Revisiting the Trans-Sacral Approach for Large Rectal Adenomas, Surgical Technique, and Oncological Outcome: a Case Series

Abstract

The standard oncologic surgeries for rectal carcinoma are radical trans abdominal procedures, However, these radical procedures are not suitable for large rectal adenomas. The transsacral approach for rectal adenoma was first described by Kraske and since then it has been utilized for various benign conditions of low and mid-rectum as well as for certain cancers. We are presenting a series of 5 consecutive cases of trans-sacral resection done in the past 7 years between January, 2016, until June, 2023, at the Department of Surgical Oncology, Cancer Research Institute, HIMS Dehradun, for large mid- and lower rectal adenoma. There were 5 patients who underwent transsacral excision of rectal adenoma. Three patients were male and 2 were female. All the patients underwent surgery after confirming the diagnosis of adenoma and metastatic work up. The postoperative histopathological examination showed adenocarcinoma infiltrating submucosa (T1) in one patient; however, other 4 patients had adenoma reconfirmed. The transsacral approach may not be the method of choice for the rectal carcinoma but it is a very useful surgical alternative to the large rectal adenoma where there is no invasive component and which cannot be managed by any other methods.

Introduction

The standard oncologic surgeries for rectal carcinoma are radical trans abdominal procedures. They can be either sphincter salvage surgery like anterior resection or low anterior resection or non-sphincter salvage surgery like abdominoperineal resection. These radical procedures can be performed in both minimally invasive or open methods. The radical surgery is performed for invasive malignancies of rectum; hence, total mesorectal excision is done which ensures low recurrence rates and good long-term oncologic outcome [1, 2]. However, these radical procedures are not suitable for rectal adenomas and procedures like endoscopic mucosal resection, endoscopic mucosal dissection, transanal endoscopic microsurgery, or transsacral resection are utilized. Among these procedures most are unsuitable for large adenomas of mid- or lower rectum. Hence, the right management option is a matter of dilemma.

The transsacral approach for rectal adenoma was first described by Kraske, and since then it has been utilized for various benign conditions of low and mid-rectum as well as for certain cancers [3, 4]. However, in cancers this procedure is avoided because of complications like local pain, dyschezia, fecal incontinence, dysuria, sexual dysfunction, and posterior rectocele. Other complications have been reported such as rectocutaneous fistulas, perineal infections, incisional hernia, as well as local failure [5, 6]. Nevertheless, in properly selected patients where other procedures cannot be performed, the transsacral approach is a suitable alternative.

Here in this article we present a case series of patients with large rectal adenoma managed by transsacral approach, the surgical technique, outcome, and utility.

Material and Methods

We are presenting a series of 5 consecutive cases of trans-sacral resection done in the past 7 years between January, 2016, and June, 2023, at the Department of Surgical Oncology, Cancer Research Institute, HIMS, Dehradun. All 5 patients presented with large polypoidal growth in the mid- or lower rectum and multiple biopsies were showing adenoma. However, these growths were large so not amenable for colonoscopic resection and performing radical procedures like LAR or APR was not justified as there was no evidence of malignancy. Hence, with such presentation trans-sacral approach provides adequate exposure to the growth as well as freedom of resection with proper mucosal margin and minimal morbidity.

A detailed history was taken and a thorough clinical examination was done for all the patients. The history regarding symptoms, risk factors, and metastatic features was taken. The per rectal examination was done to document the extent of growth from anal verge, circumferential involvement, and mobility. The colonoscopy was advised to all the patients to look for the whole colon as well as to perform a biopsy. The biopsy was performed with the help of a proctoscope as well for some patients. The multifocal lesions were ruled out with the help of the colonoscopic examination. The biopsy of adenoma was reconfirmed with another repeat biopsy. The preoperative imaging study was done in the form of contrast enhanced MRI or computed tomography (Fig. 1). The patients were selected for trans-sacral resection only after confirming a large mobile polypoidal lesion and ruling out multifocal or invasive cancer.

Fig. 1.

Computed tomography image of rectal adenoma

Surgical Procedure

The surgical procedure was completed in general or spinal anesthesia and in a prone jackknife position. The buttocks were either taped or sutured to the side to spread the gluteal cleft for proper exposure. A vertical downward skin incision was placed on the natal cleft starting just above the coccyx until perianal region. The distal coccyx was transected (Fig. 2). The care was taken not to cut through the anal verge routinely, but if required for the exposure it was divided. The Waldeyer’s fascia was opened to expose the perirectal fat. The perirectal fat was carefully separated from the rectal wall and rectum was exposed posteriorly. However, the anterior wall of the rectum was not disturbed due to the risk of opening up the pouch of Douglas. At this point the rectal incision was placed in the posterior wall of rectum guided by digital rectal examination (Fig. 3). En-bloc full thickness excision of the lesion with the mesorectum was performed under direct vision, while maintaining a sufficient surgical margin (Figs. 4 and 5). The specimen was examined for margin and the rectum was examined for any residual tumor. The rectal wall defect was sutured in the interrupted single-layer anastomosis. A single drain was placed outside the anastomosis and skin was closed primarily (Fig. 6). The specimen was marked with sutures for orientation and sent for histopathological examination. The patients were nursed in a prone position in the postoperative period, and gradually oral diet was introduced and subsequently discharged.

Fig. 2.

Vertical incision in the natal cleft and excision of coccyx

Fig. 3.

Posterior rectal incision with exposed rectal adenoma

Fig. 4.

Rectal defect post adenoma excision

Fig. 5.

Rectal adenoma excised specimen

Fig. 6.

Skin closure

Results

There were a total of 8 patients who underwent transsacral excision of rectal adenoma. However, 3 patients were lost to follow-up and no records were available. Hence, we are presenting a series of 5 patients (Table 1). Three patients were male and 2 were female. All the patients were in the middle age group and rectal adenoma was present in the lower or mid-rectum for every patient. All the patients underwent surgery after confirming the diagnosis of adenoma and metastatic work up. The postoperative histopathological examination showed adenocarcinoma infiltrating submucosa (T1) in one patient; however, other 4 patients had adenoma reconfirmed. The size of the excised adenomas are mentioned in Table 1. In the postoperative period, one patient had bleeding and another patient had superficial surgical site infection; both of them were managed conservatively. None of the operated patients had incontinence issues and postoperative pain due to excised coccyx. Currently all the patients are under regular follow-up.

Table 1.

Patient characteristics and oncological outcome

Patients	Age	Sex	Distance from anal verge	HPE report	Size of the adenoma	Postoperative complication
1	54 years	Female	6 cm	Tubulovillous adenoma	4.1 × 2.7 × 2.0 cm	None
2	45 years	Male	7 cm	Villous adenoma	5.3 × 3.5 × 1.8 cm	Bleeding
3	39 years	Male	5 cm	Villous adenoma	4.7 × 3.8 × 2.5 cm	None
4	52 years	Female	6 cm	Adenocarcinoma	4.5 × 5.2 × 1.9 cm	SSI
5	37 years	Male	7 cm	Tubulovillous adenoma	3.8 × 4.6 × 2.1 cm	None

Discussion

Local excision methods, i.e., transanal excision, transsacral excision, transanal endoscopic microsurgery (TEM), and transanal minimally invasive surgery (TAMIS), have been established for early rectal cancers in recent years [7]. The transsacral surgeries were popularized by Kraske [3]; however, traditionally it has a high complication rate. The transanal or colonoscopic removal of rectal polyp is the current procedure of choice but large rectal adenomas of lower or mid-rectum are a challenge. The large rectal polyp may harbor invasive malignancy which may not be picked up in multiple biopsies; hence, en bloc excision is required [8, 9]. The en bloc removal of large rectal polyp through the transanal route is most often not possible and the specimen is delivered in a piecemeal manner. In a situation where even the lesion is small but no conclusive preoperative biopsy can be obtained after repeated attempts, the transsacral approach is suitable. Another difficulty is transanal method inability to visualize the proximal extent due to large adenoma blocking most of the lumen, thus, compromises on the margin [10, 11]. Transabdominal surgery can solve this problem but it violates the pouch of Douglas. The transsacral route appears to be the safest and most appropriate option in carefully selected patients. The importance of careful selection of cases is again emphasized by the fact that usually the large polyps can have small base, which can be excised through a trans rectal approach (either by TAE or TAMIS). Hence, only large adenomas with large base should be selected for the transsacral surgery. In the present series we have seen that transsacral route can be utilized with minimal morbidity for large adenoma patients with large base.

Local resection of invasive tumors has a high rate of recurrence. The recurrence is generally local and regional, and according to Bentrem et al. the median time recurrence is 2 years [12]. The recurrent tumors are more difficult to manage as they are generally more aggressive and advanced as compared to the primary tumor [13]. Further, the rate of recurrence increases with the depth of tumor invasion as well as the tumor differentiation [14]. Hence, for the above reasons, we have chosen the transsacral approach for only large rectal adenoma where there was no evidence of invasive malignancy. This procedure gives the freedom of removal of large adenoma with minimal morbidity and easy accessibility which otherwise would have required either major laparotomy or tedious transanal techniques. Another advantage of this procedure is that the major and radical surgery can be reserved for the recurrence as a salvage option [15]. Our approach is also supported by many studies who stated that posterior transacral technique is a useful approach for benign rectal lesions which cannot be managed adequately by any other methods or in patients where radical surgeries cannot be performed [15–17]. Another advantage of this procedure is that it can be used in old and frail patients as well where the patient is not suitable for laparotomy [18]. We have come across only a few patients in the last 8 years where there was challenge in the management. After considering other options, the transsacral approach deemed most suitable and it is worth reporting the result.

Conclusion

The aim of this study was to remove the scare around the transsacral approach. The transsacral approach may not be the method of choice for the rectal carcinoma but it is a very useful and safe surgical alternative to the large rectal adenoma where there is no invasive component and which cannot be managed by any other methods. Hence, proper selection of cases must be done. The advantage of this method is that it is easy to perform with minimum surgical risk and en bloc removal of specimens for proper histopathological and margin assessment. Last but not the least, a good knowledge of anatomy should be applied for meticulous dissection which ensures good outcome and minimal complications.

Author Contribution

Conceptualization: Dr. Sunil Saini and Dr. Sourabh Nandi; methodology: Dr. Sourabh Nandi and Dr. Chiranjit Mukherjee; formal analysis and investigation: Dr. Sourabh Nandi and Dr. Madiwalesh Chhebbi; writing—original draft preparation: Dr. Sourabh Nandi and Dr. Sunil Saini; writing—review and editing: Dr. Anshika Arora; Supervision: Dr. Sunil Saini.

Declarations

Ethical Approval

Not applicable.

Consent to Participate

Taken.

Conflict of Interest

The authors declare no competing interests.