Modified Technique for Abdominal Phase of Minimally Invasive McKeown Esophagectomy

Esophagectomy is associated with significant postoperative morbidity and mortality (1). In an effort to reduce these outcomes, many medical communities have adopted minimally invasive techniques for esophagectomy. A variety of minimally invasive techniques have been established (2,3). The authors’ center has been offering minimally invasive McKeown esophagectomy with extracorporeal gastric conduit formation since 2012, using a safe and straightforward eight-step technique for the abdominal component of the procedure. Patient positioning and port placement techniques are illustrated in the accompanying visual media.Step 1: Liver RetractionSurgeons use the "fan" retractor from the fifth port at the xiphoid process to retract the liver. Some surgeons use suturing techniques to retract the liver, but it takes some time. The fan retractor gives an excellent view without suturing.Step 2: Opening the Gastrohepatic LigamentThe dissection starts at the gastrohepatic ligament and proceeds towards the right crus of the diaphragm along the gastrodiaphragmatic ligament. The right gastric artery is preserved at the site of the lesser curvature. With the help of the assistant, compression of the stomach improves surgical visualization of the vascular structures within the omental bursa. Circumferential dissection of the right and left crura, including complete division of the phrenoesophageal ligament, is performed.Step 3: Abdominal Lymph Node DissectionDuring the abdominal phase, a critical step is to begin the dissection by incising the peritoneum covering the pancreas and proceeding towards the common hepatic artery. Due to the presence of small vascular structures, great care must be taken to avoid unnecessary bleeding. The use of the Harmonic scalpel during this procedure offers significant advantages. The arterial sheath at the junction of the left gastric artery and the common hepatic artery is then opened, allowing extensive and safe dissection of the lymph nodes. While lymph node dissection around the celiac trunk is occasionally performed, this is not standard practice due to the low likelihood of metastasis. Paracardial nodes are always dissected.Step 4: Management of the Left Gastric VesselsAfter a complete dissection of the lymph nodes, surgeons can easily dissect the left gastric bundle. The left gastric artery is transected with Hem-o-lok clips or staplers.Step 5: Management of Posterior Gastric Vessels and AdhesionsRetraction of the gastric fundus allows optimal visualization of the gastroesophageal junction and the esophageal hilum. Further dissection facilitates identification of the distal end of the esophagus, previously dissected in the thoracic phase. Increased mobilization may widen the esophageal hiatus and reduce the abdominal pressure resulting from carbon dioxide insufflation. According to the authors’ experience, this reduced pressure should not affect the subsequent surgical procedure.Step 6: Management of the Short Gastric Arteries and the Splenic HilumThe assistant surgeon performs appropriate lateral retraction of the stomach using a gauze band. Dissection of four to five rows of short gastric arteries and selected arterial branches from the splenic artery is performed with direct visualization of the spleen and its vasculature. Dissection continues along the gastric wall. The fundus of the stomach is delicate and prone to tearing if handled during the laparoscopic part of the procedure. Therefore, it is imperative to avoid contact with this region of the stomach.Step 7: Dissection of the Gastrocolic Ligament Along the Greater Curvature by Mini LaparotomyThe skin incision below the subxiphoid process is extended to create the gastric conduit. The stomach is pulled up through the incision and the gastrocolic ligament is dissected, preserving the right gastroepiploic artery. To the right, the gastrocolic ligament is completely dissected to the proximal duodenum. On the left side, the gastrocolic ligament is completely divided.Step 8: Creation of the Gastric ConduitThe gastric conduit is created extracorporeally using a linear stapler, taking care to maintain a width of 4 to 5 cm. The staple line is reinforced with a continuous 4-0 prolene suture. Hemostasis along the staple line is assessed and the viability of the gastric conduit is assessed. A feeding jejunostomy is then created.In conclusion, this modified technique provides a safe operating environment and is easily reproducible and learnable for thoracic surgeons with limited laparoscopic experience. By eliminating the possibility of touching or clamping the gastric conduit throughout the procedure, it minimizes the risk of conduit injury. It also provides better exposure of the splenic hilum and reduces the likelihood of splenic injury. In addition, it has the potential to reduce overall operative time.Reference(s)1. Hao Wang, Han Tang, Yong Fang, Lijie Tan, Jun Yin, Yaxing Shen, et al. Morbidity and Mortality of Patients Who Underwent Minimally Invasive Esophagectomy After Neoadjuvant Chemoradiotherapy vs. Neoadjuvant Chemotherapy for Locally Advanced Esophageal Squamous Cell Carcinoma: A Randomized Clinical Trial; JAMA Surg. 2021 May 1;156(5):444-451.2. Shawn S Groth, Bryan M Burt. Minimally invasive esophagectomy: Direction of the art. J Thorac Cardiovasc Surg. 2021 Sep;162(3):701-704.3. van der Sluis PC, Schizas D, Liakakos T, van Hillegersberg R. Minimally invasive esophagectomy. Dig Surg. 2020; 37(2):93-100.</p

Characterization of TLX Expression in Neural Stem Cells and Progenitor Cells in Adult Brains

<div><p>TLX has been shown to play an important role in regulating the self-renewal and proliferation of neural stem cells in adult brains. However, the cellular distribution of endogenous TLX protein in adult brains remains to be elucidated. In this study, we used immunostaining with a TLX-specific antibody to show that TLX is expressed in both neural stem cells and transit-amplifying neural progenitor cells in the subventricular zone (SVZ) of adult mouse brains. Then, using a double thymidine analog labeling approach, we showed that almost all of the self-renewing neural stem cells expressed TLX. Interestingly, most of the TLX-positive cells in the SVZ represented the thymidine analog-negative, relatively quiescent neural stem cell population. Using cell type markers and short-term BrdU labeling, we demonstrated that TLX was also expressed in the Mash1+ rapidly dividing type C cells. Furthermore, loss of TLX expression dramatically reduced BrdU label-retaining neural stem cells and the actively dividing neural progenitor cells in the SVZ, but substantially increased GFAP staining and extended GFAP processes. These results suggest that TLX is essential to maintain the self-renewing neural stem cells in the SVZ and that the GFAP+ cells in the SVZ lose neural stem cell property upon loss of TLX expression.Understanding the cellular distribution of TLX and its function in specific cell types may provide insights into the development of therapeutic tools for neurodegenerative diseases by targeting TLX in neural stem/progenitors cells.</p> </div

Co-staining of TLX cell type-specific markers in the SVZ.

<p><b>A.</b> Co-staining of TLX with Nestin in the SVZ of mouse brains. <b>B.</b> Co-localization of TLX with Mash1 in the SVZ of mouse brains. <b>C.</b> Co-staining of TLX with DCX in both the SVZ and the rostral migratory stream (RMS). LV stands for the lateral ventricles. Scale bar, 20 µm for all panels. Examples of TLX and Mash1 double-positive cells were indicated by arrows.</p

Reduced neural progenitor populations in the SVZ of TLX−/− brains.

<p><b>A.</b> short-term (6 hr pulse) BrdU labeling along with Mash1 and TLX staining in the SVZ of wild type (WT) and TLX−/− brains. The top panels show Mash1 single staining and the bottom panels show merged images of Mash1, brdU and TLX triple staining. B. Quantification of Mash1+ cells in the SVZ of WT and TLX−/− brains. Data are represented as means ± s.d. *p<0.001 by Student's t-test. C. Quantification of Mash1+Ki67+ cells from Mash1+ cells in the SVZ of WT and TLX−/− brains. Data are represented as means ± s.d. *p<0.001 by Student's t-test. <b>D.</b> DCX and TLX staining in the SVZ of WT and TLX−/− brains. The top panels show DCX single staining and the bottom panels show merged images of DCX and TLX double staining. Scale bar, 20 µm for all panels.</p

Co-staining of TLX and BrdU in the SVZ.

<p>Co-staining of TLX and BrdU in the SVZ of mice that were treated with BrdU for 1 week, followed by 4 week survival (long-term BrdU labeling), mice that were treated with BrdU once follwed by 6 hr survival (6 hr BrdU chase), or mice that were treated with BrdU once daily for 1 week (1 week BrdU treatment). LV stands for the lateral ventricles. Scale bar, 20 µm for all panels. Examples of TLX-positive, BrdU label-retaining cells that represent the ventricle-containing B1 cells were indicated by arrows, and examples of TLX-positive, BrdU label-retaining non-ventricle-containing B2 cells were indicated by arrowheads.</p

Reduced BrdU label-retaining cells and increased GFAP-positive cells in the SVZ of TLX−/− brains.

<p><b>A.</b> There are reduced numbers of total cells and BrdU label-retaining cells in the SVZ of TLX−/− brains as revealed by Dapi staining (blue) and BrdU label (green) -retaining, and increased GFAP-positive cells as revealed by GFPA staining (purple). Both wild type (WT) and the TLX−/− mice were treated with BrdU once daily for 1 week, followed by 4 week survival. <b>B.</b> Quantification of Dapi-positive cells in the SVZ of wild type (WT) and TLX−/− brains. *p = 0.0015 by Student's t-test, n = 3. <b>C.</b> Quantification of BrdU label-retaining cells in the SVZ of WT and TLX−/− brains. *p = 0.019 by Student's t-test, n = 3. Error bars are standard deviation of the mean. Scale bar, 20 µm for all panels.</p

Whole mount staining revealed increased GFAP staining and scar-like GFAP-positive signals in the SVZ of TLX−/− brains.

<p><b>A.</b> GFAP staining in the SVZ of TLX+/− and TLX−/− brains. Dapi and Vimentin (vim) staining was included as counter staining. <b>B.</b> Images of higher magnification of vimentin (1), GFAP(2), Dapi (3), and merged (4) staining in the SVZ of TLX−/− brains. Scale bar, 20 µm for all panels. Loss of Dapi staining in the Scar-like GFAP+ foci was indicated by asterisks.</p

Some actions of objects.

Some actions of objects.</p

Different types of questions.

Different types of questions.</p

Schematic diagram of the KG of alpine skiing events.

Schematic diagram of the KG of alpine skiing events.</p