are you using it for in your practice? 
2. Practice pattern – what does your referral pattern look like for these cases 
1. Are YOU seeing these wounds in the clinic, taking them for debridement, and then doing your flaps there independently? 
2. Are you called in at the end of a case after the muscle has already been elevated off of the transverse processes and you are coming in and starting from there?  
3. How does you approach differ? 

1. Case Steps: 

1. Markings? 
2. Initial Dissection? 
3. When elevating in plane above the muscle how do you manage latissimus/trapezius? Raise as a composite layer with overlying skin/fat? Independently? 
4. Will you release/divide the paraspinous muscle fascia, do you think this gives you significantly more release? 
5. How far are you dissecting laterally above the paraspinous? 
1. Pearls: 
1. At the flap course you mentioned dividing the muscle and utilizing its segmental blood supply to rotate and medialize the flap into the midline, can you walk us through this? 
2. V to Y closure? 

1. Disaster Cases: 

1. Multiple reoperations, skin edges are terrible and torn up, difficult to distinguish layers – how do you approach this? 
1. Post-op: 
1. Wound vac? Dressing? Suture for closure? 

1. Complications: 

1. Seroma – how many drains do you typically place and in which layers? 
2. Dehiscence? 
1. Other: 
1. What c-spine wounds in your opinion are more amenable to pedicled/rotational trapezius vs paraspinous or trapezial advancement flaps ? 
2. What do you think about prophylactic muscle flap closure in all spine cases? Some spine cases? 

Thanks,