The Drooping Tip
Pertinent anatomy and etiology
The tip, shape, position and definition of a nose are determined primarily by a framework of cartilage, skin and a soft tissue envelope. The “mechanisms” that support the tip of the nose are generally split into two categories: “major” and “minor” tip support mechanisms. The three mechanisms that fall within the major category include the cartilage of the medial and lateral crura, the fibrous attachments of the medial crural footplates to the posterior caudal septum, and the fibrous attachments between the lateral crura and upper lateral cartilages. Minor tip support mechanisms include the interdomal ligaments, the dorsal cartilaginous septum, the fibrous attachments of the lower lateral crura to the pyriform aperture, the attachments between the alar cartilage and the overlying skin and soft tissue envelope, the membranous septum, and the nasal spine.
Whether endonasal or external, rhinoplasty procedures tend to disrupt at least one of the nasal tip’s many support mechanisms, creating risks for unintended outcomes. One of the possible outcomes is a post-rhinoplasty “drooping tip.” To avoid this scenario, surgeons must exercise caution by anticipating and compensating for a destabilized tip, which can result from any of a variety of incisions (standard transcolumellar, intercartilaginous, transfixion, and marginal incisions). Common rhinoplasty maneuvers that tend to destabilize nasal support can include aggressive or overzealous resectioning of the lower lateral cartilage, reduction of the nasal spine or anterior septal angle, and interrupted strip techniques. A ptotic, or drooping, nasal tip can also be caused by gratuitous transfixion incisions. If a surgeon fails to manage excessively long lateral crura or weak and short medial crura, the post-operative result could likewise be a sudden loss of tip support.
Surgical Evaluation and Management
Evaluating a ptotic nasal tip requires extremely thorough examination and palpation to assess the firmness and condition of the tip and determine the size, strength, shape, position, and integrity of the lower lateral cartilages. It is also important to identify the level of scar tissue incurred from a previous surgery. In addition, the nose must be evaluated for its projection, rotation, tip definition, and symmetry of the alar cartilages, the nasolabial angle, alar base width, and nasal length.
Patients with post-operative ptosis will commonly have an underprojected, under-rotated tip with an acute nasolabial angle. Another typical feature of a ptotic nose is a polybeak deformity, which happens when a patient has excessive scar tissue or cartilaginous dorsum. To allow the surgeon to plan prior to the surgery, the pre-operative evaluation should also determine whether the patient has excessive long lateral crura or weak and short medial crura that must be addressed.
Deciding how best to correct a ptotic nasal tip depends primarily on the source of the condition. But in most cases, the surgeon will have to adjust the nasal projection and rotation and restore the tip support mechanisms that were lost in a previous operation. To do this, Dr. Rizk will usually opt to perform an external rhinoplasty, which provides greater exposure when suturing the tip, batten, columellar struts, cap and onlay grafts. It also enables a more precise diagnosis and is particularly useful in cases involving asymmetrical nasal tips.
There are some cases, however, when external surgery may not the best option for managing tip ptosis—cases in which the acute nasolabial angle is caused by a redundant anterior membranous septum resulting from a previous rhinoplasty. To treat this problem, an endonasal approach is preferable to resect the anterior membranous septum through a complete transfixion incision and to place plumping grafts and septocolumellar sutures to maintain tip support and position.
Aside from such cases, the external approach is generally the preferred method for treating drooping tips. To begin, various cartilage grafts are harvested from various parts of the patient’s nose to replace tissue that may have been damaged or missing from a previous surgery. A posterior auricular incision is made to harvest auricular cartilage. Septal cartilage is harvested through a hemitransfixtion incision, if possible, to avoid further instability to any major tip support mechanisms. If a caudal septal deviation is present, the surgeon will free it from the nasal spine, reposition it, and use a 5.0 polydioxanone (PDS) suture to stitch it to the nasal spine periosteum. If the cartilage is weak, more than 1 cm of caudal and dorsal septal strut is left in place. If the septal or auricular cartilage is not enough, irradiated costal cartilage is used in its place.
The external rhinoplasty then proceeds with bilateral marginal incisions that connect in an inverted "v" transcolumellar incision. When excessive scar tissue exists, the dissection plane proceeds just short of the alar cartilages, to avoid thinning of the skin tissue. The dissection continues to the radix, if the dorsum also needs to be modified. When the skin and soft tissue envelope is lifted, a detailed analysis then takes place. Excessive scar bands and contractures are released to mobilize the lower lateral cartilages, which the surgeon will evaluate for strength, integrity, symmetry, and scar tissue, paying close attention to the lateral crura, domes, and medial crura. The skin and soft tissue envelope are also assessed for their thickness and the anterior septal angle for its function in supporting the nasal tip.
The examination of the lower lateral cartilages will determine their integrity, symmetry, excessive resection, or malposition. Any cartilage fragments that have been displaced are freed from the vestibular skin and are realigned, wherever possible. A cephalic trim may be used to correct excessive height in the lateral crura. If the cartilage is strong, at least 7mm of lateral crural vertical height should be preserved; at least 8mm should be preserved if the cartilage is weak. To maintain open airways, alar batten grafts may be used to address over resected lateral crura. Septal cartilage and auricular cartilage grafts are meticulously molded and sutured onto the remnant alar cartilages to ensure symmetry with 5.0 PDS sutures. As needed, inter and intradomal sutures are placed using horizontal mattress sutures (4.0 or 5.0 PDS) to improve tip definition and projection and to correct excessive dome separation or biphidity.
As aforementioned, the lateral crural overlay is an effective technique for correcting excessively long lateral crura that may cause the nasal tip to droop. Overlays can provide increased rotation, deprojection, and increased tip support. After the lower lateral cartilages are freed from the vestibular skin in the middle of the lateral crus, a vertical incision is made in the lateral crus approximately 8mm to 10mm lateral to the dome. The surgeon then repositions the tip and sutures the overlapped margins of the lateral crura with two transcartilaginous horizontal mattress 5.0 PDS sutures.
For patients who develop tip ptosis after rhinoplasty, a columellar strut is often used to reinforce the medial crural component of the nasal tripod, by stabilizing weak medial crura and straightening medial crura that have curled. The strut is positioned in a pocket between the medial crura, extending from just short of the anterior nasal spine to the junction of the medial crura and intermediate crura. The strut is usually stitched to the medial crura using two or three 5.0 PDS horizontal mattress sutures. Preserving the natural divergence of the intermediate crura that forms the infratip break is key to success.
For ptosis patients who experienced an overaggressive resection of the caudal septum in a previous operation, caudal septal extension grafts can help enhance tip support and correct a retracted columella. For those with an acute nasolabial angle, plumping grafts are also helpful to augment the premaxilla.
Tip grafting is a highly effective technique for enhancing the definition of the nasal tip, particularly when there are deficiencies in the alar cartilages. Shield grafts, which are typically placed after the columellar strut is stabilized with sutures, can support tip projection and stabilize a drooping tip. Though, for thin-skinned patients, the graft must be carefully beveled to create a smooth appearance and avoid any unsightly edges.
Sometimes the caudal margins of the medial and intermediate crura must be shaved to create a smooth surface for the graft. Additionally, an ideal graft will have a curve that avoids damaging the infratip in the transition from the medial crura to the intermediate crura. The graft typically requires three sets of sutures—one for each of the caudal margins of the medial, intermediate, and lateral crura. If additional projection is needed, the superior edge of the shield graft can project above the domes. While the graft is in place, continued refinements can be made to address misalignments or asymmetries.
Careful attention must be paid to the supratip. If repositioning maneuvers causes supratip fullness or a polybeak to persist, it is imperative to identify the etiology of the polybeak and correct it. Polybeak deformities are managed by shaving the dorsal septal cartilage in the supratip region. For thick-skinned patients or those who may have developed scar tissue in the supratip from a previous rhinoplasty, measures can be taken to debulk the scar or fibro fatty tissue. This must be performed with caution to avoid visible cartilage graft edges.