Without question, the introduction of open rhinoplasty has increased the emphasis on preservation and support of existing structure in rhinoplasty. The unparalleled view afforded by open rhinoplasty has decreased the learning curve of surgeons in the most difficult of plastic surgery procedures to achieve commendable results. However, open rhinoplasty has the disadvantage of increased operative time, prolonged postoperative swelling, and loss of nasal tip support if compensatory measures are not performed. In addition, open rhinoplasty patients may have more scar contracture from complete degloving of the soft tissue of the nose, resulting in asymmetries revealed after long healing periods.
Traditional endonasal rhinoplasty is a classic reductive operation, frought with a steep learning curve, and difficulty in achieving natural symmetric results. Many of the concepts introduced by external rhinoplasty have now been incorporated with endonasal rhinoplasty approach. The advent of structure concepts in modern day endonasal rhinoplasty techniques has increased the versatility of endonasal rhinoplasty and allowed for more predictable control of postoperative tip position.
Structural concepts integration into endonasal rhinoplasty allows for more predictable outcomes in rhinoplasty surgery.
Base stabilization and control of projection
A key concept fundamental in all types of rhinoplasty is stabilization of the nasal base. Stabilization of the nasal base helps in maintaining projection. This concept has been discussed in detail in regards to external rhinoplasty but has not been addressed in endonasal rhinoplasty.
The support of the nose has classically been divided into major and minor tip support mechanisms. The major tip support mechanisms include the length and strength of the lower lateral cartilages, the ligamentous articulation between the medial crus and septum, and the ligamentous attachment of the lower lateral cartilages and upper lateral cartilages. Recently these mechanisms have been questioned. Dyer showed that the major tip support mechanism
Many maneuvers in rhinoplasty disrupt ligamentous support and consequently result in loss of tip projection. Rhinoplasty can be destabilizing. Beatty, Dyer and Shawl examined tip support with various maneuvers in rhinoplasty. The found that division of the ligamentous attachments between the lower lateral cartilages resulted in 25% loss of tip support. Recontouring of these fibers increased tip support by 33% and the addition of a columellar strut further increased support by 44% from preoperative levels. This study found that open rhinoplasty approach was not destabilizing in of itself, but did not examine separation of the fibers between the lower lateral cartilages.
Adams, Rohrich, and associates found that external rhinoplasty was more destabilizing than endonasal rhinoplasty in the setting of a fresh cadaver. The mean loss of tip projection for the open approach was 3.43 mm versus 1.98 mm for the closed approach (p < 0.001). There was a significantly larger loss of tip projection in open versus closed procedures for cephalic trim, cephalic trim and interruption of the lower lateral cartilages, and cephalic trim with interruption of the lower lateral cartilages and septum removal (p < 0.001, 0.001, and 0.001, respectively). Septoplasty itself was found to be the most destabilizing maneuver of all rhinoplasty maneuvers in both endonasal and external rhinoplasty techniques.
Many primary noses operated on have poor projection preoperatively. A recent study by Constantian demonstrated that 66% of patients he treated had underprojected nasal tips based on comparison of the nasal tip to the anterior septal angle. Based on that study, inherent tip supporting mechanisms in the majority of patients seeking rhinoplasty can be deemed to be weak preoperatively and must be fortified postoperatively in order to prevent any untowards sequlae. The combination of poor tip projection with further loss of projection due to disruptive rhinoplasty techniques illuminate the need for stabilization of the nasal base in rhinoplasty.
In patients with adequately projected nose or slightly overprojected noses, the tongue in groove maneuver provides powerful stabilization and additional support to the tip. The technique was originally described by Kridel and associates. The key concept is that the medial crura overlap and are fixated with the stable septum. If the septum is weak caudally or off midline, other techniques may be preferred.
One of the most difficult aspects of endonasal surgery is predicting postoperative tip position. The majority of nasal tips in the postoperative period will lose projection and counterrotate to some degree. This phenomenon is dependent on the relative size and strength of the medial crus to the lateral crus. If the medial crus is small in relation to the lower lateral cartilages, it will remain a challenge to maintain projection and an appropriate naso-labial angle. If the medial crus are long in relation to the lower lateral cartilages, the tip will likely stay with an open nasolabial angle postoperatively.
In order to compensate for this postoperative loss of projection, a transient tongue in groove suture technique is necessary. Dissection takes place between the medial crura. The tip is positioned along the septum in the location to provide appropriate rotation, projection, counter rotation. Typically, a rapidly absorbable suture, such as a 4-0 chromic will be used to position the tip in a slight overly rotated and projected position. The purpose of the chromic suture is to allow for early scarification to occur between the medial crus and the septum, the most significant tip supportive mechanism. The nasal tip will lose projection and counterrotate over a period of weeks.
In some instances, a permanent suture can be used to suture the medial crus directly to the nasal septum. It is important when using a permanent suture to make sure that the suture remains submucosal. The disadvantage of this suture is that placement requires additional dissection along the lateral surface of the medial crus.
In patients with dependent tips and require substantial strength, a longer absorbing suture can be used such as a 4-0 PDS may be advantageous. This suture has the advantage of increased strength, often necessary in thick skinned patients. The disadvantage is that the suture, when placed transcutaneously, is an irritant to the skin and will cause columellar erythema postoperatively.
In patients who are underprojected preoperatively, a columellar strut may be necessary to allow for appropriate projection. The placement of columnar struts allows for increased strength in projection of the nose. The strut is usually placed in combination with a tongue in groove procedure to provide maximal tip support.
There are two basic methods of placing a columellar strut. The first method is to place the strut over the nasal tip into a pocket in the columella. This method provides a moderate degree of support. The second method involves dissection through the medial crus on one side and placement of the strut between the medial crural space. This technique allows the strut to be placed spring-loaded and allows for restoration of the nasal tip projection. This technique will provide more support than the former technique.
A extended tip graft is sometimes necessary for further projection. It differs from a shield graft in several manners. A shield graft is sutured to the underlying nasal tip structure. As open rhinoplasty complete degloving of the nasal skin, eventual contraction of the skin will lead to visibility of the tip graft if it is not camouflaged appropriately. The endonasal rhinoplasty has less contraction than the external approach. Consequently, the tip graft is less likely to become visible. The difficulty in endonasal approach is camoflauge. Crushed cartilage can be placed along the tip graft to provide appropriate. The graft should be thinned to curve given the infratip lobula a gentle bend.
In certain cases it may be necessary to place a double-layer tip graft or an onlay tip graft.
The challenge in placement through an endonasal technique lies in placing the grafts in a precise pocket. A precise pocket allows for the graft to be in the precise position in the postoperative period. Unfortunately, a precise pocket mandates that a relatively thick piece of cartilage is placed and camoflauge techniques are very difficult. A more ideal situation is to place the graft in an ideal position and then secure it through the nasal tip with suture stabilization.
Resupport of lower lateral cartilage weakness
Recognition of cephalically postioned cartilages is an important factor in both aesthetic and functional recontouring of the nose. Constantian described the “parenthesis deformity” as occurring in 46% of patients with the axis of the lower lateral cartilage directed toward the medial canthus rather than the lateral canthus.
Without placement of alar batten grafts, several consequences are likely to occur. First of all, the alar margins are likely to contract cephalically leading to alar retraction. The ala will become weaker and external nasal valve collapse is a potential sequlae. Finally, accentauation of the alar crease in an abnormal medial location will lead to a paradoxically rounder more bulbous appearing nose.
Severely cephalically positioned cartilages are best approached from an open approach. This is due to several complex repositioning maneveurs which . Constantian describes repositioning of the alar cartilages via an endonasal approach. However, this technique
Mildly cephalically rotated cartilages, may benefit from placement of alar batten grafts. Placement of alar batten and rim grafts will provide increased triangularity and structure to the nose and prevent the unwanted sequlae.
Addressing internal nasal valve and middle vault deficiencies
There is no question that placement of spreader grafts is more difficult throught an endonasal approach. In cases of airway obstruction, the endonasal approach is acceptable for placement of the graft. However, in severly deviated noses, disarticulated upper lateral cartilages, the endonasal technique is very difficult.
Endonasal rhinoplasty has long been considered a reductive operation. With the introduction of cartilage grafting and support and better understanding of nasal dynamics, endonasal rhinoplasty can be performed in a predictable manner. The advantages of shorter operative time, less prolonged postoperative swelling, less postoperative skin contracture have allowed endonasal rhinoplasty to continue to serve a prominent role in addressing nasal deformities.
“The nose should fit the face”
A strong jawline would suggest a stronger nose.