When the Bone Flap Hits the Floor

To the Editor:

We read with interest Jankowitz and Kondziolka's (⁷) article, “When the Bone Flap Hits the Floor,” and the accompanying comments in the September 2006 issue of Neurosurgery. As pointed out by the authors, dropping a bone flap is a rare and serious occurrence. We were somewhat surprised, however, by the authors' conclusions and by the commentaries, which suggested that safe reuse of a dropped flap was a fait d'accompli.

Our hospital policy on this subject relies on the surgeon's own risk-benefit assessment of reusing the dropped tissue. If replacement with an alternate piece of tissue or synthetic material is possible, we recommend that the tissue be discarded (³). Thus, a bone flap would be replaced by a mesh cranioplasty. If a tissue cannot be replaced, such as a donor organ, the implantation must proceed ahead after appropriate processing of the tissue.

What is the risk posed to the patient by reusing a dropped flap and what is appropriate processing of this tissue? Despite having read Jankowitz and Kondziolka's article, we do not know the answer to either of these questions. None of the methods described in their review have been investigated or validated to an extent to which they can be recommended for clinical practice. Of the nine patients in their study who did not go on to cranioplasty or for whom follow up information was not available, only one was followed for more than 1 year. Given that bone flaps are attached using wires, the Centers for Disease Control and Prevention require that these patients be followed for at least 1 year when tracking surgical site infections (¹⁰). Furthermore, passive retrospective determination of wound infections is notoriously inaccurate. An active prospective surveillance program whereby all patients are contacted postoperatively by someone other than their surgeon is recommended to determine whether or not infections may have developed postoperatively (⁸). Finally, given that the expected rate of post-craniotomy infection ranges from 1.72 to 2.40 infections per 100 procedures (¹⁰), any study that attempts to accurately measure the impact of dropped flaps on infection rates would require much larger numbers.

There is evidence that some of the recommended techniques may actually be harmful; both povidone-iodine (^4,5) and chlorhexidine (^9,11,12) antiseptics have been linked to outbreaks and, paradoxically, can act as growth media for resistant organisms. Tissues may be damaged by autoclaving, which is one reason why ethylene oxide or gamma irradiation are recommended for tissue banking (¹). Furthermore, bloody tissues may also continue to harbor viable organisms, despite exposure to sterilization temperatures in an autoclave (²).

If the tissue must be reused, we recommend washing it with sterile saline and antibiotics, as this is the safest choice and will theoretically decrease microbial burden without further contaminating the tissue or damaging it (⁶). Antibiotics may assist in decreasing the microbial burden even further. One may also consider continuing administration of postoperative antibiotics for a longer duration than normal.

In an era of increased focus on patient safety issues, there is the question of liability risk for poor patient outcomes owing to the reuse of dropped tissue. In the absence of sound and reliable evidence for the best practice regarding reuse, whereby patient safety may be put at substantial risk, the precautionary principle would suggest that the most prudent course of action is to avoid using the dropped tissue unless there is no alternative. In this era of evidence-based practice guidance, we all must resist the temptation to suggest treatments, even “soft” guidelines based solely on Class 3 evidence. Whatever decision is made regarding reuse of the tissue, full disclosure to the patient of actions taken and reasons why, must occur.

1.

American Association of Tissue Banks: Standards for Tissue Banking. Mclean, American Association of Tissue Banks, 2002.

2.

Association for the Advancement of Medical Instrumentation: Good Hospital Practice: Steam Sterilization and Sterility Assurance. Arlington, Association for the Advancement of Medical Instrumentation, 1994.

3.

Bernstein M: The drop attack. CMAJ172:668–669, 2005.

4.

Centers for Disease Control (CDC): Contaminated Povidone-Iodine Solution–Texas. MMWRWeekly38:133–134, 1989.

5.

Craven DE, Moody B, Connolly MG, Kollisch NR, Stottmeier KD, McCabe WR: Psudobacteremia caused by povidone-iodine solution contaminated with Pseudomonas cepacia. N Engl J Med305:621–623, 1981.

6.

Hirn M, Laitinen M, Pirkkalainen S, Vuento R: Cefuroxime, rifampicin and pulse lavage in decontamination of allograft bone. J Hosp Infect56:198–201, 2004.

7.

Jankowitz BT, Kondziolka DS: When the bone flap hits the floor. Neurosurgery59:585–590, 2006.

8.

Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR: Guideline for prevention of surgical site infection, 1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J Infect Control27:96–134, 1999.

9.

McAllister TA, Lucas CE, Mocan H, Liddell RH, Gibson BE, Hann IM, Platt DJ: Serratia marcescens outbreak in a paediatric oncology unit traced to contaminated chlorhexidine. Scott Med J34:525–528, 1989.

10.

National Nosocomial Infections Surveillance System: National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2004, issued October 2004. Am J Infect Control32:470–485, 2004.

11.

Sobel JD, Hashman N, Reinherz G, Merbach D: Nosocomial Pseudomonas cepacia infection associated with chlorhexidine contamination. Am J Med73:183–186, 1982.

12.

Vigeant P, Loo VG, Bertrand C, Dixon C, Hollis R, Pfaller MA, McLean AP, Briedis DJ, Perl TM, Robson HG: An outbreak of Serratia marcescens infections related to contaminated chlorhexidine. Infect Control Hosp Epidemiol19:791–794, 1998.