Internal Valve Stenosis Rhinoplasty

In 1894, Franke performed nasal-flow experiments in models and cadavers and found that whirl formation occurred near the head of the turbinate during calm breathing.[2] The term nasal valve was first coined by Mink in 1903.[3] He developed this concept further in 1920, suggesting that the greatest area of resistance was in the limen nasi or the union of the lobular cartilage and ULCs.

In 1940, Uddstromer found that 70% of the resistance of the nose was produced in the nasal valve area and the remaining 30% was due to the nasal fossa. Van Dishoeck further investigated the mechanisms of the nasal valve in 1942, and in 1970, Bridger and Proctor wrote about a "flow-limiting segment" that included the limen nasi and the pyriform aperture. In 1972, Bachman and Legler found the pyriform aperture to have the smallest cross-sectional area of the nasal airway.

In 1983, Haight and Cole continued Bridger and Proctor’s studies and demonstrated that the maximal nasal resistance was localized near the pyriform aperture and depended on engorgement of the head of the inferior turbinate.[4]

Frequency

As many as 13% of the patients with chronic nasal obstruction have nasal valve collapse. Of these patients, 88% have unilateral collapse.

Constantian found, however, that up to 50% of the patients post rhinoplasty had internal nasal valve obstruction.[5]

External nasal valve collapse can be found in patients without a history of trauma or surgery. These patients commonly have an overprojecting nose with extremely narrow nostrils. Another cause, though uncommon, can be an extremely wide columella, as seen in the image below.

Internal nasal valve collapse can be divided depending on the structure that caused the collapse. In many cases, more than one structure is affected. The most common cause is probably septal deviation, as seen in the image below. The second cause is collapse secondary to rhinologic surgery, especially after removal of the nasal roof. Khosh found, in 53 patients, the following causes of nasal valve collapse: previous rhinoplasty (79%), nasal trauma (15%), and congenital anomaly (6%).[6]

Septum

Deviations of the caudal septum are the most common cause of valvular collapse. They are usually secondary to trauma. The septum can be overly thick in the valvular area, decreasing the space in it. Also, an absence of cartilage in this area leaves a flaccid septum that moves during inspiration.

Upper lateral cartilage

Thickened cartilage can compromise an adequate aperture. The cartilage can also be twisted, deflected, or associated with excessive return of the caudal border. An absence of cartilage, either congenital or iatrogenic, can produce a flaccid valve that collapses during inspiration.

Lower lateral cartilage

Overresection during rhinoplasty can weaken the cartilage and cause inspiratory collapse. Deformation of the cartilage can be a result of trauma or congenital malformations of the cartilage. Also, scarring due to surgery can produce the lateral crura to obstruct the nasal valve, as shown below.

Mucosa

Trauma or previous surgery can create webs or stenosis in the valvular area. The tissue can also be too thick, reducing the lumen of the valve. This can be a result of inflammation or hypertrophy. Minman et al describe the presence of a septal body in the valvular area. Benign tissue similar to the turbinates, it can produce stenosis of the nasal valve if the nasal cycle is in the congestive stage.

Inferior turbinate

Hypertrophy of the inferior turbinate can significantly increase nasal resistance. Several studies have demonstrated that the head of the turbinate is responsible for most of this increase. In comparison, the body and tail of the turbinate play minor roles in nasal resistance. The increase in size can be secondary only to mucosa or bone hypertrophy.

Pyriform aperture

Although uncommon, some patients may have deformities of the pyriform aperture that reduce the space of the nasal valve. The first description the authors found of a congenital stenosis of the pyriform aperture was made by Brown et al in 1989;[7] other reports have followed, such as Ramadan, 1995; Fornelli, 2000;[8] and Lee, 2002.[9] A more common cause of obstruction is the osteotomy made during a rhinoplasty. In particular, the type known as low-to-low is blamed for excessive narrowing of the pyriform aperture. Some modifications to this procedure allow an osteotomy to be performed without compromising the space in the valve.

Rhinoplastic procedures are particularly prone to disturbing the nasal valve area. Hump removal affects the nasal valve in several ways. If the hump is particularly large, separation of the ULC can be necessary. Resection of the T-shaped area of the dorsal border of the septum produces a narrower area in the roof. If the mucosa in the valve is not protected during the surgery, which occurred with the use of many older techniques, scarring of the valve can lead to structure formation or stenosis of the valve.

In reduction rhinoplasties, the cross-sectional area of the overall nose is reduced. This increases the resistance to airflow. If the nasal valve is not properly repaired during the surgery, patients may report nasal obstruction after the surgery, even if this was not reported preoperatively. Overresection of the lower lateral cartilage can lead to pinching and inspiratory collapse.

Age is another factor to consider. The relaxation of tissues may eventually produce a flaccid valve. In these cases, surgery of the valve can correct the loss of patency.

The internal nasal valve works as a flow-limiting area. The fixed part of the valve is composed of the septum and the pyriform aperture. The ULC and the mucosa of the turbinate act as the mobile part. When air is inspired, it is forced through this narrow area, increasing its speed and pressure. Just after passing the valve, the air expands in the bony cavum, creating turbulence that promotes contact between the air and the mucosa. In this way, the inspired air is cleansed of particles, humidified, and heated or cooled (depending on its temperature).

Because it is the narrowest part of the nose, the nasal valve can be affected by minute alterations of the nasal anatomy that would not be important in other areas. The angle between the ULC and the nasal septum is 10-52°. Internal nasal valve collapse occurs when, for some reason, this angle is diminished. The result is an increase in nasal resistance to airflow; consequently, the patient reports nasal obstruction. The opposite is known as ballooning. In this case, the nasal valve is excessively open.

The increase in nasal resistance is also related to abnormalities of pulmonary function. These changes in pulmonary function return to normal after septal surgery is performed and nasal resistance is decreased.

Patients primarily report nasal obstruction. Other symptoms are crusting and bleeding, but these are more often associated with septal deviation.

Diagnosis can be difficult if the physician does not visualize the valvular area. Examining the valve without disturbing it with a nasal speculum is important because the speculum usually opens the valve. Sometimes, trimming the vibrissae is necessary to obtain a clearer view of the valve. Another method is to use a 0° endoscope.

The Cottle test is useful to evaluate nasal valve stenosis. The cheek of the evaluated side is gently pulled laterally with 1-2 fingers, which opens the valve. The examiner then asks the patient to breathe and evaluates if breathing is better before or after pulling the cheek. A positive test result is when the patient feels less resistance with the valve opened. This test is easy and quick to perform (see the image below).

The internal nasal valve is limited medially by the nasal septum. Laterally, in its superior part, it is limited by the caudal border of the ULC, where it forms the limen nasi with the cephalic border of the lobular cartilage. The angle between the septum and the ULC is 10-15° in the noses of white persons. Persons of other races demonstrate great variability in this nose measurement, as previously mentioned (22.5-52º). In this area, epithelium shifts from the skin of the vestibule to the respiratory mucosa of the bony cavum.

The pyriform aperture continues the limit of the valve from the ULC to the floor. The head of the inferior turbinate is immediately posterior to the pyriform aperture and plays an important role in the function of the valve, which is the reason it is also considered part of the internal nasal valve (see the image below). In some patients, particularly white persons, the caudal border of the ULC scrolls externally in what is called the returning of the ULC. When this returning is excessive, it can produce valve collapse.

In addition to the typical reasons to avoid surgery (eg, bleeding disorders), other contraindications include the following:

• Excessive scarring due to multiple previous surgeries, which may compromise the outcome of the procedure

• The presence of cheloid scarring

• Unrealistic patient expectations

CT scanning of paranasal sinuses

Axial and coronal views provide good information on the patency of the nasal valve, especially the area under the nasal dorsum (nasal valve area), which is sometimes difficult to visualize. This study is comparatively affordable and can also provide insight into other nasal structures. However, it should not be considered a substitute for a comprehensive physical examination, particularly in the most anterior part of the nose. In the first image below, a normal valvular area can be observed in the axial view. The coronal view (second image) shows a contact area between the right nasal wall and the septum. Both images are from the same patient.

 

Rhinomanometry

This helps to evaluate the airflow resistance offered by each cavity. It is a useful test, but it does not provide information about the location of the obstruction.

A study by Gagnieur et al suggested that the efficacy of four-phase rhinomanometry may be comparable to that of physical examination in determining whether or not nasal obstruction is caused by internal valve collapse. The investigators found that in patients with internal valve collapse, the size of the inspiratory loop area (the “area defined by the path of the flow/pressure curve in the two phases of inspiration”) was significantly greater than in patients with nasal obstruction resulting from a different cause, with the diagnostic sensitivity and specificity of the loop area being 88.3% and 89.9%, respectively.[10]

Acoustic rhinometry

This method was introduced in the late 1980s. Results provide information about the cross-sectional area of the nose. It can provide information about the position of the obstruction. Results from the anterior portion of the nose are more accurate than results from the posterior, making this test particularly suitable for evaluating the valve. Acoustic rhinometry is important to evaluate the symmetry of the areas because the cross-sectional area varies depending on the size of the nose.

The nasal valve is better explored without instruments because tools can open the valve and produce the false impression that the area is normal. A headlight and an endoscope are the only necessary instruments to examine the nasal valve. In many male patients (and some females), the vibrissae are thick, making direct visualization of the area difficult. If this occurs, one option is to trim them until the valve can be visualized.

The Cottle test is a good method to examine the vestibular portion of the nasal valve. It consists of pulling the nasolabial fold upward and laterally and asking the patient if breathing is better (see the image below). An affirmative answer implies that a collapse of the valve is present on that side. A negative answer means the cause of the obstruction is elsewhere in the nose. A false-positive result can occur in patients with collapse of the nasal ala. False-negative results are observed in patients with scars or webs in the valve that prevent it from opening. False-negative results also occur in those with narrowing of the pyriform aperture secondary to congenital malformation or after an excessive narrowing of the nasal base with an osteotomy.

When the valvular collapse is secondary to inflammation of the mucosa covering the valve (eg, secondary to allergic rhinitis or infection), proper treatment, such as anti-inflammatory agents or antibiotics, help to resolve the problem.

Collapse secondary to mechanical obstruction is more common. In this case, surgery is the only solution. Some patients use a self-adhesive stent that opens the nasal valve; however, this is only a temporary solution.

Many techniques can be used to correct a stenotic or collapsed nasal valve. Depending on the type of pathology, the surgeon can choose to use one or several methods. The scope of techniques varies from sutures to the application of grafts. The common goal is to open the valve, restoring the appropriate anatomy. Explaining each technique is beyond the scope of this article; however the following is a summary of these techniques depending on the structure modified.

Valvuloplasty

A valvuloplasty is the surgery historically used to reconstruct the nasal valve. The goal of this surgery is to open the valve by removing the returning ULC and trimming the caudal border of the cartilage. It is not the only technique used to correct valvular alterations, but it provides an excellent view of the caudal border of the ULC and can be used in conjunction with other techniques. Because the valve is formed by several different structures, other techniques may be necessary, depending on the type of deformity that produced the stenosis.

The goal of this procedure is to expose the caudal border of the ULC to correct any deformity (eg, resection of the caudal border of the ULC, excessive returning of the ULC). Steps of this procedure include the following:

1. Expose the caudal border of the ULC through an intercartilaginous incision. Avoid damaging the valvular mucosa in order to decrease the risk of a synechia. Intercartilaginous incisions are better placed 1-2 mm caudal to the border of the ULC. The area of transition from skin to respiratory epithelium is prone to developing unwanted scarring or synechiae.

2. Undermine the skin over the dorsum.

3. To obtain better exposure, gently retract the alar margin of the nostril with a 10- or 12-mm double hook.

4. Grasp the caudal border of the ULC with an Adson-Brown or similar forceps.

5. Dissect the mucosa in the underside of the ULC with the tip of a Walter or curved Iris scissors.

6. Similarly separate the upper side of the ULC from the subcutaneous tissue until the caudal border is completely visible.

7. Repeat the same procedure if the dorsum is visible from both sides.

8. Almost any deformity of the ULC can be identified this way.

9. If a septoplasty or rhinoseptoplasty was performed and the caudal border of the septum was resected, resect a similar amount of the caudal border of the ULC. This maintains the proportions between the septum and the ULC.

10. Resection of the caudal border of the ULC reduces its flexibility. To maintain it, removing a small triangle near the septum is necessary.

11. If another deformity is present, direct surgery to correct it. For example, if the ULC is twisted, a batten may be necessary to straighten it.

12. Spreader grafts can be inserted and fixed through this incision to increase the cross-sectional area of the nose.

13. When intercartilaginous incisions do not allow enough space to see and work because of the complexity of the stenosis, an open approach provides excellent exposure (ie, when spreader grafts and flaring sutures are applied in the same procedure).

14. A dry field is important in this surgery because the space is limited and bleeding can obstruct the visual field and make the procedure time consuming. To avoid this, the cul-de-sac can be infiltrated 5-10 minutes prior to the incision. Apply only a small amount of lidocaine and epinephrine (Octocaine with epinephrine [2%], Xylocaine with epinephrine [2%]). Approximately 0.5 mL is needed in each valve to avoid distortion of the structures. Help from an assistant is invaluable.

15. Suturing of the intercartilaginous incision is performed at the end of the surgery, when all other maneuvers have been completed. Some prefer to use catgut or 4-0 Vicryl with ophthalmic needles. These small curved needles are easy to handle in the confined space of the vestibule.

Spreader grafts

Described by Sheen in 1984, these grafts have proven to be a valuable resource not only to avoid the inverted-V deformity, but also to straighten a twisted dorsum (see the image below) and to increase the cross-sectional area of the valve.

The grafts are placed between the septum and the ULC (see image below), which increases the width of the roof on each side.

Even though the increase is small, it is usually enough to increase the patency of the valve. A common mistake is to make the grafts too wide. Usually, 2 mm is enough to place the suture without breaking the graft. The authors suture the graft with 5-0 nylon (see the image below).

These grafts are used by the main author as the primary method to increase the opening of the valvular area. Most authors use them in open rhinoplasty, as the suturing and placement is easier. However, it is completely possible to place them in a closed rhinoplasty. A retrospective study by Samaha and Rassouli of 100 patients indicated that endonasal placement of spreader grafts is a safe and effective treatment for internal nasal valve insufficiency. In the only aesthetic or functional complications, a cartilaginous dorsal spur was seen in three patients as the graft’s cephalic edge became visible, while in one patient, an ecchymosis developed along the dorsum, producing a hump that resolved in two months.[11]

Another retrospective study, by Talmadge et al, found at minimum 1-year follow-up that improvement in Nasal Obstruction Symptom Evaluation (NOSE) scores did not differ significantly between patients with nasal valve stenosis who underwent endoscopic spreader graft placement and those who were treated with open spreader graft surgery.[12]

Although the original technique uses one graft per side, the authors have occasionally needed to use two in case of a severe collapse of the valve, as shown in the pictures below.

Conchal cartilage butterfly graft

This graft has been found useful by Friedman and Cook in primary rhinoplasty.[13] It has been used traditionally for secondary surgery when too much ULC has been resected. The natural convexity and rigidity of the conchal cartilage is an excellent option to open the ULC.

The technique involves the removing a piece of conchal cartilage, trimming it to the size of the dorsal defect, and beveling the border to smooth the contour of the dorsum. It is applied through an intercartilaginous incision over the ULCs. Because the concave side is facing the ULCs, the upward pull of the graft ends will help open the valves.

A cadaveric study by Brandon et al suggested that in internal valve stenosis, nasal airflow resistance will undergo a greater decrease in association with butterfly grafts (range, 20-51%) than with spreader grafts (range, 2-29%).[14]

Nasal valve lift

A study by Heppt et al indicated that nasal valve stenosis can successfully be treated with a nasal valve lift. In the report, one group of patients was treated with lift only, with absorbable, polylactic acid, self-retaining cone threads employed, while a second group also underwent radio frequency turbinoplasty. In the lift-only patients, the pretreatment visual analogue scale (VAS) score for sense of obstruction averaged 7.2, with this dropping to 2.3 a week after the nasal valve lift and the arithmetic mean reaching 4.0 by 24 months following treatment. In the group that underwent lift plus turbinoplasty, the preoperative VAS score also averaged 7.2, with the arithmetic mean 1 week postoperatively being 2.4, and the average sense of obstruction at 24 months being 3.0.[15]

Normal preoperative examinations are performed, and no special care is required. The surgery is often performed in combination with septoplasty or rhinoseptoplasty. Local or general anesthesia can be used.

Because the valve is formed by several structures, the surgery is directed toward realigning the obstructing parts.

Septum

If a caudal deviation is causing the obstruction, a septoplasty corrects the problem. Septoplasty can be a difficult surgery because caudal deviations are commonly complex deformities of the septal framework and obtaining a completely straight septum proves to be a frustrating task. In some cases, obtaining straight cartilage from the posterior septum and transplanting it is preferable. This is particularly true in those patients with horizontal fractures of the caudal septum (eg, Chevallet fracture). The use of battens is sometimes necessary to keep the repaired septum straight.

Nasal roof

The nasal roof can be excessively narrowed after rhinoplasty or with congenital or traumatic deformities. In these cases, the use of spreader grafts, is particularly useful.[16] They keep the nasal profile straight, and they also increase the cross-sectional area of the entire nasal valve.

Upper lateral cartilage

If the cartilage is thick or if excessive returning of the caudal border of the cartilage occurs, modification is possible by resecting the caudal border and reshaping the valve. This is commonly a surgery performed concomitantly with septoplasty. Also, the previously mentioned spreader grafts can modify the position of the cartilage, allowing the valve to open. In case the cartilage is absent, a graft can be fashioned from septal or auricular cartilage. Another method described to open the nasal valve is to apply a flaring suture that lifts the ULCs. A combination of both techniques has recently been reported to have the best results. The ULC can be sutured using several different techniques, including mattress sutures and suspension sutures.[17]

This last option was described by Paniello and modified by Lee and Glasgold.[18, 19] This option involves a couple of suspension sutures anchored in the soft tissue near the infraorbital rim that lateralizes and elevates the ULC. They reported better breathing in all patients.

Lower lateral cartilage

When the alar cartilage is weakened after surgical overresection or trauma, its rigidity must be restored. The basic method consists of applying a batten of cartilage to keep the lobule rigid during inspiration. A method described by O'Halloran in 2003 consists of the removal of excessive skin in the valvular area through an incision anterior to the LLC.[20]

Inferior turbinate

The simplest procedure is outfracture of the inferior turbinate. A 2009 study by Buyulku performing CT scan after outfracture of the inferior turbinate during septoplasty (before the surgery and 9 months after), found that the average distance from the turbinate to the lateral nasal wall diminished 15-29%.[21] Although this procedure is easy to perform and has minimal complications, if mucosal edema exists, it can be insufficient to allow for an adequate airflow. In these cases, a combination of procedures can be performed.

Although complete resection of the turbinate is best avoided, conservative resection (or manicuring) of the head of the turbinate significantly decreases the total resistance offered by the internal valve. This procedure, when performed properly, is a useful tool when the other areas are difficult to correct. Unless hypertrophy is extremely large, resecting more than 2 cm from the head typically is not necessary because the airflow follows a superior direction afterwards.

When hypertrophy of the cavernous sinuses in the turbinate are the cause of obstruction, several procedures are described to reduce the bulk of the turbinal stroma. Diode-laser, electrocautery, radiofrequency, and coblation are used to produce limited damage to the cavernous sinuses and stroma and reduce the volume of the turbinate after scarring take place. Having used all of them, the lead author has had the best results with coblation. Care should be taken not to apply too much energy with these procedures, in order to avoid a potential turbinal necrosis.

Another method to reduce the volume is with the use of a microdebrider introduced in the head of the turbinate. The device suctions and cuts the stroma, effectively reducing the bulk of the turbinate.

Pyriform aperture

Narrow pyriform apertures should be handled depending on the origin of the constriction. Congenital pyriform stenosis can be produced from an excess of bone. This bone can be drilled away through a sublabial approach. If the stenosis was produced by an excessive narrowing of the nasal bones in a previous surgery, it can be handled with resection of a small wedge of bone in the narrowest area. Another approach is to displace the bones laterally (outfracture) after performing new osteotomies. In this case, performing medial and lateral osteotomies is recommended. If neither procedure is successful, conservative resection of the head of the inferior turbinate is an alternative plan. In many patients, more than one procedure is necessary to open the valve. In 2009, Seren proposed the use radiofrequency in the lateral nasal wall, near the pyriform aperture, to decrease the volume of the tissue in the area.[22]

Synechia or scarring of the mucosa of the valve

This situation is difficult to handle. Obstructive scarring is common after surgery. Resection of the synechia or scarring is performed with scissors. Because some synechia and scars are quite thick, a good method is to clamp the valve with a forceps for 5 minutes before the procedure in order to obtain better hemostasis. Good results have been obtained by separating both sides of the valve with a silicone sheet (Silastic). Because the author routinely uses silicone (Silastic) splints for septal surgery, the splint must simply be cut into a proper shape and size and then sutured to the septum with nylon 3-0 or 4-0 suture. A contralateral splint is recommended to avoid unnecessary damage to the mucosa.

The incisions are closed with 4-0 catgut or Vicryl, preferably with ophthalmic needles to facilitate the closure. A typical dressing is applied for the rest of the nose, depending on the surgery performed (eg, dressing and cast for rhinoplasty).

The need for hospitalization depends on the type of anesthesia used, the recovery of the patient, and the evaluation of the physician. Because the procedure is primarily performed in combination with septoplasty, the same care for this procedure applies.