Standardize the surgical technique and clarify the oncologic significance of robotic D3-D4 lymphadenectomy for upper rectum and sigmoid colon cancer with clinically more than N2 lymph node metastasis.

BACKGROUND: The territory of D3-D4 lymphadenectomy for upper rectal and sigmoid colon cancer varies, and its oncological efficacy is unclear. This prospective study aimed to standardize the surgical technique of robotic D3-D4 lymphadenectomy and clarify its oncologic significance. METHODS: Patients with upper rectal or sigmoid colon cancer with clinically suspected more than N2 lymph node metastasis were prospectively recruited to undergo standardized robotic D3-D4 lymphadenectomy. Immediately postsurgery, the retrieved lymph nodes were mapped to five N3-N4 nodal stations: the inferior mesenteric artery, para-aorta, inferior vena cava, infra-renal vein, and common iliac vessels. Patients were stratified according to their nodal metastasis status to compare their clinicopathological data and overall survival. Univariate and multivariate analyses were performed to determine the relative prognostic significance of the five specific nodal stations. Surgical outcomes and functional recovery of the patients were assessed using the appropriate variables. RESULTS: A total of 104 patients who successfully completed the treatment protocol were assessed. The standardized D3-D4 lymph node dissection harvested sufficient lymph nodes (34.4±7.2) for a precise pathologic staging. Based on histopathological analysis, 28 patients were included in the N3-N4 nodal metastasis-negative group and 33, 34, and nine patients in the single-station, double-station, and triple-station nodal metastasis-positive groups, respectively. Survival analysis indicated no significant difference between the single-station nodal metastasis-positive and N3-N4 nodal metastasis-negative groups in the estimated 5-year survival rate [53.6% (95% CI: 0.3353-0.7000) vs. 71.18% (95% CI: 0.4863-0.8518), P=0.563], whereas patients with double-station or triple-station nodal metastatic disease had poor 5-year survival rates (24.76 and 22.22%), which were comparable to those of AJCC/UICC stage IV disease than those with single-station metastasis-positive disease. Univariate analysis showed that the metastatic status of the five nodal stations was comparable in predicting the overall survival; in contrast, multivariate analysis indicated that common iliac vessels and infra-renal vein were the only two statistically significant predictors (P<0.05) for overall survival. CONCLUSIONS: Using a robotic approach, D3-D4 lymph node dissection could be safely performed in a standardized manner to remove the relevant N3-N4 lymphatic basin en bloc, thereby providing significant survival benefits and precise pathological staging for patients. This study encourages further international prospective clinical trials to provide more solid evidence that would facilitate the optimization of surgery and revision of the current treatment guidelines for such a clinical conundrum.

Wearable mobile health device for monitoring postoperative ambulation among patients with colorectal cancer undergoing minimally invasive surgery: A prospective comparison study.

BACKGROUND: This study aimed to evaluate the feasibility of using mHealth devices for monitoring postoperative ambulation among patients with colorectal cancer undergoing minimally invasive surgery (MIS). METHODS: Patients with colorectal cancer undergoing MIS were prospectively recruited to wear mHealth devices for recording postoperative ambulation between October 2018 and January 2021. The primary outcome was the compliance by evaluating the weekly submission rate of step counts. The secondary outcome was the association of weekly step counts and postoperative length of stay. RESULTS: Of 107 eligible patients, 53 patients wore mHealth devices, whereas 54 patients did not. The average weekly submission rate was 72.6% for the first month after surgery. The total step counts <4000 or >10 000 in the postoperative week one were negatively associated with postoperative length of stay (ß = -2.874, p = 0.038). CONCLUSIONS: mHealth devices provide an objective assessment of postoperative ambulation among patients with colorectal cancer undergoing MIS. CLINICAL TRIAL REGISTRATION: NCT03277235.

Changing patterns and surgical outcomes of small bowel obstruction in the era of minimally invasive surgery for colorectal cancer.

INTRODUCTION: This study aimed to investigate whether the incidence, patterns, and surgical outcomes of small bowel obstruction (SBO) have changed in the era of minimally invasive surgery (MIS) for primary colorectal cancer (CRC). METHODS: Consecutive patients who underwent laparotomy for SBO were divided into MIS and traditional open surgery (TOS) groups based on the previous colorectal cancer operation technique used. The MIS group was selected from 1544 consecutive patients who underwent MIS as a treatment for primary CRCs between 2014 and 2022, while the TOS group was selected from 1604 consecutive patients who underwent TOS as a treatment for primary CRCs between 2004 and 2013. The demographics, clinicopathological features, and surgical outcomes were compared between the two groups. RESULTS: The SBO incidence in patients who underwent MIS for primary CRC was significantly lower than that in patients who underwent TOS (4.4%, n =68/1544 vs. 9.7%, n =156/1604, P <0.0001). Compared with the TOS group, the MIS group had significantly different ( P <0.0001) SBO patterns: adhesion (48.5 vs. 91.7%), internal herniation (23.5 vs. 2.6%), external herniation (11.8 vs. 1.9%), twisted bowel limbs (4.4 vs. 0.6%), ileal volvulus with pelvic floor adhesion (5.9 vs. 1.9%), and nonspecific external compression (5.9 vs. 1.3%). A subset analysis of patients with adhesive SBO (ASBO) showed that the MIS group tended to ( P <0.0001) have bands or simple adhesions (75.8%), whereas the TOS group predominantly had matted-type adhesions (59.4%). Furthermore, SBO in the MIS group had an acute (<3 months) or early (3-12 months) onset (64.7%), while that in the TOS group ( P <0.0001) had an intermediate or a late onset. When the surgical outcomes of SBO were evaluated, the TOS group had significantly more ( P <0.0001) blood loss and longer operation time; however, no significant difference was observed in the surgical morbidity/mortality (Clavien-Dindo classification ≧3, 11.8 vs. 14.1%, P =0.6367), hospitalization, and readmission rates between the two groups. Postoperative follow-up showed that the estimated 3-year (11.37 vs. 18.8%) and 6-year (25.54 vs. 67.4%) recurrence rates of SBO were significantly lower ( P =0.016) in the MIS group than in the TOS group. CONCLUSIONS: The wide adoption of MIS to treat primary CRC has led to a lower incidence, altered patterns, and reduced recurrence rates of SBO. Awareness of this new trend will help develop surgical techniques to prevent incomplete restoration of anatomical defects and bowel malalignments specifically associated with MIS for CRC, as well as facilitate timely and appropriate management of SBO complications whenever they occur.

Impact of positron-emission tomography on the surgical treatment of locoregionally recurrent colorectal cancer.

BACKGROUND: The effect of positron emission tomography (PET) on the surgical treatment of locoregionally recurrent colorectal cancer (LRRCRC) remains unclear and warrants further investigation. MATERIAL AND METHODS: A total of 193 patients with LRRCRC were identified from a prospectively maintained institutional database, of whom 134 LRRCRCs were deemed resectable and underwent resection with curative intent, whereas the remaining 59 LRRCRCs were unresectable. Patients with resectable LRRCRC were further classified according to whether recurrence was detected solely by PET (n = 35, PET-only group) or by a combination of computed tomography (CT)/magnetic resonance imaging (MRI) and PET (n = 99, CT/MRI/PET group). Clinicopathologic features, operative morbidity/mortality, and overall survival were compared between the patient groups based on long-term follow-up for at least 5 years. RESULTS: Patients in the PET-only group tended to have less extensive organ resection (p = 0.0074), less blood loss (p < 0.0001), and shorter operation time and hospitalization (p < 0.0001), but surgical complication and readmission rates were not significantly different (p > 0.05) compared with the CT/MRI/PET group. Although the PET-only group had significantly higher R0 resection rate (80 % vs. 54.55 %, p = 0.0079), they also had a higher risk (17.14 % vs. 2.02 %, p = 0.0011) of sham operation. The estimated 5-year and 10-year survival rates significantly decreased in order (p < 0.0001) from PET-only (85.71 % and 57.98 %) and CT/MRI/PET (41.41 % and 15.93 %) to unresectable group of patients (16.95 % and 1.88 %). Subset analysis of the CT/MRI/PET group indicated that PET improved surgical decision-making because 24 (24.2 %) LRRCRCs that manifested on CT/MRI as equivocal lesions were later confirmed by PET as resectable recurrences, while 18 (19.4 %) LRRCRCs that manifested on CT/MRI as resectable lesions were later diagnosed by PET as more disseminated unresectable recurrences and precluded futile surgery. CONCLUSION: PET alone can identify a subset (20.9 %) of LRRCRCs with less tumor burden for timely surgery; PET in combination with CT/MRI can better define the resectability of LRRCRCs. The positive impacts of PET can translate into better surgical outcomes, with enhanced safety and patient survival.

A Botanical Drug Extracted From Antrodia cinnamomea: A First-in-human Phase I Study in Healthy Volunteers.

LEAC-102 is an emerging drug extracted from the medicinal fungus Antrodia cinnamomea (AC), which is traditionally used to ameliorate fatigue and liver disorders arising from excessive alcohol consumption. AC has been used as a health product with an immunomodulatory function, but its anticancer effect has not been applied in clinical therapy as a drug. This first-in-human study examined the safety and tolerability of LEAC-102 as a new drug in healthy adults.This standard 3 + 3 dose-escalation study included 18 participants administered LEAC-102 at doses of 597.6, 1195.2, 1792.8, 2390.4, or 2988 mg/day for 1 month plus 7 days of safety follow-up. The maximum planned dose was 2988 mg. Dose-limiting toxicity (DLT) was monitored from the start of LEAC-102 administration up to the final visit. The dose of LEAC-102 was escalated to the subsequent cohort as long as there was no DLT in the previous cohort. Tolerability, clinical status, safety (by laboratory parameters), and adverse event occurrence were documented weekly during the treatment and 1 week after the conclusion of the treatment.All clinical biochemistry profiles were in the normal range, and no serious adverse effects were observed. The maximum tolerated dose of LEAC-102 was determined to be 2988 mg/day because one participant experienced urticaria. Additionally, our exploratory objectives revealed that LEAC-102 significantly elevated natural killer, natural killer T, and dendritic cells in a dose-dependent manner, activated effector T cells, and upregulated programmed cell death-1 expression.The outcomes suggested that LEAC-102 was well tolerated and safe in healthy adults and exhibited potential immunomodulatory function.Supplemental data for this article is available online at https://doi.org/10.1080/07315724.2022.2032868 .

Technical feasibility of robotic vs. laparoscopic surgery for locally advanced colorectal cancer invading the urinary bladder.

BACKGROUND: The aim of this study was to determine if robotic surgery can reproduce the technical advantages and oncologic outcomes of laparoscopic surgery for the treatment of locally advanced colorectal cancer invading the urinary bladder. METHODS: We retrospectively reviewed the prospectively maintained data of patients with locally advanced colorectal cancer invading the urinary bladder undergoing robotic or laparoscopic surgery between June 2006 and November 2020. Clinicopathologic features, surgical outcomes, and oncologic efficacy were compared between patient groups of robotic or laparoscopic surgery. All patients underwent surgery with the intent of R0 resection for the primary tumor. Major surgical complications were defined as Clavien-Dindo grade ≥ III. Multivariate regression analysis was performed to identify risk factors. RESULTS: A total of 41 patients (M:F = 32:9; median age: 63 [42-88] years) were analysed; 32 underwent laparoscopic surgery and 9 underwent robotic surgery. There was no statistically significant difference between the two groups in baseline demographic and clinicopathologic features. There were no significant differences in terms of mean operative time (353.24 vs. 387.33 min), mean blood loss (315.00 vs. 171.11 mL), mean number of lymph nodes harvested (27.16 vs. 23.50), R0 resection (89.7 vs. 66.7%), conversion (12.5 vs. 11.1%), major complication rate (9.4 vs. 22.2%), mean time to flatus passage (4.8 vs. 4.1 days), mean postoperative length of hospital stay (18.9 vs. 19.8 days), 5-year disease-free survival rate (64.6 vs. 62.5%) and overall survival rate (75.3 vs. 83.3%). Multivariate analysis showed that R1 resection was the only independent prognostic factor for reduced disease-free survival (hazard ratio 21.386; 95% confidence interval 1.991-229.723; p = 0.0115). CONCLUSIONS: Robotic surgery can reproduce the technical advantages and oncologic outcomes of laparoscopic surgery for the treatment of locally advanced colorectal cancer invading the urinary bladder. However, larger studies are mandatory to clarify the role of robotic surgery in such a scenario.

The necessity of abdominal drainage for patients with complicated appendicitis undergoing laparoscopic appendectomy: a retrospective cohort study.

BACKGROUND: This study aimed to evaluate the necessity of abdominal drainage after laparoscopic appendectomy in patients with complicated appendicitis. METHODS: Patients with acute appendicitis undergoing laparoscopic appendectomy at two hospitals between January 2014 and December 2018 were retrospectively included. Complicated appendicitis was defined as the American Association for the Surgery of Trauma (AAST) grade ≥ II. The patients were classified according to the AAST grade and the indwelling of abdominal drainage. The postoperative surgical outcomes and recovery were compared among patient groups to evaluate the impact of abdominal drainage for patients with complicated appendicitis undergoing laparoscopic appendectomy. RESULTS: A total of 1241 patients was retrospectively included. Among them, there were 820 patients with simple appendicitis (AAST grade I) and 421 patients with complicated appendicitis (AAST grade ≥ II). For complicated appendicitis, the drainage group (N = 192) tended to harbor more overall complications, intra-abdominal abscess formation, time to resume a soft diet, and the postoperative length of hospitalization (P = 0.0000 for all). Multivariate logistic regression confirmed that abdominal drainage increased the risk of overall complications [Odds ratio (OR) 2.439; 95% confidence interval (CI) 1.597-3.726; P ≤ 0.0001] and failed to decrease the risk of intra-abdominal abscess formation (OR 1.655; 95% CI 0.487-5.616; P = 0.4193). Multivariate linear regression analysis also showed that the drainage group harbored longer postoperative length of hospitalization (Coefficients: 20.697; 95% CI 15.251-26.143; P < 0.0001) and time to resume a soft diet (Coefficients: 45.899; 95% CI 34.502-57.297; P < 0.0001). CONCLUSIONS: Abdominal drainage did not prevent overall complications in patients with complicated appendicitis; paradoxically, it delayed the convalescence. Our results discourage the routine use of abdominal drainage and suggest that abdominal drainage should be performed sparingly.

Ovarian mucinous cystadenoma with a mural nodule of osteosarcoma: A case report.

OBJECTIVE: Osteosarcoma as a mural nodule in the ovary is extremely rare. We aimed to describe a case of a mural nodule with features of an osteosarcoma arising in an ovarian mucinous cystadenoma. CASE REPORT: The 65-year-old woman presented with progressive abdominal swelling and poor intake. Image studies showed a huge (diameter, >30 cm) intra-abdominal multiloculated cystic lesion, suspected to be an ovarian tumor. She underwent unilateral salpingo-oophorectomy with no postoperative adjuvant therapy. She was disease-free at 16-month follow-up. CONCLUSION: Osteosarcoma presenting as a primary ovarian neoplasm is rare, either as a pure osteosarcoma or arising from a teratoma. However, two osteosarcoma cases occurring arising from a mural nodule in an ovarian mucinous neoplasm have been reported. There is no consensus regarding the treatment strategy for osteosarcomatous mural nodules in mucinous tumors because of its rarity. More case studies are needed before its pathogenesis can be fully understood.

Downstaged ypT0-2N0 rectal cancer after neoadjuvant chemoradiation therapy may not need adjuvant chemotherapy: a retrospective cohort study.

PURPOSE: Current guidelines suggest that adjuvant chemotherapy (AC) be administered to all locally advanced (clinically T3-4 or N-positivity) rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT) and radical surgical resection regardless of the final pathological staging (yp staging). This study aimed to evaluate the necessity of AC for ypT0-2N0 rectal cancer. METHODS: Patients with ypT0-2N0 rectal cancer, who received nCRT and radical surgical resection, were recruited retrospectively at a university hospital. The main outcome was to evaluate the 5-year overall survival (OS) and disease-free survival (DFS) between ypT0-2N0 rectal cancer patients with AC and those without AC. We also identified potential independent prognostic factors associated with poor outcomes. RESULTS: One hundred and ten ypT0-2N0 rectal cancer patients (ypT0: n = 6; ypT1: n = 44; ypT2: n = 60) were followed up for a median of 60 months. No significant difference was observed in DFS and 5-year OS between patients with AC and those without AC. The risk of recurrence was associated with the postoperative pathological staging (0% with ypT0, 2.4% with ypT1, and 10% with ypT2). In the multivariate analysis, retrieval of < 12 lymph nodes was an independent favorable prognostic factor, which correlated with a higher OS (HR: 2.263; 95% CI: 1.093-4.687, P = 0.028). Intra-tumor lymphovascular and perineural invasion were poor prognostic markers for shorter DFS (HR: 5.940; 95% CI: 1.150-30.696, P = 0.033). CONCLUSION: Postoperative AC is not required for patients with ypT0-2N0 rectal cancer downstaged by nCRT, especially in those without poor prognostic factors.

Applicability of minimally invasive surgery for clinically T4 colorectal cancer.

The role of minimally invasive surgery (MIS) to treat clinically T4 (cT4) colorectal cancer (CRC) remains uncertain and deserves further investigation. A retrospective cohort study was conducted between September 2006 and March 2019 recruiting patients diagnosed as cT4 CRC and undergoing MIS at a university hospital and its branch. Patients' demography, clinicopathology, surgical and oncological outcomes, and radicality were analyzed. A total of 128 patients were recruited with an average follow-up period of 33.8 months. The median time to soft diet was 6 days, and the median postoperative hospitalization periods was 11 days. The conversion and complication (Clavien-Dindo classification ≥ II) rates were 7.8% and 27.3%, respectively. The 30-day mortality was 0.78%. R0 resection rate was 92.2% for cT4M0 and 88.6% for pT4M0 patients. For cT4 CRC patients, the disease-free survival and 3-year overall survival were 86.1% and 86.8% for stage II, 54.1% and 57.9% for stage III, and 10.8% and 17.8% for stage IV. With acceptable conversion, complication and mortality rate, MIS may achieve satisfactory R0 resection rate and thus lead to good oncological outcomes for selected patients with cT4 CRC.

Is single-incision laparoscopic appendectomy suitable for complicated appendicitis? A comparative analysis with standard multiport laparoscopic appendectomy.

BACKGROUND: Despite emerging evidences on the feasibility and efficacy of single-incision laparoscopic appendectomy (SILA) for managing simple appendicitis, advancing its use for treating complicated appendicitis remains unwarranted. This study aimed to evaluate the surgical outcome of SILA compared with that of standard multiport laparoscopic appendectomy (MPLA) in the management of complicated appendicitis. METHODS: Between July 2013 and September 2017, 40 patients who underwent SILA and 150 patients who underwent MPLA for the treatment of complicated appendicitis, defined as AAST grades II-V, were recruited for this study. The demographic characteristics, intraoperative and recovery parameters were retrospectively recorded. No routine drainage was placed in the SILA group. RESULTS: SILA was smoothly performed without requiring conversion to MPLA. No significant difference was observed between the 2 groups in demography and preoperative severity. The operation duration was approximately 8 min shorter in the SILA group than in the MPLA group, without a statistical difference (60.03 ± 21.01 vs. 68.04 ± 32.03 min, p = 0.222). The recovery parameters, including soft diet intake and postoperative hospitalization, were more favorable in the SILA group (p < 0.001). Despite the absence of routine drainage in the SILA group, only 1 patient developed an intra-abdominal hematoma necessitating further computed tomography-guided drainage. CONCLUSION: SILA is safe and feasible for the management of complicated appendicitis. SILA had non-inferior results to MPLA in terms of time to resume oral intake and postoperative hospital stay. Furthermore, this study posted a question on the concept of routine postoperative drainage in complicated appendicitis.

The occurrence of primary hepatic adenoma in deceased donor renal transplant recipient.

MAIN FINDINGS: We reported a case of new-onset, multi-focal hepatic adenoma in an 18 year-old man with no classic risk factors occurring forty months after a renal transplant from a cadaver donor. Histopathology of the adenoma was examined and genotype and phenotype were also analyzed. Histopathologic examination of the adenoma showed no malignancy. Genotype and phenotype analysis revealed no HNF1α or ß-catenin gene mutations and no inflammatory infiltration. The patient was well and disease-free postoperatively. CASE HYPOTHESIS: Hepatic adenoma occurs mostly in those taking oral contraceptives or androgenic-anabolic steroids or in those with hereditary diseases. Hepatic adenoma in a renal transplant recipient is rare and has only been reported in one case with glycogen storage disease type Ia. Immunosuppressive treatment might have contributed to the development of the neoplasm. PROMISING FUTURE IMPLICATIONS: Although malignant change occurs most often in ß-catenin gene mutation hepatic adenoma, surgical resection of the adenoma in a patient under immunosuppressive therapy should be considered in order to avoid the possibility of malignant transformation or hemorrhagic rupture.

The Occurrence of Primary Hepatic Adenoma in Deceased Donor Renal Transplant Recipient

Main findings: We reported a case of new-onset, multi-focal hepatic adenoma in an 18 year-old man with no classic risk factors occurring forty months after a renal transplant from a cadaver donor. Histopathology of the adenoma was examined and genotype and phenotype were also analyzed. Histopathologic examination of the adenoma showed no malignancy. Genotype and phenotype analysis revealed no HNF1α or β-catenin gene mutations and no inflammatory infiltration. The patient was well and disease-free postoperatively. Case hypothesis: Hepatic adenoma occurs mostly in those taking oral contraceptives or androgenic-anabolic steroids or in those with hereditary diseases. Hepatic adenoma in a renal transplant recipient is rare and has only been reported in one case with glycogen storage disease type Ia. Immunosuppressive treatment might have contributed to the development of the neoplasm. Promising future implications: Although malignant change occurs most often in β-catenin gene mutation hepatic adenoma, surgical resection of the adenoma in a patient under immunosuppressive therapy should be considered in order to avoid the possibility of malignant transformation or hemorrhagic rupture. .

Learning curve of single-port laparoscopic appendectomy for noncomplicated acute appendicitis: a preliminary analysis compared with conventional laparoscopic appendectomy.

BACKGROUND: The aim of this study was to delineate the learning curve of single-port laparoscopic appendectomy for noncomplicated appendicitis. PATIENTS AND METHODS: Thirty patients who underwent single-port laparoscopic appendectomy between July 2009 and June 2010 were compared retrospectively with 30 prior consecutive patients who underwent surgery in the three-port manner. Operative duration, number of conversions, time to resumption of oral intake, length of hospital stay, and complications were used as the indicators of the learning curve. RESULTS: Demographics were similar between the single-port and three-port groups. A significant decrease in operative duration was noted after a surgical experience of 10 patients. An operative duration equivalent to that of the conventional three-port method could be achieved after 30 cases. CONCLUSIONS: Single-port laparoscopic appendectomy is a safe and feasible procedure. The learning curve could be overcome safely without major complications. Our preliminary analysis showed that 30 cases are sufficient to achieve an equivalent operative duration compared with conventional three-port laparoscopic appendectomy.

Laparoscopic resection for submucosal tumors near the esophagogastric junction: feasibility and short-term outcome.

BACKGROUND: Minimally invasive surgery has proved to be effective and efficient in the management of gastric submucosal tumors (SMT). However, confronting a SMT near the esophagogastric junction (EGJ) is still challenging because of the potentially devastating risks of stenosis or leakage. This study evaluated the safety, feasibility, and oncological efficacy of laparoscopic resection for SMTs located near the EGJ. METHODS: From December 2008 to November 2011, we enrolled a total of 19 patients diagnosed with gastric SMTs located near the EGJ who underwent laparoscopic surgery. The clinicopathological characteristics and surgical outcomes of the 19 patients were recorded and reviewed retrospectively. RESULTS: All 19 patients underwent laparoscopic resections of their gastric SMTs without complications during the study period. There were 9 men and 10 women, with a mean age of 63.3 ± 15.1 years (range 33-86 years). The operative duration was 187.8 ± 58.9 minutes (range 90-310 minutes). Intraoperative localization included endoscopy (n = 3), tattooing (n = 2), and combined modalities (n = 1). The exogastric (n = 12) and transgastric methods (n = 7) were used. The histopathology showed 10 gastrointestinal stromal tumors, 7 leiomyomas, 1 hyperplastic polyp, and 1 lipoma. The postoperative courses for all cases were uneventful. The mean follow-up period was 16.7 ± 9.4 months, with no recurrence noted. CONCLUSIONS: Laparoscopic resections for gastric SMTs near the EGJ are safe and feasible, with satisfactory oncological outcomes in the short term.

Gasless laparoscopy-assisted surgery for intraabdominal/retroperitoneal tumor of unknown origin: a bridge between total laparoscopic surgery and conventional open surgery.

INTRODUCTION: Gasless laparoscopy-assisted surgery has been utilized in many abdominal diseases, and it has been proved to be effective and efficient compared with conventional open surgery. The study was conducted to evaluate the efficacy of gasless laparoscopy-assisted surgery in management of intraabdominal/retroperitoneal tumor of unknown origin. METHODS: From June 2004 to April 2009, nine patients who underwent gasless laparoscopy-assisted surgery for intraabdominal/retroperitoneal tumor of unknown origin were recruited. Intraabdominal/retroperitoneal tumor of unknown origin was defined as (1) diagnosis of enlarged retroperitoneal lymph node; (2) evaluation of peritoneal or mesenteric lesion, or tumor of nondigestive systems; and (3) staging of intraabdominal malignancy. RESULTS: Four patients underwent gasless laparoscopy-assisted surgery for retroperitoneal enlarged lymph nodes, four for evaluation of intraabdominal lesion, and two for staging of the malignancy. Sufficient tissue was obtained from all patients, and the diagnosis was as follows: three lymphomas, three peritoneal carcinomatoses, two chronic imflammations, and one benign tumor. CONCLUSIONS: Three purposes can be achieved: a familiar method for the surgeon compared with total laparoscopic surgery, easy accessibility for further oncological management, and intraoperative miniconversion for peritoneal examination. It is a safe and effective way to obtain tissue for pathology and feasible in case of necessary sequential tumor resection.