Fusion Fascia Research Articles

Retrocolic Fascia-An Anatomical and Multidetector Computed Tomographic Angiography (MDCTA) Morphometric Analysis in Patients with Right Colon Cancer.

This study aims to delineate anatomical landmarks crucial for complete mesocolic excision, focusing on Gerota's fascia, which guides surgical dissection in right-sided colon cancer, forming the posterior limit. Employing a multimodal approach, the research aims to understand the fascial anatomy and its variations under pathological conditions. Three methods were applied: a pilot dissection on an embalmed cadaver for clear anatomical presentation of prerenal fascia, Mimics segmentation of the fascia and its relationship with the colon, and a retrospective analysis of MDCTA scans from 196 patients (mean age 65.73 y, 118 F/78 M). Systematic measurements of fascial thickness were taken at key renal levels-upper pole, hilum, lower pole, and infra-renal. Covariates analyzed included Body Mass Index, age, and sex. The pilot dissection revealed the renal fascia of Gerota as the only true retrocolic compact connective tissue and the fusion fascia of Toldt as a mesh of strands of loose connective tissue and fat lobules. MDCTA showed clearer visualization of Gerota's fascia at the hilum and inferior renal pole, predominantly on the left. There were significant differences in fascial thickness between sides (1.30 mm on the right and 1.34 mm on the left) and a positive correlation with BMI, whereas age and sex showed no significant effects. Gerota's fascia is a critical anatomical landmark in CME for right colon cancer. This study highlights the fascia's structural integrity, unaffected by the tumor, underscoring its importance in surgical navigation.

Retroperitoneum revisited: a review of radiological literature and updated concept of retroperitoneal fascial anatomy with imaging features and correlating anatomy

PurposeSpread of disease in the retroperitoneum is dictated by the complex anatomy of retroperitoneal fasciae and is still incompletely understood. Conflicting reports have led to insufficient and incorrect anatomical concepts in radiological literature.MethodsThis review will discuss previous concepts prevalent in radiological literature and their shortcomings will be highlighted. New insights from recent anatomical and embryological research, together with imaging examples, will be used to clarify patterns of disease spread in the retroperitoneum that remain unexplained by these concepts.ResultsThe fusion fascia and the renal fascia in particular give rise to planes and spaces that act as vectors for spread of disease in the retroperitoneum. Some of these planes and structures, such as the caudal extension of the renal fascia, have previously not been described in radiological literature.ConclusionNew insights, including the various fasciae, potential spaces and planes, are incorporated into an updated combined retroperitoneal fascial concept.

Robotic spleen‑preserving suprapancreatic and splenic hilar lymph node dissection using the preemptive retropancreatic approach in total gastrectomy for gastric cancer.

Advanced gastric cancer that has not invaded the greater curvature is a good indication for total gastrectomy (TG) with spleen-preserving suprapancreatic and splenic hilar lymph node dissection (LND). However, the suprapancreatic and splenic hilar LND increases the area of dissection of the pancreas, and prolonged pressure drainage of the pancreas is required to maintain a clear operative view. This can lead to an increased risk of postoperative pancreatic complications. To report the efficacy of our novel preemptive retropancreatic approach (PRA) for the suprapancreatic and splenic hilar LND in robotic TG (RTG). We report our experience with nine patients with gastric cancer who underwent spleen-preserving splenic hilar LND using PRA during RTG at Hokkaido University from October 2018 to November 2021. The PRA involves initial dissection of the left side of the retropancreatic space, followed by the release of the adherence between the retroperitoneum surface and the pancreas (fusion fascia), which provides a good operative field and prevents contact with the pancreas during the suprapancreatic and splenic hilar LND in RTG. The median operating time was 488min (254-564min). The median intraoperative bleeding was 55mL (0-115mL). One patient had postoperative complications (above grade II of the Clavien-Dindo classification), but there were no postoperative pancreatic complications. The spleen-preserving suprapancreatic and splenic hilar LND using PRA could help to reduce the postoperative pancreatic complications associated with RTG.Trial registration number and date of registration The Hokkaido University Hospital institutional review board approved the data collection and analysis. The trial registration number and date of registration are No. 021-0022 and July 26, retrospectively registered.

Feasibility study of immediate breast reconstruction with fusion fascia combined with implants

Objective: To investigate the oncologic and surgical safety of the fused fascia method for immediate breast reconstruction with implants. Methods: The clinical data of 343 patients with immediate breast reconstruction with implants in Tianjin Medical University Cancer Hospital from 2014-2017 were retrospectively analyzed to compare the 5-year local recurrence-free survival, 5-year disease-free survival and 5-year overall survival of patients with breast reconstruction by fusion fascia and other methods, and to analyze the complication incidences of implant removal between different implant groups. Results: Of the 343 patients with breast reconstruction, 95 were in the fused fascia group (fascia group) and 248 were in the non-fascia group (25 in the bovine pericardial patch group and 223 in the muscle flap group). At a median follow-up of 49 months, the differences in 5-year local recurrence-free survival (90.1% and 94.9%, respectively), 5-year disease-free survival (89.2% and 87.6%, respectively), and 5-year overall survival (95.2% and 95.1%, respectively) between patients in the fascial and non-fascial groups were not statistically significant (P>0.05). The complication incidence of implant removal was 24.0% (6/25) in the patch group and 2.1% (2/95) and 2.2% (5/223) in the fascia and muscle flap groups, respectively. Conclusion: Immediate breast reconstruction with fused fascial combined with implant is safe and feasible, less invasive than muscle flaps, more economical and with fewer complications than patches.

There is no fusion fascia in the abdomen and extraperitoneal fascia always surrounds the mesentery.

Toldt's fascia has always been described as a fusion fascia formed by two layers of visceral peritoneum when the mesentery attaches to the posterior abdominal wall. However, there is still no consensus about the mesentery and its surrounding fascia based on the current anatomic theories. This study aimed to determine the anatomical structures of the abdomen and provide a correct surgical plane for mesenteric-based surgery. Surgical videos of 121 patients who underwent laparoscopic operations of the digestive tract were reviewed to identify and compare the anatomical structures of the mesentery and associated fascia. Twenty-one postoperative specimens were stained with hematoxylin and eosin to indicate the histological appearance of the mesentery and its surrounding fascia. Furthermore, dynamic models had been established to explain the formation mechanism of the associated histological structures in different regions during the progression of mesenteric attachment. The fasciae surrounding the mesentery, including the submesothelial connective tissue, the subserosal connective tissue, Toldt's fascia, and "angel hair," have the same histological characteristic to extraperitoneal fascia. The general anatomical structure of the abdomen can be divided into three layers (abdominal wall, urogenital system, and digestive system) and two interlayers (transversalis fascia and extraperitoneal fascia). The extraperitoneal fascia surrounds the entire digestive system and is the natural layer separating adjacent structures from each other. Typical histological structures in the regions of posterior attachment include the fascia propria of the mesentery, mesofascial plane, extraperitoneal fascia, retrofascial plane, and anterior renal fascia. The urogenital system is surrounded by similar histological structures. There is no fusion fascia in the abdomen due to retreat of the visceral peritoneum, and all of the fasciae surrounding the mesentery are extraperitoneal fascia. This study demonstrates that the typical histological structures in the regions of attachment and mesofascial plane are the correct anatomic interface for mesenteric-based surgery.

Acute abdominal pain due to sigmoid volvulus with persistent descending mesocolon: a case report

BackgroundPersistent descending mesocolon, an anomaly of fixation of the mesentery of the descending colon, can sometimes cause complications such as intestinal obstruction and intussusception. We present the first reported case of sigmoid volvulus with persistent descending mesocolon.Case presentationAn 82-year-old Japanese man had intermittent lower abdominal pain. Abdominal computed tomography showed dilation and a shift to the right side of the sigmoid colon, but no findings of volvulus. The next day, he presented continuous lower abdominal pain with bloody stool. A second abdominal computed tomography showed strangulation and dilation of the sigmoid colon, with shift from the right side of the abdominal cavity to the pelvic space. This suggested the descending colon was running to the medial side with sigmoid volvulus. Emergency surgery was performed for volvulus with persistent descending mesocolon. Operative findings revealed dilation of the sigmoid colon with a partial poorly colored region and strangulation that caused volvulus. After releasing the strangulation of the sigmoid colon, the descending colon was revealed to be running more to the medial side, with adherence to small intestinal mesentery. There was no Toldt’s fusion fascia at the descending colon. Persistent descending mesocolon was therefore diagnosed due to abnormality of fixation of the descending colon. The sigmoid colon, including the poorly colored region, was resected and reconstructed, while the inferior mesenteric and left colonic arteries were preserved because of the complexity of the vascular system running around the descending and sigmoid colon due to the shortened mesentery. These findings were pathologically compatible with circulatory compromise and intestinal degeneration due to sigmoid volvulus. The patient had no complications after discharge, including in relation to defecation.ConclusionPersistent descending mesocolon can occasionally cause acute abdominal symptoms requiring immediate treatment. A computed tomography finding of the descending colon running more to the medial side than ordinary cases can aid diagnosis of persistent descending mesocolon.

Gastrointestinal: A wandering pancreatic adenocarcinoma.

A 79-year-old woman was referred to our hospital complaining of upper abdominal pain. She had no history of diabetes mellitus or other malignant diseases. Blood analysis showed no atypical findings other than elevated levels of CEA and Dupan-2. Contrast-enhanced computed tomography (CT) showed a 50 × 40-mm mass with poor contrast and irregular margins in the head of the pancreas (Fig. 1). Invasion into the superior mesenteric artery and portal vein was also evident. Histopathological examination of a specimen from endoscopic ultrasound-guided fine needle aspiration revealed adenocarcinoma. We diagnosed the mass as locally advanced unresectable pancreatic adenocarcinoma, and decided to perform chemoradiotherapy in order to help control the cancer and slow down its growth. To design radiotherapy, we performed CT on inhalation and free-breathing. The pancreatic mass was on the right side of the spine on inhalation, but surprisingly appeared on the left side of the spine on free-breathing (Fig. 2). We administered radiation at 1.8 Gy/day with fixation of the mass using a body shell and also administered gemcitabine. On day 8 after therapy, the patient developed multiple cerebral infarctions associated with Trousseau syndrome. She subsequently received best supportive care. In general, pancreatic masses have been considered immovable, because the pancreas is fixed to the retroperitoneum with the duodenum. The anterior surface of the pancreas is covered by parietal peritoneum and the inferior border abuts the root of the transverse mesocolon. A loose connective tissue layer, known as the fusion fascia of Treitz in the region of the head of the pancreas and as the fusion fascia of Told in the region of the body and tail, is coherent with the posterior of the pancreas. Some reports have pointed out that the pancreas can change position in some patients, particularly women. However, few reports in the English literature have described a wandering pancreatic mass. A case of wandering neuroendocrine tumor of the head of the pancreas has been reported, involving an encapsulated mass. In that case, CT showed a shift of the large mass in the pancreas from the right to the left side of the aorta. However, wandering pancreatic adenocarcinoma has not previously been reported. Malrotated pancreas or pancreatic volvulus has been reported with wandering spleen as a very rare clinical entity, but the present case demonstrated no clinical complications, such as mobile spleen or other abdominal organs. In our case, acquired pancreatic mobilization due to tissue weakening was speculated as the cause of motility. Pancreatic carcinoma should also be considered among the differential diagnoses for mobile abdominal mass.

Initial Experience with the Comprehensive Modified Laparoscopic Pyeloplasty Technique Based on Membrane Anatomy for Treating Ureteropelvic Junction Obstruction

Objective: The aim of the objective was to present our initial experience and evaluate the feasibility of the novel comprehensive modified laparoscopic pyeloplasty (CMLP) technique based on membrane anatomy. Materials and Methods: Forty-eight patients underwent CMLP from February 2016 to October 2020. CMLP involves the following: dissection of the ureter was based on the fascia or fusion fascia formed by embryonic development. The ureter was separated from the ureteral sheath, and the pelvis and ureter were incised with incomplete amputation. The first stitch was placed between the lower point of the spatulated ureter and the lowest corner of the renal pelvis to ensure correct orientation of the anastomosis; anastomosis of the renal pelvis and ureter was performed using the touchless technique. Results: All CMLPs were completed successfully without conversion. The mean overall operating time was 230.96 min. The median estimated blood loss was 50.00 (interquartile range 20.00–57.50) mL. The average postoperative hospital stay was 9.31 days. The average follow-up time was 24.73 months. No major complications occurred. In 1 case, revision laparoscopic pyeloplasty was performed, but the obstruction persisted after double J stent removal, so ultimately, the double J stent required regular replacement. Another asymptomatic patient with hydronephrosis experienced failed treatment and is still under follow-up. The overall success rate was 95.83% (46/48). The success rate in patients with recurrent ureteropelvic junction obstruction (UPJO) was 87.5% (7/8). Conclusions: CMLP is a practical and effective treatment option for UPJO with a high success rate. An advantage of CMLP is the clear surgical field.

Holistic view of surgery based on membrane anatomy for gastrointestinal tumor

The mesentery is a continuous unity and the operation of digestive carcinoma is the process of mesenteric resection. This paper attempts to simplify the formation process of all kinds of fusion fascia in the process of digestive tract embryogenesis, and to illuminate the continuity of fusion fascia with a holistic concept. This is helpful for beginners to reversely dissect the fusion fascia and maintain the correct surgical plane during operation, and to achieve the purpose of complete mesenteric resection.

Robotic Distal Gastrectomy With a Novel "Preemptive Retropancreatic Approach" During Dissection of Suprapancreatic Lymph Nodes for Gastric Cancer.

Abrogating contact with the pancreas in suprapancreatic lymph nodes dissection for gastric cancer can prevent pancreatic fistula because of postoperative pancreatic damage. Our novel "Preemptive retropancreatic approach" is a useful technique that minimizes pancreatic compression during robotic distal gastrectomy (RDG) with multijointed forceps. Here, we report the usefulness of RDG for gastric cancer surgery using our novel "Preemptive retropancreatic approach". "Preemptive retropancreatic approach": initial dissection of the bilateral retropancreatic space, the adherence between the retroperitoneum surface and the pancreas (fusion fascia) is released, providing a good operative field and hindering contact with the pancreas in suprapancreatic lymph nodes dissection during RDG. We herein reported consecutive 30 patients with gastric cancer who underwent RDG at Hokkaido University from September 2014 to March 2020. All operations were performed by a single surgeon (Y.E.). The median operating time was 281 minutes (132 to 415). The median intraoperative bleeding was 0 ml of blood (0 to 255). There were 2 incidences of postoperative complications (≥Clavien-Dindo classification II), and there were no cases of postoperative pancreas-related complications. The median length of hospital stay after the surgery was 10 days (6 to 33). As RDG for gastric cancer is still in its early introductory phase, its superiority has yet to be definitively established. However, we believe that "Preemptive retropancreatic approach" may reduce postoperative pancreatic-related complications in suprapancreatic lymph nodes dissection.

Gastric equivalent of the 'Holy Plane' to standardize the surgical concept of stomach cancer to mesogastric excision: updating Jamieson and Dobson's historic schema.

Surgery for curable gastric cancer has historically involved dissection of lymph nodes, depending on the risk of metastasis. By establishing the concept of mesogastric excision (MGE), we aim to make this approach compatible with that for colorectal cancer, where the standard is excision of the mesentery. Current advances in molecular embryology, visceral anatomy, and surgical techniques were integrated to update Jamieson and Dobson's schema, a historical reference for the mesogastrium. The mesogastrium develops with a three-dimensional movement, involving multiple fusions with surrounding structures (retroperitoneum or other mesenteries) and imbedding parenchymal organs (pancreas, liver, and spleen) that grow within the mesentery. Meanwhile, the fusion fascia and the investing fascia interface with adjacent structures of different embryological origin, which we consider to be equivalent to the 'Holy Plane' in rectal surgery emphasized by Heald in the concept of total mesorectal excision. Dissecting these fasciae allows for oncologic MGE, consisting of removing lymph node-containing mesenteric adipose tissue with an intact fascial package. MGE is theoretically compatible with its colorectal counterpart, although complete removal of the mesogastrium is not possible due to the need to spare imbedded vital organs. The celiac axis is treated as the central artery of the mesogastrium, but is peripherally ligated by tributaries flowing into the stomach to feed the spared organs. The obscure contour of the mesogastrium can be clarified by thinking of it as the gastric equivalent of the 'Holy Plane'. MGE could be a standard concept for surgical treatment of stomach cancer.

Treatment of Advanced Pancreatic Body and Tail Cancer by En Bloc Distal Pancreatectomy with Transverse Mesocolon Resection Using a Mesenteric Approach.

Pancreatic body and tail cancer easily invades retroperitoneal tissue, including the transverse mesocolon. It is difficult to ensure a dissected peripancreatic margin with standard distal pancreatectomy for advanced pancreatic body and tail cancer. Thus, we developed a novel surgical procedure to ensure dissection of the peripancreatic margin. This involved performing dissection deeper than the fusion fascia of Toldt and further extensive en bloc resection of the root of the transverse mesocolon. We performed distal pancreatectomy with transverse mesocolon resection (DP-TCR) using a mesenteric approach and achieved good outcomes. There are two main considerations for surgical procedures using a mesenteric approach: 1) dissection deeper than the fusion fascia of Toldt (securing the vertical margin) and 2) modular resection of the pancreatic body and tail, with the root of the transverse mesocolon and adjacent organs in a horizontal direction (ensuring the caudal margin). From 2017 to 2019, we performed DP-TCR using a mesenteric approach for six patients with advanced pancreatic body and tail cancer. Histopathological radical surgery was possible in all patients who underwent DP-TCR. No Clavien-Dindo grade IIIa or worse perioperative complications were observed in any patient. We believe that DP-TCR is useful as a radical surgery for advanced pancreatic body and tail cancer with extrapancreatic invasion.

The mesopancreas and pancreatic head plexus: morphological, developmental, and clinical perspectives.

Total mesopancreas excision has been found to be helpful for increasing no residual tumor resection rate and improving the prognosis of pancreatic cancer. This study analyzed the relationships among the mesopancreas and pancreatic head plexus from the morphological, developmental, and clinical perspectives. Twenty-four cadavers were employed. The upper abdominal viscera were resected en-bloc with the hepatoduodenal ligament, abdominal aorta, and nerve plexuses, and the innervation of the pancreas was dissected. Ten additional cadavers were used for histological examination of the pancreatic head and neck, part of the duodenum, the superior mesenteric artery (SMA) and its surrounding tissues, and the related arteries and veins. As results, cross-sections of the SMA revealed 6-9 layers of membranous structures resembling the layers of an onion, and the nerve fibers of the superior mesenteric plexus ran between the layers. Loose areolar tissue, adipose tissue, and lymphatics existed between the SMA and the pancreatic head/uncinate process, along with abundant thin blood vessels and capillaries, but very few nerves were found approaching the pancreas. Several parallel layers of collagen fibers (so-called Treitz's fusion fascia) existed between the dorsal aspect of the pancreatic head and the aortocaval plane. The mesopancreas was continuous and connected with the para-aortic area. It may be better termed the mesopancreatoduodenum than the mesopancreas, as the duodenum-pancreas-SMA forms a complex morphological, developmental, functional, and pathological structure.

Anatomical observation and clinical significance of rectosacral fascia in total mesorectal resection

Objective: To observe the anatomical architecture of rectosacral fascia and discuss the best plan for accurate peri-rectal dissection in laparoscopic/robotic total mesorectal resection (TME). Methods: A descriptive cohort study was carried out. A total of 127 patients with rectal cancer who underwent TME in the Department of Colorectal Surgery at the affiliated Union hospital of Fujian Medical University were included, patients' demographics with their pathological details and operation videos were collected for analysis. Another 20 high-definition images of post-TME surgical specimens were collected from our digital database. A total of 28 cadaveric models were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University, to observe the anatomical details of rectosacral fascia. Results: (1) Anatomical observation showed that the pre-hypogastric fascia attaches to the proper fascia of the mesorectum in a horizontal arc posteriorly, forming the rectosacral fascia. If this fusion couldn't be identified and appropriately transected during posterior space dissection, it would be easy to destroy the proper fascia and dissect through the mesorectum resulting in residual mesorectum tissue. After the fascia transaction, the proper fascia of the mesorectum is still intact distally. The upper part of rectosacral fascia bilaterally re-separated again into the proper fascia and pre-hypogastric fascia. The pre-hypogastric fascia acts as a "fascia barrier" when dissecting the lateral space constantly from posterior to anterior. The right attachment of the rectosacral fascia was gradually transected. The pelvic plexus from the right S2-S4 was covered by the pre-hypogastric fascia which is considered the outer side layer of rectosacral fascia laterally. It was observed that the fascia continued with the anterior layer of the Denonvilliers' fascia, which has been transected during anterior space dissection. The proper fascia, which is the inner side layer of rectosacral fascia laterally, was still intact. The edge of the right rectosacral fascia attachment ran obliquely from the back and upward into the front direction. The left extension was similar to the right. (2) Cadaveric specimens: at the level of the lower edge of S4 vertebral body, the pre-hypogastric fascia fused with the proper fascia to form the rectosacral fascia. The right attachment margin of the rectosacral fascia was cut off step by step. The attachment margin of the rectosacral fascia went from the back and upward to the front downward direction. The right edge of rectosacral fascia attachment continued with the anterior layer of the Denonvilliers' fascia at the pre-rectal space and attached to the pre-hypogastric fascia laterally. The pelvic plexus sends out many tiny rectal branches on the anterolateral side, which pass through the transitional area between pre-hypogastric fascia and the anterior layer of the Denonvilliers' fascia to innervate the rectum. (3) TME specimens observation: the posterior attachment of rectosacral fascia was curved around the mesorectum with bilateral oblique attachments. The mesorectum was covered by fusion fascia below the posterior and bilateral attachment margin while it was covered only by the proper fascia above it. Conclusion: according to the morphological characteristics of rectosacral fascia, the rectosacral fascia should be dissected at the level of S4 vertebral body posterior to the rectum in an arc, shape and then enter the superior-levator space. Before dissecting the bilateral spaces, the anterior space of the rectum should be dissected first. The anterior layer of the Denonvilliers' fascia should be cut off into an inverted "U" shape, and then the lateral space should be dissected from anterior to posterior. Finally, the lateral attachment of rectosacral fascia was transected to ensure the integrity of the mesorectum without damaging the pelvic plexus branches and NVB.

481 - Significant impact of three-dimensional volumetry of perinephric fat on the console time during robot-assisted partial nephrectomy

To assess the impact of volumetry of perinephric fat (PNF) on the perioperative outcomes of robot-assisted partial nephrectomy (RAPN). Between 2016 and 2019, a single surgeon performed RAPN for 128 patients with clinical T1a-b renal tumors at our institution, and the 70 most recent patients were included in this study to minimize the effects of surgical experience. PNF was defined as a fatty area around the kidney within the anatomical structures, including the lateroconal fascia, fusion fascia, psoas muscle, lumbar quadrate muscle and diaphragm, and its volume was calculated based on reconstructed three-dimensional computed tomography images using the SYNAPSE VINCENT system. In this series, the trifecta and MIC (margin, ischemia and complications) score system outcomes were achieved in 69 (98.6%) and 64 patients (91.4%), respectively. The median PNF volume in the 70 patients was 166.05 cm3, which was significantly correlated with both the body mass index (BMI) and Mayo adhesive probability (MAP) score (correlation coefficient = 0.68 and 0.74, respectively). There was no significant difference in the R.E.N.A.L. nephrometry score, PNF volume or console time during RAPN among 5 groups consisting of 14 consecutive patients. Of several factors examined, the console time was significantly affected by the sex, MAP score and PNF volume, and only the PNF volume was independently associated with the console time. Even if performed by an experienced robotic surgeon beyond the initial learning curve, the PNF volume may influence the console time during RAPN.

The Retropancreatic Fusion Fascia Oriented Splenic Hilar Lymphadenectomy Versus Laparoscopic Approach In D2 Total Gastrectomy.

BackgroundThe retropancreatic fusion fascia is recognized as the anatomical landmark during retropancreatic mobilization. However, its role in D2 total gastrectomy for proximal advanced gastric cancer (PAGC) remains unexplored. This study aimed to develop the retropancreatic fusion fascia-oriented ex vivo approach for splenic hilar lymphadenectomy (RP-SL) to avoid difficulty in using the total laparoscopic approach (TL-SL).Material/MethodsThe data for patients with PAGC who underwent D2 total gastrectomy were retrieved from our clinical database and electronic medical records (December 2016 to December 2018), with a 1:1 match ratio for balance of the 2 groups.ResultsIn sum, 84 matched patients were included in the study. There were 2360 retrieved lymph nodes (LNs), with an average of 28.10. Sixteen patients were confirmed with positive splenic hilar lymphadenectomy, and the mean harvested lymph nodes (LNs) were significantly increased in the RP-SL group compared to the TL-SL group (3.07 vs. 2.29, P<0.001), decreased operative time (193.21 min vs. 247.74 min, P<0.001), and less blood loss (96.90 mL vs. 185.24 mL, P=0.001) in the RP-SL group. Postoperative hospital stay (6.55 days vs. 7.26 days), rate of morbidity (9.50% vs. 11.91%), and overall costs (¥65255.64 vs. ¥64419.91) were comparable between the groups (P>0.05).ConclusionsThe landmark at the conjunction between the superior mesenteric vessels and the inferior pancreatic margin made it feasible to identify the retropancreatic areolar. The RP-SL approach was safe and efficient for splenic hilar lymphadenectomy.

Significant impact of three-dimensional volumetry of perinephric fat on the console time during robot-assisted partial nephrectomy

BackgroundTo assess the impact of volumetry of perinephric fat (PNF) on the perioperative outcomes of robot-assisted partial nephrectomy (RAPN).MethodsBetween 2016 and 2019, a single surgeon performed RAPN for 128 patients with clinical T1a-b renal tumors at our institution, and the 70 most recent patients were included in this study to minimize the effects of surgical experience. PNF was defined as a fatty area around the kidney within the anatomical structures, including the lateroconal fascia, fusion fascia, psoas muscle, lumbar quadrate muscle and diaphragm, and its volume was calculated based on reconstructed three-dimensional computed tomography images using the SYNAPSE VINCENT system.ResultsIn this series, the trifecta and MIC (margin, ischemia and complications) score system outcomes were achieved in 69 (98.6%) and 64 patients (91.4%), respectively. The median PNF volume in the 70 patients was 166.05 cm3, which was significantly correlated with both the body mass index (BMI) and Mayo adhesive probability (MAP) score (correlation coefficient = 0.68 and 0.74, respectively). There was no significant difference in the R.E.N.A.L. nephrometry score, PNF volume or console time during RAPN among 5 groups consisting of 14 consecutive patients. Of several factors examined, the console time was significantly affected by the sex, MAP score and PNF volume, and only the PNF volume was independently associated with the console time.ConclusionEven if performed by an experienced robotic surgeon beyond the initial learning curve, the PNF volume may influence the console time during RAPN.

The fusion fascia of Fredet: an important embryological landmark for complete mesocolic excision and D3-lymphadenectomy in right colon cancer.

The fusion fascia of Toldt is a well-known landmark used by colorectal surgeons. On the contrary, the fusion fascia of Fredet (the plane between the ascending mesocolon and the visceral duodenal-pancreatic peritoneum) still remains a neglected embryological structure. Aim of this study was to provide an anatomic description of this fascia and its application to minimally invasive D3-lymphadenectomy (D3-L) and complete mesocolic excision (CME) for right colon cancer. First phase: Cadaveric dissection and anatomic description of the fascia of Fredet. Second phase: prospective evaluation of its surgical application ina consecutive series of laparoscopic right hemicolectomies with CME and D3-L at a tertiary hospital. The fascia of Fredet was identified and dissected in one fresh and two formalin-fixed cadavers. The trunk of Henle and the medial border of the superior mesenteric vein defined the medial limit of this embryologic plane. Seventeen patients were operated on. Laparoscopic dissection of the fascia of Fredet was possible in every patient. Median operative time was 210 (120-380) min. There were no major postoperative complications. All cases were adenocarcinomas, except one adenomatous polyp. T stage was Tis in three, T2 in two, T3 in seven, and T4 in five patients. Median number of harvested lymph nodes was 24 (9-39). Lymphatic invasion was found in six patients. All resections were classified as satisfactory mesocolic excision and R0. Median postoperative length of stay was 6 (4-20) days. Median follow-up time was 28 (16-41) months. Local and distal recurrence rate was 0. The fusion fascia of Fredet is useful to achieve CME and D3-L in right colon cancers with reduced risk of intraoperative complications. This structure is particularly suitable for minimally invasive surgery; therefore, we encourage awareness of the fascia of Fredet by colorectal surgeons.

Laparoscopic surgery of total mesorectal excision based on pelvic membrane anatomy

Total mesorectal excision (TME) is the basic principle of surgery in rectal cancer which requires en bloc removal of the tumor and its regional lymph nodes. This conincides with the theory of membrane anatomy that emphasizes en bloc resection and avoids cancer leakage. The basis of membrane anatomy is the fusion of peritoneum and three key pointsare needed to understand the fusion and fusion fascia:(1) the fusion only occursin peritoneum; (2) the inside of fusion fascia cannot be separated; (3) the fusion can be diversiform. Only mastering these key points can we comprehend and apply this theory dialectically. The membrane anatomy in rectum is different from stomach or colon because of its specific location. The posterior space of rectum is filled with the loose connective tissue which is the degeneration of peritoneum fusion. In this space, the anterior lay of presacral fascia fuses with the proper fascia of rectum at the S4 level and separates the space into the retrorectal space and the supralevator space. Denonvilliers fascia is the fusion fascia in front of rectum, which forms the prerectal space and retroprostatic space, and extends to lateral pelvic wall with fusion of the parietal fascia of pelvis, covering the neurovascular bundle (NVB) together. The proper fascia of rectum surrounds the middle rectal artery, the pelvic plexus rectal branch and the adipose tissue to form the lateral rectal pedicle at 10 o'clock and 2 o'clock near the pelvic floor. At the level of levator ani hiatus, the fusion of levator ani muscle fascia and the proper fascia of rectum forms the Hiatal ligament, which fixs the anal canal and closes the levator ani hiatus.This article intends to discuss the above points from the perspective of membrane anatomy, in order to better guide surgeons to complete laparoscopic total mesorectal excision for rectal cancer.

An anatomical hypothesis: a "concentric-structured model" for the theoretical understanding of the surgical anatomy in the upper mediastinum required for esophagectomy with radical mediastinal lymph node dissection.

Understanding the surgical anatomy is the key to reducing surgical invasiveness especially in the upper mediastinal dissection for esophageal cancer, which is supposed to have a significant impact on curability and morbidity. However, there is no theoretical recognition regarding the surgical anatomy required for esophagectomy, although the surgical anatomy in abdominal digestive surgery has been developed on the basis of embryological findings of intestinal rotation and fusion fascia. Therefore, we developed a hypothesis of a 'concentric-structured model' of the surgical anatomy in the upper mediastinum based on human embryonic development. This model was characterized by three factors: (1) a concentric and symmetric three-layer structure, (2) bilateral vascular distribution, and (3) an 'inter-layer potential space' composed of loose connective tissue. The concentric three-layer structure consists of the 'visceral layer', the 'vascular layer', and the 'parietal layer': the visceral layer containing the esophagus, trachea, and recurrent laryngeal nerves as the central core, the vascular layer of major blood vessels surrounding the visceral core to maintain the circulation, and the parietal layer as the outer frame of the body. The bilateral vascular distribution consists of the inferior thyroid arteries and bronchial arteries originating from the bilateral dorsal aortae in an embryo. This bilateral vascular distribution may be related to the formation of the proper mesentery of the esophagus and frequent lymph node metastasis observed in the visceral layer around recurrent laryngeal nerves. The three concentric layers are bordered by loose connective tissue called the 'inter-layer potential space'. This inter-layer potential space is the fundamental factor of our concentric-structured model as the appropriate surgical plane of dissection. The peripheral blood vessels, nerves, and lymphatics transition between each layer, thereby penetrating this loose connective tissue forming the inter-layer potential space. Recurrent laryngeal nerves also transition from the vascular layer after branching off from the vagal nerves and then ascend consistently in the visceral layer. We investigated the validity of this concentric-structured model, confirming the intraoperative images and the surgical outcomes of thoracoscopic esophagectomy in a prone position (TSEP) before and after the introduction of this hypothetical anatomy model. A total of 226 patients with esophageal cancer underwent TSEP from January 2015 to December 2016. After the introduction of this model, the surgical outcomes in 105 patients clearly improved for the operation time of the thoracoscopic procedure (160 min vs. 182 min, P=0.01) and the incidence of recurrent laryngeal nerve palsy (19.0% vs. 36.4%, P=0.004). Moreover, we were able to identify the concentric and symmetric layer structure through surgical dissection along the inter-layer potential space between the visceral and vascular layers ('viscero-vascular space') in all 105 cases after introduction of the hypothetical model. The concentric-structured model based on embryonic development is clinically beneficial for achieving less-invasive esophagectomy by ensuring a theoretical understanding of the surgical anatomy in the upper mediastinum.