Laparoscopic ultrasound

A Comparison of Near-Infrared Autofluorescence Findings in Benign Versus Malignant Adrenal Tumors

BACKGROUND

Many adrenal tumors are deemed radiologically indeterminate and surgically removed. Adrenal tissue, like parathyroid glands, exhibits near-infrared autofluorescence (NIRAF) properties. This study was designed to investigate the potential of NIRAF to differentiate benign versus malignant adrenal tumors.

METHODS

Patients undergoing adrenalectomy between October 2021 and May 2023 were prospectively studied. Adrenalectomy specimens were inspected with NIRAF imaging. Specimen autofluorescence (AF) characteristics were recorded. Comparisons were made between different tumor types and a logistic regression model was constructed to differentiate benign versus malignant tumors. A receiver operating characteristic curve was used to identify an optimal AF threshold differentiating benign versus malignant tumors.

RESULTS

A total of 108 adrenal specimens were examined: adrenocortical adenomas/other benign lesions (n = 72), pheochromocytomas (n = 18), adrenocortical neoplasms of uncertain behavior (n = 4), and malignant tumors (n = 14). A significant difference in normalized AF intensity was identified when comparing adrenocortical adenomas (3.08 times background) with pheochromocytomas (1.95, p = 0.001) and malignant tumors (1.11, p < 0.0001). The Area Under the Curve differentiating benign vs malignant tumors was 0.87, with an optimal normalized AF threshold at 1.93.

CONCLUSIONS

Different adrenal pathologies exhibit diverse AF properties. These findings suggest a potential intraoperative utility of NIRAF in predicting benign versus malignant nature for radiologically indeterminate adrenal tumors.

Intraoperative Ultrasound in Minimally Invasive Laparoscopic and Robotic Pediatric Surgery: Our Experiences and Literature Review

Ultrasound (US) is a non-invasive imaging technique frequently used to examine internal organs and superficial tissues, and invaluable in pediatric patients. In a surgical setting, intraoperative ultrasound allows to highlight anatomical structures in detail during traditional open and minimally invasive surgery, thanks to the use of specific probes. In fact, laparoscopic and robotic ultrasonography requires the development of specialized transducers that fit through laparoscopic trocars. In adults, laparoscopic ultrasound is used during cholecystectomy before dissection of the triangle of Calot, to guide liver biopsies and ablation procedures and for the staging of patients with pancreas adenocarcinoma. However, the applications in the pediatric field are still limited. This paper aims to share our preliminary experience with ultra-sound in minimally invasive laparoscopic and robotic pediatric surgery, describing two cases in which intra-operative ultrasound was applied, and to present a review of the literature on the state of the art of the actual uses in pediatric surgery.

Photoacoustic imaging of posterior periodontal pocket using a commercial hockey-stick transducer

SIGNIFICANCE

Photoacoustic imaging has shown advantages over the periodontal probing method in measuring the periodontal probing depth, but the large size of conventional photoacoustic transducers prevents imaging of the more posterior teeth.

AIM

Our aim is to develop a photoacoustic imaging system to image the more posterior periodontal pocket.

APPROACH

We report a clinical "hockey-stick"-style transducer integrated with fibers for periodontal photoacoustic imaging. Cuttlefish ink labeled the periodontal pocket as the photoacoustic contrast agent.

RESULTS

We characterized the imaging system and then measured the pocket depth of 35 swine teeth. Three raters evaluated the performance of the hockey-stick transducer. The measurements between the Williams probing (gold standard) and the photoacoustic methods were blinded but highly correlated. We showed a bias of ∼0.3  mm for the imaging-based technique versus Williams probing. The minimum inter-reliability was over 0.60 for three different raters of varying experience, suggesting that this approach to measure the periodontal pocket is reproducible. Finally, we imaged three pre-molars of a human subject. We could access more upper and posterior teeth than conventional linear transducers.

CONCLUSIONS

The unique angle shape of the hockey-stick transducer allows it to image more posterior teeth than regular linear transducers. This study demonstrated the ability of a hockey-stick transducer to measure the periodontal pocket via photoacoustic imaging.

A comparison of indocyanine green fluorescence and laparoscopic ultrasound for detection of liver tumors

BACKGROUND

Indocyanine green (ICG) fluorescence imaging (ICG-FI) has been suggested for intraoperative identification of liver tumors. We aim to compare the intraoperative diagnostic utility of this imaging modality with laparoscopic ultrasound (LUS).

METHODS

This is an IRB-approved prospective study. ICG was administered intravenously 1-2 days before surgery. The findings on ICG-FI were compared to those on preoperative cross-sectional imaging (POCSI), LUS, diagnostic laparoscopy (DL).

RESULTS

A total of 144 lesions (62 superficial [visible on DL] and 82 deep) were detected in the study patients. POCSI identified 74%, LUS identified 92%, and ICG-FI identified 43%. ICG-FI detection rate was higher for superficial (95%) versus deep lesions (4%). 3% (4/144) of all lesions were seen only on ICG-FI. However, all of these lesions were small and superficial lesions that were apparent on DL.

CONCLUSION

Although ICG-FI allowed detection of small superficial lesions that were not identifiable by POCSI or LUS, these lesions were apparent on DL even before ICG-FI. Therefore, its utility as an intraoperative diagnostic modality is limited at the dosage and timing used in the study. We believe that rather than a diagnostic tool, it has more potential for a dynamic use in guiding the resection of superficial lesions and delineating segmental/lobar anatomy.

Evaluation and management of adrenal neoplasms: endocrinologist and endocrine surgeon perspectives

The evaluation and management of adrenal disease is a complex endeavor that relies on an expert knowledge of human physiology and anatomy. Careful and proper patient assessment mandates a balanced approach which marries the disciplines of endocrinology, surgery, and radiology. Any of these three specialties may be on the front line in performing the initial workup when an adrenal neoplasm is discovered. With an ever-increasing volume of cross-sectional imaging, be it CT, MRI, or PET, large numbers of adrenal incidentalomas are being discovered. A close collaboration amongst specialties should strive to streamline the initial evaluation and minimize unnecessary testing and treatment.

Efficacy of laparoscopic ultrasonography in laparoscopic resection of insulinoma

Insulinoma is the most common functioning islet cell tumor of the pancreas, with an annual incidence of 4 cases/1 million individuals. It is treated by surgical methods. Open surgery was once considered the standard approach for the treatment of insulinoma. However, the procedure is traumatic and requires a large incision, which does not satisfy the growing expectations of minimally invasive management of small-sized tumors. Insulinomas are usually benign solitary tumors and mostly occur sporadically, which makes them suitable candidates for laparoscopic management. The potential advantages of laparoscopic management of insulinoma over open surgery include shorter duration of hospitalization, quicker recovery, and better cosmetic effect. However, because of the small tumor size as well as the depth and uncertainty of the location of the tumor, laparoscopic localization of the lesion without tactile sensation is difficult. Laparoscopic ultrasonography can detect about 90% of insulinomas, and its sensitivity is comparable to that of manual palpation along with intraoperative ultrasonography during open surgery; thus, it ensures the feasibility of laparoscopic management of insulinoma and reinforces its advantage as a minimally invasive procedure. Laparoscopic ultrasonography is vital for the localization of insulinomas and characterization of the surrounding pancreatic structure and should, therefore, be considered an integral part of the laparoscopic management of insulinoma.

Intraoperative ultrasonography: a useful tool in retrolaparoscopic nephron-sparing surgery

OBJECTIVE

To evaluate the value of intraoperative laparoscopic ultrasonography (ILUS) in retrolaparoscopic nephron-sparing surgery.

METHODS

A total of 81 cases were studied during a 5-year period: 38 patients with a benign renal tumor who underwent enucleation of the tumor and 43 patients with a suspected malignant renal tumor who underwent wedge resection of the tumor. ILUS was used to evaluate renal perfusion, locate the tumor, precisely delineate the tumor border, characterize the tumor, and look for any suspected satellite renal masses.

RESULTS

All procedures were successful without conversion to open surgery. The mean operating time was 106 min for enucleation (range 70- 150 min) and 114 min for wedge resection (range 80- 235 min). The mean size of benign tumors was 4.02 cm and that of malignant tumors was 3.13 cm, and all margins were negative. An additional renal artery branch was detected in 11 patients. In 2 cases the operative procedure was changed based on the ILUS findings. No satellite lesion was found in any of the patients with malignant tumors.

CONCLUSIONS

ILUS provides significant benefit in retrolaparoscopic nephron-sparing surgery. In a number of situations, especially endogenic lesions, it is an essential surgical tool.

Solitary pelvic kidney encountered during laparoscopic colectomy

We report a case of solitary pelvic kidney encountered during laparoscopic colectomy. A 55-year-old man was admitted to undergo laparoscopic colectomy for an early sigmoid colon cancer, which had been detected after a polypectomy. The kidneys were not clearly visualized in their normal position by ultrasonography. During the operation, anomalous vessels in the presacral space and a mass covered with fatty tissue were identified. We converted the operation to a mini-laparotomy, and on performing intraoperative ultrasonography a solitary pelvic kidney was detected. An anterior resection was performed without operative complications. Laparoscopic ultrasonography (LUS) and hand-assisted laparoscopic surgery (HALS) should be considered as feasible adjuvants, when difficult situations arise during laparoscopic colectomy. In case of uncertainty about anatomical orientation or identification, it is prudent to convert to open surgery thereby preventing intraoperative complications such as injury to anomalous vessels or the ureter.

Laparoscopic adrenalectomy: balancing the operative indications with the technical advances

Laparoscopic adrenalectomy contributed significantly to reduction of morbidity and improvement of postoperative patient recovery time. The adoption of this technique had substantial impact on the management of adrenal incidentalomas. Although laparoscopic adrenalectomy should be in general avoided for known primary adrenal cancers, it is appropriate for metastasectomy of isolated adrenal metastatic disease.

Laparoscopic ultrasound: a survey of its current and future use, requirements, and integration with navigation technology

BACKGROUND

Laparoscopic ultrasound (LUS) increases surgical safety by allowing the surgeon to see beyond the organ surface, by visualizing vascular structures and by improving surgical precision of tumor resection. A questionnaire-based survey was used to investigate the current use and future expectations of LUS technology.

METHODS

A questionnaire consisting of 26 questions was distributed manually at four different conferences (60% at the European Association for Endoscopic Surgery (EAES) conference, Stockholm 2008). The answers were summarized with descriptive statistics and nonparametric tests at a significance level of 0.05.

RESULTS

The questionnaire was answered by 177 surgeons from 40 different countries (85% from Europe). Of these surgeons, 43% use ultrasound during laparoscopic procedures. Generally, more LUS users are found at university hospitals than at general community hospitals. Surgeons use LUS primarily in procedures related to the liver (67% of the surgeons who use LUS), but LUS also is used in other procedures related to the pancreas, biliary tract, and colon. In a 5-year perspective, 82% of surgeons believe in an increased use of LUS, and 79% of surgeons also think that the use of LUS combined with navigation technology will increase and that the most important requirements for such a system are good image quality, easy interpretation, and a high degree of precision.

CONCLUSIONS

Although the surgeons believe LUS has advantages, only 43% of the respondents reported using it. The surveyed surgeons were largely positive toward an increased use of LUS in a 5-year perspective and believe that LUS combined with navigation technology will contribute to improving the surgical precision of tumor resection.

Navigated ultrasound in laparoscopic surgery

Laparoscopic surgery is performed through small incisions that limit free sight and possibility to palpate organs. Although endoscopes provide an overview of organs inside the body, information beyond the surface of the organs is missing. Ultrasound can provide real-time essential information of inside organs, which is valuable for increased safety and accuracy in guidance of procedures. We have tested the use of 2D and 3D ultrasound combined with 3D CT data in a prototype navigation system. In our laboratory, micro-positioning sensors were integrated into a flexible intraoperative ultrasound probe, making it possible to measure the position and orientation of the real-time 2D ultrasound image as well as to perform freehand 3D ultrasound acquisitions. Furthermore, we also present a setup with the probe optically tracked from the shaft with the flexible part locked in one position. We evaluated the accuracy of the 3D laparoscopic ultrasound solution and obtained average values ranging from 1.6% to 3.6% volume deviation from the phantom specifications. Furthermore, we investigated the use of an electromagnetic tracking in the operating room. The results showed that the operating room setup disturbs the electromagnetic tracking signal by increasing the root mean square (RMS) distance error from 0.3 mm to 2.3 mm in the center of the measurement volume, but the surgical instruments and the ultrasound probe added no further inaccuracies. Tracked surgical tools, such as endoscopes, pointers, and probes, allowed surgeons to interactively control the display of both registered preoperative medical images, as well as intraoperatively acquired 3D ultrasound data, and have potential to increase the safety of guidance of surgical procedures.

Bilateral laparoscopic adrenalectomy for corticotrophin-dependent Cushing's syndrome: a review of the Mayo Clinic experience

BACKGROUND

There has been a rapid shift from open to laparoscopic approaches in adrenal surgery, but the safety and efficacy of bilateral laparoscopic adrenalectomy (BLA) in patients with corticotrophin (ACTH)-dependent Cushing's syndrome continues to be defined.

OBJECTIVE

Review outcomes in the largest series of patients reported to date undergoing BLA for ACTH-dependent Cushing's syndrome.

DESIGN

Retrospective review study.

PATIENTS

Between January of 1995 and October of 2006, BLA was attempted in 68 patients with ACTH-dependent Cushing's syndrome (26 ectopic ACTH syndrome; 42 persistent pituitary-dependent Cushing's syndrome following pituitary surgery).

MEASUREMENTS

Review of peri-operative morbidity and mortality, biochemical parameters and patient-reported symptom response from chart review and mailed questionnaire.

RESULTS

BLA was successfully completed in 59 of 68 patients (87%); nine (13%) required conversion to open adrenalectomy (OA). Intra-operative complications occurred in three patients (4.4%) (two BLA, one OA), and non-operative complications occurred in 11 (16%) patients (eight BLA, three OA). There were no peri-operative deaths. Median hospitalization was 5.5 days (range, 3-28) and 11.9 days (range, 4-29) for the BLA and OA groups, respectively. In patients with follow-up data available, all achieved biochemical resolution and at least partial clinical resolution of signs and symptoms associated with hypercortisolism. Resolution of hypertension, diabetes and obesity was achieved in 64%, 29% and 35% of patients carrying those diagnoses prior to surgery, respectively.

CONCLUSIONS

This study further supports the role of BLA as an effective treatment option for patients with ACTH-dependent Cushing's syndrome.

3-D ultrasound guidance of surgical robotics: a feasibility study

Laparoscopic ultrasound has seen increased use as a surgical aide in general, gynecological, and urological procedures. The application of real-time, three-dimensional (RT3D) ultrasound to these laparoscopic procedures may increase information available to the surgeon and serve as an additional intraoperative guidance tool. The integration of RT3D with recent advances in robotic surgery also can increase automation and ease of use. In this study, a 1-cm diameter probe for RT3D has been used laparoscopically for in vivo imaging of a canine. The probe, which operates at 5 MHz, was used to image the spleen, liver, and gall bladder as well as to guide surgical instruments. Furthermore, the three-dimensional (3-D) measurement system of the volumetric scanner used with this probe was tested as a guidance mechanism for a robotic linear motion system in order to simulate the feasibility of RT3D/robotic surgery integration. Using images acquired with the 3-D laparoscopic ultrasound device, coordinates were acquired by the scanner and used to direct a robotically controlled needle toward desired in vitro targets as well as targets in a post-mortem canine. The rms error for these measurements was 1.34 mm using optical alignment and 0.76 mm using ultrasound alignment.

Surgical robotics and image guided therapy in pediatric surgery: emerging and converging minimal access technologies

Minimal access surgery (MAS) is now commonplace in the armamentarium of the pediatric surgeon, and is being applied to a growing list of pediatric surgical diseases. Robot-assisted surgery and image guided therapy (IGT) have evolved as innovative minimal access approaches, and hold the promise of advancing MAS far beyond what is currently possible. The aims of this article are to describe the currently available robotic, and image guided therapy systems, review their present and potential applications, and discuss the future directions of these converging technologies.

Image-guided therapy and minimally invasive surgery in children: a merging future

Minimally invasive image-guided therapy for children, also known as pediatric interventional radiology (PIR), is a new and exciting field of medicine. Two key elements that helped the rapid evolution and dissemination of this specialty were the creation of devices appropriate for the pediatric population and the development of more cost-effective and minimally invasive techniques. Despite its clear advantages to children, many questions are raised regarding who should be performing these procedures. Unfortunately, this is a gray zone with no clear answer. Surgeons fear that interventional radiologists will take over additional aspects of the surgical/procedural spectrum. Interventional radiologists, on the other hand, struggle to avoid becoming highly specialized technicians rather than physicians who are responsible for complete care of their patients. In this article, we briefly discuss some of the current aspects of minimally invasive image-guided therapy in children and innovations that are expected to be incorporated into clinical practice in the near future. Then, we approach the current interspecialty battles over the control of this field and suggest some solutions to these issues. Finally, we propose the development of a generation of physicians with both surgical and imaging skills.

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.