Yanghee Woo

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.

Elevated high-sensitivity C-reactive protein, a marker of advanced stage gastric cancer and postgastrectomy disease recurrence

Gastric cancer recurrence after curative surgery remains high. Although no preoperative marker of gastric cancer progression after radical gastrectomy exists, recent studies suggest that C‐reactive protein (CRP) is associated with cancer progression. Our study evaluated the significance of preoperative high‐sensitivity CRP (hs‐CRP) levels as a marker of disease progression after radical gastrectomy.

Novel application of simultaneous multi-image display during complex robotic abdominal procedures

BackgroundThe surgical robot offers the potential to integrate multiple views into the surgical console screen, and for the assistant’s monitors to provide real-time views of both fields of operation. This function has the potential to increase patient safety and surgical efficiency during an operation. Herein, we present a novel application of the multi-image display system for simultaneous visualization of endoscopic views during various complex robotic gastrointestinal operations.All operations were performed using the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA, USA) with the assistance of Tilepro, multi-input display software, during employment of the intraoperative scopes. Three robotic operations, left hepatectomy with intraoperative common bile duct exploration, low anterior resection, and radical distal subtotal gastrectomy with intracorporeal gastrojejunostomy, were performed by three different surgeons at a tertiary academic medical center.ResultsThe three complex robotic abdominal operations were successfully completed without difficulty or intraoperative complications. The use of the Tilepro to simultaneously visualize the images from the colonoscope, gastroscope, and choledochoscope made it possible to perform additional intraoperative endoscopic procedures without extra monitors or interference with the operations.ConclusionWe present a novel use of the multi-input display program on the da Vinci Surgical System to facilitate the performance of intraoperative endoscopies during complex robotic operations. Our study offers another potentially beneficial application of the robotic surgery platform toward integration and simplification of combining additional procedures with complex minimally invasive operations.

Laparoscopic Distal Gastrectomy with an Intracorporeal Gastroduodenostomy Using a Circular Stapler

w s o s d T Laparoscopic gastrectomy for the treatment of gastric cancer has gained worldwide acceptance. Although minimally invasive surgery provides several benefits that open surgery does not, the minilaparotomy required for performing an extracorporeal reconstruction during the surgery decreases the advantages of the minimally invasive approach. On the other hand, a totally intracorporeal procedure, which more closely fits the concept of minimally invasive surgery, offers improved visualization of the surgical field, better cosmetic results, and earlier bowel function recovery than does laparoscopically assisted or open gastrectomy. Gastroduodenostomy is the reconstruction method of choice after gastrectomy. It provides more physiologic flow of food contents through the duodenum and decreases the possibility of metabolic problems and nutritional deficiency. However, previous methods of gastroduodenosomy during laparoscopic-assisted distal gastrectomy reuire a minilaparotomy, usually on the anterior abdominal all above the duodenal bulb, for the application of a urse-string instrument on the duodenum. Before the ntroduction of gastroduodenostomy techniques using a inear stapler, the lacking of a safe and fast intracorporeal urse-string suture technique to substitute for the current xtracorporeal purse-string technique made minilapaotomy unavoidable. Currently, the only intracorporeal gastroduodenostomy techniques involve the use of a linear stapler. These procedures are technically demanding, require well-trained surgical teams, and are costly; one of these methods requires 6 staplers. Here we introduce the intracorporeal gastroduodenostomy method using a circular stapler with a new pursestring suture technique and present patient outcomes. This technique involves a completely laparoscopic gastroduode-

Robotic surgery for gastric cancer: a technical review

Minimally invasive gastric cancer surgery is gaining acceptance, especially in the treatment of patients with early gastric cancer. While offering patients the benefits of minimally invasive surgery, laparoscopic surgery is limited by several disadvantages such as altered operating view and lack of versatility in surgical instrumentation. Robotic surgery offers the surgeon the benefit of superior 3D visualization, the freedom of the EndoWrist function, and the tremble-filtered control of the four robotic arms. Due to the technical advantages of the robotic surgical system, robotic surgery may facilitate the expansion of minimally invasive surgery over laparoscopy. The application of robotic surgery for gastric cancer is increasing in experienced centers. Most reports of the robotic operating methods are only slightly modified from the laparoscopic technique. Robotic gastric cancer surgery including radical subtotal gastrectomy with D2 lymph node dissection is technically feasible and safe and results in similar short-term postoperative outcomes when compared to laparoscopic surgery. The role of robotic surgery in gastric cancer is promising but awaits further comparative studies of long-term results and cost-effectiveness.

In Vitro Adenosine Triphosphate Based Chemotherapy Response Assay in Gastric Cancer

Purpose The purpose of this study was to investigate the reliability and the clinical applicability of the adenosine-triphosphate-based chemotherapy response assay (ATP-CRA) as a method of determining in vitro chemosensitivity in patients with gastric cancer. Materials and Methods A total of 243 gastric cancer tissue samples were obtained from gastrectomies performed between February 2007 and January 2010. We evaluated the effectiveness of the ATP-CRA assay in determining the chemosensitivity of gastric cancer specimens using eleven chemotherapeutic agents - etoposide, doxorubicin, epirubicin, mytomicin, 5-fluorouracil, oxaliplatin, irinotecan, docetaxel, paclitaxel, methotraxate, and cisplatin - for chemosensitivity studies using ATP-CRA. We assessed the failure rate, the cell death rate, and the chemosensitivity index. Results The failure rate of ATP-CRA was 1.6% (4/243). The mean coefficient of variation for triplicate ATP measurements was 6.5%. Etoposide showed the highest cell death rate (35.9%) while methotrexate showed the lowest (16.6%). The most active chemotherapeutic agent was etoposide, which most frequently ranked highest in the chemosensitivity test: 31.9% (51/160). Oxaliplatin was more active against early gastric cancers than advanced gastric cancers, whereas docetaxel was more active against advanced cancers. The lymph node negative group showed a significantly higher cell death rate than the lymph node positive group when treated with doxorubicin, epirubicin, and mitomycin. Conclusions ATP-CRA is a stable and clinically applicable in vitro chemosensitivity test with a low failure rate. The clinical usefulness of ATP-CRA should be evaluated by prospective studies comparing the regimen guided by ATP-CRA with an empirical regimen.

A Novel Prediction Model of Prognosis After Gastrectomy for Gastric Carcinoma: Development and Validation Using Asian Databases.

Objective: The prognoses of gastric cancer patients vary greatly among countries. Meanwhile, tumor-node-metastasis (TNM) staging system shows limited accuracy in predicting patient-specific survival for gastric cancer. The objective of this study was to create a simple, yet universally applicable survival prediction model for surgically treated gastric cancer patients. Summary Background Data: A prediction model of 5-year overall survival for surgically treated gastric cancer patients regardless of curability was developed using a test data set of 11,851 consecutive patients. Methods: The models coefficients were selected based on univariate and multivariate analysis of patient, tumor, and surgical factors shown to significantly impact survival using a Cox proportional hazards model. For internal validation, discrimination was calculated with the concordance index (C-statistic) using the bootstrap method and calibration assessed. The model was externally validated using 4 data sets from 3 countries. Results: Our models C-statistic (0.824) showed better discrimination power than current tumor-node-metastasis staging (0.788) (P < 0.0001). Bootstrap internal validation demonstrated that coefficients remained largely unchanged between iterations, with an average C-statistic of 0.822. The model calibration was accurate in predicting 5-year survival. In the external validation, C-statistics showed good discrimination (range: 0.798–0.868) in patient data sets from 4 participating institutions in 3 different countries. Conclusions: Utilizing clinically practical patient, tumor, and surgical information, we developed a universally applicable prediction model for accurately determining the 5-year overall survival of gastric cancer patients after gastrectomy. Our predictive model was also valid in patients who underwent noncurative resection or inadequate lymphadenectomy.

Selecting incision-dominant cases for robotic liver resection: towards outpatient hepatectomy with rapid recovery

Background The premise of minimally invasive surgery (MIS) is to minimize facial and muscle injury in order to enhance recovery from surgery. Robotic MIS surgery for resection of tumors in solid organs is gaining traction, though clear superiority of this approach is lacking and robotic surgery is more expensive. Our philosophy in robotically-assisted hepatectomy has been to employ this approach for cases where location of tumors make difficult a classical laparoscopic approach (superior/posterior tumors), and cases where the incision for an open operation dominates the course of recovery. Methods This is a retrospective review of a prospectively collected database. Results In this study we report 97 cases of liver resection subjected to the robotic approach, of which 90% were resected robotically. The mean operative time was 186±9 min; mean blood loss was 111±15 mL, and complications occurred in 9%. Two thirds of the patients remained in hospital 3 days or less, including three patients subjected to hemihepatectomy (2 left and 1 right). Fourteen individuals were discharged on the same day. The strongest predictors of long hospital stay (>3 days) were major hepatectomy (P=0.007), complications (P=0.008), and operative time >210 min (P=0.001). Conclusions With thoughtful case selection, this is a first demonstration that hepatectomy can be conducted as an out-patient or short-stay procedure.

Long-term oncologic outcomes of robotic gastrectomy for gastric cancer compared with laparoscopic gastrectomy.

8 Background: Although robotic gastrectomy (RG) showed satisfactory early postoperative outcomes, the oncologic safety of RG for gastric cancer remains a concern. We aimed to evaluate the oncologic safety of RG by comparing its long term outcomes with that of laparoscopic gastrectomy (LG). Methods: From July 2005 to December 2009, we performed 313 RGs and 524 LGs to the patients with gastric cancer. We retrospectively analyzed the patients’ characteristics, operative outcomes, overall survival (OS) and relapse-free survival (RFS), then compared between RG and LG groups using a prospectively maintained database. Results: With a median follow-up of 46 (1-80) months, there was no difference in the OS (log-rank p=0.625) nor in the RFS (p=0.761) between the two groups. When we compared the two groups stage by stage, the OS and RFS also did not differ significantly. Postoperative recurrence was observed in 17 patients (5.4%) in RG and 18 (3.4%) in LG, which showed no significant difference (p=0.745). The patter...

Successful cholecystectomy during robotic gastrectomy.

Abstract Background: Surgeons have successfully combined various laparoscopic procedures with increasing technical ease. However, few reports exist regarding the feasibility of combined robotic operations. We present our institutions successful concomitant robotic surgery for early gastric cancer and coexisting gallbladder disease. Material and methods: From our prospectively collected database, seven patients who received robotic cholecystectomies during their robotic gastric cancer operations were retrospectively compared to 247 patients who underwent robotic gastrectomies alone. Preoperative patient characteristics, operative factors, postoperative length of stay, and complications were evaluated. Results: The preoperative patient characteristics and operative factors did not differ between the two groups. All robotic cholecystectomies were performed with the same ports and instruments used during robotic gastrectomies without open conversion, robot redocking or patient repositioning. Mean time to perform robotic cholecystectomies was 15.1 + 3.2 minutes. The combined group had no mortality, one wound infection, and one intraabdominal fluid collection at the gastric resection bed, which were comparable to the gastrectomy alone group. The mean postoperative length of hospital stay was unaltered by the addition of the cholecystectomy. Conclusions: Robotic cholecystectomies can safely and efficiently be combined with robotic gastric cancer surgery, yielding several benefits. Improving robotic technology and experience may allow surgeons to efficiently combine more complicated procedures.