To the Editor—We read with interest the elegant study by Iu et al1 on the prevalence and severity of retinopathy of prematurity (ROP) in a tertiary hospital in Hong Kong. Compared with their data in which the incidence of ROP was 16.9% in 89 premature infants screened over 1 year,1 our analysis of 602 infants screened over 7 years2 and another local study of 513 infants over 5 years3 revealed a ROP prevalence of 28.2 and 18.5%, respectively. We would like to highlight the point that the prevalence rates could be related to the case-mix. We had a larger proportion of high-risk infants. Our youngest mean gestational age was 29⁺³ weeks compared with 30⁺² weeks in Iu et al’s study1 and 30 weeks in Yau et al’s study.3 We also had a higher proportion of extremely low birth weight (ELBW) infants (<1000 g; 24.1%2 vs 19.1%1). This may reflect socio-economic differences and the complexity of cases. Among ELBW infants, however, a comparable percentage (70.6%1 vs 71.7%2) developed ROP and treatment rates among the studies were also very similar (3.4%1, 3.8%2, and 3.7%3).

While all three studies adopted the Royal College of Ophthalmologists ROP guidelines,1 2 3 Iu et al1 identified 11 infants who would not have been screened had the American Academy of Pediatrics’ criteria been applied, and none of whom developed ROP. Within our cohort, three of 93 infants who exceeded the American screening guidelines developed ROP with subsequent spontaneous resolution. This highlights the need for future re-evaluation of guideline selection.

1. Iu LP, Lai CH, Fan MC, Wong IY, Lai JS. Screening for retinopathy of prematurity and treatment outcome in a tertiary hospital in Hong Kong. Hong Kong Med J 2017;23:41-7. Crossref

2. Luk AS, Yip WW, Lok JY, Lau HH, Young AL. Retinopathy of prematurity: applicability and compliance of guidelines in Hong Kong. Br J Ophthalmol 2017;101:453-6. Crossref

3. Yau GS, Lee JW, Tam VT, et al. Incidence and risk factors of retinopathy of prematurity from 2 neonatal intensive care units in a Hong Kong Chinese population. Asia Pac J Ophthalmology (Phila) 2016;5:185-91. Crossref

To the Editor–I read with interest the case report by Ng et al1 of a young Indian male who was diagnosed with neurocysticercosis (NCC). The patient presented with headache and monoparesis with no history of fever or seizures. Magnetic resonance imaging delineated a well-circumscribed hypointense cystic lesion with a contrast-enhancing wall and an eccentric intracystic signal with perilesional oedema. Such a characteristic ring-enhancing lesion with eccentric intracystic signal suggestive of scolex is definitive radiological evidence of NCC as per the absolute diagnostic criteria described by Del Brutto.2

Brain abscess, another differential considered by the authors, seems unlikely in the absence of fever. Malignant glioma was another consideration but the lesion was so well demarcated it was dismissed by the authors. In such a case of a young male who was resident in a cysticercosis-endemic area and who had characteristic neuroimaging findings, therapy for NCC in the form of steroids and cysticidal therapy was warranted. There seems to have been no indication for proceeding with craniotomy to excise the lesion. In addition, the patient had no seizures, precluding refractory epilepsy as a justification for surgical intervention. If the entire lesion with firm capsule was excised as stated, and in the absence of any other documented NCC lesion or cysticercosis at any other site such as soft tissue or muscle, there would have been no reason to prescribe cysticidal therapy.

1. Ng EP, Woo PY, Wong AK, Chan KY. Neurocysticercosis in a young Indian male. Hong Kong Med J 2016;22:399.e1-3. Crossref

2. Del Brutto OH. Diagnostic criteria for neurocysticercosis, revisited. Pathog Glob Health 2012;106:299-304. Crossref

To the Editor—Novel psychoactive substances (NPSs) are recently available unlicensed drugs that are chemically or pharmacologically similar to conventional drugs of abuse. Their rapid and protean emergence has created many challenges for clinicians, laboratories, social workers, and regulatory authorities. Our laboratory has repeatedly identified NPSs.1 2 We report the discovery of 2-(diphenylmethyl)-pyrrolidine (desoxy-D2PM), an NPS present in an over-the-counter slimming product available in local convenience stores.

Undeclared desoxy-D2PM was detected in a slimming product branded “B-finn” purchased in Thailand by a patient. Subsequently, we obtained a slimming product of the same brand in a local drugstore and detected the presence of desoxy-D2PM. The Department of Health was notified and a product recall was initiated.3 Shortly after, desoxy-D2PM was detected in the urine specimen of another unrelated patient.

Desoxy-D2PM is structurally related to methamphetamine, which inhibits noradrenaline and dopamine re-uptake. Desoxy-D2PM has been reported to have appetite suppressing, euphoric, and stimulant effects.4 Overdose of desoxy-D2PM may lead to violent behaviour, hallucinations, and sympathomimetic toxicity.4

In Hong Kong, desoxy-D2PM is yet to be listed as a dangerous drug under the Dangerous Drugs Ordinance at the time of writing. Nonetheless its ready availability in drugstores and convenience stores before the recall, and its presence in the urine of an unrelated patient, raise concern about its unintentional use by the general public. This case and our previous local reports of NPS1 2 5 highlight the importance of a toxicology surveillance system in Hong Kong.

1. Tang MH, Ching CK, Tsui MS, Chu FK, Mak TW. Two cases of severe intoxication associated with analytically confirmed use of the novel psychoactive substances 25B-NBOMe and 25C-NBOMe. Clin Toxicol (Phila) 2014;52:561-5. Crossref

2. Tang M, Ching CK, Tse ML, et al. Surveillance of emerging drugs of abuse in Hong Kong: validation of an analytical tool. Hong Kong Med J 2015;21:114-23. Crossref

3. Recall of slimming product with undeclared Western drug ingredients (with photo). 25 Jul 2016. The Government of the HKSAR press release. Available from: http://www.info.gov.hk/gia/general/201607/25/P2016072500603.htm. Accessed Aug 2016.

4. Dargan P, Wood D. Novel psychoactive substances: classification, pharmacology and toxicology. UK: Academic Press; 2013.

5. Poon WT, Lai CF, Lui MC, Chan AY, Mak TW. Piperazines: a new class of drug of abuse has landed in Hong Kong. Hong Kong Med J 2010;16:76-7.

To the Editor—I read with interest a recent article titled “Colorectal endoscopic submucosal dissection at a low-volume centre: tips and tricks, and learning curve in a district hospital in Hong Kong” written by Chong et al1 in the June 2016 issue of the Hong Kong Medical Journal. In this series of 71 patients in whom the colonic endoscopic submucosal dissections (ESDs) were performed in an untutored manner, the overall perforation rate and incomplete resection (R1) rate was 15.5% and 42%, respectively. The authors remarked that similar results had been reported by Berr et al in 2014,2 and claimed they were compared favourably with outcomes achieved by expert centres in Japan. Nonetheless, when we read carefully the quoted publication of Saito et al,3 the perforation rate by the Japanese endoscopist was only 4.9%, and the curative resection rate was up to 89%. I found it an extremely misleading proclamation by the authors that their ESD results were comparable with that of Japanese experts, while their perforation rate was indeed 3 times higher and complete resection rate was only half that in Saito’s series.

It is an undeniable fact that ESD is a new minimally invasive treatment for large adenomatous (including lateral spreading type) colonic polyps. The authors should not encourage performing the procedure without supervision. There are several issues that should raise concern:

(1) There was no mention of any ethics approval application in the article. Did patients undergoing this procedure know that their endoscopist had not undergone formal training beforehand? Did the first cohort of patients know their ESD would be performed on an experimental basis and not under any supervision?

(2) In 2009, there were already a reasonable number of endoscopists in Hong Kong with experience in ESD. Why did the authors insist on starting this procedure in an untutored manner?

(3) In the article, the authors reported that the endoscopist had attended a workshop in which he gained hands-on experience of ESD by attempting the procedure in a porcine model. It is common knowledge that most of these workshops held by various training centres are by no means a legitimate reason to start a new high-risk procedure by the novice. They are just educational programmes that aim to enhance the knowledge and interest of delegates in new therapeutic technology. The authors’ recommendation to start performing a novel invasive procedure without formal training and expert coaching goes against the current trend of accreditation and credentialing in advanced endoscopy.4

1. Chong DH, Poon CM, Leong HT. Colorectal endoscopic submucosal dissection at a low-volume centre: tips and tricks, and learning curve in a district hospital in Hong Kong. Hong Kong Med J 2016;22:256-62. Crossref

2. Berr F, Wagner A, Kiesslich T, Friesenbichler P, Neureiter D. Untutored learning curve to establish endoscopic submucosal dissection on competence level. Digestion 2014;89:184-93. Crossref

3. Saito Y, Uraoka T, Yamaguchi Y, et al. A prospective, multicenter study of 1111 colorectal endoscopic submucosal dissections (with video). Gastrointest Endosc 2010;72:1217-25. Crossref

4. Kumta NA, Yamamoto H, Haber GB. Training the next generation of Western endoscopists in endoscopic submucosal dissection. Gastrointest Endosc 2014;80:680-3. Crossref

To the Editor—An untutored approach to acquire a new technique is the worst choice yet it is inevitable when “a reasonable number of endoscopists” with expertise in endoscopic submucosal dissection (ESD) is not available. “Formal training” in terms of workshop attendance and animal model practice was the best available training while “expert coaching” remained a utopia in Hong Kong before 2009 when there was no single endoscopist who had performed more than 35 colorectal ESDs. The only published data on colorectal ESD in Hong Kong was derived from 65 patients over a 4-year period, from 2010 to 2013, and reflected the absence of an expert prior to 2010.1 As stated in our paper, “The low case volume and the absence of expertise in western countries leads to the development of untutored colorectal ESD when it is impossible to have a step-up approach in ESD training starting from the stomach before proceeding to colon.”2 The untutored approach is not an experimental trial that requires ethical approval. Both the endoscopist and the patient should be well prepared with facilities available before the start of such a new procedure, and patient safety is a top priority. From the endoscopist’s perspective, acquirement of knowledge and technique through workshop attendance, continual animal model hands-on training, clinical observation at an expert centre, and a low threshold of conversion to hybrid technique (endoscopic mucosal resection) for unfavourable lesions should be ensured. This was reflected in our reported first learning curve where 57.7% of patients needed to undergo the hybrid technique for en-bloc resection. From the patient’s perspective, careful patient selection, full explanation of the traditional and new treatment option with informed consent for immediate conversion to traditional laparoscopic colectomy if required should be offered. This is why ESD should be performed in an operating theatre with an anaesthetist in attendance. It can allow one-stop treatment in case of failure to remove the lesion or if complications arise. In our case series, two patients were cured by one-stop treatment and made an uneventful recovery.

Perforation is considered the major morbidity in ESD. Saito et al3 quoted an immediate perforation in 54 (4.9%) patients and delayed perforation in four (0.4%) with an overall perforation rate of 5.3% in a multicentre study of 1111 patients from 1998 to 2008.3 If we look at an earlier paper by Taku et al4 on iatrogenic colonoscopic perforation in Japan from 1999 to 2003, ESD perforation occurred in six out of 43 patients at a perforation rate of 14% and is comparable with our series. In our paper we concluded “Untutored colorectal ESD at a low-volume centre was an option in the absence of enough experts to supervise the procedure... When more endoscopists have gained experience in colorectal ESD, a structured training programme with accreditation can be established.” Seven years after we started the procedure, structured guidelines for management of early gastrointestinal (GI) cancers are finally available.5 In the section on endoscopist’s credentialing process, structured training in ESD includes (1) attendance at workshops dedicated to early GI cancer training; (2) animal model hands-on training; (3) dedicated centre observation; and (4) minimal 10 cases of successful and non-complicated ESD under supervision before being independent, preferably started from the rectum. When untutored colorectal ESD will cease in Hong Kong, it will remain an option in other countries with insufficient experienced supervisors.

1. Hon SS, Ng SS, Wong TC, et al. Endoscopic submucosal dissection vs laparoscopic colorectal resection for early colorectal epithelial neoplasia. World J Gastrointest Endosc 2015;7:1243-9. Crossref

2. Chong DH, Poon CM, Leong HT. Colorectal endoscopic submucosal dissection at a low-volume centre: tips and tricks, and learning curve in a district hospital in Hong Kong. Hong Kong Med J 2016;22:256-62. Crossref

3. Saito Y, Uraoka T, Yamaguchi Y, et al. A prospective, multicenter study of 1111 colorectal endoscopic submucosal dissections (with video). Gastrointest Endosc 2010;72:1217-25. Crossref

4. Taku K, Sano Y, Fu KI, et al. Iatrogenic perforation associated with therapeutic colonoscopy: a multicenter study in Japan. J Gastroenterol Hepatol 2007;22:1409-14. Crossref

5. Task Force on Endoscopic Diagnosis and Management of Early GI Cancers, Hospital Authority. Guidelines on endoscopic diagnosis and management of early GI cancers and guidelines on handling and pathological examination of endoscopic submucosal dissection (ESD) specimens for GI neoplastic lesion. Hong Kong: Hospital Authority; 2015.

To the Editor—I thank Ho et al1 for their very interesting article “Prevalence of pre-sarcopenia and sarcopenia in Hong Kong Chinese geriatric patients with hip fracture and its correlation with different factors” in the February 2016 issue of the Hong Kong Medical Journal. I would like to mention another recent sarcopenia study in elderly Chinese men and women with a mean age of 81 years. The research group led by Hong et al2 showed that 42% of female patients and 84% of male patients with hip fracture were sarcopenic. In this study, the prevalence of sarcopenia with vertebral fracture was 34% in women and 40% in men. I agree with the authors that screening measures should be implemented more.1 In a general practice setting, measurement of SARC-F sarcopenia scale is feasible, simple, quick and inexpensive, and does not expose the patient to any particular strain (Table).3 The scale has also been evaluated in elderly patients in Hong Kong with direct measurement of muscle mass, strength, and physical performance.4 5 If a SARC-F score of ≥4 has been measured in an older patient, diagnosis of sarcopenia can be substantiated rather quickly.3 In my opinion, the SARC-F screen for sarcopenia should be routinely carried out among the Chinese elderly population every time they consult their doctor.

1. Ho AW, Lee MM, Chan EW, et al. Prevalence of pre-sarcopenia and sarcopenia in Hong Kong Chinese geriatric patients with hip fracture and its correlation with different factors. Hong Kong Med J 2016;22:23-9. Crossref

2. Hong W, Cheng Q, Zhu X, et al. Prevalence of sarcopenia and its relationship with sites of fragility fractures in elderly Chinese men and women. PLoS One 2015;10:e0138102. Crossref

3. Malmstrom TK, Morley JE. SARC-F: a simple questionnaire to rapidly diagnose sarcopenia. J Am Med Dir Assoc 2013;14:531-2. Crossref

4. Woo J, Leung J, Morley JE. Validating the SARC-F: a suitable community screening tool for sarcopenia? J Am Med Dir Assoc 2014;15:630-4. Crossref

5. Woo J, Leung J, Morley JE. Defining sarcopenia in terms of incident adverse outcomes. J Am Med Dir Assoc 2015;16:247-52. Crossref