Preoperative dual-phase 3D CT angiography assessment of the right hepatic artery before gastrectomy

Study on the application of preoperative three-dimensional CT angiography of perigastric arteries in laparoscopic radical gastrectomy

To investigate the clinical value and significance of preoperative three-dimensional computerized tomography angiography (CTA) in laparoscopic radical gastrectomy for gastric cancer. The clinical data were analyzed retrospectively from 214 gastric cancer patients. We grouped according to whether to perform CTA, and we compared and analyzed the difference of the data between the two groups. The perigastric arteries were classified according to CTA images of patients in the CTA group. The celiac trunk was classified according to Adachi classification: Type I (118/125, 94.4%), Type II (3/125, 2.4%), Type III (0/125, 0%), Type IV (1/125, 0.8%), Type V (2/125, 1.6%), Type VI (1/125, 0.8%). Hepatic artery classification was performed according to Hiatt classification: Type I (102/125, 81.6%), Type II (9/125, 7.2%), Type III (6/125, 4.8%), Type IV (2/125, 1.6%), Type V (3/125, 2.4%), Type VI (0, 0%), Others (3/125, 2.4%). And this study combined vascular anatomy and surgical risk to establish a new splenic artery classification model. In comparison, the operation time, first exhaust time, and estimated blood loss in the CTA group were significantly lower than those in the non-CTA group. In addition, the blood loss in the CTA group combined with ICG (Indocyanine Green) labeled fluorescence laparoscopy was significantly less than that in the group without ICG labeled. Preoperative CTA could objectively evaluate patients' vascular route and variation and then help us avoid or decrease the risk of vascular injury and bleeding. When combined with ICG labeled fluorescence laparoscopy, it could further reduce the risk of iatrogenic injury during the operation and improve postoperative recovery.

Clinical significance of aberrant left hepatic artery during gastrectomy: A systematic review

BACKGROUND

Vascular variations are frequently encountered during surgery. Approximately thirty percent of these variations are aberrant left hepatic arteries originating from the left gastric artery.

AIM

To summarize the safety and feasibility of aberrant left hepatic arteries (ALHA) ligation in gastric cancer patients who underwent laparoscopic-assisted gastrectomy (LAG).

METHODS

The literature search was systematically performed on databases including PubMed, Embase, and Cochrane Library. The publishing date of eligible studies was from inception to June 2021.

RESULTS

A total of nine studies were included according to the inclusion and exclusion criteria in this review. The variation rate of ALHA ranged from 7.00% to 20.70%, and four studies compared the differences between the ALHA ligation group and the preservation group. Only one study showed worse postoperative outcomes in the ALHA ligation group. In all the included studies, a significant difference was found between the ALHA ligation group and the preservation group in terms of postoperative liver enzymes after LAG. However, there was no significant difference in the number of retrieved lymph nodes between the two groups.

CONCLUSION

In conclusion, it is not always safe and feasible for surgeons to ligate the ALHA during LAG surgery, and it is necessary for gastric cancer patients to undergo preoperative examination to clarify the ALHA subtypes, measure the diameter of the ALHA, and determine whether the patients have chronic liver disease.

Simultaneous presence of the hepato-spleno-mesenteric trunk, a common trunk for both inferior phrenic arteries, the left gastric artery, and a common hepatic artery that ran behind the portal vein in a patient with gastric cancer

The celiac artery usually trifurcates into the common hepatic artery, splenic artery, and left gastric artery, but it is known to present several anatomical variations. In such cases, detailed knowledge of the variation is needed preoperatively to safely perform surgery. A 77-year-old woman was referred to our hospital for the treatment of gastric cancer. She had a triple anatomical variation: simultaneous presence of the hepato-spleno-mesenteric trunk, a common trunk for both inferior phrenic arteries and the left gastric artery, and a common hepatic artery that ran behind the portal vein. We detected this variation on routine preoperative multidetector computed tomography angiography, and safely and adequately performed laparoscopic distal gastrectomy.

Real-time identification of aberrant left hepatic arterial territories using near-infrared fluorescence with indocyanine green during gastrectomy for gastric cancer

BACKGROUND

An aberrant left hepatic artery is frequently encountered during upper gastrointestinal surgery, and researchers have yet to propose optimal strategies with which to address this arterial variation. The objective of this study was to determine whether the areas perfused by an aberrant left hepatic artery can be visualized in real-time using near-infrared fluorescence imaging with indocyanine green.

METHODS

Patients with gastric adenocarcinoma who underwent minimally invasive radical gastrectomy from May 2018 to August 2019 were enrolled and retrospectively analyzed at a single-center. Patients with an aberrant left hepatic artery and normal preoperative liver function were examined. After the clamping of an aberrant left hepatic artery, indocyanine green was administered via a peripheral intravenous route during surgery. Fluorescence at the liver was visualized under near-infrared fluorescence imaging.

RESULTS

In 31 patients with aberrant left hepatic arteries, near-infrared fluorescence imaging was used without adverse events associated with indocyanine green. Six (19%) patients were reported to have an aberrant left hepatic artery upon preoperative CT imaging, while all other instances were detected during surgery. Fluorescence excitation on the liver was, on average, visible after 43 s (range, 25-65). Fluorescence across the entire surface of the liver was noted in 20 (65%) patients in whom the aberrant left hepatic artery could be ligated. Aberrant left hepatic arteries were safely preserved in 10 (32%) patients who showed areas of no or partial fluorescence excitation. Guided by near-infrared fluorescence imaging, ligation of aberrant left hepatic arteries elicited no significant changes in postoperative liver function.

CONCLUSION

Near-infrared fluorescence imaging facilitates the identification of aberrant left hepatic arterial territories, guiding decisions on the preservation or ligation of this arterial variation.

Split-bolus injection protocol with optimized timings of contrast medium injection and CT scanning for 3D CT angio-venography before laparoscopic gastrectomy

PURPOSE

To propose an optimization method of contrast medium injection for the split-bolus protocol based on the contrast medium pharmacokinetics and investigate the utility of the optimized split-bolus protocol in 3D CT angio-venography for laparoscopic gastrectomy.

MATERIALS AND METHODS

A pharmacokinetic relationship between injection duration and time to the peak enhancement was taken into account in the protocol design. The first 20 consecutive patients underwent a multi-phase scan with a single-bolus injection (single-bolus protocol), and the next 20 underwent the proposed split-bolus protocol. CT attenuations of the arteries and veins and dose-length products (DLPs) were compared between the two protocols. Two radiologists visually assessed arterial and venous depictions and the misregistrations.

RESULTS

Mean arterial CT attenuations were not significantly different between the two protocols. Though mean venous CT attenuations for the split-bolus protocol were 7-11% lower than those of the single-bolus protocol, they were visually evaluated as similar. The mean DLP of the split-bolus protocol was 46% lower than that of the single-bolus protocol. Misregistration between the arteries and veins occurred 35-80% during the single-bolus protocol, but was not indicated in the split-bolus protocol.

CONCLUSION

The split-bolus protocol with optimized timing was more effective for providing improved image quality with reduced radiation dose compared with the single-bolus protocol in 3D CT angio-venography for laparoscopic gastrectomy.

The Short-Term Outcomes of Gastric Cancer Patients Based on a Proposal for a Novel Classification of Perigastric Arteries

PURPOSE

To establish a novel classification of perigastric arteries by computerized tomography angiography (CTA) and discuss its influence in patients' short-term clinical outcomes.

METHODS

The clinical data were analyzed retrospectively from 680 gastric cancer patients. The types of the perigastric artery were classified according to CTA image and we compared the short-term clinical outcomes.

RESULTS

The perigastric arteries can be divided into seven categories. Type I, trifurcation of the celiac trunk (CT) (294/343, 85.7%); type II, hepatosplenic trunk, left gastric artery (LGA) arising from the abdominal aorta (8/343, 2.3%); type III, hepatogastric trunk, splenic artery arising from the superior mesenteric artery (SMA) (2/343, 0.6%); type IV, celiacomesenteric trunk (5/343, 1.5%); type V, common hepatic artery (CHA) arising from the SMA, gastrosplenic trunk (11/343, 3.2%); type VI, aberrant (accessory or replaced) left hepatic artery arising from LGA (21/343, 6.1%); and type VII, CHA arising from LGA (2/343, 0.6%). The number of retrieved LNs in the CTA group was significantly higher than that in the non-CTA group. However, the operation time, estimated blood loss, intraoperative vascular injury, and medical cost of the CTA group were significantly less than those in the non-CTA group. Of note, in patients with BMI ≥ 25.0, higher LNs retrieval and less vascular injury were still present in the CTA group, which was of vital importance in clinical practice. Furthermore, the CTA group displayed shorter hospital stay (LOS).

CONCLUSION

We established a new perigastric artery classification. Application of the classification can improve the short-term clinical outcomes of patients.

Preserving a Replaced Left Hepatic Artery Arising from the Left Gastric Artery During Laparoscopic Distal Gastrectomy for Gastric Cancer

BACKGROUND

A replaced left hepatic artery (RLHA) arising from the left gastric artery (LGA) is occasionally encountered during laparoscopic gastrectomy. Although the RLHA is usually divided at the root level as RLHA preservation might result in inadequate lymph node dissection, blood flow disruption by RLHA division may lead to hepatic ischemia. To date, there is no consensus on RLHA preservation. Thus, we aimed to evaluate the efficacy of RLHA preservation by investigating the short-term outcomes of patients with RLHA who underwent laparoscopic distal gastrectomy (LDG).

METHODS

A total of 106 patients with an aberrant LHA from the LGA were identified as having gastric cancer and underwent LDG from 2012 to 2018. Finally, 55 patients were retrospectively diagnosed with RLHA by preoperative computed tomography and included in this study. Patients were classified into the divided (n = 18) or preserved (n = 37) group. Clinicopathological factors and surgical outcomes were compared between the two groups.

RESULTS

The RLHA preservation rate in patients who had been preoperatively diagnosed with RLHA was 88%. No significant difference was found in the number of harvested lymph nodes between the groups. The incidence of hepatic infarction was significantly higher in the divided group (16.7% vs. 0%, p = 0.031). Moreover, RLHA division caused postoperative transaminase elevation and was an independent risk factor for postoperative transaminase elevation (odds ratio: 55.8, p < 0.001).

CONCLUSIONS

Surgical procedures of RLHA preservation reduced postoperative transaminase elevation and hepatic infarction in patients who underwent LDG. Surgeons should confirm the RLHA preoperatively and preserve it to prevent hepatic damage.

Efficacy of non-rigid registration technique for misregistration in 3D-CTA fusion imaging

PURPOSE

To assess whether fusion 3D-CTA images can be corrected using non-rigid registration (NRR) for gastroenterology imaging.

METHODS

This study included 55 patients before gastroenterology surgery who underwent preoperative 3D-CTA prior to gastroenterological surgery. We recorded the coordinate of measurement points on the arterial vessels (X, Y, and Z) in each portal phase, original image of the arterial phase, and arterial phase with NRR. The distance of misregistration between the two points was calculated with the coordinate of the original image with NRR and that of the portal phase as true value.

RESULTS

The distance of misregistration between the two points in the original arterial and portal phase images was significantly higher than that in the arterial phase image with NRR on all directions (p < 0.01).

CONCLUSIONS

This study showed that NRR may correct misregistration on fusion 3D-CTA imaging. Hence, it can visualize correctly the anatomy of the vessel.

Diagnosis of invasion depth in resectable advanced gastric cancer for neoadjuvant chemotherapy: An exploratory analysis of Japan clinical oncology group study: JCOG1302A

BACKGROUND

Neoadjuvant chemotherapy (NAC) is increasingly used for resectable locally advanced gastric cancer (LAGC). JCOG1302A investigated the diagnostic criteria of LAGC patients with cT3-4/N1-3 to minimize contamination of pathological stage I as a candidate for NAC. In JCOG1302A, 77.2% of cT3-4 tumors diagnosed via a combination of endoscopy and computed tomography (CT) were pT3-4. However, the role of endoscopic ultrasonography (EUS) and additional diagnostic procedures/modalities remains unclear. Here, we investigated whether EUS, thin-slice CT, and foaming agent (FA) in CT contribute to accurate diagnosis of AGC invasion depth.

METHODS

Using JCOG1302A study data, we compared positive predictive value (PPV), negative predictive value (NPV), and kappa index (KI) between conventional and additional diagnostic procedures to identify pT3-4: conventional endoscopy (CE) with versus without EUS, 1-mm versus 5-mm CT slice, and CT with versus without FA.

RESULTS

We analyzed 1232 patients' data. PPV, NPV, and KI were 79.2%/73.7%, 59.2%/58.8%, and 0.38/0.39 (CE alone/CE with EUS), 77.8%/75.5%, 62.9%/71.2%, and 0.38/0.39 (5-mm CT/1-mm CT), and 78.6%/75.1%, 60.9%/69.7%, and 0.38/0.40 (CT without FA/CT with FA), respectively. Overall, there were no remarkable differences in any comparison. More specifically, PPV and KI were slightly higher with CE alone rather than CE with EUS. Although NPV was higher for 1-mm CT and CT with FA, PPV was rather higher for 5-mm CT and CT without FA.

CONCLUSION

Additional diagnostic procedures/modalities, like EUS, 1-mm slice CT, or FA in CT may not improve the diagnostic accuracy of invasion depth in resectable LAGC.

Surgical treatment of rectal cancer with a Retzius shunt: a case report

Background

A case of a short circuit (Retzius shunt) from the inferior mesenteric vein (IMV) to the inferior vena cava (IVC) without accompanying portal hypertension due to liver cirrhosis is rare.

Case presentation

An 83-year-old woman who was followed after surgery for thyroid and breast cancer was incidentally found to have rectal cancer on computed tomography (CT). Preoperative three-dimensional CT showed a venous malformation forming a short circuit (Retzius shunt) from the IMV to the IVC. Laparoscopic anterior rectal resection was performed. Operative findings included the Retzius vein crossing the abdominal aorta and the inferior mesenteric artery (IMA) to the IVC and a number of engorged vessels in the mesentery. The Retzius vein and IMA were clipped without major bleeding, and tumor-specific mesorectal excision was then performed. The patient’s postoperative clinical course was good, and she was discharged without complications.

Conclusions

Preoperative imaging enabled identification of an unexpected rare disease, thus reinforcing the importance of preoperative imaging.

Surgical Anatomy of the Superior Mesenteric Vessels Related to Pancreaticoduodenectomy: a Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Mesopancreas dissection with central vascular ligation and the superior mesenteric artery (SMA)-first approach represent the cornerstone of current principles for radical resection for pancreatic head cancer. The surgeon dissecting around the SMV and SMA should be aware regarding the anatomical variants in this area. The aims of this systematic review and meta-analysis are to detail the surgical anatomy of the superior mesenteric vessels and to propose a standardized terminology with impact in pancreatic cancer surgery.

METHODS

We conducted a systematic search to identify all published studies in PubMed/MEDLINE and Google Scholar databases from their inception up to March 2017.

RESULTS

Seventy-eight studies, involving a total of 18,369 specimens, were included. The prevalence of the mesenteric-celiac trunk, replaced/accessory right hepatic artery (RRHA), common hepatic artery, and SMV inversion was 2.8, 13.2, 2.6, and 4.1%, respectively. The inferior pancreaticoduodenal artery has its origin into the first jejunal artery, SMA, and RRHA, in 58.7, 35.8, and 1.2% of cases, respectively. The SMV lacks a common trunk in 7.5% of cases. The first jejunal vein has a trajectory posterior to the SMA in 71.8% of cases. The left gastric vein drains into the portal vein in 58%, in splenic vein (SV) in 35.6%, and into the SV-PV confluence in 5.8% of cases.

CONCLUSIONS

Complex pancreaticoduodenal resections require detailed knowledge of the superior mesenteric artery and vein, which is significantly different from the one presented in the classical textbooks of surgery. We are proposing the concept of the first jejunopancreatic vein which impacts the current oncological principles of pancreatic head cancer resection.

Comparison of CTA and DSA in the diagnosis of superior mesenteric artery dissecting aneurysm

Objective

To compare computed tomography arteriography (CTA) and digital subtraction arteriography (DSA) in the diagnosis of superior mesenteric artery dissecting aneurysm (SMADA).

Methods

All SMADA patients who underwent CTA and DSA at one of two medical centers between May, 2007 and April, 2017 were identified. The accuracy of CTA and DSA for the depiction of morphologic characteristics of SMADA was analyzed.

Results

Fourteen patients (12 men; mean age, 55.1 ± 6.4 years) were included in this study. The mean diameter of the dissecting aneurysm was 3.78 ± 1.53 mm on CTA and 3.81 ± 1.54 mm on DSA ( p = 0.96). The luminal stenosis was 0.52 ± 0.27 on CTA and 0.35 ± 0.23 on DSA ( p = 0.09). The thrombosed false lumen was visualized on CTA in 79% (11/14) of patients but in no patients on DSA ( p < 0.001). The entry points of the dissection were visualized on CTA in 64.3% (9/14) of patients and on DSA in 100% (14/14) of patients ( p = 0.041); CTA and DSA did not visualize re-entry points in any patients. The intimal flap was visualized on CTA in 71.4% (10/14) of patients and on DSA in 78.6% (11/14) of patients ( p > 0.05). Branch vessel involvement was visualized in 7.1% (1/14) of patients on CTA but in no patients on DSA ( p > 0.05).

Conclusions

CTA can be used in place of DSA for the diagnosis of SMADA. Although CTA may exaggerate the degree of luminal stenosis and is weak in depicting the entry points of SMADA, this modality more accurately depicts the thrombosed false lumen and branch vessel involvement.

Three-dimensional computed tomography simulation for laparoscopic lymph node dissection in the treatment of proximal gastric cancer

Application of laparoscopic surgery (LS) has expanded worldwide in the various fields due to the potential advantage of being less invasive than open surgery; however difficulty in recognizing positional relationship of the organs is one of the disadvantages of this kind of surgery. In order to compensate this drawback, preoperative three-dimensional computed tomography (3D-CT) simulation is regarded as promising. In gastric cancer surgery, 3D-CT simulation seems particularly effective in the splenic hilar dissection, because this region is associated with remarkable anatomical variation with complexity. As effects from the use of 3D-CT simulation, reduction of blood loss or complication rate, shortening of operation time and enhancement of surgical quality are expected. In this article, we introduce our methodological protocol of 3D-CT simulation in gastric cancer surgery with clinical case examples, and also additionally review previous publications reporting this imaging technology.

Recognition Accuracy Using 3D Endoscopic Images for Superficial Gastrointestinal Cancer: A Crossover Study

Aim. To determine whether 3D endoscopic images improved recognition accuracy for superficial gastrointestinal cancer compared with 2D images. Methods. We created an image catalog using 2D and 3D images of 20 specimens resected by endoscopic submucosal dissection. The twelve participants were allocated into two groups. Group 1 evaluated only 2D images at first, group 2 evaluated 3D images, and, after an interval of 2 weeks, group 1 next evaluated 3D and group 2 evaluated 2D images. The evaluation items were as follows: (1) diagnostic accuracy of the tumor extent and (2) confidence levels in assessing (a) tumor extent, (b) morphology, (c) microsurface structure, and (d) comprehensive recognition. Results. The use of 3D images resulted in an improvement in diagnostic accuracy in both group 1 (2D: 76.9%, 3D: 78.6%) and group 2 (2D: 79.9%, 3D: 83.6%), with no statistically significant difference. The confidence levels were higher for all items ((a) to (d)) when 3D images were used. With respect to experience, the degree of the improvement showed the following trend: novices > trainees > experts. Conclusions. By conversion into 3D images, there was a significant improvement in the diagnostic confidence level for superficial tumors, and the improvement was greater in individuals with lower endoscopic expertise.

Should an Aberrant Left Hepatic Artery Arising from the Left Gastric Artery Be Preserved during Laparoscopic Gastrectomy for Early Gastric Cancer Treatment?

Purpose

During laparoscopic gastrectomy, an aberrant left hepatic artery (ALHA) arising from the left gastric artery (LGA) is occasionally encountered. The aim of this study was to define when an ALHA should be preserved during laparoscopic gastrectomy.

Materials and Methods

From August 2009 to December 2014, 1,340 patients with early gastric cancer underwent laparoscopic distal gastrectomy. One hundred fifty patients presented with an ALHA; of the ALHA was ligated in 116 patients and preserved in 34 patients. Patient characteristics, postoperative outcomes and perioperative liver function tests were reviewed retrospectively. Correlations between the diameter of the LGA measured on preoperative abdominal computed tomography and postoperative liver enzyme levels were analyzed.

Results

Pearson's correlation analysis showed a positive correlation between the diameter of the LGA and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels on postoperative day 1 in the ALHA-ligated group (P=0.039, P=0.026, respectively). Linear regression analysis estimated the diameter of the LGA to be 5.1 mm and 4.9 mm when AST and ALT levels were twice the normal limit on postoperative day 1.

Conclusions

We suggest preserving the ALHA arising from a large LGA, having diameter greater than 5 mm, during laparoscopic gastrectomy to prevent immediate postoperative hepatic dysfunction.