Nucleotide-guided mesorectal excision combined with endoluminal locoregional resection by transanal endoscopic microsurgery in the treatment of rectal tumors: technique and preliminary results

Ostomy closure rate during COVID-19 pandemic: an Italian multicentre observational study

During the corona virus disease 2019 (COVID-19) pandemic, most of the surgical procedures were performed for emergencies or oncologic reasons to the detriment of the remaining elective procedures for benign conditions. Ileostomy or colostomy creation are sequelae of oncologic or emergency colorectal surgery, but their closure does not fall within the definition of oncologic or emergency surgery. The aim of this retrospective multicentre observational study is to report the impact of COVID-19 pandemic on the ostomy closure rate in Italy. Data regarding ileostomy and colostomy creation and closure from 24 Italian centres, during the study period (March 2020-February 2021) and during the control period (March 2019-February 2020) were collected. Three hospitals (12.5%) were COVID free. The number of colostomies and ileostomies created and closed in the same period was lower ( -18.8% and -30%, respectively) in the study period in comparison to the control period (p = 0.1915 and p = 0.0001, respectively), such as the ostomies closed in the analysed periods but created before (colostomy -36.2% and ileostomy -7.4%, p = 0.2211 and p = 0.1319, respectively). Overall, a 19.5% reduction in ostomies closed occurred in the study period. Based on the present study, a reduction in ostomy closure rate occurred in Italy between March 2020 and February 2021. During the pandemic, the need to change the clinical practice probably prolonged deterioration of quality of life in patients with ostomies, increasing number of stomas that will never be closed, and related management costs, even if these issues have not been investigated in this study.

Upstaging nodal status in colorectal cancer using ex vivo fluorescence sentinel lymph node mapping: preliminary results

BACKGROUND

Sentinel lymph node (SLN) mapping using near-infrared fluorescence (NIRF) imaging is a recent technique to improve nodal staging in several tumors. The presence of colorectal cancer (CRC) micro-metastases has recently been defined as N1 disease and no longer as N1mi, determining the need for adjuvant chemotherapy. In CRC, the reported rate of SLN micro-metastases detected by ultrastaging techniques is as high as 30%. The aim of this prospective study is to report the preliminary results of the sensitivity analysis of NIRF imaging for ex vivo SLN mapping and the research of micro-metastases in CRC, in patients with node-negative disease (NND).

MATERIAL AND METHODS

On the specimen of 22 CRC patients, 1 mL of ICG (5 mg/mL) was injected submucosally around the tumor to identify SLNs. NND SLNs were further investigated with ultrastaging techniques.

RESULTS

Three-hundred and sixty-three lymph nodes were retrieved (59 SLNs; mean per case: 2.7). The detection, sensitivity and false-negative rate were 100%, 100% and 0% respectively. Ultrastaging investigations showed no micro-metastases in the NND SLNs.

CONCLUSIONS

The ex vivo SLN fluorescence-based detection in CRC was confirmed to be easy to perform and reliable. In this preliminary results report of an ongoing study, the SLN assay was congruent with the nodal status, as confirmed by histological investigations.

A New Concept Compliant Platform with Spatial Mobility and Remote Actuation

This paper presents a new tendon-driven platform with spatial mobility. The system can be obtained as a monolithic structure, and its motion is based on the concept of selective compliance. The latter contributes also to optimizing the use of the material by avoiding parasitic deformations. The presented platform makes use of lumped compliance with three different kinds of elastic joints. An analysis of the platform mobility based on finite element analysis is provided together with an assembly mode analysis of the equivalent pseudo-rigid body mechanism. Surgical operations in laparoscopic environments are the natural fields of applications for this device.

Grasping and Releasing Agarose micro Beads in Water Drops

The micromanipulation of micro objects is nowadays the focus of several investigations, specially in biomedical applications. Therefore, some manipulation tasks are required to be in aqueous environment and become more challenging because they depend upon observation and actuation methods that are compatible with MEMS Technology based micromanipulators. This paper describes how three grasping-releasing based tasks have been successfully applied to agarose micro beads whose average size is about 60 μm: (i) the extraction of a single micro bead from a water drop; (ii) the insertion of a single micro bead into the drop; (iii) the grasping of a single micro bead inside the drop. The success of the performed tasks rely on the use of a microgripper previously designed, fabricated, and tested.

Design and Validation of a Single-SOI-Wafer 4-DOF Crawling Microgripper

This paper deals with the manipulation of micro-objects operated by a new concept multi-hinge multi-DoF (degree of freedom) microsystem. The system is composed of a planar 3-DoF microstage and of a set of one-DoF microgrippers, and it is arranged is such a way as to allow any microgripper to crawl over the stage. As a result, the optimal configuration to grasp the micro-object can be reached. Classical algorithms of kinematic analysis have been used to study the rigid-body model of the mobile platform. Then, the rigid-body replacement method has been implemented to design the corresponding compliant mechanism, whose geometry can be transferred onto the etch mask. Deep-reactive ion etching (DRIE) is suggested to fabricate the whole system. The main contributions of this investigation consist of (i) the achievement of a relative motion between the supporting platform and the microgrippers, and of (ii) the design of a process flow for the simultaneous fabrication of the stage and the microgrippers, starting from a single silicon-on-insulator (SOI) wafer. Functionality is validated via theoretical simulation and finite element analysis, whereas fabrication feasibility is granted by preliminary tests performed on some parts of the microsystem.

A Feasibility Study of a Novel Piezo MEMS Tweezer for Soft Materials Characterization

The opportunity to know the status of a soft tissue (ST) in situ can be very useful for microsurgery or early diagnosis. Since normal and diseased tissues have different mechanical characteristics, many systems have been developed to carry out such measurements locally. Among them, MEMS tweezers are very relevant for their efficiency and relative simplicity compared to the other systems. In this paper a novel piezoelectric MEMS tweezer for soft materials analysis and characterization is presented. A theoretical approach has developed in order to carry out the values of the stiffness, the equivalent Young’s modulus, and the viscous damping coefficients of the analyzed samples. The method has been validated by using both Finite Element Analysis and data from the literature.

Is a drain necessary after anterior resection of the rectum? A systematic review and meta-analysis

OBJECTIVE

The anastomotic leak rate in colorectal surgery is highest in patients receiving anterior rectal resections. The placement of prophylactic pelvic drains remains a routine option for preventing postoperative leaks, despite increasing evidence suggesting no clinical benefit. The present study seeks to identify a consensus on the use of prophylactic drains in anterior rectal resections.

METHODS

A systematic search was conducted of MEDLINE, Scopus, EMBASE, and Cochrane Library databases to identify clinical trials comparing the use of drainage to non-drainage in cases of colorectal anastomosis.

RESULTS

Three randomized clinical trials (RCTs) and two controlled clinical trials (CCTs) were identified that met the inclusion criteria, with a total of 1702 patients with rectal cancer who underwent anterior resection: 1206 with a pelvic drain and 496 without a pelvic drain. Meta-analysis showed that the use of a drain did not significantly improve the outcomes of anastomotic leaks; the overall reoperation rate during the 30-day postoperative period and the postoperative mortality were statistically lower in the drained group (OR 2.82, 95% CI 1.33 to 5.97; I2 = 0%).

CONCLUSIONS

The use of prophylactic pelvic drainage after anterior rectal resections does not provide significant benefits with respect to anastomotic leaks and overall complication rates. However, an approximately threefold reduction of the postoperative mortality of the drained patients was observed. Given the limitations of the present study, these findings warrant the use of a drain after anterior rectal resection. Nevertheless, due to the low quality of the available data, further multicenter trials with uniform inclusion criteria are needed to evaluate drain usage in the anterior rectal resection.

Toward Operations in a Surgical Scenario: Characterization of a Microgripper via Light Microscopy Approach

Micro Electro Mechanical Systems (MEMS)-Technology based micro mechanisms usually operate within a protected or encapsulated space and, before that, they are fabricated and analyzed within one Scanning Electron Microscope (SEM) vacuum specimen chamber. However, a surgical scenario is much more aggressive and requires several higher abilities in the microsystem, such as the capability of operating within a liquid or wet environment, accuracy, reliability and sophisticated packaging. Unfortunately, testing and characterizing MEMS experimentally without fundamental support of a SEM is rather challenging. This paper shows that in spite of large difficulties due to well-known physical limits, the optical microscope is still able to play an important role in MEMS characterization at room conditions. This outcome is supported by the statistical analysis of two series of measurements, obtained by a light trinocular microscope and a profilometer, respectively.

A modified sentinel lymph node technique combined with endoluminal loco-regional resection for the treatment of rectal tumours: a 14-year experience

AIM

After endoluminal loco-regional resection (ELRR) by transanal endoscopic microsurgey (TEM) the N parameter may remain undefined. Nucleotide-guided mesorectal excision (NGME) improves the lymph node harvest. The aim of the present study is to evaluate the long-term oncological results after ELRR with NGME.

METHOD

A total of 57 patients were enrolled over the period January 2001 to June 2015. All patients underwent ELRR by TEM. Prior to surgery, 99 m-technetium-marked nanocolloid was injected into the peritumoural submucosa. After removal of the specimen, the residual defect was probed to detect any residual radioactivity and 'hot' mesorectal fat was excised. All patients were included in a 5-year follow-up programme.

RESULTS

Significant radioactivity in the residual cavity was found in 28 out of 57 patients (49%). The mean number of lymph nodes harvest in irradiated and nonirradiated patients was 1.66 and 2.76, respectively. After 68.2 months' follow-up overall survival was 91.2%, disease-related mortality 3.5% and disease-free survival 89.5%. Two patients developed pulmonary metastases: one ypT3N0 patient underwent lung lobectomy after chemotherapy and one pT2N0 patient was managed with lung radiotherapy. Both patients are currently alive and disease-free at 48 months' follow-up. Two patients developed local recurrence 1 year after ELRR, both treated with neoadjuvant chemo-radiotherapy and total mesorectal excision. Comparing the present series with previous patients who did not undergo NGME, an increased number of harvested lymph nodes were observed, with a statistically significant difference (P = 0.0085).

CONCLUSION

NGME during ELRR improves the lymph node harvest and staging accuracy. The long-term results showed satisfactory local (3.5%) and distant (7%) recurrence rates.

Early laparoscopic cholecystectomy is superior to delayed acute cholecystitis: a meta-analysis of case-control studies

BACKGROUND

Since the advent of laparoscopic cholecystectomy (LC) there has been continued debate regarding the management of acute cholecystitis with either early or delayed LC. Nearly all studies have demonstrated that early LC has a significantly shorter total length of hospital stay compared with delayed LC. Although previous randomized controlled trials and meta-analysis have shown clinical outcomes to favour early surgery, clinical practice continues to vary significantly worldwide. In addition, there is much confusion in the optimal timing for early LC with definitions of early varying from 72 h to 7 days. There have been numerous case-control studies investigating the timing of LC in acute cholecystitis. The aim of this paper is to pool the results from all case-control studies to investigate outcomes including mortality rates, complication rates, length of hospital stay and conversion rates to open procedures.

METHODS

A search of electronic databases was performed for case-control studies published between 1985-February 2015.

RESULTS

Results from 77 case-control studies showed statistically significant reductions in mortality, complications, bile duct leaks, bile duct injuries, wound infections, conversion rates, length of hospital stay and blood loss associated with early LC. Although LC within the 72-h window is optimal, patients operated after this window still benefit from early surgery compared to delayed surgery. The duration of symptoms in acute cholecystitis should not influence the surgeons' willingness to operate acutely.

CONCLUSIONS

Early LC is clearly superior to delayed LC in acute cholecystitis. The most recent evidence-based practice strongly suggests that early LC should be standard of care in the management of acute cholecystitis.

Local resection of early rectal cancer

The introduction of the National Danish screening programme for colorectal cancer will result in the detection of more early rectal cancers (ERC), which may be considered for local excision. For the low risk≤T1 cancer, the oncological outcome at local excision in smaller patient series has shown similar results to conventional surgery, but with a significantly lower rate of serious complications, morbidity and mortality. The challenge is correct preoperative staging, and a meticulous systematic histopathological staging of the excised specimen to distinguish the low risk from high-risk cases, where rescue surgery may be considered. The establishment of a regional or national clinical database is necessary to improve the local treatment of ERC.