Tobacco smoking is one of the most significant public health problems worldwide. The adverse effects of smoking on health are well known.1 According to the World Health Organization (WHO), the annual death toll could rise to more than eight million by 2030, unless urgent action is taken against smoking.2

In Hong Kong, 11.1% of the population aged 15 years or above are daily smokers. Men are the high-risk group and have a 22% prevalence of being smokers, which is much higher than in women (4%).3 The situation is particularly alarming, as the smoking population is becoming younger.3 Smoking contributes a large public health and medical burden to society.

The Hong Kong SAR Government has implemented numerous policies and enacted legislation on many occasions to combat tobacco smoking. Such action has entailed raising tobacco tax, making amendments to the existing Smoking (Public Health) Ordinance to prohibit smoking in public places, restricting the sale of tobacco products and tobacco advertising. While strategies such as taxation and prohibition of advertising are proven to be effective, one effective strategy that should not be ignored is “smoking cessation advice” (SCA) delivered by health care professionals.

Smoking tobacco has been identified as an important cause of various oral diseases and pathologies. It is one of the most important factors predisposing to pre-cancerous lesions and cancer of the oral cavity, the reported pooled cancer risk being 3.4-fold higher than in non-smokers.4 It also increases the risk of periodontal diseases,5 complications after extractions,6 and increased rates of implant failures.7 Cross-sectional studies show that smokers have more tooth loss.8 Other easily recognised effects include staining of teeth,9 dental restorations, and prosthesis10 as well as alteration of taste perception11 and halitosis.12 All these have detrimental effects on the quality of life of smokers because of reduced chewing efficiency, poor aesthetics, and poor self-esteem.13

The benefits of smoking cessation are substantial. Evidence shows that smoking counselling given by dental professions can be effective and comparable to that offered by other primary care professionals.14 15 16 Around a quarter of the population have regular dental checkups and 53% have their teeth checked every 1 or 2 years.17 In their daily practice, dental professionals have access to a large patient population, including smokers. Besides, the detrimental effects of smoking on the oral cavity can be readily demonstrated directly and thus easily appreciated by patients; this acts as a strong motivator to quit smoking.16 Moreover, dental treatments entailing multiple visits provide good opportunities to motivate, reinforce, and support smoking cessation. Thus, dental professionals are in an excellent position for delivering advice and counselling to smokers. Notably, counselling by dentists has been reported to achieve an 8.6% cessation rate after 1 year, and over 16% when also coupled with nicotine replacement therapies.18 Despite these observations, delivery of SCA by dentists remains less than satisfactory.19 20 21 22 According to the literature, the reported barriers to such activity include lack of time, resources, remuneration, training, and fear of damaging dentist-patient rapport.23

In Hong Kong, a study conducted in 2006 showed that more than half of all medical doctors did not have adequate knowledge (53%) or favourable attitudes (55%) towards smoking cessation.24 Slightly over 40% lacked confidence in delivery of SCA. Although 77% of them obtained information on the smoking status of their patients, only 29% advised them to quit smoking, reflecting a low involvement of medical doctors in the promotion of smoking cessation.24

Local published data on the dentists’ attitudes, practices, and barriers to delivering SCA to patients are limited, except for one study by Lu et al.25 The rationale of the present study was to collect data from local dentists, and compare local results with those gleaned from international studies.

The objectives of the present study were: (1) to assess the attitudes of dentists towards SCA; (2) to investigate the current practice of dentists in respect of SCA; (3) to examine the perceived barriers to offering SCA; and (4) to seek possible relationships between the characteristics of dentists and their SCA activity.

A 17-item structured, self-administered and validated questionnaire developed by Stacey et al26 in 2006 in the UK was adopted as the survey instrument. The questionnaire consisted of three main parts: (1) smoking cessation views and activities of the dental team; (2) perceived barriers to giving SCA; and (3) perception of the importance of the smoking cessation role of the dental team and general medical practitioners. It was pilot-tested with a small convenience sample (n=20) of dentists.

The target population consisted of 2026 general dentists registered with the Hong Kong Dental Council, whose correspondence addresses are available on a website27 that is open to the general public. The inclusion criterion was any dentist who was currently having a dental practice in Hong Kong with a valid address at the time of this survey. A systematic sample (every 6th dentists on the list) was drawn from the 2026 registered general dentists in Hong Kong, so as to yield the desired sample size. A sample size of 324 subjects was calculated as needed based on a 5% margin of error (type I error), and 95% confidence level, assuming 50% response after distribution. Thus, 330 questionnaires were mailed in January 2012 with stamped self-addressed reply envelopes. Other means of reply allowed were by fax or by online completion of the questionnaires via a designated website. Another follow-up round of 330 questionnaires was sent to these dentists again 3 weeks after the first mailing.

A pilot study was carried out with a convenience sample (n=20) to ensure the face validity of the questionnaire. Test-retest reliability test was also performed using these 20 subjects who were asked to complete the questionnaire a second time (2 weeks later). The questionnaire was viewed by three experts in dental public health to ensure its suitability for the present study.

All data were analysed with the Statistical Package for the Social Sciences (Windows version 19.0; SPSS Inc, Chicago [IL], US). Frequency distributions were generated to illustrate the demographic data, their attitudes, practices, and perceived barriers in SCA. To examine any relationships between demographic variables and outcomes, unconditional logistic regression analysis was performed with each demographic variable and the outcome variables (attitudes, practices, perceived barriers). Multiple logistic regression was then performed for variables that yielded a P value of <0.25 in the individual analysis. The final model contained those statistically significant variables, using a stepwise-forward Wald logistic regression. The significance level was set at 0.05.

From the 330 selected dentists, 223 questionnaires were returned (163 by mail, 39 by fax, 21 online), of which five were incomplete. Thus, 218 questionnaires were valid for analysis, yielding a response rate of 66%. Alarmingly, less than one fourth of the dentists had received training in SCA. Only 16% of them had received such training during their undergraduate training and only 12% during postgraduate training. Moreover, only approximately 60% of the dentists claimed that they knew the contact of relevant supporting agencies for SCA. Table 1 shows the background of these dentists.

Nearly 97% of the dentists claimed that they would enquire about their patients’ smoking status, yet only around half of them would always do so as a routine (Fig 1). About 97% would enquire about smoking status whenever a patient presented with oral diseases related to smoking (eg periodontal disease and leukoplakia). The percentage of routine enquiries about smoking status when patients presented with oral white lesion (a symptom of oral pre-cancer) was slightly higher (73%) than those presented with periodontal disease (66%).

For dentists who would not routinely enquire about the smoking status, around half (53%) would always do so when patients presented with an oral white lesion, and around 40% would do so when the latter presented with periodontal disease.

For dentists who would always enquire about smoking status, 95% claimed they actually offered SCA. The majority of the dental practices (93%) entailed SCA offered by the dentists themselves, only 16% had dental nurses/hygienists who offered such advice and only 3% had practice managers/receptionists who did so.

After adjustments and exclusion of non-significant variables in the unconditional logistic regressions, only three variables were retained in the final model and were found to be statistically significant. These were the type of practice, receipt of training in SCA, and age. Government dentists, those who had received training in SCA, and those aged over 40 years were more likely to always enquire about their patients’ smoking status (outcome variable of the model, P<0.05; Table 2).

Trained dentists were more likely to always enquire about smoking when patients presented with periodontal disease than non-trained dentists, the respective odds ratio (OR) and 95% confidence interval (CI) being 3.3 and 1.5-7.2. Government dentists were also more likely to enquire about smoking when patients presented with a white oral lesion (OR=2.9; 95% CI, 1.4-6.1).

Similar results prevailed with respect to actually offering SCA to patients. Government dentists offered such advice more often than non-government dentists according to the logistic regression analysis (OR=8.3; 95% CI, 1.1-64.4).

Moreover, government dentists were more likely to know how to contact supporting agencies (OR=2.3; 95% CI, 1.1-4.6) than non-government counterparts, and trained dentists were more likely to know how to contact supporting agencies (OR=14.3; 95% CI, 4.2-48.5) than those non-trained.

A high proportion (89%) of dentists agreed or strongly agreed that the dental team has an important role in delivering SCA to patients; the percentage who agreed or strongly agreed that medical doctors had an important role was slightly higher (93%).

Trained dentists were 8.5 times more likely to think that it was imperative for dental teams to offer SCA (P<0.05). Almost all (98%) of those who received training thought that dentists should offer SCA, which was more than that for those who did not have such training (86%; P=0.014).

When dentists were asked who should offer SCA in the team, most (approximately 90%) claimed that they should be responsible, whilst 41% thought that nurses should also be involved, and 47% felt that hygienists too should be involved. However, only 16% of such personnel were actively involved in offering SCA; the percentages were even lower for receptionists (3%) and practice managers (1%).

Among the potential barriers listed in the questionnaire, the most important one identified by the dentists was the “possibility of losing patients” (31%), followed by the “lack of training” (25%) and the “unlikely to be successful” (14%). On the other hand, the “lack of time”, the “lack of fee”, and the “not perceived as my role” were not regarded as important (Fig 2).

This study gathered information on the current attitudes, practices, and perceived barriers among dentists in delivering SCA to Hong Kong patients, which could have implications for the development of training programmes and provide directions for future research.

The present study showed that Hong Kong dentists generally had positive attitudes and knowledge about SCA, and recognised the adverse effects of smoking on oral health, as reflected by the high percentages for enquiry about a patient’s smoking status. Moreover, nearly 90% expressed positive attitudes towards SCA, in that they agreed it had an important role to play.

Government dentists and dentists who received training were significantly more likely (approximately 3 times) to routinely enquire about a patient’s smoking status than other dentists. Trained dentists were also approximately 14 times more likely to know how to contact local supporting agencies, and more than 8 times as likely to offer SCA to the patients. They also perceived their role in offering SCA as very important and were more actively involved than other team members in its delivery. These results were similar to those for Hong Kong medical doctors,24 as well as findings of other international and local studies.20 21 22 25

This study reflects the importance of training and guidelines, although these were not widely available. Only a small proportion (16%) of dentists received training in SCA during their undergraduate studies. Notably, for local students the limited practical training in essential techniques for delivering SCA to patients was similar to the situation in the United States and Europe.28 29 Research has shown that to increase the effectiveness of SCA, education is needed to expand both didactic knowledge and clinical competencies to help patients quit smoking.30 Evidence also suggests that training should be provided early and continued throughout subsequent courses.31 Inclusion of both theoretical and practical training (counselling skills, problem-solving strategies) should be considered in future undergraduate curricula. Moreover, continuing professional education programmes focusing on hands-on SCA techniques could help dentists acquire better knowledge and more up-to-date techniques. According to the results, the continuing education programmes should be directed towards younger and non-government dentists.

The Department of Health has guidelines on SCA for the government dental officers, which includes annual updating of the patient’s smoking status, provision of SCA, and obtaining patient consent for referral to Tobacco Control Office when needed. This may be one reason government dentists were more likely to enquire about a patient’s smoking status, offer SCA, and confirm the importance of relevant guidelines. As in other countries, many dentists are not familiar with guidelines like the “5A approach”.32 Evidence suggests that dentists familiar with guidelines are more likely to engage in SCA.33 Local information and guidelines on SCA are mostly unclear, as they were not being designed specifically for dentists and may not be readily accessible to them.34 Not surprisingly, only approximately 60% of the dentists knew how to contact supporting agencies. Thus, clear, evidence-based, and easily accessible guidelines designed for the dental profession should be developed to facilitate the effective delivery of SCA by dental professionals.

Recently, a WHO Collaborating Centre for Smoking Cessation and Treatment of Tobacco Dependence was set up by Department of Health. It aims to provide evidence-based smoking cessation training for health care personnel. It also aims to develop, test, and evaluate models of smoking cessation to support WHO’s initiatives on assistance in the dissemination of relevant information on smoking cessation. Hopefully therefore, the dental profession will have more opportunities to receive training in SCA in the near future.35

Despite their apparently positive attitudes to SCA, only around half of the dentists always enquired about each patient’s smoking status and, if indicated, offered SCA. These findings are consistent with those from Australia36 and for Hong Kong medical doctors.24 The difference in the beliefs and the actual practice of dentists suggest barriers to implementation. In the present study, “lack of training”, “possibility of losing patients”, and “unlikely to be successful” were regarded as important barriers by the dentists, and were similar to those reported in the UK26 and Malaysia.20 They suggest that dentists lack confidence in delivering SCA and reinforce the importance of adequate training. Dentists worry that by offering SCA, they might damage relationships with their patients. However, in reality, research indicates that over half of the patients expect their dentists to discuss issues related to smoking.37 Also, such discussion could cultivate rapport between the dentists and the patients. Thus, actually delivering SCA could be very cost-effective in terms of gaining patient trust. To encourage involvement of dentists in delivering SCA, efforts should be directed at reducing the above-mentioned barriers (provision of adequate training, informing the dentists about current evidence, reducing their worries about damaging relationships with patients).

In this study, over 40% of the dentists expressed that other personnel in their teams (nurses, hygienists) should be involved in delivering SCA, though the percentages were lower than those in the UK.26 Thus, dentists generally recognised the importance of the team approach to delivering SCA, and the literature indicates that such team members (including administrative staff) are in a good position to do so.18 38 This is especially true for the hygienists, who are responsible for managing periodontal diseases that are smoking-related and require multiple visits, and therefore offer excellent opportunities to deliver SCA.39 40

The team approach should be encouraged, and as team leader, the dentist has overall responsibility and should actively involve other staff.41 In order to increase the effectiveness, training of the entire dental office team could be considered.42 The proportion of local dentists who thought practice managers and receptionists should be involved was low compared to that reported from the UK.26 Variations in dental clinic organisation in different countries may be part of the reason; for example, locally it is not common to involve dental practice managers in patient care.

As mentioned previously, various aspects of our results were generally comparable to those of other studies. The response rate in the present study was just under 70%, which was higher than 60% reported from the UK,26 and 55% reported from Malaysia,20 as well as 19% reported for Hong Kong medical doctors24 and 50% in another study on Hong Kong dentists.25 Our higher questionnaire response rate could be because the questions were simple, straightforward, and not time-consuming. Notably, the locally developed questionnaire used by Lu et al25 (on Hong Kong dentists) gathered more detailed information than we did.

The relatively low response rate in our study may limit the generalisability of the results, and our sample size was less than ideal. A full population survey should be conducted if resources and time permit. The tendency of respondents to provide positive, favourable responses may be a source of bias, resulting in an over-optimistic estimate of SCA implementation. The characteristics of the non-respondents were not known due to the anonymous nature of the questionnaire. The questionnaire was comparatively simple, and did not address specific aspects of knowledge on SCA, nor any specific aspects of advice offered to patients. This limited the scope of information being collected. Due to time and resource limitations, other important personnel, such as nurses and hygienists, were not surveyed.

A qualitative design could be considered to gain a deeper understanding on the beliefs and barriers to SCA with respect to the dental professions. Thereafter an updated questionnaire could be designed and validated, specifically for the local setting. This could entail specific questions on the knowledge of dentists regarding SCA and the specific activities they and their teams undertake. Further research could also focus on evaluating the effectiveness of different smoking cessation training programmes and practical approaches to SCA.

The present research showed that dentists in Hong Kong generally have positive attitudes towards their role in delivering SCA to patients. However, barriers like the relative lack of training and guidelines, the lack of confidence, and fear of damaging relationships with patients may prevent them from delivering the relevant advice. Local guidelines specifically designed for the dental profession should be developed and relevant resources made readily accessible. More importantly, adequate practical training programmes should be included in both the undergraduate curriculum and continuing education activities, especially for the private and younger dentists.

1. World Health Organization. WHO report on the global tobacco epidemic, 2011: Warning about the dangers of tobacco. Geneva: WHO; 2011.

2. WHO key facts about tobacco. Available from: http://www.who.int/mediacentre/factsheets/fs339/en. Accessed 29 Apr 2012.

3. Census and Statistics Department, Hong Kong. General household survey and thematic household survey, 2011. Available from: http://www.census2011.gov.hk/en/index.html. Accessed Feb 2014.

4. Gandini S, Botteri E, Iodice S, et al. Tobacco smoking and cancer: a meta-analysis. Int J Cancer 2008;122:155-64. CrossRef

5. Bergstrom J. Periodontitis and smoking: an evidence-based appraisal. J Evid Based Dent Pract 2006;6:33-41. CrossRef

6. Johnson NW, Bain CA. Tobacco and oral disease. EU-Working Group on Tobacco and Oral Health. Br Dent J 2000;189:200-6.

7. Reibel J. Tobacco and oral diseases. Update on the evidence, with recommendations. Med Princ Pract 2003;12 Suppl 1:22-32. CrossRef

8. Ylöstalo P, Sakki T, Laitinen J, Järvelin MR, Knuuttila M. The relation of tobacco smoking to tooth loss among young adults. Eur J Oral Sci 2004;112:121-6. CrossRef

9. Eriksen HM, Nordbo H. Extrinsic discoloration of teeth. J Clin Periodontol 1978;5:229-36. CrossRef

10. Asmuseen E, Hansen EK. Surface discoloration of restorative resins in relation to surface softening and oral hygiene. Scan J Dent Res 1986;94:174-7.

11. Pasquali B. Menstrual phase, history of smoking and taste discrimination in young women. Percept Mot Skills 1997;84:1243-6. CrossRef

12. Rosenberg M. Clinical assessment of bad breath: current concepts. J Am Dent Assoc 1996;127:475-82. CrossRef

13. Gerritsen AE, Allen PF, Witter DJ, Bronkhorst EM, Creugers NH. Tooth loss and oral health–related quality of life: a systematic review and meta-analysis. Health Qual Life Outcomes 2010;8:126. CrossRef

14. Needleman IG, Binnie VI, Ainamo A, et al. Improving the effectiveness of tobacco use cessation (TUC). Int Dent J 2010;60:50-9.

15. John J. Tobacco smoking cessation counselling interventions delivered by dental professionals may be effective in helping tobacco users to quit. Evid Based Dent 2006;7:40-1. CrossRef

16. Warnakulasuriya S. Effectiveness of tobacco counseling in the dental office. J Dent Educ 2002;66:1079-87.

17. Census and Statistics Department, Hong Kong. General household survey and thematic household survey, report no. 45. Available from: http://smokefree.hk/UserFiles/resources/smoking_risk_cessation/thematic_household_surveys/THS_45Report.pdf. Accessed Feb 2014.

18. Cohen SJ, Stookey GK, Katz BP, Drook CA, Christen AG. Helping smokers quit: a randomized controlled trial with private practice dentists. J Am Dent Assoc 1989;118:41-5.

19. Allard RH. Tobacco and oral health: attitudes and opinions of European dentists; a report of the EU working group on tobacco and oral health. Int Dent J 2000;50:99-102. CrossRef

20. Ibrahim H, Norkhafizah S. Attitudes and practices in smoking cessation counselling among dentists in Kelantan. Archives of Orofacial Sciences 2008;3:11-6.

21. Uti OG, Sofola OO. Smoking cessation counseling in dentistry: attitudes of Nigerian dentists and dental students. J Dent Educ 2010;75:406-12.

22. Victoroff KZ, Dankulich-Huryn T, Haque S. Attitudes of incoming dental students toward tobacco cessation promotion in the dental setting. J Dent Educ 2004;5:563-8.

23. Watt RG, McGlone P, Dykes J, Smith M. Barriers limiting dentists' active involvement in smoking cessation. Oral Health Prev Dent 2004;2:95-102.

24. Abdullah AS, Rahman AS, Suen CW, et al. Investigation of Hong Kong doctors' current knowledge, beliefs, attitudes, confidence and practices: implications for the treatment of tobacco dependency. J Chin Med Assoc 2006;69:461-71. CrossRef

25. Lu HX, Wong MC, Chan KF, et al. Perspectives of the dentists on smoking cessation in Hong Kong. Hong Kong Dent J 2011;8:79-86.

26. Stacey F, Heasman PA, Heasman L, Hepburn S, McCracken GI, Preshaw PM. Smoking cessation as a dental intervention—views of the profession. Br Dent J 2006;201:109-13. CrossRef

27. The Hong Kong Dental Council. Lists of Registered Dentists in Hong Kong, September 2011. DCHK website: http://www.dchk.org.hk/docs/List_of_Registered_Dentists_Local.pdf. Accessed 2 Jan 2012.

28. Geller AC, Powers CA. Teaching smoking cessation in U.S. medical schools: a long way to go. Virtual Mentor 2007;9:21-5. CrossRef

29. Raupach T, Shahab L, Baetzing S, et al. Medical students lack basic knowledge about smoking: findings from two European medical schools. Nicotine Tob Res 2009;11:92-8. CrossRef

30. Ramseier CA, Christen A, McGowan J, et al. Tobacco use prevention and cessation in dental and dental hygiene undergraduate education. Oral Health Prev Dent 2006;4:49-60.

31. Brown RL, Pfeifer JM, Gjerde CL, Seibert CS, Haq CL. Teaching patient-centered tobacco intervention to first-year medical students. J Gen Intern Med 2004;19:534-9. CrossRef

32. Succar CT, Hardigan PC, Fleisher JM, Godel JH. Survey of tobacco control among Florida dentists. J Community Health 2011;36:211-8. CrossRef

33. Hu S, Pallonen U, McAlister AL, et al. Knowing how to help tobacco users. Dentists' familiarity and compliance with the clinical practice guideline. J Am Dent Assoc 2006;137:170-9. CrossRef

34. Tobacco Control Office, Department of Health, Hong Kong. Health promotion-tobacco control resources centre. Available from: http//www.tco.gov.hk/English/health/health_tcrc.html. Accessed 1 May 2012.

35. Hong Kong Council on Smoking and Health. News update—First WHO collaborating centre for smoking cessation officially launched in Hong Kong. COSH Website: http://smokefree.hk/en/content/web.do?page=news20120410. Accessed 4 May 2012.

36. Trotter L, Worcester P. Training for dentists in smoking cessation intervention. Aust Dent J 2003;48:183-9. CrossRef

37. Rikard-Bell G, Donnelly N, Ward J. Preventive dentistry: what do Australian patients endorse and recall of smoking cessation advice by their dentists? Br Dent J 2003;94:159-64. CrossRef

38. Pizzo G, Piscopo MR, Pizzo I, Giuliana G. Smoking cessation counselling and dental team [in Italian]. Ann Ig 2006;18:155-70.

39. Severson HH, Andres JA, Lichtenstein E, Gordon JS, Barckley MF. Using the hygiene visit to deliver a tobacco cessation program: results of a randomized clinical trial. J Am Dent Assoc 1998;129:993-9. CrossRef

40. Stevens VJ, Severson H, Lichtenstein E, Little SJ, Leben J. Making the most of a teachable moment: a smokeless-tobacco cessation intervention in the dental office. Am J Public Health 1995;85:231-5. CrossRef

41. Campbell HS, Sletten M, Petty T. Patient perceptions of tobacco cessation advice in dental offices. J Am Dent Assoc 1999;130:219-26. CrossRef

42. Wood GJ, Cecchini JJ, Nathason N, Hiroshige K. Office based training in tobacco cessation for dental professionals. J Am Dent Assoc 1997;128:216-24. CrossRef

Ultrasound-guided percutaneous biopsy is a well-established means for diagnosis of focal or diffuse disease in solid organs. It is generally safe and confers minimal risk of complications. However, it is contra-indicated in patients with bleeding tendencies, which means that histological diagnosis may be lacking and sometimes life-saving treatment cannot be commenced. Plugging of the biopsy tract is a promising technique to decrease the risk of post-biopsy haemorrhage, for which Gelfoam is the most commonly used agent. In this article, we share our experience in performing this procedure using Gelfoam slurry followed by Gelfoam torpedo in patients at high risk of post-procedure haemorrhage in our institution.

The Department of Radiology and Organ Imaging, United Christian Hospital, is the main radiology training centre of the Kowloon East Cluster, Hong Kong. Apart from diagnostic imaging, we provide both emergency and elective interventional radiology services. In the form of a retrospective study approved by our local ethics committee, since 2005, it has been our standard practice to plug the biopsy tract in all patients considered at risk of haemorrhage after having ultrasound-guided percutaneous biopsy of a solid organ. Our departmental registry recorded all the cases receiving plugged percutaneous biopsy (PPB) of solid organs performed from 1 January 2005 to 30 September 2012. There was no reported refusal of the procedure by any patient. Demographic data, indication for the biopsy and for plugging of the biopsy tract, details of the biopsy technique, biopsy results, and any episodes of post-biopsy haemorrhage treated by transfusion or any other type of intervention were reviewed for each patient. Relevant details are listed in Table 1.

All PPBs were performed under strict aseptic conditions with instruments as shown in Figure 1. A biopsy path avoiding critical structures and major vessels was selected under ultrasound guidance. The length of the biopsy path starting from the organ capsule to the target region was measured (Fig 2a). A strip of Gelfoam of the same length and with a width of approximately 2 mm was cut from a sheet of Gelfoam. Before being cut, the sheet of Gelfoam was compressed manually to expel all air bubbles. A Gelfoam torpedo was formed by rolling the strip of Gelfoam into a rod-like structure (Fig 2b). The remaining Gelfoam sheet was then cut into tiny pledgets of around 2 mm x 2 mm in size. A syringe filled with Gelfoam pledgets and another syringe filled with saline were both connected to a 3-way stopcock. Macerating the suspension with two syringes and a 3-way stopcock allowed further decreases in size of the pledgets into a slurry (Fig 2c). After the Gelfoam torpedo and slurry were ready, the puncture site was injected with local anaesthetic (5-10 mL of 1-2% lignocaine) and a small skin incision was created. Patients were then instructed to hold their breath while a coaxial introducer needle (17G or 19G, CareFusion; Waukegan [IL], US) was advanced to the target region. The stylet of the coaxial introducer needle was removed, with the outer sheath held firmly in place. A Temno biopsy needle (18G or 20G, CareFusion) was then inserted through the sheath under ultrasound guidance. Biopsy specimens were obtained in a standard manner. After removal of the Temno needle between passes, the stylet of the coaxial introducer needle was reinserted into the sheath to decrease the chance of haemorrhage. After adequate specimens were obtained by inspection, 1 to 2 mL of Gelfoam slurry was injected into the sheath of the coaxial introducer needle (Fig 3). The Gelfoam torpedo was then placed at the hub of the sheath of the coaxial introducer needle (Fig 4a) and pushed by the stylet until the echogenic tip of the stylet was advanced to the organ capsule (Fig 4b). The outer sheath was then withdrawn while keeping the stylet still (Fig 4c), so that the Gelfoam torpedo could be deployed along it and therefore sealing the biopsy tract. Finally, the entire coaxial introducer needle was removed.

During a 7-year period, we performed 11 cases of plugged percutaneous solid organ biopsy in 11 patients, all of whom were considered at high risk of post-biopsy bleeding due to the reasons listed in Table 1. The mean patient age was 58 (standard deviation [SD], 14) years. Three patients were male and eight were female. The target organ was the liver in 10 cases and the spleen in one. The indications for biopsy were to achieve a diagnosis of a focal mass in five cases, and characterisation of diffuse hepatic diseases in six (Table 1). The number of needle passes ranged from one to four, with a mean of 2.5 (SD, 0.9). In all cases, the combination of a coaxial introducer needle and Temno needle (both by CareFusion) were used. The combination of a 17G coaxial introducer needle and 18G Temno needle was used in eight biopsies, while the combination of a 19G coaxial introducer needle and 20G Temno needle was used thrice. All the biopsies were technically successful in obtaining adequate specimens for a histological diagnosis. None of the patients experienced post-biopsy haemorrhage treated by transfusion or any other form of intervention.

Ultrasound-guided percutaneous solid organ biopsy is a well-established means of diagnosing focal or diffuse disease in solid organs. In general, it is safe and confers minimal risk of complications. Major and minor complication (mainly bleeding) rates of 0.8% and 2-3.8%, respectively, have been reported.1 2 Many factors increase the risk of post-biopsy haemorrhage, which can be divided into lesional, technical, and patient-related. Lesional factors consist of peripheral subcapsular location, close proximity to major vessels, hypervascularity, and hypervascular biopsy sites (such as the spleen). Technical factors include increased numbers of needle passes, large needle sizes, use of cutting needles, blind biopsies, and less-experienced operators.3 Patient factors include coagulopathy, platelet dysfunction or thrombocytopenia, medications (eg antiplatelet agents and anticoagulants), chronic liver disease, haematological malignancy, presence of moderate-to- severe ascites, and uncooperative patients.2 4 5 Some studies showed that peripheral blood coagulation indices have a poor correlation with liver bleeding time following laparoscopic biopsy, which might be caused by low regional platelet counts, clotting factor deficiencies in the liver parenchyma, and the lack of mechanical compression of the biopsy tract by inelastic tissue (eg cirrhotic liver).6 Therefore operators should always be prepared for the possibility of significant post-biopsy haemorrhage, even in patients with normal clotting profiles and platelet counts.

Obviously, the main contra-indication to image-guided percutaneous solid organ biopsy is a bleeding diathesis.2 However, histological diagnosis is critical and even lifesaving, by means of achieving correct treatment. In the past, transjugular liver biopsy had been advocated in patients with bleeding diathesis, massive ascites, and poor respiratory control.7 8 However, this has multiple disadvantages. In particular, it is not feasible for liver lesions far from the major hepatic veins. Moreover, it is technically demanding and associated with a high rate of insufficient specimen retrieval for satisfactory histological examination (11.2-29%).7 9 10 11 12 It can also give rise to complications at the puncture site (jugular vein) and induce arrhythmias during right atrial passage. Haemoperitoneum is possible if the liver capsule is perforated, which can sometimes be fatal.

Plugged percutaneous biopsy is an alternative to transjugular liver biopsy in patients at high risk of bleeding.2 8 13 It was first described by Riley et al in 1984.13 In plugged biopsy, the tract is embolised (plugged) after the percutaneous biopsy, thus decreasing the risk of haemorrhage. Multiple studies on PPB have demonstrated at least a 95% success rate in obtaining adequate specimens for histological diagnoses. It is also a safe procedure with a complication rate of less than 2% (Table 27 8 9 14 15 16). It has the obvious advantages of being direct and can be used to biopsy focal hepatic lesions away from major hepatic veins and in other organs. Also, a larger biopsy needle can be used, which increases the chance of obtaining adequate specimens. Finally, it does not involve the vascular system or passage through the right atrium and thus the relevant complications can be avoided.

The most commonly used embolic agent is Gelfoam, which is an absorbable compressed gelatin sponge prepared from purified porcine skin.3 7 It is capable of absorbing up to 45 times its weight of whole blood, and induces haemostasis by speeding up thrombus formation and providing structural support for the clot. Gelfoam is a temporary embolic agent, which is usually completely absorbed within a few days or weeks, depending on the amount used, the degree of saturation with blood, and the application site. It is widely used in tract plugging as it is relatively inexpensive and readily available. It is easy to use and can be prepared in different forms, depending on the site of application. In our centre, Gelfoam was prepared in the form of torpedo and slurry. The Gelfoam torpedo was made from tight rolling of a small strip and used at the site of active bleeding. Due to their larger size, Gelfoam torpedoes can remain at the site of deployment instead of being flushed away by blood. The drawback of the torpedo is that distal embolisation cannot be achieved. In contrast, Gelfoam slurry is suitable for distal embolisation. It can be prepared by mixing tiny Gelfoam pledgets with contrast or saline. Further decrease in size of the pledgets can be created by macerating the suspension with two syringes and a 3-way stopcock. The syringe should be held nose up as Gelfoam floats in fluid. The disadvantage of slurry is that it is difficult to deploy at sites of active bleeding, as the suspension can be flushed away by blood. In our centre, we injected Gelfoam slurry first for distal embolisation and then filled up the rest of the biopsy tract with a torpedo. To the best of our knowledge, plugging of the biopsy tract using a combination of Gelfoam slurry followed by Gelfoam torpedo is a new technique that has not been previously described. Gelfoam is safe to use most of the time, although there is a minute risk of non-targeted embolisation of the biliary or vascular systems and of becoming a nidus for microbial growth.3

Apart from plugging of the biopsy tract, there are other measures to decrease the risk of bleeding in patients undergoing solid organ biopsy. First, as appropriate, we should try to correct any coagulopathy by administration of fresh frozen plasma, platelets, coagulation factors, and vitamin K, whilst also withholding antiplatelet or anticoagulant medications if at all feasible. Although not related to the bleeding risk, red cell or whole blood transfusion should be given before the biopsy to significantly anaemic patients. Next, careful planning of the method of biopsy is important. A safe biopsy path not traversing vessels or critical structures should be sought. Leaving adequate distance of normal parenchyma from the organ capsule and the biopsy site can also help mechanical compression of the biopsy tract by virtue of tissue elasticity, after the needle is removed. We have to strike a balance between the tissue yield and the use of smaller needles. The use of a coaxial system allows multiple needle passes with just a single puncture. Reducing ascites, if present with diuretics or paracentesis, can also decrease the risk of haemorrhage.

One limitation of our study was the small sample size. Second, it was a retrospective observational study without a control group. A large-scale prospective randomised controlled study may be ideal to validate the efficacy and safety of PPB. We share our experience in this small-scale study to raise the awareness of this procedure (especially for those not specialised in interventional radiology), as it shows that PPB is a simple and safe method with a high technical success rate that can help prevent post-biopsy haemorrhage.

Plugging of the biopsy tract with Gelfoam slurry followed by a Gelfoam torpedo is a direct, simple, safe, and effective means of preventing haemorrhage in patients at high risk of post-biopsy haemorrhage.

1. Hatfield MK, Beres RA, Sane SS, Zaleski GX. Percutaneous imaging-guided solid organ core needle biopsy: coaxial versus non coaxial method. AJR Am J Roentgenol 2008;190:413-7. CrossRef

2. Albeniz Arbizu E, Lopez San Roman A, Garcia Gonzalez M, et al. Fibrin-glue sealed liver biopsy in patients with a liver transplantation or in liver transplantation waiting list: preliminary results. Transplant Proc 2003;35:1911-2. CrossRef

3. Azar N, Delman T, Nakamoto D. Transcutaneous management of bleeding after solid organ biopsy what the radiologist needs to know and use. US Radiology 2011;3:53-6.

4. Chuah SY. Liver biopsy-past, present and future. Singapore Med J 1996;37:86-90.

5. Sherlock S, Dick R, Van Leeuwen DJ. Liver biopsy today. The Royal Free Hospital Experience. J Hepatol 1984;1:75-85. CrossRef

6. Ewe K. Bleeding after liver biopsy does not correlate with indices of peripheral coagulation. Dig Dis Sci 1981;26:388-93. CrossRef

7. Zins M, Vilgrain V, Gayno S, et al. US-guided percutaneous liver biopsy with plugging of the needle track: a prospective study in 72 high-risk patients. Radiology 1992;184:841-3.

8. Atar E, Ben Ari Z, Bachar GN, et al. A comparison of transjugular and plugged-percutaneous liver biopsy in patients with contraindications to ordinary percutaneous liver biopsy and an "in-house" protocol for selecting the procedure of choice. Cardiovasc Intervent Radiol 2010;33:560-4. CrossRef

9. Kamphuisen PW, Wiersma TG, Mulder CJ, de Vries RA. Plugged-percutaneous liver biopsy in patients with impaired coagulation and ascites. Pathophysiol Haemost Thromb 2002;32:190-3. CrossRef

10. Lebrec D, Goldfarb G, Degott C, Rueff B, Benhamou JP. Transvenous liver biopsy: an experience based on 1000 hepatic tissue samplings with this procedure. Gastroenterology 1982;83:338-40.

11. Velt PM, Choy OG, Shimkin PM, Link RJ. Transjugular liver biopsy in high-risk patients with hepatic disease. Radiology 1984;153:91-3.

12. Wolska-Krawczyk M, Krawczyk M, Katoh M, et al. Liver fibrosis: how many samples in transjugular liver biopsy are sufficient? Histological vs. clinical value. Abdom Imaging 2013;38:461-4. CrossRef

13. Riley SA, Ellis WR, Irving HC, Lintott DJ, Axon AT, Losowsky MS. Percutaneous liver biopsy with plugging of needle track: a safe method for use in patients with impaired coagulation. Lancet 1984;2:436. CrossRef

14. Tobin MV, Gilmore IT. Plugged liver biopsy in patients with impaired coagulation. Dig Dis Sci 1989;34:13-5. CrossRef

15. Sawyerr AM, McCormick PA, Tennyson GS, et al. A comparison of transjugular and plugged-percutaneous liver biopsy in patients with impaired coagulation. J Hepatol 1993;17:81-5. CrossRef

16. Smith TP, McDermott VG, Ayoub DM, Suhocki PV, Stackhouse DJ. Percutaneous transhepatic liver biopsy with tract embolization. Radiology 1996;198:769-74.