W.J. Hyung

Intraoperative tumor localization using laparoscopic ultrasonography in laparoscopic–assisted gastrectomy

BackgroundDuring laparoscopic-assisted gastrectomy, it is impossible to identify early gastric cancer (EGC) lesions; therefore, a precise localization technique is needed. In this study, we used laparoscopic ultrasonography (LUS) after endoscopic clipping as a method of localizing EGC and evaluated the effectiveness of this method.MethodsA prospective study of 17 patients who had undergone laparoscopic—assisted gastrectomy was performed. Three endoscopic clips were applied just proximal to the tumor during the preoperative endoscopy. The applied clips were detected from the serosal side of the stomach using LUS. The serosal surface of the lesion was marked with dye.ResultsIn all patients, endoscopic clips were applied proximal to the lesion without complications, and the applied clips were confirmed by plain abdominal radiography. The clips were successfully detected by LUS in all patients. In the resected specimen, the serosal surface, marked with dye, was always just above the clips in the anterior wall or on the anterior wall opposite the clips applied in the posterior wall. The mean detection time was 4.7 min (range, 2–8). With this procedure, two patients underwent total gastrectomy and 15 patients underwent distal subtotal gastrectomy with gastroduodenostomy or gastrojejunostomy. Histological examination confirmed that the resection margins were tumor free in all patients. There was no operative morbidity related to the LUS procedure.ConclusionsUsing LUS to detect endoscopic clips is an easy, safe, and accurate method to localize EGC lesions in laparoscopic-assisted gastrectomy.

Major early complications following open, laparoscopic and robotic gastrectomy

Laparoscopic and robotic gastrectomy have been adopted rapidly despite lack of evidence concerning technical safety and controversy regarding additional benefits. This study aimed to compare clinically relevant complications after open, laparoscopic and robotic gastrectomy.

Magnetic PECA nanoparticles as drug carriers for targeted delivery: Synthesis and release characteristics

Magnetic poly(ethyl-2-cyanoacrylate) (PECA) nanoparticles containing anti-cancer drugs (Cisplatin and Gemcitabine) were prepared by inter-facial polymerization. The spherical nanoparticles (d = 250 ± 15 nm) with smooth surfaces and moderately uniform size distributions were obtained. The amount of magnetite encapsulated inside the polymer matrix was increased up to 14.26% (w/w) by controlling the initial weight ratio of monomer/magnetite. It was found that the amount of Cisplatin encapsulated in the magnetic nanoparticle is much higher than that of Gemcitabine because Cisplatin (hydrophobic) is highly soluble in the oil phase and encapsulated easier inside nanoparticles compared to Gemcitabine (hydrophilic). The presence of magnetite and its super-paramagnetic characteristic were confirmed by FTIR spectra and VSM. In-vitro experiments of drug release and magnetic mobility under external magnetic field demonstrated that magnetic poly(ethyl-2-cyanoacrylate) (PECA) nanoparticles can be a highly versatile magnetic drug carrier with sustained release behaviour and sufficient magnetic susceptibility.

Impact of pretreatment thrombocytosis on blood-borne metastasis and prognosis of gastric cancer

BACKGROUND Thrombocytosis has been associated with malignancies and poor prognostic implications in cancer patients. In the present study the prognostic significance of pretreatment platelet (PLT) level was assessed with regard to recurrence and survival in patients with primary gastric adenocarcinoma. METHODS The authors reviewed the prospective data of 1593 gastric cancer patients who received curative gastrectomy with extended lymphadenectomy. The correlations of PLT level with recurrence and overall survival were evaluated by both univariate and multivariate analyses. RESULTS Thrombocytosis (≥ 40 × 10(4)/ μL), present in 6.4% of the patients prior to curative surgery, was more frequently associated with advanced T and N classification, larger tumor size, anemia, and leukocytosis (p < 0.05). In patients with pretreatment thrombocytosis compared to those without it, five-year survival rate was worse (56.9% vs. 65.5%; p = 0.043), and recurrence rate was higher mainly due to the frequent hematogenous spread (51.0% vs. 34.5%; p < 0.001). Furthermore, risk of blood-borne metastasis was almost three-fold higher in patients with pretreatment thrombocytosis (Odds ratio 2.83 [95% CI 1.67-4.77], p < 0.001). CONCLUSIONS Pretreatment thrombocytosis correlated significantly with poor prognosis and can be used as an independent predictor of recurrence by blood-borne metastasis in gastric cancer.

Rapid and safe learning of robotic gastrectomy for gastric cancer: Multidimensional analysis in a comparison with laparoscopic gastrectomy

BACKGROUND The learning curve of robotic gastrectomy has not yet been evaluated in comparison with the laparoscopic approach. We compared the learning curves of robotic gastrectomy and laparoscopic gastrectomy based on operation time and surgical success. METHODS We analyzed 172 robotic and 481 laparoscopic distal gastrectomies performed by single surgeon from May 2003 to April 2009. The operation time was analyzed using a moving average and non-linear regression analysis. Surgical success was evaluated by a cumulative sum plot with a target failure rate of 10%. Surgical failure was defined as laparoscopic or open conversion, insufficient lymph node harvest for staging, resection margin involvement, postoperative morbidity, and mortality. RESULTS Moving average and non-linear regression analyses indicated stable state for operation time at 95 and 121 cases in robotic gastrectomy, and 270 and 262 cases in laparoscopic gastrectomy, respectively. The cumulative sum plot identified no cut-off point for surgical success in robotic gastrectomy and 80 cases in laparoscopic gastrectomy. Excluding the initial 148 laparoscopic gastrectomies that were performed before the first robotic gastrectomy, the two groups showed similar number of cases to reach steady state in operation time, and showed no cut-off point in analysis of surgical success. CONCLUSIONS The experience of laparoscopic surgery could affect the learning process of robotic gastrectomy. An experienced laparoscopic surgeon requires fewer cases of robotic gastrectomy to reach steady state. Moreover, the surgical outcomes of robotic gastrectomy were satisfactory.

Relevance of lymph node metastasis along the superior mesenteric vein in gastric cancer

The purpose of this study was to evaluate the prognostic value of lymph node metastasis along the superior mesenteric vein (station 14v) to determine the need for 14v dissection in gastric cancer surgery.

Lymph node dissection around the splenic artery and hilum in advanced middle third gastric carcinoma.

AIM To evaluate the clinicopathological factors influencing lymph node metastasis around the splenic artery and hilum and the effect of spleen-preserved lymphadenectomy in advanced middle third gastric carcinoma. METHODS We retrospectively studied 131 patients with advanced middle third gastric carcinoma who had received D2 lymphadenectomy and lymph node dissection around the splenic artery and hilum, from 2000 to 2004. Of these patients, 62 simultaneously underwent splenectomy and 69 underwent spleen-preserved lymphadenectomy. RESULTS The incidences of Nos. 10 and 11 lymph node metastases were 21% and 15%, respectively, in advanced middle third gastric carcinoma. A tumor size larger than 5 cm, metastases of Nos. 1 and 7-9 lymph node were independent risk factors for metastasis of No. 10 and/or No. 11 lymph node. The spleen-preserved group had a slightly better survival rate and a relatively lower rate of postoperative complications than the splenectomy group. No. 10 and/or No. 11 lymph node metastasis was an independent prognostic factor, while splenectomy was not. CONCLUSIONS It is necessary to remove the lymph nodes around the splenic artery and hilum to achieve radical resection in advanced middle third gastric carcinoma patients with risk factors. Our results demonstrate that spleen-preserved lymphadenectomy is a good option for those patients.

Correlation between lymph node count and survival and a reappraisal of lymph node ratio as a predictor of survival in gastric cancer: A multi-institutional cohort study.

PURPOSE The purpose of this study is to evaluate the correlation between lymph node count (LNC) and survival and to evaluate whether lymph node ratio (LNR) which is related to LNC is a better predictor of survival for gastric cancer than the N category of UICC/AJCC through a multi-institutional cohort study. METHODS The study cohort included 3284 patients from eight institutions. Lower and upper quartiles of LNC were used for comparisons. The cut-off values (0, 0.06, 0.27, and 0.49) for the LNR categories were based on Classification and Regression Trees techniques. Akaike information criteria (AIC) for Cox regression models was used to evaluate goodness of fit between competing predictor variables (LNR vs. N category). RESULTS The 5-year disease-specific survival (DSS) rates of lower and upper quartiles of LNC were 82.2% and 84.8%. In the subgroup analysis of pN category, the upper quartile of LNC showed better survival than the lower quartile in pN2, pN3a, and pN3b subgroups. Regarding LNR, 5-year DSS of LNR 0, 0-0.06, 0.06-0.27, 0.27-0.49, and >0.49 was 95.3%, 88.7%, 70.6%, 42.7%, and 17.2% respectively. Multivariate analysis showed that pT, pN, LNR, residual tumor status, distant metastasis, and tumor differentiation significantly affected survival. The analysis also confirmed superiority of LNR compared with N category in the AIC analysis. CONCLUSION Higher LNC correlated with better survival in patients with pN2, pN3a, and pN3b gastric cancer. Our data indicate that LNR is a better predictor of survival than N category of UICC/AJCC.

Risk factors for double primary malignancies and their clinical implications in patients with sporadic gastric cancer

AIMS We carried out a large scale study to identify the risk factors for double primary malignancy (DPM) development in gastric cancer patients and to evaluate the clinical implications for these patients. METHODS A total of 2593 patients who underwent gastrectomy for primary gastric cancer from January 2005 to November 2010 were reviewed with regard to DPM. We compared the clinicopathological characteristics, risk factors for developing DPM, and prognosis between the DPM+ group and the DPM- group. RESULTS Of the 2593 patients, 152 (5.9%) were diagnosed with DPM. The most common accompanying malignancies were colorectal, lung and thyroid. Multivariate analysis indicated that age (p = 0.016) and MSI status (p = 0.002) were associated with a higher frequency of DPM. 30.3% of patients were diagnosed with DPM within 1 year around perioperative period and 53.3% of patients had DPM detected during 5 years of post-operative follow up periods. Although there was no significant difference in overall survival between the DPM+ and DPM- group, DPM+ patients had a worse prognosis than DPM- patients in stage I gastric cancer. CONCLUSIONS Gastric cancer patients over the age of 60 or with a MSI-high status had an increased risk for developing DPM. Further, in stage I gastric cancer, the presence of DPM was associated with a worse prognosis. Therefore, careful pre- and postoperative surveillance is especially important in these patients.

Locoregional relapse after gastrectomy with D2 lymphadenectomy for gastric cancer

Risk for and site of locoregional relapse have not been well studied in patients undergoing gastrectomy with D2 lymphadenectomy for gastric cancer.