LARLUS: laparoscopic augmented reality from laparoscopic ultrasound

PURPOSE

This research endeavors to improve tumor localization in minimally invasive surgeries, a challenging task primarily attributable to the absence of tactile feedback and limited visibility. The conventional solution uses laparoscopic ultrasound (LUS) which has a long learning curve and is operator-dependent.

METHODS

The proposed approach involves augmenting LUS images onto laparoscopic images to improve the surgeon's ability to estimate tumor and internal organ anatomy. This augmentation relies on LUS pose estimation and filtering.

RESULTS

Experiments conducted with clinical data exhibit successful outcomes in both the registration and augmentation of LUS images onto laparoscopic images. Additionally, noteworthy results are observed in filtering, leading to reduced flickering in augmentations.

CONCLUSION

The outcomes reveal promising results, suggesting the potential of LUS augmentation in surgical images to assist surgeons and serve as a training tool. We have used the LUS probe's shaft to disambiguate the rotational symmetry. However, in the long run, it would be desirable to find more convenient solutions.

Initial Experience with Hybrid Partial Nephrectomy with Ultrasound-guided Balloon Catheter Occlusion of the Renal Artery for Recurrent Renal Tumors

Repeat partial nephrectomy (PN) is an effective treatment in improving the prognosis for patients with recurrent renal cancer after initial PN. However, salvage PN (sPN) is inevitably associated with a higher rate of complications, largely because of intraperitoneal adhesions and fibrosis. Here we describe three initial cases for which recurrent renal tumors were treated with a novel minimally invasive approach, namely Ultrasound-guided Renal Artery Balloon catheter Occluded Hybrid Partial Nephrectomy (UBo-HPN).With laparoscopic ultrasound (LUS) guiding a Fogarty catheter to occlude the arterial blood supply, dissection of the renal hilum and most of the abdominal cavity can be avoided. UBo-HPN was successfully performed in three patients. One case of postoperative fever (Clavien-Dindo grade II) occurred, with no other complications. The mean operative time was 106 min, with a mean warm ischemia time of 21 min. UBo-HPN may be considered a safe and effective alternative for sPN, with a minimally invasive surgical footprint and better surgical outcomes.

Mirizzi syndrome complicated by type IV cholecystobiliary fistula to the right hepatic duct

Mirizzi syndrome is a rare complication of long-term chronic cholecystitis, characterized by extrinsic compression of the common hepatic duct that may progress to development of cholecystobiliary fistula. Here we report a case of a 38-year-old female patient who underwent laparoscopic cholecystectomy with intraoperative cholangiogram for acute cholecystitis and choledocholithiasis. Intraoperatively, the patient was found to have a Mirizzi syndrome complicated by cholecystobiliary fistula to the right hepatic duct. The gallbladder was successfully removed, cholelithiasis cleared and a ureteral stent was used in reconstruction. The patient was discharged on postoperative two and was doing well on routine follow-up. Ultimately, Mirizzi syndrome is a rare clinical entity that requires careful consideration during preoperative workup and a high suspicion when abnormal anatomy is encountered intraoperatively.

Deep hashing for global registration of untracked 2D laparoscopic ultrasound to CT

PURPOSE

The registration of Laparoscopic Ultrasound (LUS) to CT can enhance the safety of laparoscopic liver surgery by providing the surgeon with awareness on the relative positioning between critical vessels and a tumour. In an effort to provide a translatable solution for this poorly constrained problem, Content-based Image Retrieval (CBIR) based on vessel information has been suggested as a method for obtaining a global coarse registration without using tracking information. However, the performance of these frameworks is limited by the use of non-generalisable handcrafted vessel features.

METHODS

We propose the use of a Deep Hashing (DH) network to directly convert vessel images from both LUS and CT into fixed size hash codes. During training, these codes are learnt from a patient-specific CT scan by supplying the network with triplets of vessel images which include both a registered and a mis-registered pair. Once hash codes have been learnt, they can be used to perform registration with CBIR methods.

RESULTS

We test a CBIR pipeline on 11 sequences of untracked LUS distributed across 5 clinical cases. Compared to a handcrafted feature approach, our model improves the registration success rate significantly from 48% to 61%, considering a 20 mm error as the threshold for a successful coarse registration.

CONCLUSIONS

We present the first DH framework for interventional multi-modal registration tasks. The presented approach is easily generalisable to other registration problems, does not require annotated data for training, and may promote the translation of these techniques.

The utility of laparoscopic ultrasound during minimally invasive liver procedures in patients with malignant liver tumors who have undergone preoperative magnetic resonance imaging

BACKGROUND

The aim of this study was to assess the utility of laparoscopic ultrasound (LUS) during minimally invasive liver procedures in patients with malignant liver tumors who underwent preoperative magnetic resonance imaging (MRI).

METHODS

Medical records of patients with malignant liver lesions who underwent laparoscopic liver surgery between October 2005 and January 2018 and who underwent an MRI examination at our institution within a month before surgery were collected from a prospectively maintained database. The size and location of tumors detected on LUS, as well as whether they were seen on preoperative imaging, were recorded. Univariate and multivariate regression analyses were performed to identify factors that were associated with the detection of liver lesions on LUS that were not seen on preoperative MRI.

RESULTS

A total of 467 lesions were identified in 147 patients. Tumor types included colorectal cancer metastasis (n = 53), hepatocellular cancer (n = 38), neuroendocrine metastasis (n = 23), and others (n = 33). Procedures included ablation (67%), resection (23%), combined resection and ablation (6%), and diagnostic laparoscopy with biopsy (4%). LUS identified 39 additional lesions (8.4%) that were not seen on preoperative MRI in 14 patients (10%). These were colorectal cancer (n = 20, 51%), neuroendocrine (n = 11, 28%) and other metastases (n = 8, 21%). These additional findings on LUS changed the treatment plan in 13 patients (8.8%). Factors predicting tumor detection on LUS but not on MRI included obesity (p = 0.02), previous exposure to chemotherapy (p < 0.001), and lesion size < 1 cm (p < 0.001).

CONCLUSION

This study demonstrates that, despite advances in MRI, LUS performed during minimally invasive liver procedures may detect additional tumors in 10% of patients with liver malignancies, with the highest yield seen in obese patients with previous exposure to chemotherapy. These results support the routine use of LUS by hepatic surgeons.

[Advantages and future perspectives of laparoscopic liver surgery]

BACKGROUND

Laparoscopic liver surgery (LLS) is increasingly utilized worldwide due to several potential advantages over open liver surgery.

OBJECTIVE

Analysis and presentation of the advantages and disadvantages of LLS in comparison to open surgery.

MATERIAL AND METHODS

Analysis of clinically relevant factors of minimally invasive liver surgery in comparison to open liver surgery in the current literature.

RESULTS

In addition to obvious cosmetic advantages, the current literature shows advantages regarding length of hospital stay and quality of life after LLC. In contrast to major liver resections, parenchyma-preserving resections often appear cost-neutral due a shorter postoperative hospital stay compared to conventional liver resections. In addition to particular personnel requirements, LLS also has technical prerequisites, such as a dedicated intraoperative ultrasound system. Furthermore, contrast-enhanced laparoscopic examinations are possible and ultrasound information can be fused with preoperative imaging. Virtual reality technology and 3‑dimensional printing are currently under investigation to improve the intraoperative anatomical orientation of LLS.

CONCLUSION

The current literature reveals significant advantages for LLS so that this procedure should be further developed in Germany in order to offer this technique to as many patients as possible.

Vessel segmentation for automatic registration of untracked laparoscopic ultrasound to CT of the liver

Purpose:

Registration of Laparoscopic Ultrasound (LUS) to a pre-operative scan such as Computed Tomography (CT) using blood vessel information has been proposed as a method to enable image-guidance for laparoscopic liver resection. Currently, there are solutions for this problem that can potentially enable clinical translation by bypassing the need for a manual initialisation and tracking information. However, no reliable framework for the segmentation of vessels in 2D untracked LUS images has been presented.

Methods:

We propose the use of 2D UNet for the segmentation of liver vessels in 2D LUS images. We integrate these results in a previously developed registration method, and show the feasibility of a fully automatic initialisation to the LUS to CT registration problem without a tracking device.

Results:

We validate our segmentation using LUS data from 6 patients. We test multiple models by placing patient datasets into different combinations of training, testing and hold-out, and obtain mean Dice scores ranging from 0.543 to 0.706. Using these segmentations, we obtain registration accuracies between 6.3 and 16.6 mm in 50% of cases.

Conclusions:

We demonstrate the first instance of deep learning (DL) for the segmentation of liver vessels in LUS. Our results show the feasibility of UNet in detecting multiple vessel instances in 2D LUS images, and potentially automating a LUS to CT registration pipeline.

Laparoscopic ultrasound guided wedge resection of the stomach: a novel procedure for gastric submucosal tumor

It is essential for the surgery of gastric submucosal tumors to resect the tumor with a negative margin and minimize the incision of the normal stomach wall. We developed a novel procedure for patients with gastric submucosal tumors using a laparoscopic ultrasound probe as a guide to determine the resection line. Since 2014, we have performed the laparoscopic ultrasound-guided wedge resection of the stomach in seven patients. The tumor was localized, and the property of the tumor was clearly identified using a laparoscopic ultrasound probe. As a result, the ideal incision line was determined without intraoperative endoscopy. The stomach wall was perforated along the marking on the planned incision line and the whole layer is subsequently incised along with the tumor. The surgical margins were negative, and there were no obvious injuries of the pseudocapsule, microscopically, in any case. It is possible that the laparoscopic ultrasound-guided wedge resection of the stomach contributes to a simplification of the surgery of gastric submucosal tumors resulting in reduced medical cost while maintaining curability and functional preservation.

Safety, quality and efficiency of intra-operative imaging for treatment decisions in patients with suspected choledocholithiasis without pre-operative magnetic resonance cholangiopancreatography

INTRODUCTION

Cholecystectomy is the accepted treatment for patients with symptomatic gallstones. In this study, we evaluate a simplified strategy for managing suspected synchronous choledocholithiasis by focussing on intra-operative imaging as the primary decision-making tool to target common bile duct (CBD) stone treatment.

METHODS

All elective and emergency patients undergoing laparoscopic cholecystectomy (LC) for gallstones with any markers of synchronous choledocholithiasis were included. Patients unfit for surgery or who had pre-operative proof of choledocholithiasis were excluded. Intra-operative imaging was used for evaluation of the CBD. CBD stone treatment was with bile duct exploration (LCBDE) or endoscopic retrograde cholangiopancreatography (LC + ERCP). Outcomes were safety, effectiveness and efficiency.

RESULTS

506 patients were included. 371 (73%) had laparoscopic ultrasound (LUS), 80 (16%) had on-table cholangiography (OTC) and 55 (11%) had both. 164 (32.4%) were found to have CBD stones. There was no increase in length of surgery for LC + LUS compared with average time for LC only in our unit (p = 0.17). 332 patients (65.6%) had clear ducts. Imaging was indeterminate in 10 (2%) patients. Overall morbidity was 10.5%. There was no mortality. 142 (86.6%) patients with stones on intra-operative imaging proceeded to LCBDE. 22 (13.4%) patients had ERCP. Sensitivity and specificity of intra-operative imaging were 93.3 and 99.1%, respectively. Success rate of LCBDE was 95.8%. Effectiveness was 97.8%.

CONCLUSIONS

Eliminating pre-operative bile duct imaging in favour of intra-operative imaging is safe and effective. When combined with intra-operative stone treatment, this method becomes a true 'single-stage' approach to managing suspected choledocholithiasis.

Cost effectiveness of intraoperative laparoscopic ultrasound for suspected choledocholithiasis; outcomes from a specialist benign upper gastrointestinal unit

INTRODUCTION

Common bile duct stones are present in 10% of patients with symptomatic gallstones. One-third of UK patients undergoing cholecystectomy will have preoperative ductal imaging, commonly with magnetic resonance cholangiopancreatography. Intraoperative laparoscopic ultrasound is a valid alternative but is not widely used. The primary aim of this study was to assess cost effectiveness of laparoscopic ultrasound compared with magnetic resonance cholangiopancreatography.

MATERIALS AND METHODS

A prospective database of all patients undergoing laparoscopic cholecystectomy between 2015 and 2018 at a district general hospital was assessed. Inclusion criteria were all patients, emergency and elective, with symptomatic gallstones and suspicion of common bile duct stones (derangement of liver function tests with or without dilated common bile duct on preoperative ultrasound, or history of pancreatitis). Patients with known common bile duct stones (magnetic resonance cholangiopancreatography or failed endoscopic retrograde cholangiogram) were excluded. Ninety-day morbidity data were also collected.

RESULTS

A total of 420 (334 elective and 86 emergency) patients were suspected to have common bile duct stones and were included in the study. The cost of a laparoscopic ultrasound was £183 per use. The cost of using the magnetic resonance cholangiopancreatography unit was £365 per use. Ten postoperative magnetic resonance cholangiopancreatographies were performed for inconclusive intraoperative imaging. The estimated cost saving was £74,650. Some 128 patients had common bile duct stones detected intraoperatively and treated. There was a false positive rate of 4.7%, and the false negative rate at 90 days was 0.7%. laparoscopic ultrasound use saved 129 bed days for emergency patients and 240 magnetic resonance cholangiopancreatography hours of magnetic resonance imaging.

CONCLUSION

The use of laparoscopic ultrasound during laparoscopic cholecystectomy for the detection of common bile duct stone is safe, accurate and cost effective. Equipment and maintenance costs are quickly offset and hospital bed days can be saved with its use.

Preclinical evaluation of ultrasound-augmented needle navigation for laparoscopic liver ablation

PURPOSE

For laparoscopic ablation to be successful, accurate placement of the needle to the tumor is essential. Laparoscopic ultrasound is an essential tool to guide needle placement, but the ultrasound image is generally presented separately from the laparoscopic image. We aim to evaluate an augmented reality (AR) system which combines laparoscopic ultrasound image, laparoscope video, and the needle trajectory in a unified view.

METHODS

We created a tissue phantom made of gelatin. Artificial tumors represented by plastic spheres were secured in the gelatin at various depths. The top point of the sphere surface was our target, and its 3D coordinates were known. The participants were invited to perform needle placement with and without AR guidance. Once the participant reported that the needle tip had reached the target, the needle tip location was recorded and compared to the ground truth location of the target, and the difference was the target localization error (TLE). The time of the needle placement was also recorded. We further tested the technical feasibility of the AR system in vivo on a 40-kg swine.

RESULTS

The AR guidance system was evaluated by two experienced surgeons and two surgical fellows. The users performed needle placement on a total of 26 targets, 13 with AR and 13 without (i.e., the conventional approach). The average TLE for the conventional and the AR approaches was 14.9 mm and 11.1 mm, respectively. The average needle placement time needed for the conventional and AR approaches was 59.4 s and 22.9 s, respectively. For the animal study, ultrasound image and needle trajectory were successfully fused with the laparoscopic video in real time and presented on a single screen for the surgeons.

CONCLUSION

By providing projected needle trajectory, we believe our AR system can assist the surgeon with more efficient and precise needle placement.

Laparoscopic thermoablation for hepatocellular carcinoma in patients with liver cirrhosis: an effective procedure for tricky tumors

The optimal treatment for hepatocellular carcinoma (HCC) is surgical resection. However, only a small percentage of patients are amenable to this option. Percutaneous radiofrequency interstitial thermal ablation (TA) proved to be effective in the treatment of unresectable HCC. Recent advances in laparoscopic ultrasound have improved the accuracy in detecting small intrahepatic HCC nodules missed by pre-operative imaging techniques. Our objective was to evaluate an operative combination of laparoscopic ultrasound with laparoscopic thermoablation (LTA) in the treatment of HCC not amenable to liver resection. The aim of our review was to evaluate the advantages and limits of the laparoscopic approach according the criteria of the evidence-based medicine. LTA of HCC proved to be a safe and effective technique both in the short- and long-term follow-up period. This technique may be indicated in selected cases when the percutaneous approach to the lesion is very difficult or contraindicated.

GPS Laparoscopic Ultrasound: Embedding an Electromagnetic Sensor in a Laparoscopic Ultrasound Transducer

Tracking the location and orientation of a laparoscopic ultrasound (LUS) transducer is a prerequisite in many surgical visualization and navigation applications. Electromagnetic (EM) tracking is a preferred method to track an LUS transducer with an articulating imaging tip. The conventional approach to integrating EM tracking with LUS is to attach an EM sensor on the outer surface of the imaging tip (external setup), which is not ideal for routine clinical use. In this work, we embedded an EM sensor inside a standard LUS transducer. We found that ultrasound image quality and the four-way articulation function of the transducer were not affected by this sensor integration. Furthermore, we found that the tracking accuracy of our integrated transducer was comparable to that of the external setup. An animal study conducted using the developed transducer suggests that an internally embedded EM sensor is a clinically more viable approach, and may be the future of tracking an articulating LUS transducer.

A pre-operative planning framework for global registration of laparoscopic ultrasound to CT images

PURPOSE

Laparoscopic ultrasound (LUS) enhances the safety of laparoscopic liver resection by enabling real-time imaging of internal structures such as vessels. However, LUS probes can be difficult to use, and many tumours are iso-echoic and hence are not visible. Registration of LUS to a pre-operative CT or MR scan has been proposed as a method of image guidance. However, the field of view of the probe is very small compared to the whole liver, making the registration task challenging and dependent on a very accurate initialisation.

METHODS

We propose the use of a subject-specific planning framework that provides information on which anatomical liver regions it is possible to acquire vascular data that is unique enough for a globally optimal initial registration. Vessel-based rigid registration on different areas of the pre-operative CT vascular tree is used in order to evaluate predicted accuracy and reliability.

RESULTS

The planning framework is tested on one porcine subject where we have taken 5 independent sweeps of LUS data from different sections of the liver. Target registration error of vessel branching points was used to measure accuracy. Global registration based on vessel centrelines is applied to the 5 datasets. In 3 out of 5 cases registration is successful and in agreement with the planning. Further tests with a CT scan under abdominal insufflation show that the framework can provide valuable information in all of the 5 cases.

CONCLUSIONS

We have introduced a planning framework that can guide the surgeon on how much LUS data to collect in order to provide a reliable globally unique registration without the need for an initial manual alignment. This could potentially improve the usability of these methods in clinic.

The Additional Value of Laparoscopic Ultrasound to Staging Laparoscopy in Patients with Suspected Pancreatic Head Cancer

BACKGROUND

This study aimed to evaluate the additional value of laparoscopic ultrasound (LUS) to staging laparoscopy (SL) for detecting occult liver metastases in patients with potentially resectable pancreatic head cancer.

METHODS

A retrospective cohort study was performed including all patients who underwent SL and LUS between 2005 and 2016. LUS was performed during SL to detect liver metastases not found by preoperative imaging or visual inspection of the liver.

RESULTS

Out of 197 patients, visual inspection during SL detected distant metastases in 29 (14.7%) patients. LUS was performed in 127 patients, revealing 3 additional liver metastases. The proportion of patients with unresectable disease after SL and negative LUS was 32.3%, which was similar to 36.6% of patients with unresectable disease after SL without LUS (difference 4.3%; 95% CI - 13-23%; P = 0.61). Sensitivity, specificity, and positive and negative predictive values of LUS to detect liver metastases were 30, 100, 100, and 94%, respectively. The proportion of patients with distant metastases diagnosed at SL significantly increased over time (P = 0.031).

CONCLUSION

The routine use of LUS during SL for patients with potentially resectable pancreatic head cancer cannot be recommended. Imaging should be repeated when significant delay occurs between index CT and the scheduled surgery.

Laparoscopic ultrasound manipulator with a spring-based elastic mechanism

PURPOSE

Image guidance is a key technology that can improve the outcome of laparoscopic surgery. However, due to the large deformation caused by digestive organs, a computer-aided navigation system based on preoperative imaging data cannot indicate the correct target position of the lesion (e.g., liver tumors and vessels invisible from the organ surface). To overcome this issue, we developed a laparoscopic ultrasound manipulator with two motorized degrees of freedom at the tip, allowing for the performance of a dexterous ultrasound scan in a confined laparoscopic surgical area.

METHOD

The developed manipulator consists of a compact and elastic structure using springs, enabling a safe ultrasound scan and avoiding excess force on the inspected organs. The manipulator is a handheld device equipped with four buttons at the handle, which the surgeon directly grasps to send a motion command to the tip structure. The developed prototype realizes two motorized degree-of-freedom motion at the tip. The size of prototype is 15.0 mm in diameter that is usable in conventional laparoscopy. The tip of the manipulator was carefully designed by considering the kinematic model and the results of the finite element analysis.

RESULTS

To assess the prototype, accuracy and rigidity were measured by using a motion processing microscope. The accuracy test showed that the proposed device has a fairly accurate characteristic as a handheld device. This was supposedly caused by the nature of compliant mechanism, which does not have mechanical play in motion. In addition, the intrinsic elastic structure (approximately 2.0 N/mm in most of the range of motion) allowed the ultrasound probe to adequately fit on the curved organ surface without extra effort of manipulation during the inspection. In the in vivo experiment, the yaw motion was found to be effective for investigating the vascular network because the manipulator allows the probe to be rotated while maintaining the same position.

CONCLUSION

The mechanical evaluation and in vivo test results showed high feasibility of the prototype. We are currently working on further mechanical improvement for commercialization and development of a real-time navigation system that can perform three-dimensional reconstruction of ultrasonographic images by implementing a magnetic position sensor at the tip of the manipulator.

Precoagulation-assisted parenchyma-sparing laparoscopic liver surgery: rationale and surgical technique

BACKGROUND

For the treatment of both primary and metastatic liver tumors, laparoscopic parenchyma-sparing surgery is advocated to reduce postoperative liver failure and facilitate reoperation in the case of recurrence. However, atypical and wedge resections are associated with a higher amount of intraoperative bleeding than are anatomical resections, and such bleeding is known to affect short- and long-term outcomes. Beyond the established role of radiofrequency and microwave ablation in the setting of inoperable liver tumors, the application of thermoablative energy along the plane of the liver surface to be transected results in a zone of coagulative necrosis, possibly minimizing bleeding of the cut liver surface during parenchymal transection.

METHODS

From January 2013 to March 2016, a total of 20 selected patients underwent laparoscopic ultrasound-guided liver resection with thermoablative precoagulation of the transection line.

RESULTS

During a period of 38 months, 50 laparoscopic thermoablative procedures were performed. Colorectal liver metastases were the most frequent diagnosis. Seventy-two percent of the nodules were removed using parenchymal transection with radiofrequency-precoagulation, while microwave-precoagulation was performed for 20 % of the resected nodules. The remaining 8 % of the nodules were treated by thermoablation alone. The hepatic pedicle was intermittently clamped in six patients. The mean blood loss was 290 mL, and four patients required perioperative transfusions.

CONCLUSIONS

Precoagulation-assisted parenchyma-sparing laparoscopic liver surgery can get minimal blood loss during parenchymal transection and lower the need for perioperative transfusions, providing a nonquantifiable margin of oncological safety on the remaining liver. Additional results from larger series are advocated to confirm these preliminary data.

Laparoscopic ultrasound procedure can reduce residual myomas in laparoscopic myomectomy for multiple myomas

PURPOSE

To clarify whether the use of laparoscopic ultrasound (LUS) during laparoscopic myomectomy could reduce the number of residual myomas after surgery.

METHODS

A cohort study was conducted. Subjects were women who underwent laparoscopic myomectomy for multiple uterine myomas for the first time. The subjects were assigned to one of two groups: LUS group or non-LUS group. All subjects underwent pelvic MRI 3 months before and 6 months after surgery, and the number of myomas on MRI was counted by radiodiagnosticians. The extraction rate and residual rate of uterine myomas were compared between the two groups.

RESULTS

Fourteen cases with and 30 cases without LUS were analyzed. Median operation times were 171 min (range 75-295) and 141 min (range 50-260) in cases with and without LUS, respectively (p = 0.077). Median extraction rates relative to the total number of myomas were 106 % (range 75-147 %) in subjects with LUS and 100 % (range 71-233 %) in subjects without LUS (p = 0.480). Numbers of residual myomas were 1 (range 0-3) in subjects with LUS and 2 (range 0-9) in subjects without LUS (p = 0.028). Median residual rates of myomas were 6.1 % (range 0-20 %) in subjects with LUS and 20.0 % (range 0-69 %) in subjects without LUS (p = 0.048). Myomas greater than 3 cm in diameter were not observed in either group.

CONCLUSIONS

The number and residual rate of myomas were significantly less in subjects with LUS as compared with those without LUS.

Application of laparoscopic ultrasound in robot-assisted minimally invasive therapy for abdominal tumors

AIM: To assess the clinical application of laparoscopic ultrasound in robot-assisted minimally invasive therapy for abdominal tumors.

METHODS: A total of 41 patients (16 patients with hilar cholangiocarcinoma, 15 patients with hepatic tumors, 9 patients with pancreatic tumors, and 1 patient with retroperitoneal tumor) underwent laparoscopic ultrasound-guided robot-assisted minimally invasive therapy for abdominal tumors. Laparoscopic ultrasound was used preoperatively to detect the number of lesions, and evaluate their location and relationship with surroundings tissue precisely. Also, by means of laparoscopic ultrasound, the surgical pathways were guided operatively, and preliminary clinical effects were evaluated postoperatively. To assess clinical efficacy, all patients were followed by contrast-enhanced CT/MRI, ultrasound, blood tests, etc.

RESULTS: All laparoscopic ultrasound-guided procedures were performed successfully. Laparoscopic ultrasound discovered undetected lesions in 10 patients, which resulted in a change in operative strategy (10/41, 24.39%). No death occurred during the perioperative period. Abnormalities were not found postoperatively by ultrasound and contrast-enhanced CT/MRI in all patients. Laboratory studies demonstrated that blood biochemical indicators decreased to normal range gradually. No severe complications occurred in both intraoperative and postoperative periods. All patients survived, and their life quality was improved significantly.

CONCLUSION: Laparoscopic ultrasound could not only guide operative strategy, but also help to decrease complications and prolong disease-free survival in the postoperative period. This technique provides a safe surgical procedure, and the therapeutic effects could be improved by application of laparoscopic ultrasound in robot-assisted minimally invasive therapy for abdominal tumors.

Long-term outcome of laparoscopic ablation therapies for unresectable hepatocellular carcinoma: a single European center experience of 426 patients

BACKGROUND

Radiofrequency ablation (RFA) is widely used as a first-line option in patients with hepatocellular carcinoma (HCC). However, since percutaneous approach of RFA may be, in some cases, unfeasible by the tumor size and its location, laparoscopic ablation therapies (LATs) were used as an alternative. Objective of the present study was to assess the efficacy of laparoscopic ultrasound examination in addition to LATs in the treatment of HCC in patients not eligible for percutaneous RFA or surgical resection.

METHODS

Four hundred and twenty-six patients who underwent LATs were analyzed. Laparoscopic approach was offered to patients fulfilling at least one of the following criteria: (a) patients with a single nodule or up to three nodules smaller than 3 cm not suitable for liver transplantation or not eligible for HR because of severe portal hypertension, impaired liver function, or coexistent comorbidities; (b) patients not suitable for percutaneous RFA because of inconvenient tumor location; and (c) short-term recurrence of HCC (<3 months).

RESULTS

Technical success was achieved in one session in 396 patients (93 %). One-month mortality and morbidity rates were 0.23 % (1 patient) and 25 % (106 patients), respectively. During a median follow-up of 37.2 months (range 2-193) in the remaining 425 patients, 276 (65 %) developed intra-hepatic recurrence: It appeared as a local tumor progression in 65 cases (15 %). Patients median survival was 39 months (95 % CI 34.8-47.2), while overall survivals at 1, 3, and 5 years were 88, 55, and 34 %, respectively.

CONCLUSIONS

In the treatment of HCC, LATs proved to be a safe and effective technique, as they permit to treat with low-morbidity-rate lesions not manageable by percutaneous approach. Moreover, they allow achieving a more accurate staging of the disease in one-fifth of patients, thus better redefining the prognosis of such individuals.

Role of laparoscopic ultrasound during diagnostic laparoscopy for proximal biliary cancers: a single series of 100 patients

BACKGROUND

Despite extensive preoperative evaluation, a significant proportion of patients with biliary cancer (BC) proves to be unresectable at laparotomy. Diagnostic laparoscopy (DL) has been suggested to avoid unnecessary laparotomy. Aim of the study was to evaluate the additional benefit of combining LUS to DL in patients with proximal BC.

METHODS

Inclusion criteria were all patients affected by proximal BC undergone DL + LUS based on the following criteria: preoperative diagnosis of gallbladder cancer, hilar cholangiocarcinomas (HC) and borderline resectable intrahepatic cholangiocarcinoma (IHC). The overall yield (OY) and accuracy (AC) of DL ± LUS in determining unresectable disease were calculated.

RESULTS

From 01/2006 to 12/2014, 107 out of 191 (56%) potentially resectable proximal BC were evaluated. One hundred patients fulfilled inclusion criteria: 44 IHC, 21 GC and 35 HC. Forty-eight (48%) patients were male with median age of 65 (41-87) years. The median number of preoperative imaging was 3 ± 0.99. Patients underwent DL + LUS 10.5 ± 15.6 days after last imaging. DL + LUS identified unresectable diseases in 24 patients, 6 (25%) of them only thanks to LUS findings (3 GC and 3 IHC). At laparotomy, 6 (4 HC and 2 GC) out of 76 patients were found unresectable because of carcinomatosis (n = 2), new liver metastasis (n = 2) and vascular invasion (n = 2). LUS increased the OY (from 18 to 24%) and AC (from 60 to 80%) in the whole group. The advantages of LUS were confirmed for GC (OY from 38.1 to 52.4%, AC from 61.5 to 84.6%) and IHC patients (OY from 11.4 to 18.2%, AC from 62.5 to 100%) but not for HC group. The presence of biliary drainage was the only factor able to predict negative yield (p < 0.001).

CONCLUSIONS

LUS increases overall yield and accuracy of DL for detecting unresectable disease in patients with preoperative diagnosis of gallbladder cancer and borderline resectable intrahepatic cholangiocarcinomas.

Laparoscopic spleen-preserving distal pancreatectomy for insulinoma: experience of a single center. Int J Surg. 2014;12 Suppl 1:S152-S155. [PMID: 24862672 DOI: 10.1016/j.ijsu.2014.05.023]

BACKGROUND

Laparoscopic spleen-preserving distal pancreatectomy is gaining acceptance for the treatment of insulinomas of the pancreatic body and tail. The aim of this report is to evaluate the feasibility, safety and outcomes of this procedure in a retrospective series.

METHODS

From May 2004 to November 2013, 9 patients underwent laparoscopic spleen-preserving distal pancreatectomy for benign insulinomas in our department. Tumors were single and sporadic in eight patients, while the remaining patient had insulinomas in the setting of multiple endocrine neoplasia type 1. Tumors were located by preoperative imaging in all cases. Laparoscopic ultrasound was always performed to guide the surgical procedure.

RESULTS

All the operations were carried out laparoscopically with a mean operative time of 110 min (range 90-210 min) and a mean blood loss of 50 ml (range 30-120 ml). One patient (11.1%) died on the 22nd post-operative day for massive intra-abdominal bleeding associated with pancreatitis of the stump. Two patients (22.2%) developed pancreatic fistula that healed conservatively. Mean postoperative hospital stay was 7.1 days (range 5-18 days). All alive patients were free from recurrence after a mean follow-up of 45 months (range 11-72 months).

CONCLUSION

Laparoscopic spleen-preserving distal pancreatectomy is safe and feasible for the management of benign insulinomas. Definition of the tumor with preoperative imaging and laparoscopic ultrasound is essential to achieve high cure rate with minimal conversion.

Laparoscopic ultrasonography versus intra-operative cholangiogram for the detection of common bile duct stones during laparoscopic cholecystectomy: a meta-analysis of diagnostic accuracy

BACKGROUND

Routine intra-operative cholangiography (IOC) during laparoscopic cholecystectomy is often not performed because of increased operative time, radiation, and failure rate. Laparoscopic ultrasound (LUS) is a less invasive alternative but studies comparing it to IOC have been of small sample size. This study aims to assess the diagnostic accuracy of LUS in detecting common bile duct (CBD) stones compared to IOC.

METHODS

This meta-analysis was executed and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) statement. 11 comparative studies (1994-2013) reporting on 12 patient groups were included. A bivariate model for diagnostic meta-analysis was used to attain overall pooled sensitivity and specificity for IOC and LUS, and their relationship assessed using a hierarchical summary receiver operating characteristic model with meta-regression.

RESULTS

IOC had a pooled sensitivity of 0.87 (95% CI 0.77-0.93) and a pooled specificity of 0.99 (95% CI 0.98-0.99) with no significant heterogeneity. The diagnostic Odds Ratio (OR) was 442 (95% CI 196-997) and pooled weighted Area Under the Curve (AUC) was 0.99 (95% CI: 0.98-1.0). LUS had a pooled sensitivity of 0.87 (95% CI 0.80-0.92) and a specificity of 1.00 (95% CI 0.99-1.00). Heterogeneity was significant for specificity results. The diagnostic Odds Ratio (OR) was 1171 (95% CI 372-3689) and the pooled, weighted AUC was 1 (95% CI: 0.99-1). Meta-regression did not identify factors that significantly predict diagnostic accuracy.

CONCLUSIONS

LUS is a potentially useful imaging modality to confirm the absence of CBD stones without needing to cannulate the biliary system.

Sensitivity of myoma imaging using laparoscopic ultrasound compared with magnetic resonance imaging and transvaginal ultrasound

STUDY OBJECTIVE

To determine the efficacy of laparoscopic ultrasound (LUS) as compared with contrast-enhanced magnetic resonance imaging (CE-MRI) and transvaginal ultrasound (TVUS) in detection of uterine myomas.

DESIGN

Retrospective study of imaging methods used in a trial of LUS-guided radiofrequency volumetric thermal ablation in women with symptomatic myomas (Canadian Task Force classification II-2).

SETTING

Eleven medical university or private outpatient surgery clinics in the United States (nine sites) and Latin America (two sites).

PATIENTS

One hundred thirty-five women with symptomatic myomas and objectively confirmed moderate to severe heavy menstrual bleeding.

INTERVENTIONS

LUS-guided radiofrequency volumetric thermal ablation of myomas.

MEASUREMENTS AND MAIN RESULTS

Preoperative TVUS scans and CE-MRIs were read at each site, and all CE-MRIs were read by a central reader. LUS-guided scans were obtained intraoperatively by each surgeon by mapping the uterus just before radiofrequency volumetric thermal ablation. The imaging methods and their yields in terms of number of myomas found per subject were as follows: TVUS, 403 myomas (mean [SD] 3 [1.8]; range, 1-8); site CE-MRI, 562 myomas (4.2 [3.8]; range, 1-18); central reader, 619 myomas (4.6 [3.7]; range, 0-20); and LUS, 818 myomas (6.1 [4.9]; range, 1-29) (p < .001). LUS was superior to TVUS, CE-MRI, and the central reader for detection of small (≤1 cm(3)) myomas. Most imaged myomas were intramural: 197 (50.9%) by TVUS, 298 (55.5%) by site CE-MRI, 290 (48.7%) by the central reader, and 386 (48.5%) by LUS.

CONCLUSION

Compared with CE-MRI and TVUS, LUS demonstrates the most myomas, regardless of size or type.

Laparoscopic staging in hilar cholangiocarcinoma: Is it still justified?

Radical resection remains the only potential curative therapy for hilar cholangiocarcinoma (HCCA). The aim of staging laparoscopic (SL) is to identify patients with previously undetected advanced disease who will not benefit from surgical palliation and therefore avoid unnecessary laparotomies. The accuracy of non-invasive imaging techniques has significantly improved during the last years. As a consequence, the diagnostic yield of SL of biliary tract malignancy should have decreased proportionally. At the same time, some authors have recently questioned the value of laparoscopic ultrasound (LUS) as a complement of SL. In this setting, the precise role of SL and LUS in the preoperative workup of HCCA remains unclear. As it seems undoubtedly clear that its efficacy has decreased in the last decades, there is a general consensus that the universal use of SL shouldn't be recommended anymore; SL should be performed only in selected patients with higher risk of holding unresectable disease (T2/T3 or Bismuth type 3/4 and patients with suspicion of metastases). It would also be recommended in patients with potentially resectable disease who would need preoperative invasive procedures. Finally, SL should be performed preceding laparotomy in one session. Further studies on the benefit of SL and LUS in this subset of HCCA patients are warranted.

Role of staging laparoscopy in gastric malignancies - our institutional experience

AIM: To investigate the value of staging laparoscopy with laparoscopic ultrasound (LUS) and peritoneal lavage cytology in patients with newly-diagnosed gastric tumours in our department.

METHODS: Retrospective review of prospectively-collected data was conducted in all patients with newly-diagnosed gastric tumours on oesophagogastroduodenoscopy between December 2003 and July 2008. All the patients had a pre-treatment histological diagnosis and were discussed at the hospital multidisciplinary tumour board meeting for their definitive management. Computed tomography scan was performed in all patients as a part of standard preoperative staging work up. Staging laparoscopy was subsequently performed in selected patients and staging by both modalities was compared.

RESULTS: Twenty seven patients were included. Majority of patients had cardio-oesophageal junction adenocarcinoma. Thirteen patients (48%) were upstaged following staging laparoscopy and one patient was downstaged (3.7%). None of the patients had procedure-related complications. None of the patients with metastasis detected at laparoscopy underwent laparotomy. Gastrectomy after staging laparoscopy was performed in 13 patients (9 R0 resections, 3 R1 resections and 1 R2 resection). Only one patient did not have gastrectomy at laparotomy because of extensive local invasion. Three patients were subjected to neoadjuvant therapy following laparoscopy but only one patient subsequently underwent gastrectomy.

CONCLUSION: In this small series reflecting our institutional experience, staging laparoscopy appears to be safe and more accurate in detecting peritoneal and omental metastases as compared to conventional imaging. Peritoneal cytology provided additional prognostic information although there appeared to be a high false negative rate.

Image-based Approach for Surgical Resection of Gastric Submucosal Tumors

Purpose

This study was done to evaluate the usefulness of preoperative computed tomography (CT) and intraoperative laparoscopic ultrasound to facilitate treatment of gastric submucosal tumors.

Materials and Methods

The feasibility of laparoscopic wedge resection as determined by CT findings of tumor size, location, and growth pattern was correlated with surgical findings in 89 consecutive operations. The role of laparoscopic ultrasound for tumor localization was analyzed.

Results

Twenty-three patients were considered unsuitable for laparoscopic wedge resection because of large tumor size (N=13) or involvement of the gastroesophageal junction (N=9) or pyloric channel (N=1). Laparoscopic wedge resection was not attempted in 11 of these patients because of large tumor size. Laparoscopic wedge resection was successfully performed in 65 of 66 (98.5%) patients considered suitable for this procedure. Incorrect interpretation of preoperative CT resulted in a change of surgery type in seven patients (7.9%): incorrect CT diagnosis on gastroesophageal junction involvement (N=6) and on growth pattern (N=1). In 18 patients without an exophytic growth pattern, laparoscopic ultrasound was necessary and successfully localized all lesions.

Conclusions

Preoperative CT and laparoscopic ultrasound are useful for surgical planning and tumor localization in laparoscopic wedge resection.

Laparoscopic intra-operative ultrasound in liver and pancreas resection: Analysis of 93 cases

INTRODUCTION

Laparoscopic inspection before pancreatic and liver surgery is a widely accepted approach and has changed the surgical strategy in a growing number of patients for the last 10 years. The addition of intra-operative ultrasound to laparoscopy has further refined surgical judgments. The aim of this study was to evaluate the impact of open (IOUS) or laparoscopic (LIOUS) ultrasound in patients undergoing hepatic or pancreatic resection for benign or malignant lesions.

MATERIALS AND METHODS

In the years 2005-2008, 45 patients (aged 42-75 years) were selected for liver resection, and 48 others (aged 14-72 years) were selected for partial pancreatic resection. Intra-operative ultrasound was performed for surgical staging. An Aloka SSD-5500 scanner (Aloka, Tokyo, Japan) was used with a flexible laparoscopic multifrequency linear and an electronic T-shaped linear probe.

RESULTS

LIOUS prevented useless laparotomies in six patients (13.3%) with liver tumors and, coupled with IOUS, revealed previously undetected tumors that required a change in the surgical strategy in 5 others (11.1%). In patients with pancreatic disease, LIOUS excluded the possibility of radical surgery in 7 patients (14.4%) due to the presence of mesenteric vein infiltration, involvement of the celiac or para-aortic nodes, or the presence of liver or peritoneal micro-metastases. In 11 patients with benign lesions, it defined the lesions' relation to the Wirsung duct and splenic vessels, and in 6 others it provided guidance for aspiration of fluid for chemical and cytologic analysis.

CONCLUSIONS

LIUOS and IOUS can play fundamental roles in selecting patients for resective surgery and in planning the surgical approach. They provided information that affected surgical strategies in 11 patients with liver disease (24.4%) and 13 with pancreas disease (27%).

Clinical application of laparoscopic ultrasonography in radiofrequency ablation for hepatic cancer

AIM: To evaluate 1aparoscopic ultrasonography in radiofrequency ablation (RFA) for hepatic cancer.

METHODS: A total of 15 patients with 20 hepatic cancer 2.5-7.3 cm in diameter with the mean size of 4.5 cm, were treated by laparoscopic radiofrequency ablation therapy under laparoscopic ultrasound guidance at our hospital form September 2007 to April 2008. One lesion was found in 12 patients, two lesions in 1 patient, and three lesions in 2 patients. Hepatitis B positive was diagnosed preoperatively in 10 patients, and hepatitis C positive in 1 patient. There were eleven patients with liver cirrhosis and nine patients with chronic calculous cholecystitis. All patients were followed up with helical computed tomographie (CT) scan and ultrasonography.

RESULTS: Laparoscopic RFA therapy was performed successfully in 12 patients. 8 of 15 patients were performed laparoscopie cholecystectomy at the same time. The mean RFA time per lesion was 40.2 ± 12.3 min, the mean total operation time was 98.7 ± 28.5 min, and the mean blood loss was 145.3 ± 82.8 mL. No specific complications developed during or after RFA therapy. During a mean follow-up period of 8 months, there were 4 patients with loca1 recurrence at the ablation site, 1 patient having a new malignant nodule, on whom percutaneous RFA therapy was performed successfully. When two of these patients took a third regular (check) reexamination, they were diagnosed with recurrent primary liver cancer and were recommended to undergo liver transplantation. The other 13 patients survived.

CONCLUSION: Laparoscopic ultrasonography has become a very useful means in laparoscopic radiofrequency ablation therapy for patients with hepatic cancer.

Anatomical segmental hepatectomy under the guidance of ultrasongraphy

AIM: To assess the feasibility, safety and clinical value of laparoscopic anatomical segmental hepatectomy under the guidance of ultrasongraphy.

METHODS: We performed laparoscopic liver resection in 20 patients from January 2005 to October 2006, including 13 cases of hepatocellular carcinoma, 1 case of cholangiocarcinoma, 3 cases of hemangioma, 1 case of adenoma, and 2 cases of liver abscess. All the cases received laparoscopic liver anatomy under endoscopic ultrasound guidance in complete pneumopertoneum.

RESULTS: The mean operating time was 188 min, and the mean blood loss was 300 mL. There were no uncontrollable complications. The mean time of hospital stay after operation was 8.6 d.

CONCLUSION: Segment-based hepatectomy under the guidance of ultrasonography conforms to the principle in tumor treatment and is worthy of being applied in liver surgery.

Laparoscopic radiofrequency ablation of hepatocellular carcinoma: A critical review from the surgeon's perspective

BACKGROUND

The treatment of choice for hepatocellular carcinoma (HCC) is surgical resection but only a small percentage of patients are operative candidates. Percutaneous radiofrequency interstitial thermal ablation (RFA) has proved to be effective in the treatment of unresectable HCC. However, there is a sub-group of patients who may benefit from a laparoscopic rather than a percutaneous approach. Laparoscopic RFA offers the combined advantages of improved tumor staging based on the intracorporeal ultrasound examination and safer access to liver lesions that are difficult or impossible to treat with a percutaneous approach. The aim of our review was to evaluate the advantages and limitations of the laparoscopic approach, according to the criteria of evidence-based medicine.

CONCLUSIONS

Laparoscopic RFA of HCC proved to be a safe and effective technique, at least in terms of the short- and mid-term results. This technique may be indicated in selected cases of HCC when percutaneous RFA is very difficult or contraindicated.