Optimal dissection for transanal total mesorectal excision using modified CO2 insufflation and smoke extraction

Comparison of laparoscopic partial nephrectomy performed with AirSeal® system vs. standard insufflator: results from a referral center

Objective

To compare perioperative and oncologic surgical outcomes during laparoscopic partial nephrectomy (LPN) performed by standard carbon dioxide insufflation, with those from surgeries in which the AirSeal® intelligent insufflation system was used for renal tumors.

Materials and methods

A total of 27 patients with renal tumor were identified, 14 underwent LPN with AirSeal® (group A) and 13 LPN with standard insufflator (group B), respectively. Demographic baseline characteristics were similar in the two groups.

Results

The size of the tumor was largest in group B (29.64 vs. 32.1 mm). The mean operative time was shorter in the AirSeal® group [group A: mean 109.0 min, median 107.5 min, interquartile range (IQR) 85; group B: mean 121.0 min, median 120.0 min, IQR 50.0]. Positive margin rates were absent in the two groups. Estimated blood loss presented a difference in the perioperative period (group A: mean 1.5 g/dL, median 1.45 g/dL; group B: mean 2.15 g/dL, median 2.2 g/dL). Time to ischemia was found to be shorter in group A with a median of 18 min compared to a median of 20 min in group B. No subcutaneous emphysema, pneumothorax, and pneumomediastinum cases occurred in either group. A postoperative complication developed in one patient requiring superselective embolization.

Conclusion

In selected patients, our preliminary surgical experience has shown that the LPN procedure performed with the aid of the AirSeal® intelligent insufflation system can be used to treat even medium-/high-complexity kidney lesions, with a reduction in operating times, lower rates of complications, and perioperative blood loss.

Clinical trial registration

AirSealV1.

The Usefulness of AirSeal™ Intelligent Flow System in Gas Insufflation Total Endoscopic Thyroidectomy

Total endoscopic thyroidectomy (TET) using low CO2 insufflation provides cosmetic advantage, excellent working space and visibility. On the contrary, suctioning blood or mist/smoke produced by energy device application causes narrowing of working space especially in neck surgery. In this regard, AirSeal intelligent flow system would be particularly suitable in TET. However, the benefit of AirSeal is unknown in TET unlike abdominal surgery. Therefore, the impact of AirSeal was evaluated in TET in this study. Twenty patients who underwent total endoscopic hemithyroidectomy were retrospectively analyzed. Insufflation was conducted by either conventional or AirSeal system according to the surgeon's preference. Short-term surgical outcomes including operation time, bleeding, frequency of scope cleaning, and disappearance of subcutaneous emphysema were compared as well as actual visibility. AirSeal application dramatically reduced obstacle smoke/mist and prevented narrowing working space by suctioning. Frequency of scope cleaning was significantly less in AirSeal group than that in conventional group (p = 0.016). In patients with nodule < 5 cm, intraoperative hemorrhage was less in AirSeal group than that in the counterpart (p = 0.077) regardless of larger nodule size in AirSeal group (p = 0.058). Notably, subcutaneous emphysema around surgical cavity disappeared significantly earlier in AirSeal group than in the counter parts (p = 0.019). On the contrary, AirSeal application did not shorten operation time in the current study. AirSeal provided excellent visibility and seamless operation. AirSeal has great potential to decrease not only surgeon's stress but surgical invasion on patients. The results in this study give rational to AirSeal application to TET.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03257-0.

Coronavirus disease 2019 pandemic and identifying insufflators with desufflation mode and surgical smoke evacuators for safe CO2 removal

INTRODUCTION

Given the propensity of severe acute respiratory syndrome coronavirus 2 to spread, it is imperative that those continuing to perform surgery take precautions to limit the potential generation of contaminated aerosols in smoke from energy-based instruments. The aim of this study was to report current data regarding insufflators with desufflation mode and similar options to safely remove CO₂ in minimal access surgery.

METHODS

A non-systematic review of the scientific literature was conducted using the PubMed database, and the main companies that provide surgical devices were contacted for information.

RESULTS

Most commercially available smoke evacuators use a combination of suction and mechanical filtering. There are also electrostatic precipitators that charge surgical smoke and retain the particles via electrostatic attraction. The search identified three insufflators with desufflation mode, four modular smoke evacuators using mechanical filtration, and only one device using electrostatic precipitation. However, none of these devices has been tested with viruses.

CONCLUSION

This review identified commercially available equipment that employs mechanical filtering and electrostatic attraction principles that can be used for pneumoperitoneum evacuation during the present coronavirus disease 2019 pandemic. This pandemic should assist in raising awareness regarding protection measures and the risk of occupational exposure in surgery.

Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision : An experimental randomized multi-arm trial with parallel treatment design

OBJECTIVE

To compare changes in microcirculation blood flow (MCBF) between pulsatile and continuous flow insufflation. Transanal total mesorectal excision (TaTME) was developed to improve the quality of the resection in rectal cancer surgery. The AirSeal IFS® insufflator facilitates the pelvic dissection, although evidence on the effects that continuous flow insufflation has on MCBF is scarce.

METHODS

Thirty-two pigs were randomly assigned to undergo a two-team TaTME procedure with continuous (n = 16) or pulsatile insufflation (n = 16). Each group was stratified according to two different pressure levels in both the abdominal and the transanal fields, 10 mmHg or 14 mmHg. A generalized estimating equations (GEE) model was used.

RESULTS

At an intra-abdominal pressure (IAP) of 10 mmHg, continuous insufflation was associated with a significantly lower MCBF reduction in colon mucosa [13% (IQR 11;14) vs. 21% (IQR 17;24) at 60 min], colon serosa [14% (IQR 9.2;18) vs. 25% (IQR 22;30) at 60 min], jejunal mucosa [13% (IQR 11;14) vs. 20% (IQR 20;22) at 60 min], renal cortex [18% (IQR 15;20) vs. 26% (IQR 26;29) at 60 min], and renal medulla [15% (IQR 11;20) vs. 20% (IQR 19;21) at 90 min]. At an IAP of 14 mmHg, MCBF in colon mucosa decreased 23% (IQR 14;27) in the continuous group and 28% (IQR 26;31) in the pulsatile group (p = 0.034).

CONCLUSION

TaTME using continuous flow insufflation was associated with a lower MCBF reduction in colon mucosa and serosa, jejunal mucosa, renal cortex, and renal medulla compared to pulsatile insufflation.

Using taTME to maintain restorative options in locally advanced rectal cancer: A technical note

BACKGROUND

The safe adoption of transanal total mesorectal excision (taTME) has occurred in Australasia as previously reported by the current authors. Planes beyond TME can be utilised in more advanced cases to achieve negative margins during transanal dissection.

METHODS

In this article we describe how taTME is used to perform an en-bloc partial vaginectomy and aid restore intestinal and vaginal continuity in a young female with a locally advanced rectal cancer and posterior vaginal wall involvement in the pre-treatment magnetic resonance imaging.

RESULTS

The transanal technique allowed the surgeons to remove a disc of vagina, ensure organ preservation and control the main R1 risk point. An R0 resection was achieved.

CONCLUSION

This technical note highlights that in experienced hands, taTME may be safely implemented to maintain restorative options in locally advanced rectal cancer requiring resection beyond the total mesorectal excision plane.

Anatomical Considerations and Procedure-Specific Aspects Important in Preventing Operative Morbidity during Transanal Total Mesorectal Excision

As transanal total mesorectal excision (taTME) becomes increasingly utilized, its technical challenges and potential pitfalls have become more clearly appreciated. This chapter explores the differences in how anatomy presents itself from the taTME vantage point as compared with traditional approaches to taTME, and how special problems unique to taTME pose a new set of operative challenges. Morbidity related, specifically, to the technique of taTME is also delineated with particular focus on male urethral injury.

Evolution of transanal total mesorectal excision according to the IDEAL framework

Tremendous innovations have taken place in surgical procedures, but contrary to drug development, this process has been unregulated in the past. IDEAL promotes a structured framework for the safe implementation and assessment of a new surgical technique or intervention, by describing five stages for evaluating and reporting of innovations: Idea, Development, Exploration, Assessment and Long term. Transanal total mesorectal excision (TaTME) is a relatively new technique in rectal cancer surgery that has attracted huge interest and increasing adoption worldwide. This review article aims to provide an overview of the evolution of TaTME, according to the IDEAL framework, which guides us in the difficult yet exciting process of surgical innovation.

Carbon Dioxide Embolism Associated With Transanal Total Mesorectal Excision Surgery: A Report From the International Registries

BACKGROUND

Carbon dioxide embolus has been reported as a rare but clinically important risk associated with transanal total mesorectal excision surgery. To date, there exists limited data describing the incidence, risk factors, and management of carbon dioxide embolus in transanal total mesorectal excision.

OBJECTIVE

This study aimed to obtain data from the transanal total mesorectal excision registries to identify trends and potential risk factors for carbon dioxide embolus specific to this surgical technique.

DESIGN

Contributors to both the LOREC and OSTRiCh transanal total mesorectal excision registries were invited to report their incidence of carbon dioxide embolus. Case report forms were collected detailing the patient-specific and technical factors of each event.

SETTINGS

The study was conducted at the collaborating centers from the international transanal total mesorectal excision registries.

MAIN OUTCOME MEASURES

Characteristics and outcomes of patients with carbon dioxide embolus associated with transanal mesorectal excision were measured.

RESULTS

Twenty-five cases were reported. The incidence of carbon dioxide embolus during transanal total mesorectal excision is estimated to be ≈0.4% (25/6375 cases). A fall in end tidal carbon dioxide was noted as the initial feature in 22 cases, with 13 (52%) developing signs of hemodynamic compromise. All of the events occurred in the transanal component of dissection, with mean (range) insufflation pressures of 15 mm Hg (12-20 mm Hg). Patients were predominantly (68%) in a Trendelenburg position, between 30° and 45°. Venous bleeding was reported in 20 cases at the time of carbon dioxide embolus, with periprostatic veins documented as the most common site (40%). After carbon dioxide embolus, 84% of cases were completed after hemodynamic stabilization. Two patients required cardiopulmonary resuscitation because of cardiovascular collapse. There were no deaths.

LIMITATIONS

This is a retrospective study surveying reported outcomes by surgeons and anesthetists.

CONCLUSIONS

Surgeons undertaking transanal total mesorectal excision must be aware of the possibility of carbon dioxide embolus and its potential risk factors, including venous bleeding (wrong plane surgery), high insufflation pressures, and patient positioning. Prompt recognition and management can limit the clinical impact of such events. See Video Abstract at http://links.lww.com/DCR/A961.

Colorectal surgeons should be open to modern surgical technologies for challenging cases

Today, colorectal surgeons globally are practicing in an exciting era where surgical technologies are constantly emerging. Most of these cutting-edge technologies are readily available in Australia and New Zealand at present. Thus the 'modern surgeon' should always be defined by this open-minded attitude towards these new and emerging surgical technologies. This review article highlights current modalities that we have been using in our north-Brisbane public and private hospitals for cases predicted to be technically challenging using minimally invasive approaches for most of them. We examined the current evidence regarding the following modalities and critiqued their use in clinical practice: lighted ureteric stents, minimally invasive surgery approaches of laparoscopy and robotic surgery, pressure barrier insufflation devices, 3D camera systems, hand-assist device ports and indocyanine green dye fluorescence angiography. The objective of this review paper is to alert colorectal surgeons to new surgical technologies available to them, to encourage colorectal surgeons' familiarization with these many technologies, and to support evidence-based consideration for the clinical use of such. These technologies should be supplemental aides to the safe, oncologically adequate and efficient operation that they already routinely perform.

The Pattern of Defects in Mesorectal Specimens: Is There a Difference between Transanal and Laparoscopic Approaches?

BACKGROUND:

Total mesorectal excision has evolved from open to minimally invasive techniques. To overcome difficulties in the lowest part of the pelvis, transanal total mesorectal excision was introduced and has gained acceptance in the recent years. The results of transanal total mesorectal excision seem to be comparable to laparoscopic total mesorectal excision. Whether or not transanal total mesorectal excision has changed the pattern of defects in the retrieved mesorectal specimens is yet to be clarified.

PURPOSE:

To determine the pattern of mesorectal defects following transanal total mesorectal excision, compared to laparoscopic total mesorectal excision. The primary end-point was the location of defects in the part of the mesorectum below the peritoneal reflection, as it is this part, which is dissected from below in the transanal total mesorectal excision procedure.

METHODS:

From our transanal total mesorectal excision database that includes all transanal total mesorectal excision procedures performed at our institution since 2013, we have included 29 patients who originally had defects in their retrieved specimens. Another 29 patients who underwent laparoscopic total mesorectal excision with mesorectal defects served as a control group. All specimen photos and pathology reports were reviewed systematically; sites and pattern of defects were defined.

RESULTS:

A higher ratio of the defects in the laparoscopic total mesorectal excision group was located below the peritoneal reflection (P = 0.043). The distribution of defects by anatomical quadrant was not statistically different between the groups.

CONCLUSIONS:

The ratio of defects below the peritoneal reflection was lower in the transanal total mesorectal excision group. Whether this is due to a lower incidence of defect in transanal total mesorectal excision is not part of our study.

Stable pneumorectum using an inline glove - a cost-effective technique to facilitate transanal total mesorectal excision

AIM

Transanal total mesorectal excision (taTME) is a novel approach for resection of the rectum. Use of a standard insufflator to create pneumorectum, however, results in bellowing-large heaving motions from insufflation of air that can frustrate surgery. We report the successful application of our technique, stable pneumorectum using an inline glove (SPRING), for the performance of transanal rectal excision in a series of 17 patients using a standard laparoscopic insufflator.

METHOD

A retrospective review of 17 patients using the SPRING technique was performed between October 2015 and October 2016. Characteristics of these patients were evaluated, and technique-related short-term outcome was reviewed.

RESULTS

The SPRING technique was successfully used in patients who underwent both minimally invasive (n = 14) and open (n = 3) approaches in the abdominal stage of the surgery. In the 12 patients who had rectal cancer for whom SPRING was used to facilitate taTME there were no conversions to an alternative access for rectal resection, the median duration of the TME part of the operation was 95 min (62-147) and there was one R1 resection (8%). Billowing was not a significant problem in any of the 17 patients during the surgery.

CONCLUSION

In this case series we have successfully shown the feasibility of the SPRING technique as a practical and cost-effective solution to the problem of billowing during taTME.

St.Gallen consensus on safe implementation of transanal total mesorectal excision

Background

The management of rectal cancer has evolved over the years, including the recent rise of Transanal Total Mesorectal Excision (TaTME). TaTME addresses the limitations created by the bony confines of the pelvis, bulky tumours, and fatty mesorectum, particularly for low rectal cancers. However, guidance is required to ensure safe implementation and to avoid the pitfalls and potential major morbidity encountered by the early adopters of TaTME. We report a broad international consensus statement, which provides a basis for optimal clinical practice.

Methods

Forty international experts were invited to participate based on clinical and academic achievements. The consensus statements were developed using Delphi methodology incorporating three successive rounds. Consensus was defined as agreement by 80% or more of the experts.

Results

A total of 37 colorectal surgeons from 20 countries and 5 continents (Europe, Asia, North and South America, Australasia) contributed to the consensus. Participation to the iterative Delphi rounds was 100%. An expert radiologist, pathologist, and medical oncologist provided recommendations to maximize relevance to current practice. Consensus was obtained on all seven different chapters: patient selection and surgical indication, perioperative management, patient positioning and operating room set up, surgical technique, devices and instruments, pelvic anatomy, TaTME training, and outcomes analysis.

Conclusions

This multidisciplinary consensus statement achieved more than 80% approval and can thus be graded as strong recommendation, yet acknowledging the current lack of high level evidence. It provides the best possible guidance for safe implementation and practice of Transanal Total Mesorectal Excision.

Transanal Total Mesorectal Excision: Why, When, and How

Transanal total mesorectal excision (taTME) has evolved over the past decade fueled by advances in minimally invasive surgery. The technique aims to overcome the constraints posed by a narrow rigid pelvis and poor TME visualization that are encountered during "top-down" rectal surgery. A more accurate pelvic dissection should subsequently result in safer oncological resections and better preservation of pelvic autonomic nerves. taTME is an advanced complex technique that requires dedicated training and experience in TME surgery. Initial results from small cohorts are promising and confirmation by randomized controlled trials is eagerly awaited.

Operative vectors, anatomic distortion, fluid dynamics and the inherent effects of pneumatic insufflation encountered during transanal total mesorectal excision

BACKGROUND

Transanal total mesorectal excision (taTME) is an altogether different approach to rectal cancer surgery, and the effects of carbon dioxide (CO₂) on this dissection remain poorly described.

METHODS

This article critically examines the effect of carbon dioxide insufflation and the workspace it creates during the process of taTME. The unique aspects of insulation with this approach are governed by the laws of physics, especially the principles of fluid dynamics, an area that remains poorly described for laparoscopy and not at all described for taTME.

RESULTS

A summary of established factors which affect the operative field of the taTME surgeon is delineated and further explored. In addition, new concepts regarding gas delivery, such as insufflation vectors, anatomic distortion, hyper-dissection, and workspace volume rate of change as a function of taTME dissection time, are addressed. Collectively, these factors pose important challenges which increase case complexity and are thus essential for taTME trainers and trainees alike to understand.

CONCLUSIONS

Although an invisible gas, CO₂ insufflation with taTME produces markedly visible effects which are imposed upon the operative field. This can result in anatomic distortion and misperception of operative planes. Thus, practicing taTME surgeons should be cognizant of these effects.

Transanal Total Mesorectal Excision: International Registry Results of the First 720 Cases

OBJECTIVE

This study aims to report short-term clinical and oncological outcomes from the international transanal Total Mesorectal Excision (taTME) registry for benign and malignant rectal pathology.

BACKGROUND

TaTME is the latest minimally invasive transanal technique pioneered to facilitate difficult pelvic dissections. Outcomes have been published from small cohorts, but larger series can further assess the safety and efficacy of taTME in the wider surgical population.

METHODS

Data were analyzed from 66 registered units in 23 countries. The primary endpoint was "good-quality TME surgery." Secondary endpoints were short-term adverse events. Univariate and multivariate regression analyses were used to identify independent predictors of poor specimen outcome.

RESULTS

A total of 720 consecutively registered cases were analyzed comprising 634 patients with rectal cancer and 86 with benign pathology. Approximately, 67% were males with mean BMI 26.5 kg/m. Abdominal or perineal conversion was 6.3% and 2.8%, respectively. Intact TME specimens were achieved in 85%, with minor defects in 11% and major defects in 4%. R1 resection rate was 2.7%. Postoperative mortality and morbidity were 0.5% and 32.6% respectively. Risk factors for poor specimen outcome (suboptimal TME specimen, perforation, and/or R1 resection) on multivariate analysis were positive CRM on staging MRI, low rectal tumor <2 cm from anorectal junction, and laparoscopic transabdominal posterior dissection to <4 cm from anal verge.

CONCLUSIONS

TaTME appears to be an oncologically safe and effective technique for distal mesorectal dissection with acceptable short-term patient outcomes and good specimen quality. Ongoing structured training and the upcoming randomized controlled trials are needed to assess the technique further.

Simple instruments facilitating achievement of transanal total mesorectal excision in male patients

AIM

To assess the efficacy of a modified approach with transanal total mesorectal excision (taTME) using simple customized instruments in male patients with low rectal cancer.

METHODS

A total of 115 male patients with low rectal cancer from December 2006 to August 2015 were retrospectively studied. All patients had a bulky tumor (tumor diameter ≥ 40 mm). Forty-one patients (group A) underwent a classical approach of transabdominal total mesorectal excision (TME) and transanal intersphincteric resection (ISR), and the other 74 patients (group B) underwent a modified approach with transabdominal TME, transanal ISR, and taTME. Some simple instruments including modified retractors and an anal dilator with a papilionaceous fixture were used to perform taTME. The operative time, quality of mesorectal excision, circumferential resection margin, local recurrence, and postoperative survival were evaluated.

RESULTS

All 115 patients had successful sphincter preservation. The operative time in group B (240 min, range: 160-330 min) was significantly shorter than that in group A (280 min, range: 200-360 min; P = 0.000). Compared with group A, more complete distal mesorectum and total mesorectum were achieved in group B (100% vs 75.6%, P = 0.000; 90.5% vs 70.7%, P = 0.008, respectively). After 46.1 ± 25.6 mo follow-up, group B had a lower local recurrence rate and higher disease-free survival rate compared with group A, but these differences were not statistically significant (5.4% vs 14.6%, P = 0.093; 79.5% vs 65.1%, P = 0.130).

CONCLUSION

Retrograde taTME with simple customized instruments can achieve high-quality TME, and it might be an effective and economical alternative for male patients with bulky tumors.

Transanal total mesorectal excision: technical aspects of approaching the mesorectal plane from below

Standardization of transanal total mesorectal excision requires the delineation of the principal procedural components before implementation in practice. This technique is a bottom-up approach to a proctectomy with the goal of a complete mesorectal excision for optimal outcomes of oncologic treatment. A detailed stepwise description of the approach with technical pearls is provided to optimize one's understanding of this technique and contribute to reducing the inherent risk of beginning a new procedure. Surgeons should be trained according to standardized pathways including online preparation, observational or hands-on courses as well as the potential for proctorship of early cases experiences. Furthermore, technological pearls with access to the "video-in-photo" (VIP) function, allow surgeons to link some of the images in this article to operative demonstrations of certain aspects of this technique.

[Minimally invasive approaches for transanal surgery]

Since the introduction of transanal endoscopic microsurgery (TEM) in the 1980 s, the minimally invasive transanal approach has been a treatment option for selected patients with colorectal diseases. Recently, transanal minimally invasive surgery (TAMIS) was introduced as an alternative technique. TAMIS is a hybrid between TEM and single-port laparoscopy and was followed by introduction of transanal total mesorectal excision (TaTME). Although the TaTME experience remains preliminary, it appears to be an attractive minimally invasive procedure for carefully selected patients with resectable rectal cancer. The objective of this review is to describe the latest technologies which enhanced progress of minimally invasive transanal approaches for endo- and extraluminal surgery in this area of colorectal surgery.

Transanal total mesorectal excision: dissection tips using 'O's and 'triangles'

PURPOSE

Transanal total mesorectal excision (taTME) requires specific technical expertise, as it is often difficult to ascertain the correct dissection plane. Consequently, one can easily enter an incorrect plane, potentially resulting in bleeding (sidewall or presacral vessels), autonomic nerve injury and urethral injury. We aim to demonstrate specific visual features, which may be encountered during surgery and can guide the surgeon to perform the dissection in the correct plane.

METHOD

Specific features of dissection in the correct and incorrect planes are demonstrated in the accompanying video.

RESULTS

The 'triangles' created using appropriate traction can aid in performing a precise dissection in the correct plane. Recognition of features described as 'O's can alert surgeons that they are entering a new fascial plane and can avoid incursion into an incorrect plane.

CONCLUSION

Understanding and recognizing the described features which can be encountered in taTME surgery, a safe and accurate TME dissection can be facilitated.

Robotic partial nephrectomy performed with Airseal versus a standard CO2 pressure pneumoperitoneum insufflator: a prospective comparative study

BACKGROUND

Airseal represents a new generation of valveless and barrier-free surgical trocars that enable a stable pneumoperitoneum with continuous smoke evacuation and carbon dioxide (CO₂) recirculation during surgery. The aim of the current study was to evaluate the potential advantages of the Airseal compared to a standard CO₂ insufflator in the field of robotic partial nephrectomy (RPN).

METHODS

Between October 2012 and April 2015, two cohorts of 122 consecutive patients with clinically localized renal cell carcinoma underwent RPN by a single surgeon, with the use of a standard CO₂ pressure insufflator (Group A, 55 patients) or Airseal (Group B, 67 patients) and were prospectively compared.

RESULTS

The two groups were similar in baseline, preoperative characteristics. The mean dimension of the lesion, as evaluated by contrast-enhanced CT scan, was 30 (median 28; IQR 2) and 39 mm (median 40; IQR 2) for Groups A and B, respectively (p < 0.05). The complexity of the treated tumors was similar, as indicated by the mean RENAL nephrometry score. Positive surgical margins rate was similar in both groups (3.6 vs 4.5 %, p = 0.8) as well as the need for postoperative blood transfusion (9.1 vs 4.5 %, p = 0.3) and the development of postoperative acute kidney injury (16.4 vs 10.4 %, p = 0.3). Mean operative time and warm ischemia time were significantly shorter in Group B. Moreover, a significant increase in the cases performed as "zero ischemia" was observed in Group B (7.3 vs 30 %, p < 0.01).

CONCLUSIONS

This is the first study comparing the Airseal with a standard CO₂ insufflator system in the field of the RPN. The preliminary outcomes in terms of overall operative time, warm ischemia time and cases performed as "zero ischemia" are better with respect to standard insufflators. The feasibility, safety and efficacy of combining laser tumor enucleation with the valve-free insufflation systems should be evaluated.

Transanal total mesorectal excision for rectal cancer: early outcomes in 50 consecutive patients

AIM

Minimally invasive approaches to proctectomy for rectal cancer have not been widely adopted due to inherent technical challenges. A modification of traditional transabdominal mobilization, termed transanal total mesorectal excision (TaTME), has the potential to improve access to the distal rectum. The aim of the current study is to assess outcomes following TaTME for rectal cancer.

METHOD

This is a retrospective analysis of a prospectively maintained database of consecutive patients who underwent TaTME for rectal cancer at a single institution. The study period was from 1 March 2012 to 31 July 2015.

RESULTS

During the study period 50 patients underwent TaTME. The median tumour distance from the anal verge was 4.4 (3.0-5.5) cm. The rate of conversion from a planned minimally invasive approach was 2.2%. The median operative time was 267.0 (227.0-331.0) min. The median lymph node yield was 18.0 (12.0-23.8), the macroscopic quality assessment of the resected specimen was incomplete in 2% and the circumferential resection margin positivity rate was 4%. Intra-operative morbidity occurred in 6% and the 30 day morbidity rate was 36%. The median length of stay was 4.5 (4.0-8.0) days. The median follow-up was 15.1 (7.0-23.2) months; two patients have developed a local recurrence and eight patients have developed distant recurrence.

CONCLUSION

These data suggest that TaTME for rectal cancer is feasible with an acceptable pathological outcome and morbidity profile. Further data on functional and long-term survival outcomes are required.

Critical concepts and important anatomic landmarks encountered during transanal total mesorectal excision (taTME): toward the mastery of a new operation for rectal cancer surgery

Over the past 3 years, colorectal surgeons have begun to adapt the technique of transanal total mesorectal excision. As international experience has been quickly forged, an improved recognition of the pitfalls and the practical details of this disruptive technique have been realized. The purpose of this technical note was to express the various nuances of transanal total mesorectal excision as learned during the course of its clinical application and international teaching, so as to rapidly communicate and share important insights with other surgeons who are in the early adoption phase of this approach. The technical points specific to transanal total mesorectal excision are addressed herein. When correctly applied, these will likely improve the quality of surgery and decrease morbidity attributable to inexperience with the transanal approach to total mesorectal excision.

Laparoscopic intersphincteric resection: indications and results

Surgical treatment of distal rectal cancer has long been based only on abdominoperineal excision, resulting in a permanent stoma and not always offering a definitive local control. Sphincter saving surgery has emerged in the last 20 years and can be offered also to patients with low lying tumours, provided that the external sphincter is not involved by the disease. An intersphincteric resection (ISR) is based on the resection of the rectum with a distal dissection proceeding into the space between the internal and the external anal sphincter. Originally described as an open procedure, it has also been developed with the laparoscopic approach, and also this technically demanding procedure is inscribed among those offered to the patient by a minimally invasive surgery. Indications have to be strict and patient selection is crucial to obtain both oncological and functional optimal results. The level of distal dissection and the extent of internal sphincter resected are chosen according to the distal margin of the tumour and is based on MRI findings: accurate imaging is therefore mandatory to better define the surgical approach. We here present our actual indications for ISR, results in terms of operative time, median hospital stay for ISR in our experience and review the updated literature.

Transanal rectal resection: an initial experience of 20 cases

AIM

Low anterior resection (LAR) can present a formidable surgical challenge, particularly for tumours located in the distal third of the rectum. Transanal total mesorectal excision (taTME) aims to overcome some of these difficulties. We report our initial experience with this technique.

METHOD

From June 2013 to September 2014, 20 selected patients underwent transanal rectal resection for various malignant and benign low rectal pathologies. All patients with rectal cancer were discussed at a multidisciplinary team meeting. Data were entered into a prospective managed international database.

RESULTS

Of the 20 patients (14 male), seventeen (85%) had rectal cancer lying at a median distance of 2 cm (range 0-7) from the anorectal junction. The operations performed included LAR (16). Abdominoperineal excision (2) and completion proctectomy (2), all of which were performed by a minimally invasive approach with three conversions. The mean operation time was 315.3 min. There were six postoperative complications of which two (10%) were Clavien-Dindo Grade IIIb (pelvic haematoma and a late contained anastomotic leakage). The median length of stay was 7 days. The TME specimen was intact in 94.1% of cancer cases. The mean number of harvested lymph nodes was 23.2. There was only one positive circumferential resection margin (tumour deposit; R1 rate 5.9%). One patient developed a distant recurrence (median follow-up 10 months, range 6-21).

CONCLUSION

TaTME was safe in this small series of patients. It is especially attractive in patients with a narrow and irradiated pelvis and a tumour in the lower third of the rectum. TaTME is technically demanding, but the good outcomes should prompt randomized studies and prospective registration of all taTME cases in an international registry.