Operative ultrasound in general surgery

Narrow-band Imaging Examination of Microvascular Architecture of Subcapsular Hepatic Tumors

BACKGROUND

Intraoperative ultrasonography is the golden standard method for evaluation of liver tumors during hepatectomy. However, in laparoscopic surgery, accurate assessment of tumors may be difficult, particularly if the lesion is located nearby the liver surface because of the challenges in handling the intraoperative ultrasound and the lack of tactile sensation. In this study, we demonstrate the preliminary results of examining the microvascular architecture of subcapsular hepatic tumors using laparoscopic narrow-band imaging (NBI) to distinguish between malignant and benign tumors.

MATERIALS AND METHODS

Thirty-five lesions were examined by NBI during laparoscopic hepatectomy for the presence of abnormal microvasculature on the liver surface in relation to hepatic tumors from January 2016 to August 2018. The microvascular findings were correlated with tumor localization and pathological diagnosis.

RESULTS

The 35 examined nodules included 11 hepatocellular carcinoma, 18 colorectal liver metastasis, and six benign nodules. The mean tumor diameter was 26.3 (3-70) mm, and the distance from the liver surface to the tumor was 0.5 (0-5) mm. Microvessels on the liver surface were clearly visualized by NBI, consistent with malignant tumor localization. The tumors were thoroughly examined for the presence of three pathological microvascular features (enlargement, tortuosity, and heterogeneity). Abnormal microvascular patterns were found in 90.9% of hepatocellular carcinoma and 77.8% of colorectal liver metastasis, whereas neither normal sites nor benign lesions displayed microvascular abnormality.

CONCLUSIONS

This study suggests that observing the microvessel image on the liver surface by NBI could be useful in tumor localization and differentiation between benign and malignant lesions.

Ecografía en cirugía general

La ecografía es un estudio de imágenes diagnósticas con una amplia historia de uso en todas las especialidades de la Medicina; su advenimiento ha ayudado al enfoque diagnóstico e, incluso, al abordaje terapéutico de los pacientes. Desde su origen en el siglo XIX con mediciones de la velocidad del sonido en el agua, hasta el desarrollo de las máquinas de ultrasonografía sustentadas en los avances de la tecnología, la física y la ingeniería, se ha utilizado de manera notable en la Medicina. No hay duda de que, en el campo de la Cirugía General, ha sido útil para el manejo de los pacientes con enfermedad abdominal. La tecnología ecográfica permite identificar las características de un órgano normal y, cuando este patrón se afecta, orienta sobre la causa o determina la enfermedad que puede estar produciendo la alteración. En la presente revisión, se hace un recuento histórico del nacimiento de la ecografía, su aplicación en el campo de la medicina y su utilidad para el cirujano general en diversas circunstancias de la práctica quirúrgica.

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.

Regenerative liver surgeries: the alphabet soup of emerging techniques

New surgical procedures taking advantage of the regenerative abilities of the liver are being introduced as potential curative therapies to these patients either to provide auxiliary support while the native liver recovers or undergoes hypertrophy. For patients with hepatocellular carcinoma outside of the Milan criteria or bilobar colorectal metastases liver transplantation is not an option. Fulminant hepatic failure can be treated but requires life-long immunosuppression. These complex surgical procedures require high quality and directed imaging.

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.

Current management of colorectal hepatic metastasis

In the USA, cancers of the colon and rectum are the third most common site of new cancer cases and cancer deaths. With improved screening and adjuvant therapy, the survival of patients has increased substantially over the last decade. However, patients with metastatic disease often have limited survival. Hepatic metastasis is one of the most frequent sites of metastatic disease. In fact, 35-55% of patients with colorectal cancer will develop hepatic metastasis at some time during the course of their disease. Patients who are able to undergo complete resection of their hepatic metastases have the best chance of long-term survival. The goal of hepatic resection is to achieve complete resection of all metastases with microscopically negative surgical margins while preserving sufficient hepatic parenchyma. Survival following hepatic resection of colorectal metastasis now approaches 35-50%. However, approximately 65% of patients will have a recurrence at 5 years. Increasingly chemotherapeutic agents are being offered in the preoperative setting prior to operation. At the time of operation, patients with extensive hepatic disease can sometimes be offered ablative therapies combined with resection or staged approaches. Modern management of hepatic colorectal metastases necessitates a multidisciplinary approach to effectively treat these patients and increase the number of patients who will benefit from resection.

Surgical therapy for colorectal metastases to the liver

Colorectal cancer is the fourth most common type of cancer in the West and the second leading cause of cancer-related deaths in the United States. Approximately 35 to 55% of patients with colorectal cancer develop hepatic metastases during the course of their disease. Surgical resection of colorectal liver metastases represents the only chance at potential cure, and long-term survival can be achieved in 35 to 58% of patients after resection. The goal of hepatic resection should be to resect all metastases with negative histologic margins while preserving sufficient functional hepatic parenchyma. In patients with extensive metastatic disease who would otherwise be unresectable, ablative approaches can be used instead of or combined with hepatic resection. The use of portal vein embolization and preoperative chemotherapy may also expand the population of patients who are candidates for surgical treatment. Despite these advances, many patients still experience a recurrence after hepatic resection. More active systemic chemotherapy agents are now available and are being increasingly employed as adjuvant therapy either before or after surgery. Modern treatment of colorectal liver metastasis requires a multidisciplinary approach in an effort to increase the number of patients who may benefit from surgical treatment of colorectal cancer liver metastasis.

Image-guidance for surgical procedures

Contemporary imaging modalities can now provide the surgeon with high quality three- and four-dimensional images depicting not only normal anatomy and pathology, but also vascularity and function. A key component of image-guided surgery (IGS) is the ability to register multi-modal pre-operative images to each other and to the patient. The other important component of IGS is the ability to track instruments in real time during the procedure and to display them as part of a realistic model of the operative volume. Stereoscopic, virtual- and augmented-reality techniques have been implemented to enhance the visualization and guidance process. For the most part, IGS relies on the assumption that the pre-operatively acquired images used to guide the surgery accurately represent the morphology of the tissue during the procedure. This assumption may not necessarily be valid, and so intra-operative real-time imaging using interventional MRI, ultrasound, video and electrophysiological recordings are often employed to ameliorate this situation. Although IGS is now in extensive routine clinical use in neurosurgery and is gaining ground in other surgical disciplines, there remain many drawbacks that must be overcome before it can be employed in more general minimally-invasive procedures. This review overviews the roots of IGS in neurosurgery, provides examples of its use outside the brain, discusses the infrastructure required for successful implementation of IGS approaches and outlines the challenges that must be overcome for IGS to advance further.

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.

Laparoscopic adrenalectomy for Conn's syndrome complicated by ipsilateral congenital pelvic kidney

A patient presented with hypertension, hypokalemia, and a 1.2-cm left adrenal tumor. Conn's syndrome was diagnosed, for which laparoscopic adrenalectomy is now the therapy of choice. This case was complicated by an ipsilateral ectopic pelvic kidney. A laparoscopic left adrenalectomy was performed via a lateral transabdominal approach. Without the usual anatomic landmark of the ipsilateral kidney, the left adrenal gland was difficult to identify, so intraoperative ultrasound was used to locate the lesion. Postoperatively, the patient's blood pressure and potassium normalized. This is the first documented report of a laparoscopic adrenalectomy performed for adrenal adenoma with the anatomic disruption of an ipsilateral pelvic kidney.

Intraoperative ultrasound

Intraoperative ultrasound (IOUS) can provide various diagnostic information that is otherwise not available, and can guide or assist various surgical procedures in real time. With refinement of equipment, IOUS is currently used in a wide variety of surgical operations,such as hepatobiliary, pancreatic, endocrine, cardiovascular,and neurologic surgery. Our overview of IOUS, including instrumentation,techniques, indications, advantages, disadvantages,and future perspective, is described in this article. Being safe, quick, accurate, and versatile intraoperatively, IOUS is a valuable technique that surgeons are recommended to master to improve intraoperative decision making and surgical procedures.

A new visualization technique for laparoscopic ultrasonography

BACKGROUND

Using laparoscopic ultrasonography (LUS) is challenging for both novice and experienced ultrasonographers. The major difficulty surgeons experience is understanding the orientation of the ultrasonography image. The purpose of this study was to assess whether providing surgeons with orientation information improves their ability to interpret LUS images.

METHODS

We performed a LUS examination on a 25-kg pig and simultaneously digitized video from the laparoscopic camera, the LUS, and a novel orientation system. From the video recordings, 12 different clips of intra-abdominal anatomy were prepared. Twenty surgeons (18 staff, 2 fellows) volunteered to participate in an experimental crossover study. Test subjects reviewed the LUS clips along with the laparoscopic video images and the orientation display. Controls reviewed the LUS clips with only the laparoscopic video images. Diagnostic accuracy was compared by using the odds ratio.

RESULTS

For all vessels, the orientation display improved the odds ratio for correctly identifying structures from 3.7 to 8.9 (P=.02). For arteries, the orientation display improved the odds ratio from 2.4 to 9.6 (P=.01). For veins, the orientation display improved the odds ratio from 4.4 to 13.6 (P=.04).

CONCLUSIONS

Providing orientation information significantly improves a surgeon's ability to interpret LUS images.

Ultrasound instrumentation

Ultrasound is used in all areas of general surgery and many surgical subspecialties. The surgeon with ultrasound skills brings a number of advantages to clinical practice, including the ability to view dynamic images that are far superior to the interpretation of static ultrasound images. However, to obtain optimal ultrasound images, the surgeon sonographer must know the equipment well. This article provides an overview of the various types of ultrasound instrumentation, their settings, their care, and their uses ina variety of clinical situations.

Utility of intraoperative liver ultrasound

Intraoperative ultrasound has become an essential tool for the surgeon in the field of hepatobiliary surgery. No preoperative study has been able to duplicate the sensitivity and specificity of IOUS in the identification of occult lesions. With recent improvements in technology, IOUS has now become an indispensable means of defining the extent of disease and respectability, and providing a guide to anatomic and nonanatomic hepatic resections and minimally invasive and percutaneous ablative techniques.

Análise evolutiva e perspectiva histórica da ultra-sonografia intra-operatória (USIO) nas afecções pancreáticas

A ultra-sonografia intra-operatória influencia a conduta cirúrgica em um número significante de pacientes operados por afecções malignas ou benignas. Ela constitui-se no método mais sensível para a detecção de pequenas lesões, especialmente no fígado e pâncreas. Nas cirurgias pancreáticas, a ultra-sonografia intra-operatória é importante na localização de tumores neuroendócrinos e na avaliação da ressecabilidade de adenocarcinomas. Ela também pode ser usada durante as cirurgias para pancreatite crônica. Os autores fazem uma revisão sobre a evolução da ultra-sonografia intra-operatória nas cirurgias pancreáticas desde o seu início até os dias atuais.

Image-guided surgery: from X-rays to virtual reality

Since the discovery of X-rays, medical imaging has played a major role in the guidance of surgical procedures. While medical imaging began with simple X-ray plates to indicate the presence of foreign objects within the human body, the advent of the computer has been a major factor in the recent development of this field. Imaging techniques have grown greatly in their sophistication and can now provide the surgeon with high quality three-dimensional images depicting not only the normal anatomy and pathology, but also vascularity and function. One key factor in the advances in Image-Guided Surgery (IGS) is the ability not only to register images derived from the various imaging modalities amongst themselves, but also to register them to the patient. The other crucial aspect of IGS is the ability to track instruments in real time during the procedure, and to portray them as part of a realistic model of the operative volume. Stereoscopic and virtual-reality techniques can usefully enhance the visualization process. IGS nevertheless relies heavily on the assumption that the images acquired prior to surgery, and upon which the surgical guidance is based, accurately represent the morphology of the tissue during the surgical procedure. In many instances this assumption is invalid, and intra-operative real-time imaging, using interventional MRI, Ultrasound, and electrophysiological recordings are often employed to overcome this limitation. Although now in extensive clinical use, IGS is often currently perceived as an intrusion into the operating room. It must evolve towards becoming a routine surgical tool, but this will only happen if natural and intuitive human interfaces are developed for these systems.

Impact of intraoperative sonography on resection and cryoablation of liver tumors

PURPOSE

We retrospectively analyzed the impact of intraoperative sonography (IOUS) on the management of patients referred for resection of liver tumors.

METHODS

Forty patients underwent IOUS with a 7-MHz curved-array sector transducer; in selected cases, a 5-MHz linear-array transducer attached to a color Doppler unit was also used. The number, size, and location of tumors on IOUS, including tumor proximity to or invasion of major vessels or invasion of the diaphragm, were compared to findings on preoperative imaging studies. The effect of these findings on surgical management was assessed. Unresectable lesions were treated by cryoablation under ultrasound guidance.

RESULTS

IOUS detected preoperatively unsuspected lesions in 7 patients (18%). Metastases suspected on CT arterial portography were ruled out in 2 patients (5%), and indeterminate lesions were diagnosed as cysts by IOUS in 2 other patients (5%). Vascular proximity or vascular or diaphragmatic invasion detected by IOUS rendered lesions unresectable in 4 patients (10%). Cryoablation under IOUS guidance and monitoring was attempted in 11 patients (28%) and performed successfully in 10.

CONCLUSIONS

IOUS changed the management in 38% of patients and guided cryoablation in 28% of patients. IOUS performed by an experienced sonologist is invaluable for the accurate assessment of liver tumor resectability; the detection of additional, preoperatively unknown lesions; and the guidance of cryoablation of unresectable tumors.

Laparoscopic ultrasound imaging of adrenal tumors during laparoscopic adrenalectomy

BACKGROUND

The purpose of this study was to determine the usefulness of laparoscopic ultrasound (LUS) during laparoscopic adrenalectomy (LA) and to define the ultrasound imaging characteristics of various adrenal tumors.

METHODS

LUS was utilized in 27 patients who underwent LA (including one bilateral adrenalectomy) from May 1994 to October 1998. Tumor size ranged from 1.0 to 5.5 cm (mean 3.3 cm), and a transabdominal lateral approach to LA was used.

RESULTS

LUS localized the adrenal gland and tumor in all 28 adrenalectomies and demonstrated the relationship of the tumor to the kidney and adjacent vascular structures (renal artery/vein and inferior vena cava). The adrenal vein was visualized sonographically in only six cases (21 %). Pheochromocytomas were mild to markedly heterogenous, whereas most aldosteronomas and cortical adenomas were homogenous. LUS provided useful information to the surgeon in 11 of 28 cases (39%) by: 1) localizing the adrenal gland and tumor and/or guiding the dissection; 2) demonstrating that tumors > or =4 cm were confined to the adrenal gland; and 3) investigating suspected pathology in other organs. Mean operating time for LUS was 10.9 min (range 5 to 24 min) and calculated hospital charges were $602.

CONCLUSIONS

LUS accurately localizes adrenal tumors, helps define their relationship to adjacent structures, and provides confirmation that larger tumors are amenable to laparoscopic resection. LUS is a useful adjunct to laparoscopic adrenalectomy in selected patients.

Intraoperative abdominal ultrasonography

BACKGROUND

Ultrasonography during abdominal surgery has been reported since the 1960s, but its use did not become widespread until the recent availability of high-frequency, high-resolution transducers. This review discusses the application of intraoperative ultrasonography to open and laparoscopic abdominal surgery.

METHODS

A literature search (Medline) was undertaken. All papers pertaining to the subject matter that were located were included in the review.

RESULTS

Intraoperative ultrasonography influences surgical strategy in up to 50 per cent of liver resections for malignancy. It is the single most sensitive technique for the detection of occult hepatic metastases at the time of primary colorectal resection. In pancreatic surgery, intraoperative ultrasonography is of value in the localization of islet cell tumours and in the assessment of resectability of adenocarcinoma. The technique may also have a role in staging laparoscopy, and in the operative management of kidney and gastrointestinal diseases.

CONCLUSION

Ultrasonography is an ideal operative tool as it is safe, reproducible and requires no special patient preparation or positioning. It should be regarded as an essential component of major hepatobiliary and pancreatic procedures. The recent availability of flexible laparoscopic probes is likely to lead to a similar impact on minimal access surgery.

History of intraoperative ultrasound

Intraoperative ultrasound (IOUS) using A-mode or non-real-time B-mode imaging started in the 1960s; however, it was not widely accepted mainly because of difficulty in image interpretation. In the late 1970s, IOUS became one of the topics in the surgical communities upon the introduction of high-frequency real-time B-mode ultrasound. Special probes for operative use were developed. In the 1980s, all over the world the use of IOUS spread to a variety of surgical fields, such as hepatobiliary pancreatic surgery, neurosurgery, and cardiovascular surgery. IOUS changed hepatic surgery dramatically because IOUS was the only modality that was capable of delineating and examining the interior of the liver during surgery. After 1990, color Doppler imaging and laparoscopic ultrasound were incorporated into IOUS. Currently, IOUS is considered an indispensable operative procedure for intraoperative decision-making and guidance of surgical procedures. For better surgical practice, education of surgeons in the use of ultrasound is the most important issue.

Surgeon-performed ultrasound: its use in clinical practice

OBJECTIVE

To highlight areas where surgeon-performed ultrasound (US) is an effective diagnostic and therapeutic tool.

SUMMARY BACKGROUND DATA

The success of US in trauma and technologic advances have enhanced the interest and ability of surgeons to perform their own US examinations.

METHODS

General surgeons perform US examinations of the thyroid gland, breast, gastrointestinal tract, peritoneal cavity (laparoscopy), and vascular system. Essentials of these examinations are discussed and a plan for educating surgical residents in US is outlined.

RESULTS

Focused assessment for the sonographic examination of the trauma patient, or FAST, is replacing central venous pressure measurements to detect hemopericardium and diagnostic peritoneal lavage to detect hemoperitoneum. Bedside US can be used to detect a pleural effusion so well in critically ill patients that lateral decubitus x-rays are rarely needed. US-directed biopsy of breast lesions is a common office procedure. Laparoscopic US allows tumor staging without formal celiotomy, and many hepatic and pancreatic surgical procedures include US as an adjunct. Endoscopic and endorectal US have added a new dimension to the assessment of many gastrointestinal lesions. Color flow duplex imaging and endoluminal US have significantly expanded the diagnostic and therapeutic aspects of vascular imaging. The training program developed at Emory University and Grady Memorial Hospital is offered as a model for educating surgical residents in US techniques.

CONCLUSIONS

US is a valuable addition to the general surgeon's diagnostic armamentarium and is rapidly becoming an integral part of the surgeon's clinical practice.

Laparoscopic and intraoperative ultrasound

OBJECTIVE

Intraoperative ultrasound has gradually expanded in the last two decades to a variety of surgical specialties and has gained an established role in many surgical procedures. Laparoscopic and thoracoscopic ultrasound are the latest modes of intraoperative sonography. They have been introduced mainly to overcome the two major drawbacks of laparoscopy, i.e. the capability of showing only the surface of the organs and the lack of manual palpation of the anatomical structures. We review and discuss the established and the most recent applications of intraoperative and laparoscopic ultrasound.

MATERIAL AND METHODS

The technology, new indications and results of intraoperative and laparoscopic ultrasound are reviewed. This review is based on the experience gained in our Institution during more than 500 surgical procedures and the analysis of the literature on the subject.

RESULTS

The yield of intraoperative and laparoscopic ultrasound consists in confirming preoperative studies and acquiring new data which would not be available otherwise. An important role of these techniques is determining the anatomy of the involved organs, thus providing a guidance for surgery. Both techniques have an important role in surgical decision-making, particularly with respect to hepatic, biliary and pancreatic malignancies. In some series the rate of major changes in the surgical strategy can be as high as 38%. A relatively new application of intraoperative ultrasound is the possibility to perform interstitial therapy of tumors at the time of the initial surgery. This can be useful, for example, in patients undergoing liver resection, when other unresectable lesions are found in a different segment or in the contralateral lobe. Finally, laparoscopic sonography has an important role in staging abdominal neoplasm, providing more information than preoperative imaging and laparoscopic exploration. This feature can be used to effectively stage gastrointestinal malignancies, pancreatic carcinoma, and abdominal lymphomas.

CONCLUSION

The application of intraoperative ultrasound will increase in the era of minimally access surgery and this will be dependent not only on technical improvements in ultrasound technology. Indeed, it may be expected that a variety of open procedures will be performed with videolaparoscopic monitoring and will need the guidance of laparoscopic sonography. In the future, the staging of abdominal neoplasm may be markedly improved by laparoscopy combined with laparoscopic ultrasound; however a cost-benefit analysis of these techniques and a comparison with preoperative tests should be carried out.

Intraoperative and laparoscopic ultrasound

Intraoperative ultrasound, whether during celiotomy or laparoscopy, plays an important role in assisting the surgeon in directing appropriate therapy for intra-abdominal diseases, particularly primary or metastatic malignancies involving the liver and primary malignancies of the pancreas and upper gastrointestinal tract. It is the most sensitive imaging technique for detecting small intraparenchymal lesions of the liver, pancreas, and other solid organs. Owing to its increased sensitivity over all commonly used preoperative imaging studies, it is responsible for changing the intraoperative treatment plan of these tumors in a significant percentage of cases. This is particularly true with respect to resectability. In the era of laparoscopic surgery, it replaces the surgeon's inability to palpate the liver and other organs during surgery. As surgeons use a laparoscopic approach with increasing frequency to treat intra-abdominal disease, they will have an increasing need to master the use of intraoperative ultrasound in order to render optimal care to their patients.

The role of intraoperative ultrasonography during laparoscopic adrenalectomy

BACKGROUND

The role of laparoscopic intraoperative ultrasonography (IOUS) in intraoperative decision making has grown rapidly in recent years. The purpose of this study was to evaluate its usefulness during laparoscopic adrenalectomy.

METHODS

Since 1995, laparoscopic ultrasonography has been used to evaluate the adrenal gland and surrounding organs in selective laparoscopic adrenalectomies. IOUS was performed in 19 of 114 laparoscopic adrenalectomies.

RESULTS

IOUS effected a change in management in 68% of these patients. IOUS displayed the location of the gland after a failed attempt at open resection; the adrenal vein, expediting control in four operations; no extraadrenal involvement by two large lesions (benign); vascular invasion in one tumor (carcinoma), prompting open resection; periadrenal invasion by one metastatic cancer and lymph node involvement in another; a 7 mm hyperaldosteronoma; no adenoma in two cases; bilateral hyperplasia; and a 14 cm cyst originating from the adrenal gland. IOUS facilitated partial adrenalectomy in two patients and revealed centrally located adenomas in two others requiring total adrenalectomy.

CONCLUSIONS

Laparoscopic IOUS during adrenal operation is valuable in selected cases. It is helpful to locate the gland and vein, confirm the presence or absence of abnormality, discern the resectability of large masses, and facilitate a partial adrenalectomy when desirable.