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Queen Mary Hospital, Hong Kong SAR

Introduction: Breast cancer patients with positive sentinel lymph nodes (SLNs) traditionally will undergo completion axillary dissection (ALND). The ACOSOG Z0011 trial has shown that those who underwent breast conservative surgery but did not undergo ALND did not fare worse compared to the ALND group when the axillary nodal burden is low. The aim of this study is to evaluate the change in peri-operative costs with application of Z0011 guidelines.

Methods: A retrospective analysis from our prospectively maintained database at a University affiliated government subsidized breast cancer centre was performed. Patients who received upfront breast conservative surgery with sentinel lymph node biopsy (SLNB) between January 2010 to June 2019 were included. A peri-operative cost analysis was performed.

Results: There were 491 patients in our cohort. Sixteen patients were excluded as their sentinel lymph nodes were positive on immunohistochemistry only. All patients received intraoperative frozen section of SLNs. One hundred and six patients had at least one positive SLN on final histology. Applying the Z0011 criteria, seventy-five patients (70.8%) met the ACOSOG Z0011 criteria for omission of ALND and 31 patients (29.2%) would have required a delayed completion ALND. Around HKD 3400 per patient could have been saved with the reduction in intraoperative frozen and ALND (cost of processing frozen section and dispensable operative costs). This could also translate into a 63% reduction in overnight hospital stay.

Conclusions: Application of Z0011 guidelines result allows less intraoperative frozen section and ALND, and is associated with a reduction of peri-operative costs.

Prince of Wales Hospital, Hong Kong SAR

Background: Superior mediastinal dissection around bilateral recurrent laryngeal nerve has been proposed for squamous cell carcinoma (SCC) of the esophagus. However, dissection during minimally invasive esophagectomy (MIE) is technically difficult. Our department introduced this method during MIE since Oct 2017. We aim to compare the outcomes of MIE with or without superior mediastinal dissection with propensity score matched analysis.

Methods: Patients who underwent MIE with R0 resection for SCC esophagus were recruited from 2004-2019. Patients were divided into two groups: with or without superior mediastinal dissection. Propensity score matching between groups was performed with age, sex, tumor staging and use of neoadjuvant therapy as the factors in a 1:2 ratio. Post-operative outcomes including morbidities, mortality, hospital stay, 1-year overall and disease-free survival were compared.

Results: Eighty nine patients fulfilled the criteria (Extended dissection n = 19, limited dissection, n = 70). After propensity score matching, 38 patients in the limited dissection group were identified. The mean age was 63.9 ± 6.5 with male predominance (93.0%). 47.4% received neoadjuvant chemoradiation. The tumor stage was comparable. More lymph nodes were retrieved in the extended dissection group. Surgical complications were similar but a higher rate of anastomotic leakage was noted in the extended dissection group. One-year disease free survival showed a better trend in the extended dissection group.

Conclusions: MIE with extended mediastinal lymphatic dissection is a safe procedure, even after neoadjuvant chemoradiation, without significant increase in complications. The disease free survival appeared to show improvement. However, a longer follow-up is required to draw a solid conclusion.

Queen Mary Hospital, Hong Kong SAR

Aim: Postoperative wound hematoma after elective thyroidectomy is a potentially life-threatening and poses a concern for adopting elective thyroidectomy in outpatient setting. The present study aimed to evaluate time of onset and risk factors of wound hematoma after elective thyroidectomy.

Methods: From 1981 to 2020, 6210 consecutive patients underwent elective thyroidectomy. Of these, 60 (1.0%) developed wound hematoma shortly after surgery (Group I) while the remaining did not (Group II). Time of onset was defined as the time between when thyroidectomy ended and hematoma was first noticed. Potential risk factors were compared. Factors significant in the univariate analysis entered into multivariate analysis by binary logistic regression analysis.

Results: Among Group I, about half of them (56.7%) required urgent re-exploration and of those, only two-thirds had identifiable bleeder(s) believed to be the cause of hematoma. The mean time of onset of wound haematoma in was 3.9 ± 6.2 h with about half occurring >6 h. Patients in group I were more likely to be male (35% vs 23.5%, P = .02), having re-operation (16.7% vs 5.5%, P < .01), longer operating time (117.9 vs 101.7 mins, P = .04), more blood loss (72.3 vs 39.1 mL, P < .01) and larger excised gland weight (66.7 g vs 54.8 g, P = .01). In multivariate analysis, only male sex (OR = 2.40, 95% CI = 1.30-4.42, P = .005) and re-operation (OR = 3.50, 95%CI = 1.611-7.620, P = .02) were independent risk factors for hematoma after elective thyroidectomy.

Conclusions: Given that almost half of the wound hematomas occurred >6 hours after elective thyroidectomy, adoption of elective thyroidectomy in outpatient setting should be carried out after careful patient selection.

Queen Elizabeth Hospital, Hong Kong SAR

Aim: Primary cardiac tumour is a rare entity in cardiac surgery. Majority of them are myxoma pathologically. This study aims to summarise the features and clinical outcomes of cardiac myxoma resection.

Methods: Between January 2010 to December 2019, 30 patients (11 men, 19 women; mean age, 58.5 ± 20.5 years) underwent surgical myxoma resection. Majority of the patients presented with cardiac symptoms (palpitations, chest pain, SOB). Others present with non-cardiac symptoms including cerebrovascular accident (CVA) and collapse. The most common site was the left atrium, followed by right atrium.

Surgery was performed via a bi-atrial approach in 56.7%, right atrial septostomy in 30.0%, left atrial septostomy in only 10.0%. One patient underwent ventriculotomy for a right ventricle myxoma. Mean myxoma size based on longest length was 4.38cm (range 2.00-7.00 cm). Six patients also underwent cardiac intervention at the same operative session for other symptomatic concomitant cardiac conditions.

Results: The mean follow-up duration was 16 months. There was no in-hospital mortality. The most common postoperative complication was atrial fibrillation (10.0%). No recurrence was detected in our patients at the point of last follow-up.

Conclusions: Patient's demographics, presenting symptoms, size of myxoma and surgical approach were comparable to other large-scale studies. Short-term survival after myxoma resection was excellent. Recurrence was not detected in our patients. Long term survival and recurrence is yet to be determined by further studies.

Tuen Mun Hospital, Hong Kong SAR

Aim: Seasonality has been shown to affect incidence of emergency surgical conditions in the west. There is yet no local data to suggest the causal relationship between seasonality and emergency surgical conditions. We aim to investigate on the effects of seasonal variation on common general surgical conditions for (a) Ruptured abdominal aortic aneurysm, (b) Perforated peptic ulcer disease (c) Ischemic bowel, and (d) Acute cholecystitis in the New Territory West Cluster (NTWC).

Methods: The present study was a retrospective study of 7653 patients who underwent emergency operations from 1st July 2008 to 30th June 2018 in the NTWC. Seasonality was defined according to the Chinese lunar calendar. Relationships between incidence of emergency surgeries performed for these conditions and seasonality were studied. Primary outcome is to analyze the presence of overall seasonal variation across the four seasons for each surgical condition by means of Goodness of fit test. Secondary outcome is to analyze the relationship of each season (spring, summer, fall, winter) and extreme weather condition, in this study, the cold weather warning, on the surgical conditions by means of 2 × 2 Chi-square test.

Results: For primary outcome, statistically significant variation exists in all general surgical conditions except ischemic bowel across the four seasons. For secondary outcomes, statistically significant relationships exist between each season and different surgical conditions. Moreover, cold weather warning has a statistically significant relationship with emergent surgeries for perforated peptic ulcer disease and ruptured abdominal aortic aneurysm.

Conclusions: There is seasonal variation in emergency surgical conditions.

Department of Surgery, Colorectal Team, United Christian Hospital, Hong Kong SAR

Aim: Perfusion is important in anastomotic healing.Indocyanine-green(ICG)fluorescence angiogram provides an objective assessment of bowel perfusion and can assist in selection of bowel transection level. This study aims to assess the impact of ICG fluorescence angiogram on colorectal surgery in a regional hospital.

Methods: This is a retrospective analysis of a prospective collected database including 149 patients underwent colorectal surgery in both elective and emergency setting from July 2017 to March 2019.We started our routine use of ICG from October 2018.Closure of stoma and reversal of Hartmann's operation were included. ICG was injected intravenously to assess the vascular supply before the proximal and distal transection. Time of visualization of ICG fluorescence and change of transection point, decision for diverting stoma and post-operation anastomotic complication were recorded.

Results: One hundred forty nine patients (M:97F:52,mean age:69) with mean ASA2.136 and13 having surgery for malignancy and benign pathology respectively. Thirty three patients (22.1%) underwent right hemicolectomy, 28 patients (18.8%) underwent left hemicolectomy and sigmoidectomy. Seventy patients (47%) underwent anterior and low anterior resection. One patient (0.7%) had closure of colostomy. ICG angiography was achieved in every patient, 10 patients (6.7%) required repeated injection with a median interval of 30s (12-105) to visualization of the signal after injection. A change in the site of bowel division in 16 patients (10.7%). Three cases had reoperation due to leakage. There was no 30 day mortality and no adverse reaction after ICG injection.

Conclusions: ICG fluorescence angiogram as an objective assessment of bowel perfusion before anastomosis in colorectal surgery is feasible. It altered operative decisions. Future study with a larger sample size should be done to assess its impact on anastomotic complication.

Queen Mary Hospital, Hong Kong SAR

Aim: Ductal carcinoma in-situ (DCIS) of breast does not metastasize to regional lymph nodes. However disease upstaging to invasive disease are not uncommon on final histopathology. Performing sentinel lymph node biopsy (SLNB) at a second operation has been considered difficult and unreliable especially in patients receiving mastectomy. Superparamagnetic iron oxide (SPIO) is a new tracer agent that resides in sentinel lymph nodes for more than 30 days. The aim of this prospective study is to evaluate this novel role of SPIO in avoiding unnecessary SLNB.

Methods: Eligible patient with pure DCIS on core biopsy will receive subareolar SPIO injection in primary breast operation. A delayed SLNB will be performed in 4 weeks from initial operation if the final histopathology shows invasive carcinoma. Primary outcome is the number of patients who can avoid a SLNB and the secondary outcome is the success rate of a delayed SLNB with SPIO.

Results: Thirty-three eligible patients were recruited from May 2018 to June 2020. The mean age was 62 (range 39-77). Sixteen patients (48.5%) had high-grade DCIS on core biospy and ten of them were mass-forming. Twenty-eight patients (84.8%) received mastectomy. In total, pure DCIS was found on final histopathology in twenty-six patients (75.8%) and all of them avoided a SLNB. Seven patients with invasive carcinoma, including six with mastectomy, had a successful delayed SLNB.

Conclusions: SPIO is a reliable tracer agent that allows delayed SLNB. Breast cancer patients with DCIS on core biopsy can potentially avoid an axillary overtreatment.

Princess Margaret Hospital, Hong Kong SAR

Aim: To validate the use of non-invasive pulse spectrophotometry for measurement of indocyanine green retention in 15 minutes (LiMON-R15) in comparison to the traditional serial blood taking method (blood-R15).

Methods: Patients indicated for ICG retention test were recruited from May to November 2019. Blood-R15 and LiMON-R15 were measured simultaneously and were compared.

Results: Thirty two out of 42 recruited patients had successful ICG R15 measurement by both LiMON and blood taking. Their median blood-R15 and LiMON-R15 were 7.6 (IQR 3.5 to 22.6) and 13.5 (IQR 9.3 to 27.0) respectively. Mean difference was -7.7 (95% CI −11.1 to −4.4). The two methods demonstrated strong correlation with Pearson correlation coefficient 0.92. Blood-R15 could be estimated to be 4.40 + 1.26 × LiMON-R15.

Conclusions: Strong correlation was demonstrated between LiMON-R15 and blood-R15, but LiMON tended to underestimate the result, requiring mathematical adjustment.

Hong Kong Children's Hospital, Hong Kong SAR Department of Diagnostic Radiology and Imaging of Queen Elizabeth Hospital, Hong Kong SAR

Aim: Venous malformation (VM) is a rare condition in children causing aesthetic and function morbidities. Treatment of VM are challenging. Primary excision can cause torrential bleeding and damage to surrounding structures with incomplete removal. Recent development of sclerotherapy is helpful but carries potential risks of scleroscent extravasation and thromboembolic complications. We have developed a hybrid approach of VM treatment with glue embolization followed by surgical removal. The efficacy of this new operation was reviewed.

Methods: Patients with VM aged under 18 years who underwent hybrid operation from 2012 to 2020 were reviewed. The operation was performed in a bi-plane fluoroscopic machine equipped operation room. With patient under general anaesthesia, N-butyl cyanoacrylate (NBCA) glue embolization of VM was performed by ultrasonic and fluoroscopic guidance, followed by immediate surgical resection and reconstruction. Demographic data, lesion characteristics, peri-operative parameters were analyzed.

Main Results: Eleven patients with median age 9 (2-15) were recruited, nine patients (82%) had lesions in the head and neck region. Eight patients (73%) had previous sclerotherapy. Median operative time was 120 (56-220) minutes and the median intra-operative blood loss was 10 (3-110) mL, nil requiring blood transfusion. Median length of stay was 3 (2-7) days. There was no post-operative complication and all patients had complete VM removal with no recurrence.

Conclusions: The hybrid approach with preceding NBCA glue embolization allows better localization of VM and prevent bleeding during excision. Further study with more patient recruitment can validate the efficacy of this treatment.