Corticosteroid-associated osteonecrosis of the femoral head in an 87-year-old patient following treatment for COVID-19-associated pneumonia: A case report.

Coronavirus disease 2019 is known to cause severe acute respiratory syndrome, and serious cases need to be treated with corticosteroids. Herein, we report an 87-year-old woman who developed bilateral osteonecrosis of the femoral head after corticosteroid treatment for coronavirus disease 2019-related pneumonia. Sixteen months after treatment, she developed right hip pain without any evidence of trauma. A diagnosis of bilateral osteonecrosis of the femoral head was made based on sclerotic bands on plain radiographs and low-signal bands on T1-weighted magnetic resonance images. The patient underwent right total hip arthroplasty 4 months after symptom onset. Histological examination of the resected femoral head revealed pathological evidence of osteonecrosis. The postoperative course was good, and the patient can now walk unassisted. To the best of our knowledge, this is the first report of histologically proven osteonecrosis after corticosteroid therapy for coronavirus disease 2019-related disease.

Myocardial extracellular volume quantification in cardiac amyloidosis: a comparative study between cardiac computed tomography and magnetic resonance imaging.

OBJECTIVES: Myocardial extracellular volume (ECV) on computed tomography (CT), an alternative to cardiac magnetic resonance (CMR), has significant practical clinical advantages. However, the consistency between ECVs quantified via CT and CMR in cardiac amyloidosis (CA) has not been investigated sufficiently. Therefore, the current study investigated the application of CT-ECV in CA with CMR-ECV as the reference standard. METHODS: We retrospectively evaluated 31 patients with CA who underwent cardiac CT and CMR. Pearson correlation analysis was performed to investigate correlations between CT-ECV and CMR-ECV at each segment. Further, correlations between ECV and clinical parameters were assessed. RESULTS: There were no significant differences in the mean global ECVs between CT scan and CMR (51.3% ± 10.2% vs 50.0% ± 10.5%). CT-ECV was correlated with CMR-ECV at the septal (r = 0.88), lateral (r = 0.80), inferior (r = 0.79), anterior (r = 0.77) segments, and global (r = 0.87). In both CT and CMR, the ECV had a weak to strong correlation with high-sensitivity cardiac troponin T level, a moderate correlation with global longitudinal strain, and an inverse correlation with left ventricular ejection fraction. Further, the septal ECV and global ECV had a slightly higher correlation with the clinical parameters. CONCLUSIONS: Cardiac CT can quantify myocardial ECV and yield results comparable to CMR in patients with CA. Moreover, a significant correlation between CT-ECV and clinical parameters was observed. Thus, CT-ECV can be an imaging biomarker and alternative to CMR-ECV. CLINICAL RELEVANCE STATEMENT: Cardiac CT can quantify myocardial ECV and yield results comparable to CMR in patients with CA, and CT-ECV can be used clinically as an imaging biomarker and alternative to CMR-ECV. KEY POINTS: • A significant correlation was found between CT myocardial extracellular volume and cardiac MR myocardial extracellular volume in patients with cardiac amyloidosis. • In CT and cardiac MR, the myocardial extracellular volume correlated well with high-sensitivity cardiac troponin T level, global longitudinal strain, and left ventricular ejection fraction. • CT myocardial extracellular volume can be an imaging biomarker and alternative to cardiac MR myocardial extracellular volume.

Assessment of the Hip Flexor Muscles Shortly after Curved Periacetabular Osteotomy using Magnetic Resonance Imaging.

BACKGROUND: Curved periacetabular osteotomy requires detachment and retraction of the hip flexors. In this study, we evaluated hip flexor muscle status by magnetic resonance imaging (MRI) shortly after curved periacetabular osteotomy. METHODS: We retrospectively evaluated 60 hips of 56 patients by MRI 1 week and 3 months after curved periacetabular osteotomy performed from August 2017 to December 2019. We classified the condition of the flexors as follows: Grade 0, normal; Grade I, strain/edema; Grade II, partial tear; and grade III, complete tear. RESULTS: At 1 week after surgery, the iliacus muscle was classified as grades I and II in 12.0 and 88.0% of hips; psoas as grades 0, I and II in 22.0, 72.0, and 6.0%; sartorius muscle as grades 0, I and II in 6.0, 62.0, and 32.0%; and rectus femoris muscle as grades 0 and I in 86.0 and 14.0%, respectively. At 3 months, 82.0, 88.0, and 96.0% of psoas, sartorius, and rectus femoris muscles, respectively, had improved to grade 0, whereas the iliacus was grades I and II in 94.0 and 6.0%, respectively. These changes in the iliacus muscle at 3 months were not significantly associated with patient characteristics, radiographic data, or clinical scores. CONCLUSIONS: All the iliacus, 78% of psoas, 94% of sartorius, and 14% of rectus femoris muscles appeared abnormal on MRI 1 week after curved periacetabular osteotomy. However, at 3 months, only 18% of psoas, 12% of sartorius, and 4% of rectus femoris muscles appeared abnormal, whereas all iliacus muscles still appeared abnormal. These abnormalities did not significantly affect clinical scores.

A case of total hip arthroplasty for nonunion after femoral trochanteric fracture surgery with complete breakage of only the compression screw of the InterTAN nail.

Intramedullary nails are an effective treatment for common femoral trochanteric fractures. However, one of their complications is implant breakage due to poor reduction and nonunion after surgery. We herein report a case of a 54-year-old man who underwent total hip arthroplasty for nonunion after internal fixation of a femoral trochanteric fracture. The femoral trochanteric fracture was treated by internal fixation using the Trigen InterTAN nail. The patient developed symptoms of hip pain 6 months after internal fixation. Nine months after internal fixation, hip radiographs and computed tomography scans showed breakage of only the compression screw. During total hip arthroplasty, we were unable to remove the lag screw and compression screw before the femoral head dislocation because no gap was present between the two screws. Thus, we removed these screws with the femoral head after dislocation of the femoral head. The removed nail was partially damaged at the lag screw hole. This change was retrospectively observed on the preoperative computed tomography scan. Three months after total hip arthroplasty, the patient was able to walk unaided and the hip pain had resolved. If only the compression screw is completely broken after internal fixation with the Trigen InterTAN nail, both the lag screw and compression screw will be difficult to remove with preservation of the femoral head. We effectively managed such a case by not only revision internal fixation but also total hip arthroplasty.

Cardiac MRI-derived Extracellular Volume Fraction versus Myocardium-to-Lumen R1 Ratio at Postcontrast T1 Mapping for Detecting Cardiac Amyloidosis.

Purpose: To evaluate the diagnostic performance of myocardium-to-lumen R1 (1/T1) ratio on postcontrast T1 maps for the detection of cardiac amyloidosis in a large patient sample. Materials and Methods: This retrospective study included consecutive patients who underwent MRI-derived extracellular volume fraction (MRI ECV) analysis between March 2017 and July 2021 because of known or suspected heart failure or cardiomyopathy. Pre- and postcontrast T1 maps were generated using the modified Look-Locker inversion recovery sequence. Diagnostic performances of MRI ECV and myocardium-to-lumen R1 ratio on postcontrast T1 maps (a simplified index not requiring a native T1 map and hematocrit level data) for detecting cardiac amyloidosis were evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity. Results: Of 352 patients (mean age, 63 years ± 16 [SD]; 235 men), 136 had cardiac amyloidosis. MRI ECV showed 89.0% (121 of 136; 95% CI: 82%, 94%) sensitivity and 98.6% (213 of 216; 95% CI: 96%, 100%) specificity for helping detect cardiac amyloidosis (cutoff value of 40% [AUC, 0.99 {95% CI: 0.97, 1.00}; P < .001]). Postcontrast myocardium-to-lumen R1 ratio showed 92.6% (126 of 136; 95% CI: 89%, 96%) sensitivity and 93.1% (201 of 216; 95% CI: 89%, 96%) specificity (cutoff value of 0.84 [AUC, 0.98 {95% CI: 0.95, 0.99}; P < .001]). There was no evidence of a difference in AUCs for each parameter (P = .10). Conclusion: Postcontrast myocardium-to-lumen R1 ratio showed excellent diagnostic performance comparable to that of MRI ECV in the detection of cardiac amyloidosis.Keywords: MR Imaging, Cardiac, Heart, Cardiomyopathies Supplemental material is available for this article. © RSNA, 2023.

A comparison of the effects of anti-reflux procedures during esophagogastrostomy after proximal gastrectomy on the postoperative quality of life.

PURPOSE: To investigate the postoperative quality of life (QOL) in patients with proximal gastric cancer (PGC) or esophago-gastric junction cancer, a nationwide multi-institutional study (PGSAS NEXT trial) was conducted. METHODS: Patients who had undergone radical resection more than 6 months previously were enrolled from 70 Japanese institutions between July 2018 and June 2020. The Postgastrectomy Syndrome Assessment Scale (PGSAS)-45 questionnaire was distributed to eligible patients, and responses were collected by mail. The main outcome measures of the PGSAS-45 were then calculated and compared. RESULTS: Questionnaires were retrieved from 1950 participants, and data from 300 patients who had undergone a proximal gastrectomy (PG) with esophagogastrostomy for PGC were analyzed. The mean esophageal reflux subscale value was 1.9 among the 276 patients who underwent an anti-reflux procedure, which was significantly better than the mean value (2.6) for the 21 patients who did not undergo an anti-reflux procedure (p = 0.002). The esophageal reflux subscale values were also compared among 3 major anti-reflux procedures: the double-flap technique (N = 153), the pseudo-fornix and/or His angle formation (N = 67), and fundoplication (N = 44); no statistically significant differences were observed. CONCLUSION: An anti-reflux procedure during esophagogastrostomy after PG for PGC is necessary to improve postoperative esophageal reflux symptoms, regardless of the type of procedure. TRIAL REGISTRATION: The PGSAS NEXT study was registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR; registration number: 000032221).

Impact of AirSeal® insufflation system on respiratory and circulatory dynamics during laparoscopic abdominal surgery.

The effect of the AirSeal® insufflation system on hemodynamic parameters, especially end-tidal carbon dioxide (EtCO2), during laparoscopic abdominal surgery remains unclear. This retrospective single-center study included 333 consecutive patients who underwent laparoscopic hepatectomy (n = 43), gastrectomy (n = 69), colectomy (n = 137), or proctectomy (n = 84) using the AirSeal®. Patient demographics and intraoperative hemodynamic parameters, such as EtCO2, peripheral capillary oxygen saturation (SpO2), and arterial systolic blood pressure (ABP), were collected and analyzed. EtCO2 was evaluated during the entire operative period (whole period) as well as the pneumoperitoneum period until specimen removal (pneumoperitoneum period). We defined "positive respiratory and circulatory responses" (positive responses) as a decrease in EtCO2 ≥ 3 mmHg in addition to decreases in SpO2 ≥ 3% and ABP ≥ 10 mmHg simultaneously, which suggest possible carbon dioxide (CO2) embolism. The median EtCO2 values of hepatectomy, gastrectomy, colectomy, and proctectomy in the whole period/pneumoperitoneum period were 37.3/37.4, 37.1/37.3, 37.4/37.9, and 38.2/38.4 mmHg, respectively. The EtCO2 of proctectomy was significantly higher than that of gastrectomy during the whole and pneumoperitoneum periods (P < 0.05). In contrast, the EtCO2 of hepatectomy was comparable to that of the other three surgeries in the whole and pneumoperitoneum periods. Meanwhile, nine (2.7%; eight hepatectomies and one proctectomy) patients showed positive responses, and one who underwent a partial hepatectomy developed a clinically manifested CO2 embolism. Positive responses occurred during venous exposure or bleeding in all nine cases. Although the EtCO2 of hepatectomy was comparable to that of the other surgeries using the AirSeal®, laparoscopic hepatectomy showed a tendency of CO2 embolism. Thus, a secure and careful surgical approach is mandatory for laparoscopic hepatectomy using the AirSeal® insufflation system.

Endoscopic full-thickness resection of an esophageal leiomyoma located in close proximity to the azygos vein.

Third-space endoscopic techniques, such as peroral endoscopic tumor resection (POET) and submucosal tunneling endoscopic resection (STER), enable access to deep organs and tissues that have been previously inaccessible with an endoscope. We present a 29-year-old man with a submucosal tumor (40 × 25 mm) located at 5 o'clock in the upper thoracic esophagus. Histological diagnosis by endoscopic ultrasound-fine needle aspiration was leiomyoma. Computed tomography showed the azygos vein posterior to the tumor. However, because endoscopic ultrasound revealed space between them, POET was performed. Because the tumor originated from the deep layer of the muscularis propria, full-thickness resection was performed to achieve R0 resection. The azygos vein arch was seen through the mediastinal space after tumor enucleation. The final histopathological diagnosis was leiomyoma. POET is a potentially revolutionary endoscopic technique that enables full-thickness resection of nonepithelial lesions. Preoperative computed tomography or endoscopic ultrasound to determine peritumoral anatomy is important to ensure safety. During the procedure, it is important to operate under direct vision, accurately identify the tumor boundary, and dissect along the boundary to avoid damaging the tumor and surrounding structures.

Relationship between perioperative oncological evaluation and recurrence using circulating tumor DNA with KRAS mutation in patients with colorectal cancer.

BACKGROUND: The detection of circulating tumor DNA (ctDNA) in colorectal cancer (CRC) by liquid biopsy may have prognostic information. In this perioperative study, we evaluate if there is a relationship between mutant allele frequency (MAF) of Kirsten rat sarcoma viral oncogene homolog (KRAS) and tumor recurrence and how that could be useful in the early detection of recurrence. METHODS: Among 304 cases of colorectal cancer surgery, ctDNA was sampled from the perioperative blood of 84 patients with CRC with KRAS mutation (exon 4 p.A146T, exon 4 p.A146V, exon 2 p.G12A, exon 2 p.G12C, exon 2 p.G12D, exon 2 p.G12S, exon 2 p.G12V, exon 2 p.G13D, exon 3 p.Q61H) and analyzed using the digital polymerase chain reaction system. The median observation period was 26 months. RESULTS: Although the relationship between the perioperative MAF of KRAS and recurrence was not proved, tumor diameter, tumor depth, and stage were correlated with the preoperative MAF of KRAS (p = 0.034, p = 0.002, p = 0.008). However, tumor diameter, tumor depth, and stage did not correlate with MAF of KRAS at postoperative day 30. CONCLUSIONS: In this study, pathological tumor size, tumor depth, and stage were correlated with preoperative MAF of KRAS, but it was unreliable to predict recurrence by detection of ctDNA with KRAS mutation in the perioperative period of colorectal surgery.

Oncological evaluation in the perioperative period using cfDNA with BRAF V600E mutation in patients with colorectal cancer.

The detection of circulating cell-free DNA (cfDNA) by liquid biopsy is reported to provide prognostic information in colorectal cancer (CRC). Although the frequency of BRAF V600E mutation in CRC is less than 10%, it is associated with poor responses to conventional chemotherapy. We conducted a prospective study to investigate the relationship between the perioperative mutant allele frequency (MAF) of BRAF V600E and tumor recurrence, and to evaluate the possibility of early detection of recurrence. Among 362 patients who underwent radical resection, cfDNA was extracted from the perioperative blood of 11 CRC patients with BRAF V600E mutation and analyzed using the digital polymerase chain reaction (dPCR) system. The median follow-up time was 22 months, and there were four cases of recurrence. Although there was no correlation between recurrence and the perioperative MAF of BRAF V600E, tumor diameter was correlated with the MAF (p = 0.024), and the MAF increased with time in two patients from whom additional samples were obtained prior to recurrence. In this study, we identified a correlation between the pathological tumor diameter and the MAF, but it was difficult to predict recurrence by measuring cfDNA with BRAF V600E mutation in the perioperative period of radical resection of CRC.

Two case of bilateral approach in laparoscopic pancreas-sparing distal duodenectomy for duodenal neoplasms arising from the distal duodenum.

INTRODUCTION: Laparoscopic pancreas-sparing distal duodenectomy is a less invasive surgical therapy; however, the anatomical complexity of the duodenum increases the difficulty of laparoscopic procedures. We introduce our technique for laparoscopic pancreas-sparing distal duodenectomy for distal duodenal tumors. PRESENTATION OF CASES: A first patient was 47-year-old woman who had 30 mm of duodenal tumor which located in third portion of duodenum. A second patient was 66-year-old man who had 35 mm of submucosal tumor which located in the third portion of duodenum. Laparoscopic pancreas-sparing duodenectomy was performed using bilateral approach for both cases. We began by dissecting an avascular area on the right side of the transverse mesocolon to mobilize the second and third portions of the duodenum with the uncinate process of the pancreas. Next, from the left side, the jejunum and the fourth portion of the duodenum were fully mobilized orally from the surrounding tissue, connecting the dissection plane with the right-side area. The jejunum and duodenum were cut with a linear stapler. Intracorporeal reconstruction was performed in an overlapped manner. We performed this procedure in two patients. Operative time was 326 and 370 min, respectively. Patients were discharged on postoperative days 9-12 without postoperative complications. DISCUSSION: Duodenal tumors are found increasingly often because of developments in endoscopic technology and techniques; therefore, establishing safe surgical procedures for duodenal tumor excision is imperative. Our surgical approach was simple and safe procedure. CONCLUSION: Laparoscopic pancreas-sparing distal duodenectomy with a bilateral approach is a useful approach without wide mobilization of duodenum.

Concurrent minimal change disease and retroperitoneal liposarcoma successfully treated by tumor resection and steroid therapy.

A 54-year-old Japanese woman developed simultaneous abdominal distension and bilateral leg edema. Her medical history and results of periodic medical check-up were unremarkable. Blood tests revealed severe hypoproteinemia and acute kidney injury, and urinalysis revealed 4+ proteinuria and 2+ hematuria. Abdominal computed tomography revealed a large intra-abdominal mass with fat tissue density. She underwent emergency tumor excision, splenectomy, and distal pancreatectomy. However, hypoproteinemia and acute kidney injury worsened. Therefore, she was transferred to the nephrology division for confirmation of diagnosis and for treatment of acute kidney injury and nephrotic syndrome. We conducted percutaneous kidney biopsy and diagnosed minimal change disease (MCD). Intravenous prednisolone was started, and heavy proteinuria and systemic edema were gradually alleviated. She achieved complete remission 2 months later, and oral prednisolone was tapered. Histopathological diagnosis of abdominal tumor was dedifferentiated liposarcoma of retroperitoneal origin. Immunohistochemical staining revealed strong expression of vascular endothelial growth factor in the tumor cells in the dedifferentiated component. Currently, her clinical course is stable without recurrence of liposarcoma and nephrotic syndrome. MCD develops in patients with Hodgkin's lymphoma, solid organ cancers, hematological malignancies, and thymoma, whereas concurrent MCD and liposarcoma are rare. Remission of nephrotic syndrome and normalized kidney function induced by steroid therapy are important for better management of patients with malignancy.

Appropriate traction can help identify the optimal dissectable layer for infrapyloric lymph node dissection in laparoscopic gastrectomy.

INTRODUCTION: Appropriate dissection of the infrapyloric lymph nodes (no. 6 LNs) is important in gastric cancer surgery. In laparoscopic surgery, dissection of the no. 6 LNs along the inner dissectable layer from the left side of patient has been reported. However, it is difficult for surgeons to provide appropriate traction with their left hand from the left side. To resolve this difficulty, we dissected the no. 6 LNs from the patient's right side to identify the optimal layer. We then evaluated the oncologic reliability of the layer and the safety of this procedure. METHODS: From the patient's right side, the surgeon used their left hand to provide appropriate traction when pulling the adipose tissue, including the no. 6 LNs. This exposed the optimal layer between the adipose tissue and the pancreas. To assess this maneuver, the surgical outcomes of patients who underwent laparoscopic distal gastrectomy from April 2011 to March 2013 were retrospectively analyzed. The surgical outcomes included the number of the no. 6 LNs resected, time to dissect the no. 6 LNs, incidence of pancreatic complications, and recurrence in the no. 6 LNs. RESULTS: There were 112 patients identified. The median number of the no. 6 LNs resected was five. The median time to dissect the no. 6 LNs was 14 minutes. Four patients developed pancreatic fistula, and another four patients developed intra-abdominal abscess. There was no recurrence in the no. 6 LNs. CONCLUSION: The optimal layer was oncologically reliable, and these procedures were safe.

Current Status of Therapeutic Drug Monitoring of 5-Fluorouracil Prodrugs.

In recent years, therapeutic drug monitoring (TDM) of intravenous administration of 5-fluorouracil (5-FU) has resulted in reduced toxicity and improved efficacy. Prodrugs of 5-FU were developed to reduce toxicity, extend the duration of action, and increase tumour selectivity of 5-FU. These drugs are important in daily practice because of their ease of administration. Dose adjustment of 5-FU prodrugs by TDM is expected to reduce its toxicity and improve its efficacy. This review focuses on data from a recent study of personalized treatment using TDM of 5-FU and its prodrugs.

Changes in Immunological Status in Patients With Metastatic Colorectal Cancer Treated With First-line Chemoimmunotherapy.

BACKGROUND/AIM: Chemoimmunotherapy is a promising treatment for various malignant diseases. In this study, we examined whether first-line chemoimmunotherapy using adoptive immune-cell therapy was effective for metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: The therapeutic efficacy and safety of the standard first-line chemoimmunotherapy with adoptive αß T cell therapy and bevacizumab were assessed using thirty-two patients with mCRC in our hospital. Immunological status after this chemoimmunotherapy was also evaluated. RESULTS: The response and disease control rates were 68.8% and 87.5%, respectively. Further, median progression-free and overall survival were 14.2 and 35.3 months. Immunotherapy-associated toxicity was minimal. Significant decrease in the change of monocyte number (p=0.006) and increase in the change of rate of lymphocyte-to-monocyte ratio (p=0.039) were seen in the complete response group. CONCLUSION: First-line chemoimmunotherapy with adoptive αß T cell therapy may be useful for mCRC.

5-Nitrouracil stabilizes the plasma concentration values of 5-FU in colorectal cancer patients receiving capecitabine.

Capecitabine is selectively converted from 5'-DFUR to 5-fluorouracil (5-FU) in tumours by thymidine phosphorylase (TP). We investigated the addition of 5-nitrouracil (5-NU), a TP inhibitor, into blood samples for precise measurements of plasma 5-FU concentrations. The plasma concentration of 5-FU was measured after capecitabine administration. Two samples were obtained at 1 or 2 h after capecitabine administration and 5-NU was added to one of each pair. Samples were stored at room temperature or 4 °C and 5-FU concentrations were measured immediately or 1.5 or 3 h later. The mean plasma 5-FU concentration was significantly higher at room temperature than at 4 °C (p < 0.001). The 5-FU concentration was significantly increased in the absence of 5-NU than in the presence of 5-NU (p < 0.001). The 5-FU change in concentration was greater in the absence of 5-NU, and reached 190% of the maximum compared with baseline. A significant interaction was found between temperature and 5-NU conditions (p < 0.001). Differences between the presence or absence of 5-NU were greater at room temperature than under refrigerated conditions. 5-FU plasma concentrations after capecitabine administration varied with time, temperature, and the presence or absence of 5-NU. This indicates that plasma concentrations of 5-FU change dependent on storage conditions after blood collection.

Onset of Arterial and Venous Thrombosis and Safety of Antithrombic Therapy in Patients with Gastrointestinal Cancer.

BACKGROUND: The objective of this study was to clarify the onset of arterial and venous thrombosis and the safety of antithrombic therapy in patients with gastrointestinal cancer. PATIENTS AND METHODS: In a retrospective cohort study of adults aged ≥ 18 years, 1187 patients with gastrointestinal cancer were admitted to our hospital between January 1, 2015 and December 31, 2017. We investigated the incidence of arterial thromboembolism (ATE) and venous thromboembolism (VTE) and serious bleeding following antithrombotic therapy. RESULTS: In the 1187 patients diagnosed with gastrointestinal cancer, VTE occurred in 4.5% of cases and ATE in 2.8% of cases, and in 7.2% of cases overall. Among 239 patients who received antithrombotic therapy, the combination antithrombotic therapy group (n = 43), such as dual antiplatelet therapy, had more major bleeding events than the monotherapy group (n = 196; 49% vs. 17%, p < 0.01). DISCUSSION: In our gastroesophageal cancer patients, arterial thrombosis occurred more frequently than venous thrombosis (17/393, 4.3% vs. 9/393, 2.3%, respectively). This result may be affected by chemotherapy or radiation therapy and needs further analysis. CONCLUSION: The risk of ATE also needs to be considered in gastrointestinal cancer patients. Combination therapy with antithrombotics increases bleeding events, so it is necessary to determine the risk of thrombosis as well as bleeding.

Mesenteric excision for esophageal cancer surgery: based on the concept of mesotracheoesophagus.

The fundamental principle of surgery for intestinal cancer is mesenteric excision. It has been widely accepted as radical surgery for colorectal cancer, and it comprises procedures such as complete mesocolic excision for colon cancer and total mesorectal excision for rectal cancer. So far, the concept of mesenteric excision of the esophagus has not been well documented, but our surgical experience with a magnified view using a thoracoscope and understanding of the surgical anatomy based on embryologic foregut development has led us to introduce the concept of mesotracheoesophagus. Using this concept, our technique is reproducible, effective, and safe for lymph node dissection along the left recurrent laryngeal nerve. Here we report our concept, procedure, and results of thoracoscopic esophageal cancer surgery.