• Endoscopic modified Lothrop procedure;
  • endoscopic frontal drill out;
  • Draf III procedure;
  • frontal sinusitis;
  • outcomes



The endoscopic modified Lothrop procedure (EMLP; also known as Draf III or frontal drillout) has recently gained popularity as a minimally invasive alternative to frontal sinus obliteration. This systematic analysis was designed to assess the safety and efficacy of the EMLP.

Study Design:

Literature review and meta-analysis.


We performed a search of all English studies published from 1990 to 2008 that reported results from a minimum of five patients undergoing the EMLP. Of the 33 papers reviewed, 18 studies (evidence level II-2 or II-3) containing data from 612 patients met inclusion criteria.


The most common indications for EMLP were chronic frontal sinusitis (75.2%) and mucocele (21.3%). Patients had an average age of 47.9 years (range, 14–89 years) and were followed for 28.5 months postoperatively. Only 20.3% of procedures were performed without image-guidance. Stents were rarely used (6%). The rate of major and minor complications was <1% and 4%, respectively. No deaths were reported. A majority of patients were discharged within 24 hours. Postoperative endoscopic findings, qualitatively reported in 394 patients, demonstrated frontal sinus patency or partial stenosis in 95.9% at last follow-up. Where specifically assessed (n = 430 patients), improvement in symptoms was achieved in 82.2% of cases, with 16% reporting no significant change, and 1.2% reporting worsening of symptoms. The overall failure rate (requiring further surgery) of EMLP was 13.9% (85/612). Of the failures, 80% underwent revision EMLP, whereas 20% elected osteoplastic frontal sinus obliteration.


When performed by an experienced surgeon, EMLP is a safe and efficacious procedure that is well tolerated. Laryngoscope, 2009