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Oakley et al.

Benefit: No clear benefit over other materials. Harm: Requires separate donor site. Cost: Moderate (operation room time for harvest). Benefits-harm assessment: Balance of benefits and harm. Value judgments: Surgeon and patient preference. Recommendation level: Option, consider in setting of low flow leaks. Intervention: Use of fat grafting for endoscopic repair of CSF leaks. Bone grafts A review of the literature revealed 5 studies that discussed the use of bone grafts for CSF leak repair. All of these studies were case series. When assessed individually, bone graft success rates were reported as 89% to 100% for first repair 62, 64, 71 and 98% for second repair, 64 similar to over all rates. Germani et al. 55 assessed various combinations of repair materials in their 55 patients, 12 of which in cluded bone. These bone-related repairs had a success rate of 83%. In the study discussed earlier by Kong et al., 58 the tighter closure attained with the “gasket seal method” (fascia overlay with iliac bone as a buttress) gave superior closure results for high-flow CSF leaks than fat grafting. Similar to fat grafts, bone grafts appear to be a good option for repair (Supporting material 4). Aggregate grade of evidence: C (Level 4: 5 studies). Benefit: No clear benefit over other materials. Harm: Requires separate donor site. Cost: Moderate (operation room time for harvest). Benefits-harm assessment: Balance of benefits and harm. Value judgments: Surgeon and patient preference with low level of evidence. Recommendation level: Option. Intervention: Use of bone grafting for endoscopic repair of CSF leaks. Allografts/xenografts One of the main benefits of using allografts or xenografts in CSF leak repairs is saving the patient the morbidity of a donor site. For it to be a valid option, however, the repair success using allografts must match that using autografts. A literature search identified 5 studies pertaining to CSF leak repair with the use of allografts or xenografts, of which 1 is a meta-analysis and 4 are case series. Reliable interpreta tion of data among some of the included studies is difficult because of small case numbers and confounding variables. In the Germani et al. 55 study, 30 patients underwent re pair with the use of acellular human dermis with or without additional layers. Success rate in the allograft group was 97% compared to a 92% success rate in the non-allograft group. The Lorenz et al. 61 study used septal cartilage be tween acellular dermal allograft layers and a mucosal free graft as an overlay, while Eloy et al. 51 used a nasoseptal flap as a final layer. Similarly, Illing et al. 76 used porcine small intestine submucosal grafts in 155 patients, often along

with a nasoseptal flap. All of these techniques showed high success rates. Allografting or xenografting for CSF leaks have high suc cess rates. The costs of the material must be taken into ac count, but has the potential to offset the cost of additional procedure time from harvesting autografts (Supporting material 5). Aggregate grade of evidence: C (Level 2: 1 study; Level 4: 4 studies). Benefit: No clear benefit over other materials, no donor site morbidity. Harm: None. Cost: Moderate additional cost of allograft material. Benefits-harm assessment: Balance of benefits and harm. Value judgments: Surgeon and patient preference with low level of evidence. Recommendation level: Option. Intervention: Use of allograft for endoscopic repair of CSF leaks. Free grafts vs vascularized grafts A total of 39 studies met inclusion criteria for this topic. Of these, 1 was a level 2a meta-analysis, 2 were level 3a systematic reviews, 1 was a level 3b case control study, and 35 were case series. The general finding of these studies was that there is no significant difference in repair success rate between free tissue grafts and vascularized flaps, or for any other repair technique or material used. Results all fell within the standard overall success rate of 70% to 100% on first attempt 4–7,10,20–24,27,39–74 and 86% to 100% on second attempt. 4, 5, 10, 20, 21, 23, 24, 27, 45, 46, 57,63–65,67, 70, 74 There are some caveats to these reported findings, specif ically with regard to defect size and CSF flow rate. In a systematic review of 38 studies, Harvey et al. 7 reported that vascularized flaps provided a superior closure com pared to free tissue grafts for large dural defects, defined as greater than 3 cm. The postoperative leak rate was 15.6% for free grafts and 6.7% for vascularized grafts ( p = 0.002). In most of the other included studies, however, the size of the defect being repaired was poorly defined. Soudry et al. 6 performed a systematic review that included 22 studies and found that although there was no difference in the efficacy of repair methods in the case of low-flow CSF leaks, vas cularized flaps were significantly more successful in closing high-flow leaks than free tissue. In comparing free grafts to vascularized grafts, the overall level of evidence is low, yet the findings are largely consis tent. With the exception of high-flow leaks and large dural defects, vascularized grafts confer no additional advantage over free grafts (Supporting material 6). Aggregate grade of evidence: C (Level 2: 1 study; Level 3: 3 studies; Level 4: 35 studies) Benefit: Large defects and high flow leaks have improved success with vascular flaps. Harm: Potential for donor site morbidity. Cost: Moderate due to increased operation room time.

International Forum of Allergy & Rhinology, Vol. 6, No. 1, January 2016

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