Midsternal Incision Closure for Surgical Assistants

First, note that there are many accepted strategies for wound closure. The technique will vary based on the weight of the patient and complexity of the wound. Regardless of the weight of the patient, the midsternal incision should be closed in three distinct layers. These include the deep, presternal fascia layer, the dermal layer, and the subcuticular layer. The suture layers should all run in a continuous fashion. Percutaneous vertical mattress sutures of Prolene are reserved for a few selected patients who have been identified as high-risk for infection or following a washout for a wound complication. In select cases, all three layers are closed with barbed suture.

To begin the procedure, the entire incision is cleaned with antibiotic-soaked laparotomy pad or Ray-Tec. Typically, an antibiotic irrigation containing a third-generation cephalosporin is used. If the patient is MRSA positive on their preoperative screening, then the irrigation will contain Vancomycin. Any superficial debris is then cleared. The incision is then dried with a separate laparotomy pad or Ray-Tec.

The suture that has been selected to close the subcuticular layer is used first. A small but substantial bite is taken on the subxiphoid pectoralis fascia. The suture is tied to itself, thus anchoring the subcuticular suture to the deep fascia. The tail of the suture is then trimmed. The suture is then passed in a backhanded fashion at the ten o’clock position at the level of the subcuticular layer. A shod is then placed on the suture to provide counter tension and keep the suture out of the field. If the closer starts at the cephalad end of the incision then the process is identical, but the initial bite will be anchored to the sternoclavicular muscle/fascia or the periosteum of the manubrium. The subcuticular suture is anchored in the deep layers to reduce overall knot burden and reduce the incidence of knots working their way out in the form of suture abscesses. This is especially important in neonates and infants.

Deep (Pre-Sternal Fascia) Layer

The importance of the deep layer of the midsternal incision, in the presternal fascia/pectoralis, cannot be understated. Ideally, the deep layer suture is a double-armed suture. If so, then the arms of the suture are passed superficial-to-deep at the eleven o’clock and one o’clock positions. No tying is necessary. One arm can be placed on the same shod as the subcuticular suture that has been set aside. Again, this is done to reduce the knot burden. There is not a need to use anything larger than a double-armed 4-0 Polydioxanone in most cases for children approximately 20 kg and below. This rule can change depending on the complexity of the incision. If a single-armed suture must be used, pass the suture in a horizontal mattress fashion through the nadir on the split linea alba/external oblique fascia and tie the suture, ensuring the knot is buried deep. This process is repeated for the dermal layer suture and is set aside. The single arm of the suture is run in a continuous fashion, including superficial bites of the xiphoid. It is important not to take full thickness bites of the xiphoid. This can lead to eversion of the xiphoid which can cause, at minimum, an unsightly deformity, or at worst, a mild pectus carinatum. The presternal fascia is closed with a continuous baseball stitch, superficial-to-deep on the contralateral side and deep-to-superficial on the ipsilateral side. The suture is tightened every three to four bites.

While near the xiphoid, it is paramount to ensure that pacing wires, intracardiac lines, or chest tubes are not included in the bites. Also, as the suture is run cephalad, avoid grabbing the tip of the needle as this will dull the tip quickly and make the remaining suturing an unpleasant experience.

As the suture is run cephalad, the bites will typically transition from linea alba to pectoralis fascia at the level of the body of the sternum. Each bite will gradually become more lateral as the suture is run cephalad from the xiphoid to the body of the sternum.

It is important to ensure that each bite includes fascia. Be disciplined about ensuring that each bite includes the fascial layer. There is no need to have the bite go more than a few millimeters lateral. The more lateral the bites are, the more the tissue will bunch and create unnecessary tension. Check multiple times throughout that the fascia is appropriately reapproximated over the sternal wires without gaps. If there are questions about the strength of the fascial layer, the bites can scythe the periosteum in between sternal wires to offload some of the tension from the fascia. Extreme caution is advised, as the running suture can get caught under the tail of the sternal wire and make for a loose suture or even break the suture.

The suture is then run continuously to the apex of the pectoralis fascia/bilateral sternocleidomastoid origins. The final bite, typically taken on the closer’s ipsilateral side, is taken backhand to allow for the knots to be buried deep. Take care to ensure the final bite only includes the ipsilateral pectoralis fascia/sternocleidomastoid head. It is easy to trap the contralateral side fascia, which then defeats the purpose of burying the final bite. A finger, or instrument, check can be done at the apex of the incision to ensure that there is no space or hole to access the sternum and mediastinal structures. The arm of the suture is then affixed to the drape with a shod, regardless of the closers’ use of a single-arm or double-armed suture.

Dermal Layer

The incision is again cleansed with an antibiotic-soaked laparotomy pad or Ray-Tec. The opposite end of the double-armed suture, or another single-armed suture anchored to the deep fascia, is passed, back-handed, to the ten o’clock position from deep to superficial, exiting in the dermal layer. The suture is then passed forehand from ten to twelve o’clock, then from twelve to two o’clock This can be done in one bite in small patients. This ensures that there are no bare areas over the underlying tissue and reduces the chances of deep knots working their way to the surface.

Bites at the nadir and the apex of the incision are small. Travel only with the length of the needle. Entrance and exit sites should nearly abut. The type of needle will also help dictate the amount of distance that is traveled between bites. For example, a 3/8 circle needle has a longer length than a ½ circle needle. The bites should be small to distribute the overall tension more equally from the wound throughout the suture. More bites equal less tension per bite.

Bites on the contralateral side as the closer are taken backhanded. This is helpful to ensure that the needle is parallel to the dermal plane. This technique also ensures that there are no bite-to-bite level changes occurring. These level changes can cause more superficial or deep tissue to be included in the bite, leading to buttonhooking or dimpling.

The incision is then closed with the continuous subcuticular technique. The entrance and exit sites of the needle on both sides should be level, completely closing off the deep fat layer from being visualized. Ultimately, this will help offload any tension from the subcuticular layer, which should be purely for cosmetic purposes. If possible, the subcuticular layer should not be relied upon to offload tension, although this is not always possible depending on the complexity of the incision. Once the apex of the incision is reached, leaving the bites loose to ensure adequate visualization, a bite is passed forehand from two to twelve o’clock then twelve to ten o’clock. An additional bite is taken at nine o’clock in a superficial-to-deep fashion in the direction of the deep layer suture. The dermal layer is then tied to the deep layer arm, using the deep layer suture as the post of the tie. The single arm of the dermal layer is then passed under the knot and cut at the level of the skin. The remaining arm in the deep layer is reaffixed to the drape.

Subcuticular Layer

The incision is again cleansed with an antibiotic soaked laparotomy pad or Ray-Tec. The suture has already been passed to the ten o’clock position at the subcuticular level. The suture is then passed forehand from ten to twelve o’clock then from twelve to two o’clock. This can be done in one bite in small patients. The bites near the nadir and apex are small bites with nearly no travel between them. Travel only with the length of the needle. Entrance and exit sites should nearly abut. The type of needle will also help dictate the amount of distance that is traveled between bites. Again, the subcuticular layer should have nearly no tension, except for complex redos. The smallest suture possible should be used. Typically, if the patient is less than 3 kg, a 6-0 suture is used. A 5-0 suture is used for most all other incisions. This layer is purely for cosmetic purposes. The incision is then closed with the continuous subcuticular technique identical to the dermal layer.

It is not necessary to grab the skin/subcuticular layer with DeBakey or Adson forceps. The subcuticular layer can be easily everted by pressing on the edge of the incision. This technique avoids any unnecessary bruising or any insult to the integrity of the subcuticular layer. Once the apex of the incision is reached, leaving the bites loose to ensure adequate visualization, a bite is passed forehand from two to twelve o’clock then from twelve to ten o’clock. An additional bite is taken at nine o’clock in a superficial to deep fashion in the direction of the deep layer suture. The subcuticular suture is then tied to the deep layer arm, using the deep layer suture as the post of the tie. The single arms of the deep layer and subcuticular layers are both passed under the knot and cut at the level of the skin.

The incision is finally cleansed with an antibiotic soaked laparotomy pad or Ray-Tec. Steristrips are placed along the length of the incision. The incision is finally covered with a sterile Primapore dressing.

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