Intraoperative ultrasound

Visualization of the Facial Nerve with Ultra-high-Frequency Ultrasound

Background

Profound variations in facial nerve branching, combined with the severe impact of facial palsy on the patient's quality of life, make surgery in this region challenging. Recent advancements in ultrasound (US) technology, including the improved visualization of small structures, have led to a sharp increase in its medical indications in various medical disciplines. We aimed to prove the feasibility of using ultra-high-frequency (UHF) US to visualize the facial nerve and to guide surgeons during surgery on and around the facial nerve.

Methods

A cadaveric study was performed on one hemi-face with a UHF US imaging system and state-of-the-art transducers. Firstly, a transcutaneous US was performed, and the facial nerve branches of interest (zygomatic, buccal, and marginal mandibular branches) were marked using US-guided color-injections of filler mixed with methylene blue. Skin and subcutaneous fat were then removed to simulate the intraoperative field. Secondly, an "intraoperative" US examination was performed, and the same branches were marked by US-guided color-injections of filler mixed with indocyanine green. Anterograde facial nerve dissection was performed, and the distance between the nerve branches and the injected filler was measured.

Results

All color-injections (mixed with both methylene blue and indocyanine green) were positioned right next to the nerve branches (<1 mm). The image quality of the US below the skin was observed to be far superior to that of the transcutaneous US.

Conclusion

UHF US can be used to visualize the facial nerve with high precision both transcutaneously and intraoperatively (after elevation of the skin flap).

Detection and management of bile duct injury during cholecystectomy

INTRODUCTION

Cholecystectomy represents one of the most performed surgical procedures. Bile duct injuries (BDIs) are a dangerous complication of this intervention. With the advent of the laparoscopy, the rate of BDIs showed a growing trend that was partially justified by the learning curve of this technique.

EVIDENCE ACQUISITION

A literature search was conducted on Embase, Medline, and Cochrane databases to identify studies published up to October 2022 that analyzed the intraoperative detection and management of BDIs diagnosed during cholecystectomy.

EVIDENCE SYNTHESIS

According to the literature, approximately 25% of BDIs is diagnosed during the laparoscopic cholecystectomy. In the clinical suspicion of BDI, an intraoperative cholangiography is performed to confirm it. Complimentary technology, such as near-infrared cholangiography, can be also adopted. Intraoperative ultrasound represents a useful tool to furtherly define the biliary and the vascular anatomy. The proper classification of the type of BDI allows to identify the correct treatment. When a good expertise in hepato-pancreato-biliary surgery is available, a direct repair is performed with good outcomes both in case of simple and complex lesions. When the local resources are limited or there is a lack of dedicated surgical experience, patient referral to a reference center shows better outcomes. In particular, complex vasculo-biliary injuries require a highly specialized treatment. The key elements to transfer the patients are a good documentation of the injury, a proper drainage of the abdomen, and an antibiotic therapy.

CONCLUSIONS

BDI management requires a proper diagnostic process and prompt treatment to reduce the morbidity and mortality of this feared complication occurring during cholecystectomy.

Comparison of imaging techniques to detect migrating foreign bodies. Relevance of preoperative and intraoperative ultrasonography for diagnosis and surgical removal

OBJECTIVE

To report the relative sensitivity of different diagnostic imaging (DI) techniques to detect migrating foreign bodies (FB) in subcutaneous and underlying soft tissue structures of dogs and evaluate the value of intraoperative ultrasonography (intraop-US).

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Forty-one dogs.

METHODS

Medical records (2007-2019) of dogs that underwent surgery for a chronic abscess or draining tract were included when preoperative US (preop-US), computed tomography (preop-CT), or preop-MRI, and at least 6 months of follow-up information were available. Collected data included the DI techniques used, DI findings, and surgical findings. The relative sensitivity of each preoperative DI (preop-DI) technique was calculated. Dogs were divided into two groups, dogs that underwent only a preop-DI examination (group A) and dogs that underwent an additional intraop-US (group B). The success rates for FB surgical removal were compared between groups.

RESULTS

The relative sensitivity of preop-US and preop-CT/MRI was 88% (95% CI, 70%-95.8%) and 57.1% (95% CI, 32.6%-78.6%), respectively. The success rate for FB removal was higher in group B (89.5%) than in group A (59.1%; P = .038). Clinical resolution occurred in 90.2% of dogs for a median duration of follow-up of 4.2 years (6 months to 9.3 years).

CONCLUSION

Preoperative US seems more suitable than preop-CT/MRI for detection of migrating FB in subcutaneous and underlying soft tissue structures. The use of intraop-US increases the success rate for FB surgical removal.

CLINICAL SIGNIFICANCE

Intraoperative US should be used in combination with preop-US to increase the likelihood of migrating FB surgical removal in dogs.

Brain Shift in Neuronavigation of Brain Tumors: An Updated Review of Intra-Operative Ultrasound Applications

Neuronavigation using pre-operative imaging data for neurosurgical guidance is a ubiquitous tool for the planning and resection of oncologic brain disease. These systems are rendered unreliable when brain shift invalidates the patient-image registration. Our previous review in 2015, Brain shift in neuronavigation of brain tumours: A review offered a new taxonomy, classification system, and a historical perspective on the causes, measurement, and pre- and intra-operative compensation of this phenomenon. Here we present an updated review using the same taxonomy and framework, focused on the developments of intra-operative ultrasound-based brain shift research from 2015 to the present (2020). The review was performed using PubMed to identify articles since 2015 with the specific words and phrases: “Brain shift” AND “Ultrasound”. Since 2015, the rate of publication of intra-operative ultrasound based articles in the context of brain shift has increased from 2–3 per year to 8–10 per year. This efficient and low-cost technology and increasing comfort among clinicians and researchers have allowed unique avenues of development. Since 2015, there has been a trend towards more mathematical advancements in the field which is often validated on publicly available datasets from early intra-operative ultrasound research, and may not give a just representation to the intra-operative imaging landscape in modern image-guided neurosurgery. Focus on vessel-based registration and virtual and augmented reality paradigms have seen traction, offering new perspectives to overcome some of the different pitfalls of ultrasound based technologies. Unfortunately, clinical adaptation and evaluation has not seen as significant of a publication boost. Brain shift continues to be a highly prevalent pitfall in maintaining accuracy throughout oncologic neurosurgical intervention and continues to be an area of active research. Intra-operative ultrasound continues to show promise as an effective, efficient, and low-cost solution for intra-operative accuracy management. A major drawback of the current research landscape is that mathematical tool validation based on retrospective data outpaces prospective clinical evaluations decreasing the strength of the evidence. The need for newer and more publicly available clinical datasets will be instrumental in more reliable validation of these methods that reflect the modern intra-operative imaging in these procedures.

Pediatric living donor left lateral segment liver transplantation for biliary atresia: Doppler ultrasound findings in early postoperative period

PURPOSE

To analyze hepatic hemodynamic parameters detected by Doppler ultrasound (DU) of uncomplicated children with biliary atresia who underwent left lateral segment living donor liver transplantation (LLS-LDLT), explore its normal change trend over time and determine the normal reference interval.

METHODS

We retrospectively involved the data from 227 biliary atresia patients (100 Males,127 Females). Hemodynamic parameters include peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI), and pulsation index (PI) of the hepatic artery (HA), portal vein velocity (PVV), portal vein flow (PVF) and hepatic vein velocity (HVV) during intra-operative and on the 1st, 3rd, 5th and 7th day after operation were collected. Repeated measures analysis of the variance and Friedman test were used to analyze the changing trend of hemodynamic parameters over time in the first week after the operation.

RESULTS

PSV_HA and EDV_HA showed a similar changing tendency at one week after surgery, with an overall decrease-rise trend; RI_HA and PI_HA also changed similarly with an overall rise-decrease trend. The HVV and PVV at surgery were lower than at all time points after surgery. As for PVF, the value of POD5 was the highest and then decreased. Additionally, this study provided the normal reference interval of hemodynamic parameters for LLS-LDLT patients, which were PSV_HA: 18.4-98.3 cm/s, EDV_HA: 0-43.3 cm/s, RI_HA: 0.41-1.0, PI_HA: 0.51-2.0, PVV: 19.0-83.7 cm/s, HVV: 19.4-68.0 cm/s, and PVF:99.5-500.0 ml/min/100 g at intraoperation. Within the first postoperative week: PSV_HA: 21.0-97.7 cm/s, EDV_HA: 0-32.7 cm/s, RI_HA: 0.47-1.0, PI_HA: 0.62-2.0, PVV: 23.0-92.0 cm/s, HVV: 19.7-86.0 cm/s, and PVF: 100.0-513.0 ml/min/100 g.

CONCLUSION

The hepatic hemodynamic of post-transplanted children detected by DU had specific changing trends and normal ranges, which provides valuable reference values for ultrasonologists and pediatric transplant clinicians.

Clinical utility of real-time ultrasound-multimodality fusion guidance for percutaneous biopsy of focal liver lesions

OBJECTIVES

To prospectively evaluate the clinical value of real-time ultrasonography (US)-computed tomography (CT)/magnetic resonance imaging (MRI) fusion imaging for percutaneous needle biopsy of focal liver lesions (FLLs), and to compare its biopsy success rate with that of conventional US-guided biopsy in a propensity-score matched group.

METHODS

This study was approved by our Institutional Review Board and informed consent was obtained from all patients enrolled in the prospective study group. Ninety patients referred to the Department of Radiology for percutaneous biopsy of FLLs were enrolled in this study. Tumor visibility, attainment of a safe access route, and technical feasibility were assessed on conventional US first and later on real-time fusion imaging by one of four abdominal radiologists. Thereafter, differences in scores between real-time fusion imaging and conventional US were determined. In addition, overall diagnostic success rates of a real-time fusion imaging-guided biopsy group and a propensity-score matched, conventional US-guided biopsy group, consisting of 100 patients used as historical control, were compared.

RESULTS

With real-time fusion imaging, tumor visibility, attainment of a safe access route, and operator's technical feasibility were significantly improved compared with conventional US (P < .001). In addition, all invisible (n = 13) and not feasible (n = 10) FLLs on conventional US became visible and feasible for percutaneous US-guided biopsy after applying the fusion system. The diagnostic success rate of real-time fusion-guided biopsy was 94.4% (85/90), which was significantly better than that obtained with the conventional US-guided biopsy (94.4% vs. 83%, P < .03), with reduced biopsy procedure times (7.1 ± 3.5 vs. 9.7 ± 2.8, P < .02).

CONCLUSIONS

Real-time US-CT/MR fusion imaging guidance was able to provide clinical value for percutaneous needle biopsy of FLLs by improving the diagnostic success rate of biopsy and by reducing procedure time.

Intraoperative ultrasound for the colorectal surgeon: current trends and barriers

Up to two thirds of patients diagnosed with colorectal cancer (CRC) develop colorectal liver metastases (CRLMs) and one quarter of patients present with synchronous metastases. Early detection of CRLM widens the scope of potential treatment. Surgery for CRLM offers the best chance of a cure. Current preoperative staging of CRC relies on computerized tomography and magnetic resonance imaging. Intraoperative ultrasound (IOUS) scans and contrast-enhanced IOUS (CE-IOUS) have been demonstrated to detect additional metastases not seen on routine preoperative imaging. IOUS is not widely used by colorectal surgeons during primary resection for CRC. Confident use of IOUS/CE-IOUS during primary resection of CRC may improve decision-making by providing the most sensitive form of liver staging even when compared with magnetic resonance imaging. This may be particularly important in the era of laparoscopic resections, where the colorectal surgeon loses the opportunity to palpate the liver. There are several implied barriers to the routine use of IOUS/CE-IOUS by colorectal surgeons. These include time pressure, familiarity with techniques, a perceived learning curve, cost implications and limitation of the modality due to operator variations. Inclusion of IOUS in the training of colorectal surgeons and further investigation of potential benefits of IOUS/CE-IOUS could potentially reduce these barriers, enabling usage during primary resection for CRC to become more widespread.

Intraoperative Ultrasound as a Screening Modality for the Detection of Liver Metastases during Resection of Primary Colorectal Cancer - A Systematic Review

Colorectal cancer (CRC) is one of the most common cancer diseases worldwide. One in 4 patients with CRC will have a disseminated disease at the time of diagnosis and often in the form of synchronous liver metastases. Studies suggest that up to 30% of patients have non-recognized hepatic metastases during primary surgery for CRC. Intraoperative ultrasonography examination (IOUS) of the liver to detect liver metastases was considered the gold standard during open CRC surgery. Today laparoscopic surgery is the standard procedure, but laparoscopic ultrasound examination (LUS) is not performed routinely. Aim To perform a systematic review of the test performance of IOUS and LUS regarding the detection of synchronous liver metastases in patients undergoing surgery for primary CRC. Method The literature was systematically reviewed using the search engines: PubMed, Cochrane, Embase and Google. 21 studies were included in the review and the key words: intraoperative ultrasound, laparoscopic ultrasound, staging colon and rectum cancer. Results Intraoperative ultrasound showed a higher sensitivity, specificity, positive predictive value and overall accuracy for the detection liver metastases during surgery for primary CRC, compared to preoperative imaging modalities (ultrasound, computed tomography (CT) and contrast-enhanced computed tomography (CE-CT)). LUS showed a higher detection rate for liver metastases compared to CT, CE-CT and magnetic resonance imaging (MRI). Conclusion This systematic review found that both IOUS and LUS had a higher detection rate regarding liver metastases during primary CRC surgery, especially liver metastases<10 mm in diameter, when compared to US, CT, CE-CT and MRI.

User-friendly freehand ultrasound calibration using Lego bricks and automatic registration

PURPOSE

As an inexpensive, noninvasive, and portable clinical imaging modality, ultrasound (US) has been widely employed in many interventional procedures for monitoring potential tissue deformation, surgical tool placement, and locating surgical targets. The application requires the spatial mapping between 2D US images and 3D coordinates of the patient. Although positions of the devices (i.e., ultrasound transducer) and the patient can be easily recorded by a motion tracking system, the spatial relationship between the US image and the tracker attached to the US transducer needs to be estimated through an US calibration procedure. Previously, various calibration techniques have been proposed, where a spatial transformation is computed to match the coordinates of corresponding features in a physical phantom and those seen in the US scans. However, most of these methods are difficult to use for novel users.

METHODS

We proposed an ultrasound calibration method by constructing a phantom from simple Lego bricks and applying an automated multi-slice 2D-3D registration scheme without volumetric reconstruction. The method was validated for its calibration accuracy and reproducibility.

RESULTS

Our method yields a calibration accuracy of [Formula: see text] mm and a calibration reproducibility of 1.29 mm.

CONCLUSION

We have proposed a robust, inexpensive, and easy-to-use ultrasound calibration method.

A novel direct spray-from-tissue ionization method for mass spectrometric analysis of human brain tumors

Real-time feedback about dissected tissue during the neurosurgical procedure is strongly requested. A novel direct ionization mass spectrometric method for identifying pathological differences in tissues is proposed. The method is based on simultaneous extraction of tissue lipids and electrospray ionization which allows mass spectrometric data to be obtained directly from soft tissues. The advantage of this method is the stable flow of solvent, which leads to stable time-dependent spectra. The tissues included necrotized tissues and tumor tissues in different combinations. Capability for direct analysis of samples of dissected tissues during the neurosurgical procedure is demonstrated. Data validation is conducted by compound identification using precise masses from the MS profile, MS/MS, and isotopic distribution structure analysis. The method can be upgraded and applied for real-time identification of tissues during surgery. This paper describes the technique and its application perspective. For these purposes, other methods were compared with the investigated one and the results were shown to be reproducible. Differences in lipid profiles were observed even in tissues from one patient where distinctions between different samples could be poor. The paper presents a proof of concept for the method to be applied in neurosurgery particularly and in tissue analysis generically. The paper also contains preliminary results proving the possibility of observing differences in mass spectra of different tumors.

Laparoscopic microwave ablation of human liver tumours using a novel three-dimensional magnetic guidance system

BACKGROUND

Accurate antenna placement is essential for effective microwave ablation (MWA) of lesions. Laparoscopic targeting is made particularly challenging in liver tumours by the needle's trajectory as it passes through the abdominal wall into the liver. Previous optical three-dimensional guidance systems employing infrared technology have been limited by interference with the line of sight during procedures.

OBJECTIVE

The aim of this study was to evaluate a newly developed magnetic guidance system for laparoscopic MWA of liver tumours in a pilot study.

METHODS

Thirteen patients undergoing laparoscopic MWA of liver tumours gave consent to their participation in the study and were enrolled. Lesion targeting was performed using the InnerOptic AIM™ 3-D guidance system to track the real-time position and orientation of the antenna and ultrasound probe.

RESULTS

A total of 45 ablations were performed on 34 lesions. The median number of lesions per patient was two. The mean ± standard deviation lesion diameter was 18.0 ± 9.2 mm and the mean time to target acquisition was 3.5 min. The first-attempt success rate was 93%. There were no intraoperative or immediate postoperative complications. Over an average follow-up of 7.8 months, one patient was noted to have had an incomplete ablation, seven suffered regional recurrences, and five patients remained disease-free.

CONCLUSIONS

The AIM™ guidance system is an effective adjunct for laparoscopic ablation. It facilitates a high degree of accuracy and a good first-attempt success rate, and avoids the line of site interference associated with infrared systems.

Intraoperative Sonography Opens New Doors for Patient Care

Intraoperative ultrasonography (IOUS) is rapidly changing as advancements in technology provide surgeons with more options for the treatment of their patients. Despite the introduction of intraoperative magnetic resonance imaging (MRI) and computed tomography (CT), advancements in IOUS technology and its low cost have kept this a viable modality. The improved image resolution that is available provides neurosurgeons, for example, with the information necessary to adequately resect cancer in the brain, including superficial and deep-set tumors, whether they are primary brain cancers or brain metastases. Strain sonography and contrast-enhanced ultrasonography (CEUS) are advancements being used to help better visualize residual tumor cells after resection. IOUS is the only modality that provides the neurosurgeon with the ability to obtain real-time imaging while a resection is taking place. All of this information helps to make the complete resection of brain cancer with the least amount of neurological damage more likely, significantly enhancing the patient’s chances of a good outcome.

Intraoperative abdominal ultrasound in oncologic imaging

Significant advances in ultrasound technology have created new opportunities for its use in oncologic imaging. The advent of new transducers with focal beam technology and higher frequency has solidified the role of intraoperative sonography (IOUS) as an invaluable imaging modality in oncologic surgery of the liver, kidneys and pancreas. The ability to detect and characterize small lesions and the precise intraoperative localization of such tumors is essential for adequate surgical planning in segmental or lobar hepatic resections, metastasectomy, nephron-sparing surgery, and partial pancreatectomy. Also, diagnostic characterization of small equivocal lesions deemed indeterminate by conventional preoperative imaging such as multidetector computed tomography or magnetic resonance imaging, has become an important application of IOUS. This article will review the current applications of IOUS in the liver, kidneys and pancreas.

Real-time three-dimensional guided ultrasound targeting system for microwave ablation of liver tumours: a human pilot study

OBJECTIVES

This study aimed to evaluate a novel three-dimensional ultrasound (US) guidance system for use in hepatic microwave ablation (MWA).

METHODS

An in vitro assessment was performed in which users with different degrees of experience were evaluated for accuracy in targeting phantom lesions embedded in agar using US alone, or US in conjunction with the InVision™ System (IVS). An eight-patient pilot trial of the IVS was then performed in the setting of open hepatic MWA, in which lesions would otherwise have been targeted with conventional US.

RESULTS

In vitro studies demonstrated that the IVS significantly improved targeting accuracy at all levels of operator experience (novice, beginner and expert). In the human trial, a total of 31 tumours were targeted and all lesions were hit in one pass, as assessed by independent US image observations. There were no adverse operative events; however, there was minor line-of-sight interference with the infra-red tracking mechanism when some lesions high on the dome of the liver were targeted.

CONCLUSIONS

The IVS significantly increased the accuracy of complex targeting procedures of phantom lesions and enhanced targeting in an eight-patient clinical pilot study. During the accrual phase of this pilot study, the development of improved non-optical tracking hardware obviated the requirement to maintain a direct line of sight. The trial was then halted prematurely in order to focus on the application of the IVS utilizing this non-optical modality.

Intraoperative ultrasound score to predict recurrent hepatocellular carcinoma after radical treatments

Despite the high complete necrosis rate of radio-frequency ablation (RFA) or the complete removal following curative hepatic resection (HR), recurrent hepatocellular carcinoma (HCC) remains a significant problem. The aim of the study is to identify some intraoperative ultrasound (IOUS) patterns, predicting intrahepatic recurrences. From January 1997 to July 2009, 410 patients with HCC were treated (162 HR and 248 RFA through a surgical access). All patients were submitted to IOUS examination: 148 IOUS were performed during the laparotomic access while 262 IOUS were performed during the laparoscopic access. Primary HCC was classified according to diameter, HCC pattern (nodular or infiltrative), echogenicity (hyper- or hypo-echoic), echotexture (homogeneous or inhomogeneous), capsular invasion, mosaic pattern, nodule in nodule aspect and infiltration of portal vessels. Number of HCC nodules was also considered. Multivariate analysis (Cox model) was performed to determine features associated with recurrent HCC using IOUS patterns that independently predicted recurrent HCC, a IOUS score was developed. The patients were followed for 3-127 months, (median follow-up: 21.5 months). In 220 patients (54%), intrahepatic recurrences occurred. In 155 patients (38%), distant intrahepatic recurrences arose in different segments at the primary tumor site. In 65 HCC cases (16%), local recurrences were found. At multivariate analysis, multiple nodules, HCC diameter (>20 mm), HCC pattern (infiltrative), hyperechoic nodule and portal infiltration were statistically significant for risk factor of intrahepatic recurrences. Therefore, a IOUS scoring system was calculated on the basis of multivariate analysis and identified three risk categories of patients: in group 1 recurrences occurred in 37%, group 2 in 46% and group 3 in 66% (p = 0.0001). IOUS is an accurate staging tool during "surgical" procedures. This study showed an added value of IOUS: it permitted to identify ultrasound patterns, which can predict the risk of HCC recurrences. The calculated IOUS score permits to intraoperatively evaluate the actual surgical choice and to program the best treatment strategies during the follow-up period.

Intraoperative ultrasound patterns predict recurrences after surgical treatments for hepatocellular carcinoma()

INTRODUCTION

Hepatocellular carcinoma (HCC) is associated with a high incidence of postoperative recurrence, despite high rates of complete necrosis with radiofrequency ablation (RFA) and curative hepatic resections (HR). The aim of this study was to identify intraoperative ultrasound patterns observed during HR or RFA that predicting intrahepatic HCC recurrence.

MATERIALS AND METHODS

From January 1997 through August 2008, we treated 377 patients with HCC (158 with HR and 219 with surgical RFA). All patients underwent intraoperative ultrasound (IOUS) examination. Primary HCCs was classified according to diameter, HCC pattern (nodular or infiltrative), echogenicity (hyper- or hypo-), echotexture (homogeneous or inhomogeneous), capsular invasion, mosaic pattern, nodule-in-nodule appearance, and infiltration of portal vessels. Number of HCC nodules was also considered. Comparisons between the groups of possible factors for intrahepatic recurrence of treated tumors were performed using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Patients were followed for 9-127 months (median: 18.6 months), and intrahepatic recurrence was observed in 198 (52.5%). In 138 patients (36.5%), recurrences were located in different segments with respect to the primary tumor. In 60 HCC tumors (16%), local recurrences were found in the same segment as the primary tumor. At univariate analysis, primary HCC echogenicity and mosaic pattern were the only factors not significant associated with intrahepatic recurrences.

CONCLUSION

IOUS is an accurate staging tool for use during "surgical" resection or RFA. This study shows that IOUS patterns can also be used to estimate the risk of post-treatment HCC recurrence. In patients at high risk for this outcome, closer follow-up and use of adjuvant therapies could be useful.

Laparoscopic drainage of pancreatic pseudocysts: a methodological approach

BACKGROUND

This paper describes our tailored and methodological approach to laparoscopic drainage of pancreatic pseudocysts (PPs) based on an anatomical classification.

METHODS

We adopted the laparoscopic approach in "all comers" who had PPs requiring surgical drainage. The recipient organ for drainage (e.g., cystgastrostomy, cystjejunostomy, or cystduodenostomy) and method of access (e.g., transgastric, endogastric, exogastric or lesser sac, and infracolic) were decided based on preoperative computed tomography (CT) and intraoperative findings. The results shown represent median (range).

RESULTS

Between 2001 and 2009, 30 laparoscopic drainage procedures for PPs were performed in 28 consecutive patients. The surgical approach included transgastric (n = 17) or endogastric (n = 3) cystgastrostomy for large retrogastric PPs (n = 20), exogastric cystgastrostomy for small perigastric PPs (n = 4), cystduodenostomy (n = 1) under ultrasound guidance, cystjejunostomy for infracolic PPs (n = 4), and one external drainage. The operative time was 118 (25-300) min. There was one conversion to laparotomy (3.3%), low morbidity (3.3%), and no mortality. The postoperative hospital stay was 2 (1-7) days. At a follow-up of 15 (1-48) months, PPs recurred in two patients (7.1%) and were drained by laparoscopic cystgastrostomy.

CONCLUSION

CT findings and laparoscopic exploration demonstrate the anatomical characteristics of PPs and enable successful planning and execution of their laparoscopic drainage.

Is intraoperative ultrasound (IOUS) still useful for the detection of liver metastases?

PURPOSE

To evaluate the clinical impact of intraoperative ultrasound (IOUS) in the detection of liver metastases during the years, as compared with those of other imaging modalities.

MATERIALS AND METHODS

All IOUS scans performed for detection of liver metastases from 2000 to 2006 were retrospectively reviewed and compared with the results of preoperative imaging modalities: Ultrasound (US), Computed Tomography (CT), and/or Magnetic Resonance (MR). The number of cases in which IOUS and preoperative imaging studies produced discordant results, in terms of presence/absence of focal liver lesions, was calculated per year. Statistical analysis was performed using the McNemar test. A p value < 0.05 was considered statistically significant.

RESULTS

Eighty-three IOUS scans performed in 2000-2003 were reviewed, and discordance with preoperative imaging findings was found in 19/83 (23%) cases. Of the 42 IOUS scans done during the 2004-2006 period, 10/42 (24%) showed discordance with preoperative studies. All metastases diagnosed with imaging studies were pathologically confirmed. The number of discordant cases in the two periods were not significantly different (p = 0.2).

CONCLUSION

IOUS is still useful in the detection of liver metastases. Its decreased use is probably due to the improved accuracy of preoperative imaging modalities.

Intraoperative ultrasound of the pancreas

Intraoperative ultrasound provides spatial resolution of the pancreas superior to computed tomography, magnetic resonance imaging, and transabdominal sonography. This pictorial essay will review common benign and malignant pancreatic processes including the following: pancreatic ductal adenocarcinoma, pancreatitis, endocrine tumors, mucinous cystic neoplasm, intraductal papillary mucinous neoplasm, serous cystadenoma, and solid pseudopapillary tumor. The use of intraoperative ultrasound in specific surgical situations will be discussed, which include the following: (1) identification of insulinoma(s) which are not detectable preoperatively, (2) identification of the pancreatic duct to determine dissection planes for chronic pancreatitis surgery (eg, Puestow procedure) and for tumor resection, and (3) staging purposes for malignant disease.

Ultrasound-guided liver resection: Early experience in a district general hospital

INTRODUCTION

Intraoperative ultrasonography (IOUS) is the gold standard for tumor staging and operative decision making in liver surgery. Providing dynamic information on tumor-vessel relationships and distribution of intrahepatic veins, IOUS is also an important support for guiding the resection. Few authors report an extensive use of IOUS-guidance as a safe and effective approach. The aim of this study is to investigate the short-term results of an early experience of ultrasound (US) guided liver resection.

METHODS

From December 2005 to December 2007 an extensive use of IOUS-guided resection was applied in 11 consecutive patients (8 males and 3 females; median age 74 years). Perioperative data were collected prospectively to assess the influence of this approach on mortality, morbidity and early recurrence.

RESULTS

Four patients had hepatocellular carcinoma, 4 liver metastases, 1 peripheral cholangiocarcinoma, 1 hemangioma and 1 inflammatory pseudotumor. A median of 1 (range: 1-4) nodule per patient was resected. Median lesion size was 44 mm. Liver procedures included: 3 wedge resections, 3 subsegmentectomies, 4 segmentectomies and 3 bisegmentectomies. Median blood loss was 235 ml. Median surgical margin in cancer patients was 5 mm (range: 1-12). An average of 1 unit of blood transfusion was administered in 5 patients. Median postoperative hospital stay was 9 days. There was no mortality. Major complications occurred in 1 patient and minor complications in 5 patients. During a median follow-up of 14 months no recurrences were observed.

CONCLUSIONS

In this study, use of IOUS-guided liver resection performed in a district general hospital proved to be a safe and effective approach in terms of short-term outcome.

Value of contrast-enhanced intraoperative ultrasound for cirrhotic patients with hepatocellular carcinoma: A report of 20 cases

AIM: To assess the clinical value of contrast-enhanced intraoperative ultrasound (CE-IOUS) as a novel tool in partial hepatectomy for cirrhotic patients with hepatocellular carcinoma (HCC).

METHODS: From January 2007 to September 2007, a total of 20 consecutive cirrhotic patients with HCC scheduled to undergo partial hepatectomy were studied. Preoperative contrast enhanced computer tomography (CT) and/or magnetic resonance (MR) scans were performed within 1-2 wk before operation. Intraoperative ultrasound (IOUS) and CE-IOUS were carried out after mobilization of the liver. Lesions on precontrast and postcontrast scans were counted and mapped. CE-IOUS was performed with intravenous injection of ultrasound contrast agents SonoVue (Bracco Imaging, Milan, Italy). Arterial, portal and late phases of contrast enhancement were recorded and analyzed. Nodules showing arterial phase hyper-enhancing and/or hypo-enhancing in late parenchymal phase were considered malignant and removed surgically. Ultrasound-guided biopsy and ethanol ablation would be an option if the nodule could not be removed surgically. Newly detected nodules on IOUS showing iso-enhancement in both arterial and late phases were considered benign. These nodules were either removed surgically if they were close to the main lesion or followed by examinations of alpha-fetoprotein (AFP) level and ultrasound and/or CT/MR every 3 mo.

RESULTS: IOUS found 41 nodules in total, among which 17 (41.46%) were newly detected compared to preoperative imaging. Thirty-three nodules were diagnosed malignant by CE-IOUS, including one missed by IOUS. The sensitivity and specificity of CE-IOUS on detecting HCC nodules are 100% (33/33 and 100% (9/9), respectively. Nine nodules were considered benign by CE-IOUS, four was confirmed at histology and five by follow-up. CE-IOUS changed the surgical strategy in 35% (7/20) of patients and avoid unnecessary intervention in 30% (6/20) of patients.

CONCLUSION: CE-IOUS is a useful means to charac-terize the nodules detected by IOUS in cirrhotic liver, to find isoechoic HCC nodules which can not be shown on IOUS and to improve the accuracy of conventional IOUS, thus it can be used as an essential tool in the surgical treatment of cirrhotic patients with HCC.

Ultrasonography of the pancreas. 7. Intraoperative imaging

The usefulness of intraoperative ultrasonography (IOUS) has been documented in the Literature since the Eighties and, although its main applications are in hepatobiliary and pancreatic surgery, it has been used also in neurosurgery, cardiovascular and endocrine surgery. The continuous technical developments have led to an increase in the diagnostic accuracy of IOUS from the Eighties to now. The use of IOUS has increased in time together with the technical innovations until, mainly in the midnineties, its value was recognized by many surgeons. This results have been obtained with scanners that allow to depict fine anatomical details and detect small lesions in real time with extremely high spatial resolution. IOUS is able to shows fine details, such as primary or secondary lesions not detectable with other preoperative imaging modalities or tumor extension and its relationship with vessels. Assessment of resectability by IOUS may determine important changes in therapeutic planning. The role of IOUS, however, has recently been down-sized, especially in those centers where preoperative imaging is advanced. This article will review the clinical role of pancreatic IOUS in the different pancreatic pathologies.

Intraoperative ultrasonography in open and laparoscopic abdominal surgery: an overview

This article reviews the current state of intraoperative ultrasonography in open surgery (IOUS) and laparoscopic surgery (LUS). The review is based on extensive study of data published (Pubmed search) and on 25 years of personal experience with intraoperative ultrasonography. The main application areas of IOUS and LUS and its use during liver, biliary tract, and pancreatic surgery are discussed. The benefits and limitations as well as future expectations with regard to the existing and emerging applications also are discussed. New developments in ultrasound technology and the increasing experience of surgeons in ultrasonography secure the future for IOUS and LUS.

Systematic hepatectomy for small hepatocellular carcinoma in Korea

BACKGROUND/PURPOSE

Systematic hepatectomy for small hepatocellular carcinoma (HCC) is a widely preferred modality, but evidence concerning its benefits is lacking. The aim of this study was to document hepatic resection for small HCC in Korea, and to determine whether patient survival or the pattern of tumor recurrence was influenced by the methods used.

METHODS

Ten major hospitals that perform hepatectomy for HCC in Korea were surveyed for surgeons' opinions concerning systematic hepatectomy and current trends in hepatic resection for small HCC. An analysis was also performed of 119 patients who underwent curative hepatectomy for small HCC (size < 5 cm) between January 2000 and December 2002 at Seoul National University Hospital. Seventy-four of these 119 patients underwent anatomical resection (AR) and 45 had a non-anatomical resection (NAR). Recurrence-free survival, recurrence pattern, overall survival rates, and the risk factors for recurrence were analyzed.

RESULTS

In the survey, eight of ten surgeons preferred systematic hepatectomy and considered it to aid prognosis. No significant difference was found between the AR and NAR groups in terms of the clinicopathologic findings, except that the presence of underlying hepatic cirrhosis was more prevalent in the NAR group. The postoperative morbidity rate was higher in the NAR group (33.3% vs 27.0%), but this difference was not statistically significant. The respective 1- and 3-year recurrence-free survival rates were 78.1% and 49.7% in the AR group, and 68.9% and 46.5% in the NAR group (P > 0.05). The corresponding 1- and 3-year overall survival rates were 88.8% and 80.8% in the AR group and 91.0% and 71.4% in the NAR group (P > 0.05).

CONCLUSIONS

Although systematic hepatectomy seems to be superior to non-anatomical hepatectomy from the oncological and anatomical aspects, this superiority is not reflected by the recurrence patterns or the survival and recurrence rates of the two procedures. Postoperative recurrence appears, rather, to be related to the underlying liver condition.

Utility of the hooking technique for cases of major hepatectomy

Currently, resective hepatic surgery should be considered an echoguided surgical procedure to guarantee conservative but radical resections. A simple and original technique guided by intraoperative ultrasonography, termed the "hooking technique," had been described previously. It enables the ligation sites of the intrahepatic vessels during systematic segmentectomy to be chosen precisely. This report describes a further application of this technique to allow safe ligation of portal vein main branches invaded by tumor thrombi during major hepatectomies.