Laparoscopic Probe Research Articles

Laparoscopic sentinel lymph node (SLN) versus extensive pelvic dissection for clinically localized prostate carcinoma

Lymph node metastasis is an important prognostic factor in prostate cancer (PC). The aim of this prospective study was to evaluate the accuracy of sentinel lymph node (SLN) biopsy by laparoscopy in staging locoregional patients with clinically localized PC. A transrectal ultrasound-guided injection of 0.3 ml/100 MBq (99m)Tc-sulphur rhenium colloid in each prostatic lobe was performed the day before surgery. Detection was performed intraoperatively with a laparoscopic probe (Gamma Sup CLERAD) followed by extensive resection. SLN counts were performed in vivo and confirmed ex vivo. Histological analysis was performed by haematoxylin-phloxine-saffron staining, followed by immunohistochemistry (IHC) if the SLN was free of metastasis. The study included 93 patients with PC at intermediate or high risk of lymph node metastases. The intraoperative detection rate was 93.5% (87/93). Nineteen patients had lymph node metastases, nine only in SLN. The false-negative rate was 10.5% (2/19). The internal iliac region was the primary metastatic site (43.3%). Metastatic sentinel nodes in the common iliac region beyond the ureteral junction were present in 13.3%. Limited or standard lymph node resection would have ignored 73.2 and 56.6% of lymph node metastases, respectively. Laparoscopy is suitable for broad identification of SLN metastasis, and targeted resection of these lymph nodes significantly limits the risk of extended surgical resection whilst maintaining the accuracy of the information.

Continuous-Wave Laser Stimulation of the Rat Prostate Cavernous Nerves Using a Compact and Inexpensive All Single Mode Optical Fiber System

Laser stimulation of the rat cavernous nerve (CN) recently has been demonstrated as an alternative to electrical stimulation for potential application in nerve mapping during nerve-sparing radical prostatectomy. Advantages include noncontact stimulation and improved spatial selectivity. Previous studies, however, have used large and/or expensive laser sources for stimulation. This study demonstrates the feasibility of optical stimulation of the rat CN, in vivo, using a compact, inexpensive all-single-mode fiberoptic system. A 1455-nm wavelength infrared diode laser beam was coupled into a 9-μm-core single-mode fiber for delivery through a 10F laparoscopic probe and used for laser stimulation of the CN in a total of eight rats, in vivo. Laser stimulation of the CN was observed at threshold temperatures of 41°C, with intracavernous pressure response times as short as 4 s, and magnitudes up to 50 mm Hg, compared with baselines of 10 mm Hg. This novel, all-single-mode-fiber laser nerve stimulation system introduces several advantages including: (1) lower cost laser; (2) more robust fiberoptic design, eliminating alignment and cleaning of bulk optical components; and (3) improved Gaussian spatial beam profile for simplified alignment of the laser beam with the nerve. With further development, laser nerve stimulation may be useful for identification and preservation of the CN during prostate cancer surgery.

Étude de faisabilité du ganglion sentinelle dans le cancer de la prostate par cœlioscopie : premiers résultats

Objectives The standard lymphadenectomy is currently a challenge in the management of prostate cancer. The aim of this prospective study was to evaluate the performance of the sentinel lymph node (SLN) by laparoscopy in patients with localized prostate cancer, candidates for local treatment. Patients and methods Patients were injected transrectal ultrasound-guided with 0.3 mL/100MBq 99 mTc-Sulfur rhenium colloid in each prostatic lobe, the day before surgery. Lymphoscintigraphy was performed after 2 hours. The detection was realized intraoperatively with a laparoscopic probe (Gamma Sup Clerad ®) followed by extensive dissection. Counts of SLN were performed in vivo and confirmed ex vivo. The histological analysis was performed by HPS staining and followed by immunochemistry if SLN was free. Results Seventy patients with carcinoma of the prostate at intermediate or high risk of lymph node metastases (D’Amico), PSA median 9.5 ng/mL [6–130], were included in the study. The lymphoscintigraphic detection rate was 94.2% (66/70) and intraoperative of 97.0% (68/70). Fourteen patients had lymph node metastases, six only in SLN. The false negative rate was 2/14 (14.0%). The internal iliac region is the first metastatic site (40.9%). Limited or standard lymph node dissection would have ignored respectively 72.7% and 59.0% of lymph node metastases. Conclusion The laparoscopy is adapted to a broad identification of SLN and targeted dissection of these lymph nodes significantly limits the risk of surgical extended dissection while maintaining the accuracy of the information.

Détection laparoscopique des ganglions sentinelles dans le cancer localisé de la prostate : résultats obtenus chez 70 premiers patients

The lymph node metastasis is an important prognostic factor in prostatic cancer. The aim of this prospective study was to evaluate the relevance of the sentinel lymph node biopsy by laparoscopy in staging locoregional patients with clinically localized PC. A transrectal ultrasound-guided injection by 0.3 mL/100 MBq (99m)Tc-sulfur rhenium colloid in each prostatic lobe was performed the day before surgery. The detection was realized intraoperatively with a laparoscopic probe (Clerad(®) Gamma Sup) followed by extensive dissection. Counts of SLN were performed in vivo and confirmed ex vivo. The histological analysis was performed by hematoxyline-phloxine-safran staining and followed by immunochemistry if SLN is free. Seventy patients with carcinoma of the prostate at intermediate or high risk of lymph node metastases were included. The intraoperative detection rate was 68/70 (97%). Fourteen patients had lymph node metastases, six only in SLN. The false negative rate was 2/14 (14%). The internal iliac region was the first metastatic site (40.9%). A metastatic sentinel node in common iliac region beyond the ureteral junction was present in 18.2%. A non-negligible sentinel metastatic region was the common iliac area (18.2%). Limited or standard lymph node dissection would have ignored respectively 72.7% and 59% of lymph node metastases. The laparoscopy is adapted to a broad identification of SLN and targeted dissection of these lymph nodes significantly limited the risk of surgical extended dissection while maintaining the accuracy of the information.

A Compact Laparoscopic Probe for Optical Stimulation of the Prostate Nerves

The cavernous nerves (CN) course along the prostate surface and are responsible for sexual function. Optical nerve stimulation (ONS) has recently been tested as a potential alternative to electrical nerve stimulation for identifying and preserving these delicate nerves during prostate cancer surgery. However, the optimal range of laser parameters for safe and consistent laser nerve stimulation is relatively narrow; low-level irradiation may not stimulate the nerve, while high-level irradiation may result in thermal damage to the nerve and loss of erectile function. The objective of this study is to design, build, and provide preliminary data on testing of a laparoscopic probe capable of delivering a collimated, flat-top spatial beam profile to the nerve surface for uniform, safe, and reproducible irradiation of the nerve. Chemical etching of the distal fiber optic tip in combination with an aspheric lens resulted in a 3.4-mm-OD laparoscopic probe capable of delivering a collimated 1-mm-diameter, flat-top laser beam over a working distance of about 20 mm. Successful ONS using this probe was observed in a rat prostate model, in vivo. Upon further testing, this probe may be useful for identifying and preserving the CN during laparoscopic nerve-sparing prostate cancer surgery.

A prototype hybrid intraoperative probe for ovarian cancer detection

A novel prototype intraoperative system combining positron detection and optical coherence tomography (OCT) imaging has been developed for early ovarian cancer detection. The probe employs eight plastic scintillating fiber tips for preferential detection of local positron activity surrounding a central scanning OCT fiber providing volumetric imaging of tissue structure in regions of high radiotracer uptake. Characterization measurements of positron sensitivity, spatial response, and position mapping are presented for Tl(204)/Cs(137) sources as well as 18F-FDG. In conjunction with co-registered frequency domain OCT measurements the results demonstrate the potential for a miniaturized laparoscopic probe offering simultaneous functional localization and structural imaging for improved early cancer detection.

Laparoscopic radioisotope-guided sentinel lymph node mapping and excision of the rectum—an experimental study

Patients with a low-risk T1 rectal carcinoma can undergo the therapy of a local excision. In these patients the lymph node (LN) status remains unknown. There is a potential risk of up to 7% for nodal metastasis. To investigate the possibility of using the sentinel lymph node (SLN) concept, an experimental study on pigs was undertaken. The objective was to laparoscopically identify and extract SLNs from the rectum using a radioisotope (RI). The experiment was conducted in 30 pigs, since the sample size calculation indicated that with 30 animals a two-sided 95% confidence interval for a single proportion using the large sample normal approximation would extend at most 0.107 from the observed proportion of 0.9. One milliliter of a mixture of the RI Technetium 99 m (Tc99 m) and patent blue V dye was administered in the rectum endoscopically and after the lapse of 1 h, we laparoscopically identified and excised all SLNs using a laparoscopic gamma camera probe. We found in all operated pigs (n = 30) at least one SLN (lymph node with highest measured counts per second (cps)). In mean we detected 1.6 SLN (range one to three SLNs). In 28 cases, the SLN concept was successful. Sensitivity for detecting SLNs was 93% (n = 28/30), the probe count rate ranged from 600-10,000 cps with a median of 3,800. Minimal invasive mapping and excision of SLN of the rectum using a RI is feasible. The sensitivity for detecting SLN was high (93%). The application of this procedure on humans seems to be possible.

The role of echo-laparoscopy in intra-operative diagnosis of duodeno-pancreatic diseases

Introduction: Laparoscopic inspection before pancreatic surgery for malignancy or benign disease is a widely accepted approach, and has been changing the surgical strategy in 20–50% of the patients, over the last ten years. The addition of intra-operative ultrasound to laparoscopy has recently further refined surgical judgment, allowing accurate definition of mesenteric axis infiltration, presence of enlarged lymphnodes, relationships of pancreatic cysts or nodules to the splenic vessels and Wirsung duct. All this information is vital for successful pancreatic surgery. Materials and methods: We hereby report our experience of 56 cases of pancreatic diseases (malignant n.42, benign n.14) treated at the Dept. of General Surgery, Monaldi Hospital, Naples, Italy, in the years 2002–2007.. Among malignant pathologies, 11 (19.6%) were judged non radically resectable and were scheduled for either palliative surgery, endoscopic or trans-hepatic stenting. All patients were studied with pre-operative ultrasound, triphasic spiral CT, tumor markers. Intra-operative echo-laparoscopy was performed for surgical staging, by means of an Aloka SSD-5500 equipment (Aloka Co. LTD, Tokyo, Japan), provided with linear laparoscopic multifrequency flexible probe. Results: Out of 31 pancreatic tumors selected for radical surgery, 7 (22.6%) were excluded by echo-laparoscopy, either because of mesenteric vein infiltration or for the presence of celiac and/or para-aortic nodes or hepatic micro-metastatic lesions. Among benign pathologies, 5 were pancreatic pseudocysts, 5 cystadenomas (serous n.2, mucinous n.3), 2 insulinomas, and 2 duodenal GIST. In all these cases echo-laparoscopy gave relevant information on anatomic relationships of the lesions to splenic vessels and Wirsung duct, allowing guidance for intra-operative fluid aspiration in 3 pseudocysts and 2 cystadenomas. In the 2 cases of duodenal tumors it defined resectability as related to Vater papilla. Conclusions: In our experience echo-laparoscopy determined surgical attitude in 11 patients (19.6%), including 7 non resectable malignant tumors, 2 insulinomas and 2 GIST tumors; it confirmed resectability in 24 malignancies (42.8%) and helped to better define diagnosis in 5 pseudocysts and 5 cystadenomas.

Liver resection with intraoperative and laparoscopic ultrasound: report of 32 cases

Careful staging of hepatic tumors is mandatory for appropriate selection of patients for liver resection. Number and relationships of liver nodules are issues of utmost importance when evaluating resectability. Sensitivity of preoperative imaging for secondary lesions has been reported between 60-75% with spiral contrast-enhanced computed cosmography (CT), 80-85% with magnetic resonance imaging (MRI), and 90-96% with intraoperative ultrasound (IOUS). Also for primary lesions IOUS has been reported to allow detection of liver nodules in 17% and modify surgical strategy in 10%. The aim of this study was to point out the usefulness of open (IOUS) and laparoscopic (LIOUS) ultrasound in patients undergoing hepatic surgery for liver tumors. In the years 2004-2006, 50 patients, mean age 66 years (range 44-76 years) were evaluated for resective surgery at the General Surgery Department of Monaldi Hospital, Naples, Italy. All of them were studied with biphasic CT and transabdominal ultrasound. Eighteen (36%) were judged unresectable. The others were scheduled for laparoscopy and LIOUS, by means of an ALOKA SSD-5500 (Aloka Co. Ltd. Tokyo, Japan), equipped with linear flexible tip laparoscopic probe. Six patients (18.7%) were excluded because of pathology diffusion; 26 (81.3%) were resected, using ultrasonic shears (Harmonic ACE, Ethicon Endo-Surgery, Cincinnati Oh., USA) for parenchymal transection, 3 (11.5%) laparoscopically and 23 (88.5%) after laparotomy. IOUS was repeated in the latter group. LIOUS spared useless laparotomies in six patients (18.7%) and, coupled with IOUS, found undetected nodes in five patients (19.2%), changing surgical strategy in three patients (11.5%). In our experience LIUOS and IOUS proved to be of utmost importance both in the selection of patients for resective surgery and in planning surgical approach. Ultrasonic shears device and systematic pedicle clamping sped up resection time and reduced intraoperative bleeding.

The role of echo-laparoscopy in abdominal surgery: five years’ experience in a dedicated center

For more than 20 years intraoperative ultrasonography (IOUS) has been considered an important diagnostic tool in abdominal surgery. In the last few years, with the spread of laparoscopic surgery, echo-laparoscopy (LIOUS) has gradually replaced open ultrasonography, aiming to achieve similar results. LIOUS was performed using an ALOKA 5.500 device, provided with a linear flexible laparoscopic probe that was compatible with a 10-mm port. IOUS was performed by means of a linear side-view, T-shaped or microconvex probe. The probes were sterilized with hydrogen peroxide. No water bath was used during the surgical examination, but full contact of the probe with the surface of the involved organ was always attempted. From 2001 to 2005, 36 liver resections, 40 pancreas procedures, 203 procedures for suspected common bile duct calculi, 541 colon and 82 stomach resections, and 82 adrenal surgery procedures were performed. IOUS or LIOUS was performed in 432 patients (43.8%). All livers and pancreases underwent intraoperative ultrasound, while biliary, colonic, gastric, and adrenal pathologies were selectively studied when there were doubts about the location and extension of the disease. IOUS and LIOUS were valuable diagnostic procedures, supplying relevant clinical information in 65.1% of the patients and modifying the surgical approach in 17.2%. LIOUS was used instead of cholangiography to study bile ducts when lythiasis was suspected, achieving high diagnostic specificity (98%) and accuracy (100%). Surgical anatomy of the bile ducts was correctly identified by LIOUS in every case. In our experience IOUS and LIOUS were of the utmost importance in better defining staging of disease, infiltration of neighboring structures, number and size of nodular lesions, and anatomy of the hepatic pedicle and intrahepatic structures, thus making it possible to more accurately plan surgical procedures.

Laparoscopic partial kidney ablation with high intensity focused ultrasound.

High intensity focused ultrasound has been performed for transrectal and extracorporeal thermal ablation of tissues. We developed and tested a laparoscopic probe that allows real-time ultrasound imaging during partial renal ablation using high intensity focused ultrasound. A Sonablate 200 (Focus Surgery, Indianapolis, Indiana) high intensity focused ultrasound system with a modified 18 mm. laparoscopic probe was used in all experiments. In 13 Yucatan mini-pigs a 5Fr ureteral catheter was inserted into the renal pelvis and 10 cc air were instilled into the collecting system. The kidney was laparoscopically dissected, the high intensity focused ultrasound probe was inserted through a 33 mm. laparoscopic port and the targeted renal pole was treated. Renal lesions were created in 12 of 13 treated kidneys under real-time ultrasound visualization. Median operative time was 180 minutes, average high intensity focused ultrasound activation time was 18.3 minutes and lesion size was 23 x 17 x 11 mm. At 4 and 14 days 4 (acute group) and 6 (subacute group) animals were available for renal functional and anatomical evaluation, respectively. No difference in renal function was seen in treated and untreated kidneys. Pathological examination at 14 days revealed homogenous and complete tissue necrosis throughout the whole volume of the lesion with sharp demarcation from adjacent normal tissue. We were able to refine a probe for laparoscopic high intensity focused ultrasound delivery capable of simultaneous ultrasound imaging. Partial renal ablation using this probe is feasible and safe, and resulted in homogenous, complete and reproducible lesions.

Usefulness of sentinel lymph node detection in early stages of cervical cancer

Sentinel lymph node (SLN) mapping in combination with surgical biopsy is an emerging technique for use in the early stages of cervical cancer. The purpose of this study was to evaluate the technique in a series of 40 consecutive women with early stage cervical cancer. Forty patients with early stage cervical cancer [FIGO stage IA2 (2), IB1 (34), IB2 (1) or IIA (3)] were referred for radical hysterectomy with pelvic lymphadenectomy. Patients were submitted to preoperative lymphoscintigraphy (four 99mTc-nanocolloid injections around the tumour) and intraoperative SLN detection. Hand-held or laparoscopic gamma probes were used to locate SLNs during surgery. The mean number of SLNs was 2.5 per patient (interiliac 49%, external iliac 19%). Of the total of 99 SLNs, six, in four women, showed metastases (all 68 non-SLNs removed were negative). In the other 36 patients, all the removed lymph nodes (sentinel and non-sentinel) were negative (0% false negative rate). During the follow-up (median 25 months), only two patients presented distant metastases: one died 6 months after surgery (two of three SLNs positive, both hot and blue), while the second patient is alive 4 years after surgery (lung metastasis, no isotope drainage, negative blue SLN). The survival rate was 95% and disease-free survival, 97%. SLN surgical biopsy based on lymphoscintigraphy and blue dye is a feasible and useful technique to avoid lymph node dissection in the early stages of cervical cancer. It has a high negative predictive value, can be incorporated into clinical routine (laparoscopy or open surgery) and is close to achieving validation in this setting.

Laparoscopic Sentinel Lymph Node Mapping for Early Gastric Cancer

Sentinel lymph node (SLN) is known as the first possible site of metastasis along the route of lymphatic drainage from the primary cancerous lesion [1]. SLN mapping has been a focus of attention in management of various solid tumors to establish individualized minimally invasive surgery. In the fields of breast cancer and melanoma, several multicentric prospective randomized control trials for SLN biopsy are ongoing, and less invasive modified surgical approaches based on the SLN status have already been put into practice. However, the application of the SLN concept for gastrointestinal (GI) malignancies was not recognized until late 1990s because of high incidence of so-called skip metastasis. From the reports in recent years, we found that socalled skip metastases in GI cancers are attributed to the aberrant lymphatic drainage from the GI tract and the most of so-called skip metastases occurred in SLNs [2, 3]. Despite the multidirectional and complicated lymphatic flow from gastric mucosa, the anatomical situation of the stomach is better suited for SLN mapping than that of organs that are embedded in closed spaces, such as the esophagus and rectum. In particular, clinically T1N0 gastric cancer seems to be a good entity for which to try to modify the therapeutic approach. Several studies supporting the validity of the SLN concept for gastric cancers have been reported in the past 5 years in settings of open surgery [4,5,6]. Two major largescale clinical trials of SLN mapping for gastric cancer in open surgery have been started in Japan. The next important issue in this field is the introduction of laparoscopic SLN mapping for early gastric cancer, to establish novel minimally invasive surgery. Laparoscopic modified surgery based on SLN status would be the goal of a minimally invasive approach for pathologically nodenegative early gastric cancer. In this issue of World Journal of Surgery, Tonouchi and colleagues present a result of laparoscopic lymphatic mapping and SLN biopsy for early gastric cancer. It is reasonable to employ the dual-tracer method with blue dye and radioactive tracer for detection of SLNs in this study. Although there are several favorable reports of dye-guided SLN mapping for gastric cancer in open surgery, laparoscopic dye-guided SLN detection for gastric cancer is not feasible. Fast transit of blue dye (5–15 min for diffusion) is a restriction of dye-guided laparoscopic detection of multidirectional SLNs of gastric cancer. Technical errors using the single mapping agent approach are reduced by adding a different approach for lymphatic mapping. The radio-guided method allows us to confirm the complete harvest of SLNs with multidirectional and widespread distribution by gamma probing while the dye procedure enables us to perform real-time observation of the visualized lymphatic vessels. Therefore, we recommend a combination of dye and radioguided methods for systematic lymphatic mapping of gastric cancer as an optimal procedure at this moment. In the present study, the authors reported the case of a false negative study that resulted from a detection error [7]. Although the SLN concept was valid (the metastatic node was radioactive) in this case, the radioactive SLN was missed by laparoscopic gamma probing due to the shine-through effect. As shown in the article by Tonouchi, we have to pay attention to the remaining issues in laparoscopic application of this technology. Laparoscopic gamma probing is still under development, and there are several technical and material limitations. Available rigid-type laparoscopic gamma probes are fixed by entry-trocar, and the freedom to search for SLN and to avoid the shine-through effect from the injection site is seriously restricted. As we have seen several breakthroughs in the field of endoscopic surgery, development of new devices may provide a new frontier of this technology. Limitation of the sensitivity of intraoperative histological examination is another serious problem that can lead to false-negative studyies [8]. After overcoming these remaining issues, laparoscopic SLN mapping for early gastric cancer could be the leading model of individualized minimally invasive approaches for study of visceral solid tumors.

Sentinel node detection in a patient with recurrent endometrial cancer initially treated by hysterectomy and radiotherapy

This is the first article reporting sentinel node identification in a patient with endometrial cancer recurring in the vagina. A 79-year-old woman presented with a midvaginal recurrence of a stage IB, grade II endometroid carcinoma that had been treated 3 years earlier by a total abdominal hysterectomy, bilateral salpingoophorectomy, and pelvic lymph node sampling, followed by adjuvant brachytherapy to the vaginal vault. A staging examination under anesthetic was performed. Preoperatively, 60-MBq technetium-labeled nannocolloid was injected in the mucosa at 3, 6, 9, and 12 o'clock just adjacent to the tumor recurrence. Three sentinel nodes were detected, respectively, in the left obturator fossa (two) and the right external iliac region, using a laparoscopic probe (Navigator) and removed for pathological assessment. As they proved to be negative, the patient underwent a total vaginectomy, parametrectomy with pelvic lymphadenectomy. The tumor was completely removed, and all lymph nodes proved to be negative. The accuracy of sentinel node identification in patients with recurrent gynecological tumors needs further evaluation. This unique case shows that sentinel node detection is possible after previous radiotherapy and surgery and hopes to stimulate further research in this field.

Laparoscopic Partial Kidney Ablation With High Intensity Focused Ultrasound

High intensity focused ultrasound has been performed for transrectal and extracorporeal thermal ablation of tissues. We developed and tested a laparoscopic probe that allows real-time ultrasound imaging during partial renal ablation using high intensity focused ultrasound. A Sonablate 200 (Focus Surgery, Indianapolis, Indiana) high intensity focused ultrasound system with a modified 18 mm. laparoscopic probe was used in all experiments. In 13 Yucatan mini-pigs a 5Fr ureteral catheter was inserted into the renal pelvis and 10 cc air were instilled into the collecting system. The kidney was laparoscopically dissected, the high intensity focused ultrasound probe was inserted through a 33 mm. laparoscopic port and the targeted renal pole was treated. Renal lesions were created in 12 of 13 treated kidneys under real-time ultrasound visualization. Median operative time was 180 minutes, average high intensity focused ultrasound activation time was 18.3 minutes and lesion size was 23 x 17 x 11 mm. At 4 and 14 days 4 (acute group) and 6 (subacute group) animals were available for renal functional and anatomical evaluation, respectively. No difference in renal function was seen in treated and untreated kidneys. Pathological examination at 14 days revealed homogenous and complete tissue necrosis throughout the whole volume of the lesion with sharp demarcation from adjacent normal tissue. We were able to refine a probe for laparoscopic high intensity focused ultrasound delivery capable of simultaneous ultrasound imaging. Partial renal ablation using this probe is feasible and safe, and resulted in homogenous, complete and reproducible lesions.

Radioguided occult colonic lesion identification (ROCLI) during open and laparoscopic surgery.

Intraoperative localization, during open and laparoscopic surgery, of small, nonpalpable colonic lesions located at peculiar sites or with concurrent inflammatory bowel alterations (diverticulosis, perivisceritis) is often difficult. The aim of our work was to assess the validity of radioguided identification after preoperative labeling. Patients who were candidates for colon surgery for occult lesions that, because of their size and location, were assumed to be difficult to detect, underwent colonoscopy 1 to 2.5 hours before surgery. A small dose of labeled albumin macroaggregates was injected with a sclerotherapy needle into the subserosa underneath the lesion. Immediately following the injection the lesion was identified with a transcutaneously placed gamma detecting probe. Intraoperative tracer detection was performed either during open surgery or by means of a laparoscopic probe (detection time 3-5 mins). The position of the lesion was marked with a suture or with a clip. Surgery was performed according to the type of lesion to be treated. In our initial clinical experience 15 colon lesions were preoperatively marked in 14 patients and were subsequently detected during surgery (four under laparoscopy) with a gamma detecting probe. This technique allows highly accurate, fast, and inexpensive surgical localization of lesions without irradiation and without complications. Our experience shows that preoperative endoscopic marking of nonpalpable colon lesions with 99mTc-labeled albumin macroaggregates followed by intraoperative detection with a gamma probe is a useful clinical method that is highly accurate and without complications.

Laparoscopic partial kidney ablation using high-intensity focused ultrasound

A laparoscopic ultrasound probe was developed for image-guided high-intensity focused ultrasound (HIFU) ablation of renal tissue. The probe expands the application of a commercially available HIFU system (SonablateTM) to laparascopic operations. It consists of a 4-MHz focused rectangular HIFU piezoceramic transducer (30×10 mm, FL=30 mm) confocally coupled with a circular central element (8 mm in diameter) used for real-time pulse-echo imaging during treatment. Precise mechanical movements of the transducer enable it to treat targeted tissue volumes. The probe was fully characterized by measuring its electrical impedance, acoustic field, and total acoustic power output. Moreover, the acoustic field was simulated using an analytical model. The laparoscopic probe was able to generate acoustic power levels up to 35 W that correspond to focal intensities over 2200 W/cm2 in tissue, sufficient for tissue ablation through rapid temperature rise (>90<th>°C) and cavitation mechanisms. The probe was tested in an in vivo animal study in which 15 pigs were treated through a sterile laparoscopic procedure. A lesion with dimensions of 23×17×11 mm ±1 mm was successfully generated in the left kidney of each pig during a treatment time of less than 30 min. Histology results demonstrated homogeneous well-delineated lesions generated in the target region.

7107 Clinical significance of hepatocyte growth factor and portal blood flow as a parameter of hepatic function following cO2pneumoperitoneum in cirrhotic patients.

Background: Laparoscopic surgery under carbon dioxide (CO2) pneumoperitoneum has many benefits. However, little is known concerning the risks of CO2pneumoperitoneum for the patients with liver cirrhosis. Influence of CO2pneumoperitoneum for the cirrhotic patients was investigated by assessing hemodynamics of portal vein and change of cytokine. Material & Methods: Participants were cholelithiasis patients divided into two groups: Group I (with liver cirrhosis: LC, n=12), and Group II (without liver cirrhosis: Control, n=12). The cross section area of the portal vein trunk (S) and the velocity of the portal blood (V) were measured using a laparoscopic pulsed Doppler ultrasonic probe (Aloka Ind., Ltd., Tokyo, Japan) inserted through the epigastric trocar when the abdomen was insufflated to an intra-abdominal pressure (IAP) of 4mmHg to 15 mm Hg preoperatively. The mean portal blood flow Φ at each IAP was calculated from the measured variables of S and V. In addition, plasma level of hepatocyte growth factor (HGF), interleukin (IL)-6, IL-8, tumor necrosis factor (TNF) were measured during CO2pneumopeitoneum. Total bilirubin (Tbil), AST, ALT were measured at postoperative day 1(1POD). Results: Laparoscopic cholecystectomy was performed successfully without any complications in all cases. With increases in IAP, S and V value were significantly decreased only in the LC group. F value was also significantly decreased with elevation of IAP in the LC group. No significant differences in changes of IL-6, IL-8 and TNF value during the preoperative CO2pneumopeitoneum were found in both group, but only HGF showed significant differences in changes of IAP in LC group. HGF and F value in IAP of 15mmHg showed significant correlations with AST and ALT at 1POD. Conclusions: On the basis of these results, HGF and F value were considered to be a good indicator for evaluation of liver function and CO2pneumopeitoneum during laparoscopic surgery would be a deteriorating factor for the patients with liver cirrhosis.

Laparoscopic ultrasonography during conservative ovarian surgery.

Most surgery for benign ovarian mass is now performed laparoscopically. Our purpose was to evaluate the usefulness of laparoscopic ultrasonography (LUS) in these operations. Forty patients treated by laparoscopic extirpation of a benign ovarian tumor were examined perioperatively using an Aloka 7.5-MHz laparoscopic probe. Findings of preoperative vaginal and perioperative laparoscopic ultrasonography were compared with histologic diagnoses. The accuracy of LUS in localizing the tumor in the ovary and ensuring surgical radicalness was evaluated. LUS enabled correct diagnosis in 34/40 and vaginal ultrasonography in 27/40 cases. Localization of the tumor was possible by LUS in all and visually in 21 ovaries. In 2 patients a radical tumor extirpation was not possible without laparoscopic ultrasonographic guidance. Diagnostic accuracy in LUS is better than in vaginal ultrasonography. LUS facilitates exact tumor localization and can be useful in confirming the radicalness of operation.

Intraoperative abdominal ultrasonography.

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