Herbert HM, Rose GE. Air Reflux After External Dacryocystorhinostomy. Arch Ophthalmol. 2007;125(12):1674-1676. doi:10.1001/archopht.125.12.1674
To ascertain the prevalence of air reflux after external dacryocystorhinostomy, its natural history, and its relation to symptomatic cure.
More than a year after lacrimal surgery, patients were contacted via a structured telephone interview and were questioned about air reflux and lacrimal symptoms.
Interviews were completed by 77 patients (98 operations). Postoperative air reflux had been noted after 46 of 98 operations (47%) and persisted in 36 of 46 eyes (78%), at a mean follow-up of 58 months. Reflux occurred in 36% (8 of 22) of eyes after membranectomy, a rate similar to that without membranectomy (38 of 76 eyes; [50%]); the relative risk of air reflux with membranectomy was 0.7 (95% confidence interval, 0.4-1.3; P = .30). Overall, symptomatic improvement was achieved in 85% of procedures (83 eyes). Reflux was associated with a higher success rate (relative risk, 1.22; P = .02) and was significantly less likely to be associated with unchanged or worse symptoms (relative risk of failure, 0.28; P = .03).
Air reflux is common after external dacryocystorhinostomy, is associated with symptomatic success, and generally persists but is rarely troublesome. Membranectomy does not increase the incidence of reflux, suggesting that the valve of Rosenmüller may not act as a 1-way valve for air flow.
External dacryocystorhinostomy (DCR) is a well-established treatment for stenosis or obstruction of the nasolacrimal duct, and good outcomes are expected.1,2 Symptomatic cure is reported in 92% of patients and anatomical success (patency to irrigation) in 95% of patients, including those with “occasional strictures of distal canaliculi requiring simple excision.”3(p1068) A 98% success rate was reported in patients undergoing primary DCR for idiopathic disease, but success was lower in patients with posttraumatic nasolacrimal obstruction (91%) and after revisional surgery (83%).3
Membranous obstruction of the medial end of the common canaliculus occurs where the valve of Rosenmüller becomes adherent to the sac wall; such blockage is treated by membranectomy, with functional success of 85% and anatomical success of 92%.4 To reduce the risk of inflammatory adhesions that cause common canalicular blockage in the early postoperative period, we routinely place silicone tubes at external DCR sites.5 The common canaliculus enters the lacrimal sac obliquely as it passes in a posteroanterior direction,6 the oblique entrance being associated with a flap of mucosa (the valve of Rosenmüller) that is thought to act as a valve by reducing the backflow of tears (or air) from the lacrimal sac into the canaliculi.7,8
Air reflux is a term used to describe retrograde passage of air from the nose to the eye, causing a sensation of cold air, or bubbles, at the inner canthus. It typically occurs with nose blowing after lacrimal surgery and has been described as a test of nasolacrimal patency after DCR.9,10 In some patients, the phenomenon may go unnoticed until they are asked to perform a Valsalva maneuver. We present the first study, to our knowledge, of the incidence of symptomatic air reflux after external DCR, performed using sutured mucosal anastomosis, and relate this symptom to functional success. The frequency is compared for patients with and without membranectomy.
A structured telephone questionnaire was administered, by a single interviewer (H.M.H.), to an unbiased sample of patients who had undergone external DCR with silicone intubation between March 1, 1994, and June 30, 2005; all the operations were performed by a single surgeon (G.E.R.). Each patient was questioned about air reflux and any persisting lacrimal symptoms.
A standard surgical technique was used.4 In particular, a large rhinostomy (>15 mm in diameter) was fashioned in all cases, and anterior ethmoidectomy was performed to allow wide anastomosis of the lacrimal sac and to reduce the risk of “sump syndrome.” The anterior and posterior mucosal anastomoses were sutured using 6/0 soluble sutures, and the internal (sac) opening of the common canaliculus was inspected directly, with excision of any membranous obstruction (membranectomy). Bicanalicular silicone intubation was performed in all cases, and the tubes were removed 4 to 6 weeks after surgery. All the patients received perioperative intravenous antibiotics and a topical combined corticosteroid antibiotic for 2 to 3 weeks after surgery.
Air reflux was defined as the sensation of cold air, or bubbles, in the inner canthus that had been noticed by the patient when nose blowing or straining. We sought to determine an estimated frequency of reflux (daily, weekly, monthly, or rarely), whether it occurred at each nose blowing, and whether reflux was troublesome (no, mildly, moderately, or severely). Where the phenomenon had ceased, an estimated duration of the experienced reflux was sought. Patients were also asked whether they knew how to prevent air reflux and whether they had experienced it before lacrimal surgery.
Persistent lacrimal symptoms were also evaluated. Patients were asked about flow symptoms (persistent watering: none, outdoors only, or indoors and outdoors) and volume symptoms (mucus or stickiness) and whether each was better, the same, or worse than before surgery. The subjective outcome was graded as symptoms that had resolved completely, were better than before, were the same, or were worse; overall functional success was defined as resolved symptoms or improved symptoms and failure as lacrimal symptoms that were the same or worse. Data were analyzed using 2 × 2 contingency tables and the Fisher exact test.
Seventy-seven patients (21 men [27%]) underwent 98 procedures and were available for follow-up at a mean of 58 months (median, 53 months; range, 9-144 months) (Table 1). The underlying diagnosis was nasolacrimal duct obstruction in 52 operations, nasolacrimal duct stenosis in 20, and membranous common canalicular block in 26 (for which DCR with membranectomy was performed). No patient had experienced preoperative air reflux, but it was present in 46 of 98 eyes (47%) after surgery; at follow-up, the symptom persisted in 36 eyes (78%) (Table 2).
With 20 of 46 procedures (43%), reflux occurred every time the nose was blown, and 3 patients reported deliberately inducing air reflux, “to check that the passages were clear,” with the presence of air reflux being reassuring to these and other patients. Most patients (85%) did not consider it troublesome, even if associated with some spattering of their eyeglasses (3 patients); 8 patients had learned to prevent air reflux by pinching the medial canthus or squeezing their eyes shut during nose blowing. In the 10 patients (22%) with late resolution of air reflux, the symptom was present for up to 3 years.
Lacrimal symptoms were cured or improved in 85% (83 of 98) of eyes, and in 4% (4 of 98) of operations the symptoms were worse; the success rates were 86% (65 of 76 cases) for DCR without membranectomy and 82% (18 of 22) when membranectomy was required (relative risk [RR] for success with membranectomy, 0.96; 95% confidence interval [CI], 0.77-1.19; P = .74). Even if improved somewhat, 45% (44 of 98) of eyes had persistent lacrimal symptoms (Table 3), of which 75% (33 of 44) had continued epiphora, 7% (3 of 44) had some volume symptoms (mucus and stickiness), and 18% (8 of 44) complained of both. Of the 41 eyes with persistent epiphora, 26 (63%) were better than before, 11 (27%) were the same, and 4 (10%) were worse. Of the 11 eyes with volume symptoms (mucus and stickiness), 7 were better after surgery, 1 was the same, and 3 were worse (Table 3). Of 83 eyes with a successful outcome, 43 (52%) had air reflux, in contrast to only 2 of 11 eyes (18%) with unchanged symptoms and 1 of 4 (25%) with worse symptoms. Air reflux was significantly more likely to occur with symptomatic success (RR, 1.22; 95% CI, 1.03-1.4; P = .02), and conversely, air reflux was less likely when postoperative symptoms were the same or worse (RR, 0.28; 95% CI, 0.08-0.94; P = .03).
The incidence of air reflux with membranectomy (8 of 22 [36%]) is similar to that without membranectomy (38 of 76 [50%]) (RR, 0.7; 95% CI, 0.4-1.3; P = .30). Reflux after DCR without membranectomy is, however, significantly related to success (RR, 1.24; 95% CI, 1.02-1.5; P = .05), but not for eyes with membranectomy (RR, 1.11; 95% CI, 0.76-1.6; P >.99). For the 83 successful cases alone, reflux occurred in 39% (7 of 18) of those requiring membranectomy and 55% (36 of 65) of those without membranectomy.
Air reflux after open lacrimal surgery seems to be a common condition, occurring in 44% of procedures, but does not seem to cause a significant problem; some patients regard the presence of air reflux as reassuring, and this is borne out by the higher incidence of reflux in successful cases (52%) compared with cases without symptomatic improvement (20%). The frequency of this phenomenon might merit discussion of this “side effect” of surgery during preoperative consent.
The valve of Rosenmüller is thought to prevent tear backflow from the lacrimal sac into the canaliculi, but this investigation suggests that in nearly half the cases it does not function as a 1-way valve for air flow. Our failure to show increased air reflux after membranectomy (removal of the valve) suggests that the absence of air reflux may be due to a mechanism other than the valve of Rosenmüller. With the Valsalva maneuver, the pressure rise in the lacrimal sac area was shown to be greater after DCR than in the normal system,11 suggesting that the valve of Hasner, at the lower end of the nasolacrimal duct, may protect the upper lacrimal system from excessive intranasal pressures. Although surgical manipulation and silicone intubation might have impaired the later function of the valve of Rosenmüller, this is unlikely to have been a major issue in this investigation.
The relatively high incidence (85%) of persistent flow symptoms in this series of patients probably reflects a high proportion of patients with nasolacrimal duct stenosis (functional lacrimal obstruction) referred to a highly specialized ophthalmic practice.
Correspondence: Geoffrey E. Rose, DSc, FRCS, FRCOphth, Lacrimal Clinic, Moorfields Eye Hospital, City Road, London EC1V 2PD, England (email@example.com).
Submitted for Publication: August 16, 2007; final revision received August 31, 2007; accepted September 6, 2007.
Financial Disclosure: None reported.