Transanal endoscopic surgery (TES) is a treatment option for polyps not amenable to endoscopic excision, and selected carcinomas of the rectum. Transanal endoscopic microsurgery (TEM) is the earliest and most common type of TES [1]. Benefits of TES include decreased postoperative pain, and shorter hospital stay and recovery time when compared with conventional transabdominal surgery. When conducted by experienced surgeons, a local excision resulting in tumor-free margins results in a satisfactory quality of life associated with minimal loss of anorectal function [2]. Buess et al. [3] were the first to design a special system for TEM, and went on to popularize this technique. The use of endoanal ultrasonography further improved preoperative assessment and treatment selection of rectal tumors for transanal endoscopic excision [4]. Close follow-up and advanced medical treatment strategies, including neoadjuvant chemotherapy and adjuvant radiotherapy, have provided satisfactory long-term oncologic outcomes after TEM surgery for early rectal cancer [5, 6].

The basic principles of both TEM and TES using a single access port are very similar. The special rectoscope of the TEM apparatus maintains CO2 insufflation in the surgical field while also stabilizing instruments in a fixed panel [7]. In both procedures, all surgical instruments are inserted into a single hole and the surgeon performs the operation with the help of a videoendoscopic system. The colorectal surgeons performing TEM at our institution are also familiar with the single-port system, an emerging technique in colorectal surgery. In this article, we aimed to present our initial experience with TES using a single access port with its technical details.

Patients and methods

After obtaining approval from the Institutional Review Board, all patients who underwent TES using a single access port at the Department of Colorectal Surgery in the Cleveland Clinic Digestive Disease Institute were included in this study. Demographics, American Society of Anesthesiologists (ASA) score, body mass index (BMI), operative technique, operative time, postoperative complications, length of hospitalization, and histopathological findings were evaluated. All patients underwent full colonoscopy and endoscopic lesion biopsy to determine surgical strategy. Endorectal ultrasonography was used to evaluate rectal wall involvement of the lesions. Preoperative abdominopelvic computed tomography (CT) was also performed as part of the routine work-up to rule out distant metastasis in patients with cancer. Full bowel preparation was used preoperatively in case of a breach in the peritoneal layer in the course of the excision. Intravenous antibiotics and venous thromboembolic prophylaxis were given preoperatively.

Operative technique

The video that was used for the article was recorded from the operation of patient number 9 (table). This patient was brought to the operating room and, following anesthesia induction and endotracheal intubation, a Foley catheter was inserted. Patient positioning was determined according to the location of the rectal tumor, so that it could be endoscopically visualized in the 6 o’clock position for optimal excision (Fig. 1). The surgeon was located between the legs, and the camera assistant situated to the right of the surgeon. A single-port device (GelPOINT Path, Applied Medical, Rancho Santa Margarita, CA) was lubricated and inserted though the anus. Rectal CO2 insufflation was established and a smoke evacuator was applied to the other side of the device. A 5 mm flexible-tip laparoscope (EndoEYE, Olympus, Orangeburg, NY) was used for visualization. The area to be excised was marked circumferentially with a hook cautery (video 1; see electronic supplementary material [ESM]). A 5 mm endoscopic grasper and a 5 mm vessel-sealing device or an electrocautery could be used to facilitate a full-thickness excision (video 2; see ESM). No articulating hand instruments were used during surgery. After complete removal of this lesion, the area was irrigated and checked for hemostasis. The excised lesion was oriented and pinned on a cork board to guide the pathologist. Rectal wall defect was closed with 2–0 polydioxanone (PDS) sutures continuously with the help of a 5 mm laparoscopic needle holder. The loose ends of the PDS were anchored using the silver bullets (video 3; see ESM). This step was followed by irrigation of the surgical field and there was no sign of incomplete closure (Fig. 2). The operation field was checked with rigid proctoscopy to ensure that the lumen was still patent and to check hemostasis once the CO2 had been removed.

Fig. 1
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Patient positioning during surgery

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Fig. 2
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Closure of the surgical field after excision

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Results

Between July 2010 and January 2013, 12 patients (ten males) underwent TES using a single access port. Median age of the patients was 63.5 years (50–84), median ASA score was 3 (2–4) and median BMI was 28.8 kg/m2 (17.4–55.6). Patient characteristics and tumor details are summarized in Table 1. Median operating time was 79 min (43–261). Ten out of 12 patients underwent a TES using a single access port directly since the lesions were not appropriate for endoscopic removal. However, colonoscopic removal was attempted in two patients. Histopathological diagnoses were as follows: tubulovillous adenoma (n = 6), tubular adenoma (n = 4), adenocarcinoma (n = 1) and neuroendocrine tumor (n = 1). Five patients were sent home on the same day as surgery and the median postoperative hospital stay was 1 day (0–38). Median estimated blood loss was 22.5 ml (2–150). One patient developed transient postoperative urinary retention which required a Foley catheter on postoperative day 1, and two patients had postoperative bleeding. The first of these patients with a long history of anticoagulant usage for coronary artery disease had rectal bleeding 13 days after surgery. The bleeding was successfully managed with medical treatment. The second patient was morbidly obese, had multiple comorbidities, and had rectal bleeding on postoperative day 7 managed with local epinephrine injection. He suffered unrelated sudden cardiac death on postoperative day 38.

Table 1 Patient and tumor characteristics
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Discussion

Currently, TEM is the most popular technique used for TES. Rectal tumors excised by TEM result in fewer surgery-related morbidities, better postoperative anorectal function, and a shortened postoperative recovery when compared with open or laparoscopic rectal resections [1, 2]. Frail elderly patients, patients who are otherwise not suitable candidates for a major rectal resection, and patients who categorically refuse radical rectal excision associated with permanent stoma creation for early-stage rectal cancer are candidates for TES [8]. Additionally, TES may also be used to excise sessile and large adenomas of the rectum in patients with any health condition. Using single-port access systems and laparoscopic instruments, transanal endoscopic resections have recently become more accessible to surgeons. Transanal endoscopic removal of a rectal adenoma using a single access port was first reported in 2010 by Atallah et al. [9]. This was followed by various reports of TES with increasing case numbers using similar platforms with acceptable outcomes [8, 10–15]. Furthermore, Lim et al. [16] showed that transanal endoscopic resection with a single access port is safe and feasible for patients with early rectal cancers, neuroendocrine tumors, and advanced rectal adenocarcinomas that responded to neoadjuvant treatment. In our series, we only had one patient with pT2 rectal adenocarcinoma; the majority of patients had multiple comorbid factors. We were able to perform full-thickness excision with clear margins of the large rectal lesions with TES using a single access port. Indications of TES using a single access port are not only limited to local excisions. It has been recently shown that fistula repairs and even proctectomy can be performed with TES using a single access port [17].

All operations in our series were performed using a single port access system and laparoscopic instruments under general anesthesia. However, it has been shown that general anesthesia is not necessary for TES [11]. Although the TEM technique has played an important role in the development of TES, it also poses technical and practical limitations. There are a number of disadvantages associated with the use of TEM apparatus, which include ergonomic difficulties caused by parallel instrument movements with very poor triangulation, which is easier to achieve with a single port for resecting lateral wall-located rectal lesions [13]. Secondly, the anal sphincter divulsion before insertion of the TEM rectoscope could cause transient or permanent fecal incontinence and negates the advantages of outpatient surgery [11]. Thirdly, the TEM system requires specific equipment and special training, which are not available in every center and are important factors that limit its widespread utilization [8]. However, previous studies have shown that TEM is cost effective when compared with conventional resection for the treatment of rectal adenomas and early rectal cancers [18]. TES using a single access port with standard laparoscopic instruments can make this approach much more accessible to many surgeons. This is especially important for many laparoscopic surgeons who have experience with conventional transanal surgery. While TEM is not part of the standard general surgery residency training, many surgeons are familiar with laparoscopic techniques. Therefore, TES using a single access port and regular laparoscopic insufflators and instruments can conveniently be utilized by general surgeons who have laparoscopic experience and an interest in transanal surgery.

Additionally, it has the potential to make the cost of TES even cheaper since it is performed with a conventional laparoscopic video system, which is widely available in most institutions. Recently, single ports specifically designed for TES have become available. The softer structure and smaller diameter of single-port devices may also cause less anatomical and functional anal canal damage when compared with the TEM rectoscope [12, 13]. It is notable that four patients in our series were discharged on the day of surgery and two were discharged on postoperative day 1. A postoperative hospital stay of less than 24 h has been described as ‘1-day surgery’ [19], and TES using a single port has the potential to become one of the ‘1-day surgery setting’ procedures. Currently, the largest series reporting the outcomes of TES using a single access port belongs to Albert et al. [20]. They published their early experience of 50 patients with no conversion due to a technical failure and satisfying results. Prospective studies are needed in order to verify these prospective benefits of TES using a single access port when compared with TEM.

During the procedure, we used a 5 mm vessel-sealing device and the same non-articulating hand instruments that are used in conventional laparoscopic procedures. A 5 mm flexible-tip laparoscope enables good visualization during surgery. Furthermore, 10 mm straight laparoscopes, articulating instruments [14] and a bipolar cautery may be utilized in TES using a single access port. However, the single-port setting does not provide stereoscopic visualization, an important characteristic of the TEM apparatus [9]. The type of operative instruments used may vary according to availability at a given institution, or surgeon preference.

In this study, we showed that TES using a single access port can be safely performed with non-articulating hand instruments. This application of single-port techniques may play a major role in the widespread utilization of TES as a treatment for large adenomas and early rectal cancers.