Systematic review and meta-analysis of laparoscopic versus open repeat hepatectomy for recurrent liver cancer

Laparoscopic vs open radical resection in management of gallbladder carcinoma: A systematic review and meta-analysis

BACKGROUND

Radical resection offers the only hope for the long-term survival of patients with gallbladder carcinoma (GBC) above the T1b stage. However, whether it should be performed under laparoscopy for GBC is still controversial.

AIM

To compare laparoscopic radical resection (LRR) with traditional open radical resection (ORR) in managing GBC.

METHODS

A comprehensive search of online databases, including Medline (PubMed), Cochrane Library, and Web of Science, was conducted to identify comparative studies involving LRR and ORR in GBCs till March 2023. A meta-analysis was subsequently performed.

RESULTS

A total of 18 retrospective studies were identified. In the long-term prognosis, the LRR group was comparable with the ORR group in terms of overall survival and tumor-free survival (TFS). LRR showed superiority in terms of TFS in the T2/tumor-node-metastasis (TNM) Ⅱ stage subgroup vs the ORR group (P = 0.04). In the short-term prognosis, the LRR group had superiority over the ORR group in the postoperative length of stay (POLS) (P < 0.001). The sensitivity analysis showed that all pooled results were robust.

CONCLUSION

The meta-analysis results show that LRR is not inferior to ORR in all measured outcomes and is even superior in the TFS of patients with stage T2/TNM Ⅱ disease and POLS. Surgeons with sufficient laparoscopic experience can perform LRR as an alternative surgical strategy to ORR.

A feasible and safe approach for repeat laparoscopic liver resection and patient selection based on standardized preoperative prediction of surgical difficulty

PURPOSE

This study was performed to propose a strategy for repeat laparoscopic liver resection (RLLR) and investigate the preoperative predictive factors for RLLR difficulty.

METHODS

Data from 43 patients who underwent RLLR using various techniques at 2 participating hospitals from April 2020 to March 2022 were retrospectively reviewed. Surgical outcomes, short-term outcomes, and feasibility and safety of the proposed techniques were evaluated. The relationship between potential predictive factors for difficult RLLR and perioperative outcomes was evaluated. Difficulties associated with RLLR were analyzed separately in two surgical phases: the Pringle maneuver phase and the liver parenchymal transection phase.

RESULTS

The open conversion rate was 7%. The median surgical time and intraoperative blood loss were 235 min and 200 mL, respectively. The Pringle maneuver was successfully performed in 81% of patients using the laparoscopic Satinsky vascular clamp (LSVC). Clavien-Dindo class ≥III postoperative complications were observed in 12% of patients without mortality. An analysis of the risk factors for predicting difficult RLLR showed that a history of open liver resection was an independent risk factor for difficulty in the Pringle maneuver phase.

CONCLUSION

We present a feasible and safe approach to address RLLR difficulty, especially difficulty with the Pringle maneuver using an LSVC, which is extremely useful in RLLR. The Pringle maneuver is more challenging in patients with a history of open liver resection.

Short- and long-term outcomes of laparoscopic versus open repeat liver resection for hepatocellular carcinoma: A multicenter study

OBJECTIVE

This multicenter study aimed to compare the short- and long-term outcomes of laparoscopic (LRLR) versus open repeat liver resection (ORLR) for recurrent hepatocellular carcinoma (HCC) using propensity score matching (PSM). Despite the expanding indications for laparoscopic liver resection, limited data regarding the outcomes of LRLR have previously been reported.

METHODS

This study included patients who underwent repeat liver resection for recurrent HCC. Patients were divided into the LRLR and ORLR groups, and their short- and long-term outcomes were compared via PSM.

RESULTS

There were 256 and 130 patients in the ORLR and LRLR groups, respectively. After PSM, 64 patients were included in each group. Intraoperative blood loss was significantly less in LRLR than in ORLR (56 vs 208 ml, P < .001). Postoperative complications of Clavien-Dindo IIIa or more were significantly less in LRLR than in ORLR (3.1% vs 15.6%, P = .030). The length of hospital stay was notably shorter in LRLR than in ORLR (9 vs 12 days, P < .001). Survival rates after repeat liver resection at 1, 3, and 5 years, respectively, were comparable at 93.4%, 81.9%, and 63.5% for ORLR and at 94.8%, 80.7%, and 67.3% for LRLR (P = .623). Subgroup analysis of patients who underwent wedge resection in repeat liver resection revealed that the postoperative complication rate was notably lower in LRLR than in ORLR (7.2% vs 21.8%, P = .030).

CONCLUSION

LRLR for recurrent HCC is a viable option due to its better short-term outcomes and comparable long-term outcomes compared to ORLR.

Outcomes and Patient Selection in Laparoscopic vs. Open Liver Resection for HCC and Colorectal Cancer Liver Metastasis

Hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM) are the two most common malignant tumors that require liver resection. While liver transplantation is the best treatment for HCC, organ shortages and high costs limit the availability of this option for many patients and make resection the mainstay of treatment. For patients with CRLM, surgical resection with negative margins is the only potentially curative option. Over the last two decades, laparoscopic liver resection (LLR) has been increasingly adopted for the resection of a variety of tumors and was found to have similar long-term outcomes compared to open liver resection (OLR) while offering the benefits of improved short-term outcomes. In this review, we discuss the current literature on the outcomes of LLR vs. OLR for patients with HCC and CRLM. Although the use of LLR for HCC and CRLM is increasing, it is not appropriate for all patients. We describe an approach to selecting patients best-suited for LLR. The four common difficulty-scoring systems for LLR are summarized. Additionally, we review the current evidence behind the emerging robotically assisted liver resection technology.

Surgical outcomes of laparoscopic versus open repeat liver resection for liver cancers: A report from a nationwide surgical database in Japan

BACKGROUND/PURPOSE

Laparoscopic (repeat) liver resection (LRLR) is a well-established liver tumor treatment. However, since its outcomes and comparison with open repeat liver resection (ORLR) in recurrent liver cancer remain inadequately studied, this study then aimed to compare their short-term outcomes for liver cancers (hepatocellular carcinoma, intrahepatic cholangiocellular carcinoma, and metastatic liver cancer).

METHODS

Repeat liver resection cases between 2013 and 2017 from Japan's National Clinical Database were extracted. We used propensity score matching (PSM) to compare the proportion of patients with postoperative complications of Clavien-Dindo classification grade II or higher (CD2+) (primary endpoint), as well as the operative time, intraoperative bleeding volume, and intraoperative transfusion implementation rate (secondary endpoints).

RESULTS

Of 2,902 patients (ORLR, 2,476; LRLR, 426), 712 (356 per type) with comparable backgrounds remained via PSM. Before and after PSM, the postoperative CD2+ complication rate was significantly lower in the LRLR group, who had shorter operative time, smaller intraoperative bleeding volume, and lower intraoperative transfusion rate, than in the ORLR group (after matching, 7.6% vs. 18.3%, p < 0.0001).

CONCLUSIONS

LRLR showed better short-term outcomes than ORLR, making it a safer and more effective liver cancer treatment.

Predicting Complications following Surgical Resection of Hepatocellular Carcinoma Using Newly Developed Neo-Glasgow Prognostic Score with ALBI Grade: Comparison of Open and Laparoscopic Surgery Cases

Background/Aim: Nutritional assessment is known to be important for predicting prognosis in patients with malignant diseases. This study examined the usefulness of a prognostic predictive nutritional assessment tool for hepatocellular carcinoma (HCC) patients treated with surgical resection. Materials/Methods: HCC patients (n = 429) classified as Child−Pugh A who underwent an R0 resection between 2010 and 2020 were retrospectively analyzed (median age 73 years, males 326 (76.0%), Child−Pugh score 5:6 = 326:103, single tumor 340 (79.2%), median tumor size 3.5 cm, open:laparoscopic = 304:125). Glasgow prognostic score (GPS) and the newly developed neo-GPS method, which uses albumin−bilirubin grade 1 instead of albumin, were evaluated to compare their usefulness for prognosis prediction. Results: Median survival time for patients with a GPS score of 0, 1, and 2 was 120, 51, and 20 months, respectively. As for neo-GPS, that for those with a score of 0, 1, and 2 was not applicable (NA), 53 months, and 35 months, respectively (each p < 0.001; c-index: 0.556 and 0.611, respectively). Furthermore, median progression-free survival was 33, 22, and 9 months, and 41, 24, and 15 months, respectively (each p < 0.001; c-index: 0.539 and 0.578, respectively). As compared to patients with a high GPS (≥1), those with a high neo-GPS (≥1) showed a greater rate of high Clavien−Dindo classification (≥3) (39.2% vs. 65.1%). A comparison of patients with a high GPS (≥1) with those with a high neo-GPS (≥1) showed no significant difference regarding frequency of open or laparoscopic hepatectomy (17.4% vs. 15.2%, p = 0.670; 44.7% vs. 43.2%, p = 0.831, respectively), while the frequency of high Clavien−Dindo classification (≥3) was lower in patients who underwent a laparoscopic hepatectomy (11.2% vs. 22.7%, p = 0.007). Conclusion: The present findings suggest that the newly developed neo-GPS based on ALBI grade is an effective prognostic nutritional assessment tool and can be used for prediction of postoperative complications.

Indications of Laparoscopic Repeat Liver Resection for Recurrent Hepatocellular Carcinoma

AIM

This study aimed to evaluate the indications of laparoscopic repeat liver resection (LRLR) for recurrent hepatocellular carcinoma from the viewpoint of its difficulty.

METHODS

One hundred and one patients who underwent LRLR and 59 patients who underwent open repeat liver resection (ORLR) were included. The difficulty was classified according to the preoperative predictive factors for difficult LRLR, including an open approach during previous liver resection, history of two or more previous liver resections, history of previous major liver resection, tumor near the resected site of the previous liver resection, and intermediate or high difficulty with the difficulty scoring system. We compared the surgical outcomes between the LRLR and ORLR groups based on the difficulty class (low- or intermediate difficiulty class, 0 to 3 predictive factors; high difficiulty class, 4 or 5 factors).

RESULTS

In the low- or intermediate difficiulty class, intraoperative blood loss and the proportion of patients with postoperative complications were significantly lower in LRLR than in ORLR, and the duration of the postoperative hospital stay was significantly shorter in LRLR than in ORLR. In the high difficiulty class, total operative time and operative time before starting hepatic parenchymal resection were significantly longer in LRLR than in ORLR, and there were no significant differences in other surgical outcomes between the two groups.

CONCLUSION

LRLR is recommended for patients in the low or intermediate difficulty class. However, LRLR does not have an advantage with longer operative time for patients in the high difficulty class compared with ORLR.

Multicenter Propensity Score-Based Study of Laparoscopic Repeat Liver Resection for Hepatocellular Carcinoma: A Subgroup Analysis of Cases with Tumors Far from Major Vessels

Simple Summary

Less morbidity is considered among the advantages of laparoscopic liver resection for HCC patients. However, our previous international, multi-institutional study of laparoscopic repeat liver resection (LRLR) failed to prove it. We hypothesize that these results may be since the study included complex cases performed during the procedure’s developing stage. To examine it, subgroup analysis based on propensity score were performed, defining the proximity of the tumors to major vessels as the complexity. A propensity score matching earned 115 each patient of LRLR and open repeat liver resection (ORLR) without the proximity to major vessels, and the outcomes were compared. With comparable operation time and long-term outcome, less blood loss and less morbidity were shown in LRLR group than ORLR. Even in its worldwide developing stage, LRLR for HCC patients could be beneficial in blood loss and morbidity for the patients with less complexity in surgery.

Abstract

Less morbidity is considered among the advantages of laparoscopic liver resection (LLR) for HCC patients. However, our previous international, multi-institutional, propensity score-based study of emerging laparoscopic repeat liver resection (LRLR) failed to prove this advantage. We hypothesize that these results may be since the study included complex LRLR cases performed during the procedure’s developing stage. To examine it, subgroup analysis based on propensity score were performed, defining the proximity of the tumors to major vessels as the indicator of complex cases. Among 1582 LRLR cases from 42 international high-volume liver surgery centers, 620 cases without the proximity to major vessels (more than 1 cm far from both first–second branches of Glissonian pedicles and major hepatic veins) were selected for this subgroup analysis. A propensity score matching (PSM) analysis was performed based on their patient characteristics, preoperative liver function, tumor characteristics and surgical procedures. One hundred and fifteen of each patient groups of LRLR and open repeat liver resection (ORLR) were earned, and the outcomes were compared. Backgrounds were well-balanced between LRLR and ORLR groups after matching. With comparable operation time and long-term outcome, less blood loss (283.3±823.0 vs. 603.5±664.9 mL, p = 0.001) and less morbidity (8.7 vs. 18.3 %, p = 0.034) were shown in LRLR group than ORLR. Even in its worldwide developing stage, LRLR for HCC patients could be beneficial in blood loss and morbidity for the patients with less complexity in surgery.

Newly-revised Pringle maneuver using laparoscopic Satinsky vascular clamp for repeat laparoscopic hepatectomy

It has been known that repeat laparoscopic hepatectomy (RLH) after open hepatectomy is technically challenging because of adhesions around the hilum. It is quite often that conventional tourniquet technique for the Pringle maneuver is difficult in RLH, and we introduced Laparoscopic Satinsky Vascular Clamp (LSVC) for inflow control in RLH. The Spiegel lobe is the anatomical landmark in LSVC technique. If a space behind the hepatoduodenal ligament and the Spiegel lobe was obtained, LSVC was applied laterally from the left side of the hepatoduodenal ligament, whereas LSVC was vertically applied for those with obstruction of a space behind the hepatoduodenal ligament. We performed 14 cases of RLH for those with histories of open hepatectomies by lateral (n = 6) and vertical (n = 8) LSVC technique with successful inflow control, confirmed by intraoperative Doppler ultrasound. Five patients underwent 2 or more previous histories of hepatectomies. The RLH included segmentectomy (n = 1), subsegmentectomy (n = 2) and partial hepatectomy (n = 11). The median time for the Pringle maneuver, operative time, and blood loss was 47 min, 237.5 min, and 160 mL. All the patients completed pure laparoscopic hepatectomy. In conclusion, LSVC technique is a safe and reliable technique for the Pringle maneuver in RLH.

Laparoscopic repeat liver resection for hepatic epithelioid hemangioendothelioma

BACKGROUND

Optimal treatment for patients with hepatic epithelioid hemangioendothelioma (HEHE) remains unclear. Laparoscopic repeat liver resection (LR) is a minimally invasive and potentially effective surgical option for multiple HEHEs.

CASE PRESENTATION

A 42-year-old woman with no relevant history was admitted for multiple liver tumors. Six tumors were observed on T2-weighted magnetic resonance imaging (MRI) including one in S2, two in S3, two in S7, and one in S8. Pathological evaluation of percutaneous tumor biopsy tissue suggested a diagnosis of HEHE and laparoscopic LR was planned. The procedure began with partial resection of S7 and partial resection of S8 and left lateral sectionectomy were performed. Another tumor was found intraoperatively on the surface of S6, necessitating removal by partial resection. Pathological evaluation of the resected tumor tissue from all seven tumors concurred with that of the preoperative biopsy. The patient was discharged on postoperative day 6 without any complications. A follow-up MRI 15 months after the primary surgery revealed one tumor each in S4, S6, and S8. Laparoscopic repeat LR was performed. The patient was discharged on postoperative day 5 without any complications. All three recurrent tumors were pathologically confirmed as HEHEs.

CONCLUSIONS

We successfully treated primary and recurrent HEHEs with laparoscopic LR, which is a reasonable minimally invasive procedure considering the possibility of multiple courses of liver surgery in patients with HEHE.

Laparoscopic repeat liver resection

Recurrence of liver cancers inside the liver are often treated with liver resection (LR). However, increased risks of complications and conversion during operation were reported in laparoscopic repeat LR (LRLR). The indication is still controversial. One multi-institutional propensity score matching analysis of LRLR vs open repeat LR for hepatocellular carcinoma, two propensity score matching analyses for colorectal metastases, and two meta-analyses including hepatocellular carcinoma, intrahepatic cholangiocarcinoma, metastases, and other tumors have been reported to date. LRLR was reported with better to comparable short-term and similar long-term outcomes. Furthermore, the shorter operation time and the smaller amount of intraoperative bleeding for LRLR was reported for the patients who had undergone laparoscopic rather than open LR as an earlier procedure. The speculations are presented, that complete dissection of adhesion can be dodged and laparoscopic minor repeated LR can minimize the liver functional deterioration in cirrhotic patients. LRLR, as a powerful local therapy, could contribute to the long-term outcomes of those with deteriorated liver function. However, the procedure is now in its developing stage worldwide and further accumulation of experiences and evaluation are needed.

Is minimally invasive surgery of lesions in the right superior segments of the liver justified? A multi-institutional study of 245 patients

BACKGROUND

Controversy exists regarding the safety and feasibility of minimally invasive resection for lesions in segments 7 or 8. We compare outcomes of minimally invasive surgery (MIS) and Open parenchymal sparing liver resections at two high-volume centers.

METHODS

From 2003 to 2016 we identified patients who underwent MIS or Open resections for lesions in segments 7 or 8 at two institutions (MSKCC and SGH). Outcomes were compared using univariate and multivariate analyses.

RESULTS

Two-hundred and forty-five patients underwent resection of lesions in segments 7 or 8 (MIS 30% and Open 70%). Compared to the Open group, the MIS group had longer operative time (223 ± 88 vs 188 ± 72 minutes, P = .003), lower blood loss (297 ± 287 vs 448 ± 670 mL, P = .03), and shorter mean length of stay (5.2 ± 7.4 vs 8.3 ± 11.7 days, P < .001), which remained significant on multivariate analysis. No differences in Pringle time, rate of postoperative complications, or R0 resections were detected.

CONCLUSIONS

With appropriately selected patients treated by experienced MIS hepatopancreatobiliary surgeons, MIS resection of segments 7 or 8 is safe with similar rates of complications and R0 resections, with significantly less blood loss and shorter length of stay.

Integrative analysis of dysregulated lncRNA-associated ceRNA network reveals potential lncRNA biomarkers for human hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is an aggressive cancer with a poor prognosis and a high incidence. The molecular changes and novel biomarkers of HCC need to be identified to improve the diagnosis and prognosis of this disease. We investigated the current research concentrations of HCC and identified the transcriptomics-related biomarkers of HCC from The Cancer Genome Atlas (TGCA) database.

Methods

We investigated the current research concentrations of HCC using literature metrology analysis for studies conducted from 2008 to 2018. We identified long noncoding RNAs (lncRNAs) that correlated with the clinical features and survival prognoses of HCC from The Cancer Genome Atlas (TGCA) database. Differentially expressed genes (lncRNAs, miRNAs, and mRNAs) were also identified by TCGA datasets in HCC tumor tissues. A lncRNA competitive endogenous RNA (ceRNA) network was constructed from lncRNAs based on intersected lncRNAs. Survival times and the association between the expression levels of the key lncRNAs of the ceRNA network and the clinicopathological characteristics of HCC patients were analyzed using TCGA. Real-time polymerase chain reaction (qRT-PCR) was used to validate the reliability of the results in tissue samples from 20 newly-diagnosed HCC patients.

Results

Analysis of the literature pertaining to HCC research revealed that current research is focused on lncRNA functions in tumorigenesis and tumor development. A total of 128 HCC dysregulated lncRNAs were identified; 66 were included in the co-expressed ceRNA network. We analyzed survival times and the associations between the expression of 66 key lncRNAs and the clinicopathological features of the HCC patients identified from TCGA. Twenty-six lncRNAs were associated with clinical features of HCC (P < 0.05) and six key lncRNAs were associated with survival time (log-rank test P < 0.05). Six key lncRNAs were selected for the validation of their expression levels in 20 patients with newly diagnosed HCC using qRT-PCR. Consistent fold changes in the trends of up and down regulation between qRT-PCR validation and TCGA proved the reliability of our bioinformatics analysis.

Conclusions

We used integrative bioinformatics analysis of the TCGA datasets to improve our understanding of the regulatory mechanisms involved with the functional features of lncRNAs in HCC. The results revealed that lncRNAs are potential diagnostic and prognostic biomarkers of HCC.

Local penetration of doxorubicin via intrahepatic implantation of PLGA based doxorubicin-loaded implants

Doxorubicin (DOX) is widely used in the chemotherapy of a wide range of cancers. However, intravenous administration of DOX causes toxicity to most major organs which limits its clinical application. DOX-loaded drug delivery system could provide a continuous sustained-release of drugs and enables high drug concentrations at the target site, while reducing systemic toxicity. Additionally, local chemotherapy with DOX may be a promising approach for lowering post-surgical recurrence of cancer. In this study, the sustained-release DOX-loaded implants were prepared by melt-molding method. The implants were characterized with regards to drug content uniformity, micromorphology and drug release profiles. Furthermore, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) analyses were carried out to investigate the drug-excipient compatibility. To determine the local penetration of DOX in liver, the minipigs received intrahepatic implantation of DOX-loaded implants by abdominal surgery. UPLC-MS/MS method was used to detect the concentration of DOX in liver tissues. Our results suggested that DOX-loaded implants delivered high doses of drug at the implantation site for a prolonged period and provided valuable information for the future clinical applications of the DOX-loaded implants.

Laparoscopic repeat liver resection for hepatocellular carcinoma: a multicentre propensity score-based study

BACKGROUND

In the absence of randomized controlled data and even propensity-matched data, indications for, and outcomes of, laparoscopic repeat liver resection for hepatocellular carcinoma (HCC) remain uncertain. This study aimed to clarify the current indications for laparoscopic repeat liver resection for HCC, and to evaluate outcomes.

METHODS

Forty-two liver surgery centres around the world registered patients who underwent repeat liver resection for HCC. Patient characteristics, preoperative liver function, tumour characteristics, surgical method, and short- and long-term outcomes were recorded.

RESULTS

Analyses showed that the laparoscopic procedure was generally used in patients with relatively poor performance status and liver function, but favourable tumour characteristics. Intraoperative blood loss (mean(s.d.) 254(551) versus 748(1128) ml; P < 0·001), duration of operation (248(156) versus 285(167) min; P < 0·001), morbidity (12·7 versus 18·1 per cent; P = 0·006) and duration of postoperative hospital stay (10·1(14·3) versus 11·8(11·8) days; P = 0·013) were significantly reduced for laparoscopic compared with open procedures, whereas survival time was comparable (median 10·04 versus 8·94 years; P = 0·297). Propensity score matching showed that laparoscopic repeat liver resection for HCC resulted in less intraoperative blood loss (268(730) versus 497(784) ml; P = 0·001) and a longer operation time (272(187) versus 232(129); P = 0·007) than the open approach, and similar survival time (12·55 versus 8·94 years; P = 0·086).

CONCLUSION

Laparoscopic repeat liver resection is feasible in selected patients with recurrent HCC.

Outcomes of laparoscopic repeat liver resection for recurrent liver cancer: A system review and meta-analysis

BACKGROUND

With the improvements of surgical instruments and surgeons' experience, laparoscopic liver resection has been applied for recurrent tumors. However, the value of laparoscopic repeat liver resection (LRLR) is still controversial nowadays, which compelled us to conduct this meta-analysis to provide a comprehensive evidence about the efficacy of LRLR for recurrent liver cancer.

METHODS

A computerized search was performed to identify all eligible trials published up to April 2019. This meta-analysis was conducted to estimate the perioperative data and oncological outcomes of LRLR by compared with open repeat liver resection (ORLR) and laparoscopic primary liver resection (LPLR). A fixed or random-effect modal was established to collect the data.

RESULTS

A total of 1232 patients were included in this meta-analysis (LRLR: n = 364; ORLR: n = 396; LPLR: n = 472). LRLR did not increase the operative time compared to ORLR (WMD = 15.92 min; 95%CI: -33.53 to 65.37; P = .53). Conversely, LRLR for patients with recurrent tumors was associated with less intraoperative blood loss (WMD = -187.33 mL; 95%CI: -249.62 to -125.02; P < .00001), lower transfusion requirement (OR = 0.24; 95%CI: 0.06-1.03; P = .05), fewer major complications (OR = 0.42; 95%CI: 0.23-0.76; P = .004), and shorter hospital stays (WMD = -2.31; 95%CI: -3.55 to -1.07; P = .0003). In addition, the oncological outcomes were comparable between the two groups. However, as for the safety of LRLR compared with LPLR, although the operative time in LRLR group was longer than LPLR group (WMD = 58.63 min; 95%CI: 2.99-114.27; P = .04), the blood loss, transfusion rates, R0 resection, conversion, postoperative complications, and mortality were similar between the two groups.

CONCLUSIONS

LRLR for recurrent liver cancer could be safe and feasible in selected patients when performed by experienced surgeons.