Help
Subscribe


GastroHep.com - the global online resource for all aspects of gastroenterology, hepatology and endoscopy

 15 December 2017

Advanced search
GastroHep.com - the global online resource for all aspects of gastroenterology, hepatology and endoscopy Profile of Roy Pounder

Home

News
Journals
Review Articles
Slide Atlas
Video Clips
Online Books
Advanced Digestive Endoscopy
Classical Cases
Conference Diary
PubMed
International GH Links
USA GH Links
National GH Links
National GI Societies
Other Useful Links




Emails on Gastroenterology and Hepatology
the National AIDS Treatment Advocacy Project
Visit the gastroenterology section of the EUMS

Personal View

EndoscopyColonoscopy

Polyps and cancer

Click a heading in the right-hand column to see the selected articles in that subject area

See any comments for this Personal View

<a href='/profiles/default.asp?person=jwaye'>Jerome Waye</a>, NYSGE Endoscopic mucosal resection of colon polyps.
Jerome Waye, NYSGE, 07 May 2006
fiogf49gjkf0d

Synopsis

The term "submucosal injection polypectomy" (SIP) more accurately describes the technique used for removal of flat colonic polyps and is preferred, in the colon, to endoscopic mucosal resection (a procedure which usually employs a special suction-activated device). Using SIP, most polyps can be safely removed from any part of the colon. The methodology is described in detail and is within the capability of most colonoscopists.

Since the first reports of colonoscopic polypectomy, the technique has evolved into the procedure of choice for removing almost all polyps located in the large bowel. Originally, colonoscopic polypectomy was limited by the enthusiasm and experience of the colonoscopist, and many would not attempt removal of large, flat polyps. As recently as 1996 [2], world-renown endoscopists were removing large polyps with the wire snare in a "freehand" method, although a safer, less risky submucosal injection technique was already described.

The colon wall is extremely thin, varying in thickness from 1.7 to 2.2 mm [19]. Approximately one third of the thickness of the colon wall is composed of mucosa, one third submucosa, and one third muscularis propria. Injection of fluid into the submucosal layer increases the distance between the mucosa and the outer muscular layer of the bowel wall.

This fluid injection procedure was first applied for increased safety in the fulguration of rectal and sigmoid polyps by Rosenberg in 1955 [12]. This useful technique was subsequently reported by Deyhle in 1973 as an adjunct to flexible endoscopic resection of colonic polyps [5]. Although well-described in the literature, the technique of submucosal injection to permit safer and easier polypectomy did not achieve widespread acceptance until further described by Tada in 1987 [18].

Multiple reports from Japan have appeared in the literature throughout the 1990s. The technique has undergone several variations, with some physicians advocating the addition of epinephrine to a saline injection, some a dye (indigo carmine), and others suggesting the use of hypertonic saline or even sodium hyaluronate [28] to maintain the fluid injection at the site of polypectomy and render the procedure even more safe than when saline alone is injected.

Endoscopic mucosal resection (EMR) in the colon has now come to have the same meaning as "saline-assisted polypectomy" (SAP), or a more recently used term, "submucosal injection polypectomy" (SIP), which more precisely describes the injection technique. Utilizing SIP, it is possible to safely remove both large and small polyps. The use of EMR has not been widely embraced by Western endoscopists, but some are beginning to use this method [7].

Indications for submucosal injection polypectomy

The indication for which SIP is most often employed is sessile polyps in the right colon. Indeed, this type of polyp is an ideal choice for injection of fluid into the submucosa to render the polypectomy safer and easier, but the removal of any polyp located between the sigmoid and the cecum may benefit from submucosal injection. In the absence of a submucosal injection of fluid, placing the snare around a polyp of over 1.5 cm in diameter may result in "bunching up" of the polyp within the closed snare. However, because of the thinness of the colon wall, it is possible that the outer muscle layer, the muscularis propria, can also be enfolded within the snare loop, and cutting across the polyp during its removal may result in a hole in the bowel wall. This complication can be avoided by injecting fluid into the submucosal space, causing the mucosa and the fluid-filled submucosa to be entrapped within the snare while keeping the muscularis propria safely away from the captured tissue.

In the rectum, where the submucosal tissue is loose and compliant, there is rarely a need for mucosal injection, even for removal of large flat polyps. Pedunculated polyps, on the other hand, are readily removed with the standard wire snare and cautery technique, usually with only one transection attempt.

In spite of some reports that injection of epinephrine into the pedicle of the polyp may decrease the tendency for post-polypectomy bleeding, that has never been substantiated. I, personally, do not inject the stalk of a pedunculated polyp with a vasoconstrictor solution because the incidence of immediate bleeding during polypectomy is only 1%, and, should bleeding occur, it can always be controlled at the time of the polypectomy procedure [25].

Some of the previous criteria used for not removing colon polyps requires revision, based on the ease of removal of large polyps following submucosal injection. These criteria were [23]:

  1. If the polyp appeared to be malignant, it should not be removed.
  2. If the polyp crosses two interhaustral folds, it should not be removed because the polyp hidden between the two folds, or on the most proximal side of the first fold, may not be amenable to endoscopic access, and therefore cannot be removed.
  3. A polyp that is greater than one third of the circumference of the bowel wall should not be removed because of its large size.
Currently, with the submucosal injection techniques, it is possible to remove most polyps, but the first criteria should always be considered: if the polyp appears to be malignant, it may not be amenable to endoscopic resection.

Polyps that cross 2 interhaustral folds are still difficult to remove, but the portion previously hidden in a valley between 2 folds, or on the proximal side of a haustral fold, can frequently be elevated into polypectomy position by injection of fluid. Occasionally, diffuse spreading-type polyps that may involve half or more of the circumference of the colon wall can be removed with the assistance of SIP. On the other hand, circumferential polyps are often not amenable to removal.

Technique of submucosal injection polypectomy

Most sessile polyps can be removed using the SIP technique. I do not feel that polyps less than 1.5 cm in diameter require the submucosal injection of saline and I use the injection method for larger polyps. Lesions over 2 cm in diameter may best be resected using the piecemeal technique. The intent of the injection is to instill saline in the submucosal space directly under the polyp, elevating the mucosa from the muscularis propria layer. A needle is placed into the submucosal space and fluid injected. My personal preference is to use saline, although some endoscopists add a tiny amount of blue dye to stain the submucosal space, ostensibly to make it easier to recognize the edges of the polyp, which are a distinct pink against a blue fluid-filled submucosal space. I have not found this to be particularly helpful, and continue to inject only physiologic saline.

If the injecting needle penetrates the bowel wall and saline is squirted into the peritoneal cavity that is not a problem. Surgeons leave a considerable amount of saline in the abdomen following a laparotomy, and are not concerned about a few milliliters of saline in the peritoneal cavity. Should a fluid elevation not be visually identified as the injection is being performed, the endoscopist should withdraw the needle as the endoscopic assistant continues to inject fluid. Once in the submucosal space, the mucosa will balloon out in response to the injected fluid. My preference is to begin the injection on the proximal edge of a polyp farthest from the scope tip because injection of a large volume of fluid into the edge of a polyp nearest the endoscope will result in a large submucosal bleb, elevating the polyp and tilting it away from the lens of the instrument. This can cause a problem because the polyp may actually disappear behind the submucosal bleb which actually hides the more proximal polyp, making it extremely difficult to remove the polyp. My preference is to inject the polyp on the proximal end by extending the needle, pointing the instrument directly down toward the base of the polyp, and making the injection on the proximal edge.

A recent position statement from the ASGE suggested that "initial injection of the distal aspect of the lesion has been advocated to optimize visibility and facility accession" [1]. This statement has to be modified according to the site where endoscopic mucosal resection will occur. If in the stomach, the distal aspect should be injected to elevate the distal portion and bring the polyp into better view. In the colon, however, it is necessary to inject the proximal portion for the reasons presented above. In any event, the injection solution should be placed into the area furthest away from the instrument tip to facilitate snare resection. If the polyp has no characteristics of malignancy, and requires a submucosal injection for polypectomy, I believe it is safe to make the injection directly into the polyp. The submucosa of the polyp is the submucosa of the colon wall, and injection directly into the polyp results in tracking of fluid into the submucosal space of the bowel wall, where the fluid will collect and the ensuing elevation can be seen.

There are theoretic considerations that should be considered when placing an injection needle directly through a polyp, with the possibility of penetrating the colon wall. The potential problem is the risk of spreading malignant cells through the bowel wall and into the peritoneal cavity. Needle tracking is not a common occurrence, with experience gained from direct percutaneous needle aspiration of malignant tumors in other sites throughout the body. In the latter instances, the risk of tumor tracking is 1 in 10,000 to 1 in 20,000 cases [14]. Needle tracking has been mentioned in a letter to the editor of Gastrointestinal Endoscopy [29], but I personally have not seen the spread of malignancy from injecting into sessile colon polyps. Of course, one should not inject into a colon polyp that is thought to contain a malignancy.

Injection volumes may range from 2 ml to 30 ml and may be repeated during the procedure as necessary [24].

Techniques for polypectomy

Lesions less than 2 cm in diameter can readily be transected with one application of the snare, providing that the entire polyp can be captured. Inclusion of a small portion of normal mucosal adjacent to the confines of the polyp does not pose a problem, providing that this portion of normal mucosa is also resting on the submucosal fluid-filled bleb. The polyp can then be removed in standard fashion using a standard polypectomy technique. Aspiration of air will decrease the tension on the bowel wall, causing the mucosa and the polyp to collapse longitudinally as well as circumferentially. This will result in thickening of the bowel wall, and the polyp will also become thicker and more readily snared. However, sufficient air distention must be maintained to permit visualization of the polypectomy events.

Position of polyp

To capture a polyp, one of the most important factors is that it be in proper position relative to the tip of the colonoscope. One of the most frustrating problems encountered during polypectomy is that the polyp is in poor position. A polyp at the 5 o'clock position in the visual field is readily snared, since, in colonoscopes, the snare enters the field at this orientation. A polyp located between 9 and 12 o'clock in the visual field is much more difficult to lasso than a polyp in the right lower quadrant, and those in the 3 or 8 o'clock position are impossible. An attempt should be made to bring all polyps into the 5 o'clock position to facilitate snare placement [22]. This can usually be accomplished by rotation of the scope to reposition the face of the scope in relation to the adenoma.

Rotation of the scope may be difficult during intubation when the instrument shaft has loops and bends. Advantageous positioning may be best accomplished when the colonoscope shaft is straight, because a straight instrument transmits torque to the tip, whereas a loop in the shaft tends to absorb rotational motions applied to the scope. It is often difficult to capture a sigmoid polyp during intubation, when the obligatory sigmoid loop is present. It may not be possible to straighten the scope in the sigmoid because rotation and loop withdrawal results in losing the scope's position. With a loop in the scope, the dial controls may no longer work effectively to turn the instrument tip because the cables which transmit motion are maximally stretched by the loop. These 2 negative forces, the inability to torque effectively, and the loss of cable-controlled tip deflection, combine to create an extremely difficult situation when attempting to maneuver the snare into position around a polyp. Maneuvering can be made considerably easier by passing the scope far beyond the polyp, even to the cecum (and thus visualize the rest of the colon) and attempt capture during the withdrawal phase of the examination. As the scope is withdrawn, the loops are removed and the polyp which proved difficult to position during intubation may be quite easily ensnared because both torque and tip deflection are responsive when the shaft is straight.

Sequential piecemeal polypectomy

The initial intent during removal of polyps over 3 cm in diameter should be to take a large portion of the polyp at the first application of the snare, with a piece of approximately 2 cm being sufficient. To accomplish this, the open loop may be placed over the polyp, with one edge of the wire loop resting on a lateral edge of the polyp. The opposite wire can be rotated into position on the polyp, and then the loop may be closed. The second application of the open snare should place the wire in the divot that was just created by removal of the first portion and swing the snare over an adjacent large portion of the remaining polyp, and again close the snare following partial aspiration of air. This piecemeal technique results in removal of sequential portions of a polyp by methodically ensnaring adjacent portions sequentially. I prefer to remove proximal portions of the polyp first, but if a large mountain-portion of the polyp blocks the view of proximal portion, that can be resected during the early phase of polypectomy.

If some bleeding occurs during polypectomy, I prefer to continue polypectomy, since removal of an adjacent portion of polyp may heat-seal the blood vessel(s) causing the bleeding. Should bleeding be a problem (this rarely occurs) during piecemeal polypectomy, injection of epinephrine into the bleeding site will control the bleeding. Rarely is there a need for clips or for an electrothermal modality to control bleeding during piecemeal polypectomy performed with SIP.

I have not found it particularly useful to make marker cautery burns on the fluid-filled submucosal mound to permit identification of the borders of the intended resection site, with the idea that these markers may help to delineate the margins of resection should the edges of the polyp become indistinct because of partial polypectomy or because of bleeding.

Rectal polyps

Large rectal polyps need not have submucosal injection because of the collapsible nature of the rectum. The rectum is quite pliable and, being a distensible organ, markedly collapses when empty, throwing the mucosa into large folds. This tendency is useful during attempts at polypectomy in the rectum, since aspiration of air will cause the volume of the rectum to shrink, resulting in pleating of the mucosa, making any polyp much more prominent. An open snare placed over a rectal polyp may have difficulty in grasping the polyp when the rectum is distended with air. However, with air aspiration, the mucosa will collapse and actually push the polyp up within the open snare, rendering it easy to capture a large portion of a polyp which can be resected.

Multiple smaller resections of a large polyp can be performed as described above using sequential piecemeal polypectomy.

Once polypectomy has been performed, there is no need to close the mucosal defect. The mucosa heals concentrically and does not re-epithelialize from the base upward. Because of this type of healing, closure of a defect with clips to bring the mucosal edges together is of little benefit because the entire base must be reepithelialized with normal mucosa, and that process progresses from the edge of the wound.

Where should polypectomy be performed?

All sessile polyps of any size, from small to hemi-circumferential, can be removed in an office on an ambulatory basis [23]. My office is remote from the hospital and is a free-standing endoscopy suite. There is no need for patients to be admitted to a hospital for removal of colon polyps, no matter how large the lesion. I use conscious sedation in all patients, without an anesthesiologist, and have all the necessary critical material for polyp removal, including clips, loops, Roth baskets, marker substances for site identification, and the argon plasma coagulator.

Equipment for SIP

Needle A standard sclerotherapy needle stiff enough to fit through a long colonoscope which may have several loops and bends. The needle bevel should be short and acutely slanted. The submucosal layer is quite thin and a long bevel may permit a portion of the needle lumen near the sharp point to be within the submucosa while part of the open needle bevel remains outside the mucosal layer. When fluid is injected, it may tend to run out across the mucosa through the free portion of the bevel instead of depositing the fluid into the desired submucosal space.

Snares Any standard snare can be used for polypectomy. I do not use the "hairy snare" with multiple small wire protrusions around the snare perimeter. I find this snare difficult to work with, and have not found it to be useful.

I often use a spike-tip snare, first described by Kanamori [10]. The spike-tip snare has a 1 mm protrusion from its tip that allows that point of the snare to be pushed into (but not through) the colon wall. This is a helpful adjunct to piecemeal polypectomy of large polyps, since it is often desired to open the snare diameter wider and more easily capture a piece of tissue by impacting the snare tip onto a nearby segment of normal mucosal and widening the snare loop by advancing the sheath. Frequently, however, the tip of the standard snare will slide across mucosa when such an attempt is made, and the tip may even burrow underneath a portion of the mucosa proximal to the polyp itself. The spike-tip snare permits anchoring of the snare tip so that pushing on the sheath causes expansion of the loop diameter while keeping the tip fixed in position. I do not use it for all piecemeal polypectomy procedures, but it is a valuable adjunct under certain circumstances, especially when the standard snare slides across the surface continually, and when the polyp is very flat and the open snare is almost parallel to the mucosal surface.

Cap-device Plastic hoods may be placed onto the tip of any endoscope, which increases the area of mucosa which is attracted to the endoscope tip by suction application. Ordinarily, with a suction channel in the colonoscope that varies from 2.8 to 3.2 mm in diameter, only a small portion of mucosa (or polyp) will be suctioned onto the instrument tip. However, addition of a plastic hood onto the tip of the instrument markedly increases the diameter of the mucosa (polyp) that will be attracted by suction.

With the cap placed onto a portion of the mucosa (polyp), the application of suction will draw more and more of the bowel wall into the suction cap. If the diameter of the suction cap is 1 cm and the suction cap is 1 cm deep, not only will the 1 cm of mucosa in contact with the rim of the cap be drawn into the cap by suction application, but 1 cm on each side will also be drawn into the cylindrical device. The total amount of mucosa suctioned into the cap will abut against one wall of the cap (1 cm), the 1 cm-wide portion originally contacted by the cap will lie against the faceplate of the instrument (1 cm), and the opposite wall of the cap perimeter will contact another 1 cm segment of mucosa. This, therefore, causes the final defect to be 3 cm in diameter rather than 1 cm in diameter.

Special snares are used for this technique, which can be formatted to lie within a ridge just at the distal end of the cap so that when the tissue has been suctioned into the cap, closure of the snare will capture the base of the aspirated tissue. This cap is probably not as useful for removal of colon polyps as it is for gastric or esophageal lesions.

There has been a great deal of reports in the literature concerning the use of caps for endoscopic mucosal resection in the upper intestinal tract. Since most of the large colon polyps that are to be resected are in the right side of the colon, passage of an endoscope with the protruding cap can be cumbersome, especially in a colon that is difficult to intubate. In addition, the application of strong suction can potentially result in all 3 layers of the thin colon wall being aspirated into the cap, with subsequent transection of the entire thickness of the wall [15].

The submucosal injection of fluid may render the use of the cap more safe, and it may be useful for rectal polyps.

Join the debate! Click here to post your comments about this Personal View Speech.

Malignancy in polyps

Sessile polyps which contain invasive carcinoma are not usually amenable to colonoscopic polypectomy. It may be difficult to visually identify the malignant polyp, but some criteria have been reported, although many malignant polyps have a benign appearance [4, 13, 17]. The features of malignancy include an irregular surface contour, ulceration, friability, firm (or hard) consistency, and thickening of the stalk [2, 3, 27].

Although polyps with these features may not be malignant, the endoscopist should pay special attention to any lesion with malignant characteristics, since it may be require a different approach. Special care must be directed toward recovering all of the fragments for histopathologic evaluation and to precisely localize the polyp's position in the colon should subsequent surgery be required. This can be accomplished with a colonoscopic tattoo using a surgical marker such as India ink or a carbon suspension.

The initial evaluation by the endoscopist is paramount, since the morphology of the lesion may be incompletely assessed once resection occurs; the pathologist may not be able to ascertain whether a polyp was sessile or pedunculated, because a short pedicle may retract completely into the polyp head. Sessile polyps tend to curl up in formalin and the site of basal attachment may not be recognizable in the pathology laboratory [3, 11].

Immediately after the polyp has been resected, the endoscopist can usually assess easily the completeness of resection by observing the polypectomy site. This assessment is not a problem with the pedunculated polyp, nor in the sessile polyp with a small attachment to the colon wall. However, in sessile polyps with a broad base, or those that require piecemeal resection, the endoscopist may not be able to know if total endoscopic resection has been performed.

Theoretically, SIP in the presence of invasive cancer (not recognized by the endoscopist on visual inspection) may result in the deposition of malignant cells deep to the polyp [29]. However, even in the presence of a cancerous polyp, I have never seen tracking of malignant cells into or through the submucosal space by submucosal injection of fluid.

The goal for submucosal injection is to markedly elevate the polyp on a thick layer of saline. This may require 6 to 10 ml of saline for a relatively small polyp, or multiple injections of 8 to 10 ml of saline around a polyp to elevate it sufficiently. Uno described a "non-lifting sign" following SIP that may be an indicator of malignancy in a polyp [20]. If the polyp contains invasive cancer into the submucosa, the polyp may not elevate with a submucosal injection. Tumor fixation will cause the polyp to not elevate, and this should be considered an indication that the polyp may contain invasive malignancy. On the other hand, if a previous attempt at polypectomy has been performed, scar tissue can fix the polyp to the submucosal layer, which will restrict the elevation of the polyp during attempt at a subsequent submucosal injection.

Completion of polypectomy

For large sessile polyps (over 3 cm in diameter) there is a considerable recurrence rate following piecemeal polypectomy. If visible tissue remains following polypectomy, on follow-up examination there is a 100% probability of having recurrent polyp. If, on the other hand, the endoscopist determines on visual grounds that the entire polyp has been removed, follow-up examination will reveal some residual polyp in 50% of patients, although the volume of residual polyp will be quite small. The residual polyp seen on follow-up colonoscopy is usually in one small mass of adenoma, because as the base heals concentrically, small fragments of tissue that remain at the base or the periphery of the polyp tend to coalesce toward the center of the healing polypectomy defect.

In order to decrease the incidence of recurrent polyp at the polypectomy site, the base and edges of the polyp can be treated with a thermal modality. Although many endoscopists treat small residual fragments of adenoma following removal of large polyps with a thermal modality, this has not been studied for any device except the argon plasma coagulator [30].

The argon plasma coagulator is a device for the delivery of high-frequency current in a monopolar mode that does not require direct contact between the probe and tissue. When the distance from probe to tissue is optimal, the monopolar circuit is completed by the flow of electrons through the activated and ionized argon gas which transmits the electrical ions from the probe electrode to the tissue. The ionized argon gas is called the argon plasma. Utilizing a combination of voltage adjustment and motion of the probe tip, the thermal penetration of tissue can be varied between fractions of a millimeter to 6 mm. In the colon, the power output setting should usually be at 40 watts, with a relatively low gas flow (0.8 liters per minute). Uses in the large bowel include treatment of post-polypectomy bleeding and ablation of residual adenomas following their piecemeal resection [6, 9, 24]. The delivery system for flexible endoscopy was developed in Germany (ERBE, Inc., Tubingen, Germany) [8, 16].

Treatment of polyp base following removal

After removing a sessile polyp in piecemeal fashion, the base may be somewhat irregular due to several individual passes of the snare. If only ragged fragments of tissue are seen at the base, a repeat examination after four to twelve weeks may reveal that the polyp has completely disappeared, since thermal energy delivered during polypectomy may slough the remnants. If visible adenoma is present, fulguration may be accomplished by using a variety of thermal devices, including the argon plasma coagulator, a Bicap, heater probe, current applied to the barely extended snare wire, or a hot biopsy forceps [21].

In spite of all attempts to totally remove large sessile polyps (over 3 mm in diameter) when the polyp appears to have been completely removed with the snare, with or without SIP, there is a 50% probability that there will be residual or recurrent adenoma at the site of original resection on the follow-up examination. If total polypectomy has not been achieved and there is visible residual adenoma left at the polypectomy site, there is no possibility of subsequent total involution and therefore residual polyp will be present on the follow-up examination. However, if visible residual adenoma is immediately treated with the argon plasma coagulator, the risk of residual adenoma falls to the 50% mark [30]. Most of these recurrences can be subsequently endoscopically resected at the follow-up examination.

Treating residual tissue with the argon plasma coagulator will reduce the recurrence rate from 100% to 50% when visible fragments of polyp have been treated following removal of large sessile polyps. A straight probe or side-fire probe may be utilized successfully. Follow-up after SIP piecemeal polypectomy should be scheduled for 3 to 6 months providing that there is no invasive malignancy in the specimen that has been resected.

Retrieval of specimens

Large sessile colon polyps that are removed from the rectum and sigmoid are readily removed utilizing suction on the tip of the endoscope. If large fragments of polyp have been resected, the suction as applied through the small suction channel at the tip of the instrument may not be sufficient to hold the polyp onto the tip of the instrument as it is withdrawn through the anal canal. Large fragments may be removed by resnaring and pulling the polyp fragment up against the faceplate of the instrument, and then removing the instrument with gentle pressure as the patient is asked to bear down in a defecatory attempt.

Polyps in the proximal colon are more difficult to remove. If the fragments are small and the polyp is relatively soft and pliable, it can be removed by suction. If suction is used, the multicompartmented suction trap with mesh compartments can be successfully employed to collect the polyp fragments within the trap to prevent them from traveling into the large suction chamber ordinarily used to collect aspirated material.

The Roth basket is an especially useful tool for retrieval of fragments of right colon polyps [23]. The basket resembles a wire snare with a soft nylon net attached to its perimeter. This can be placed over polyp fragments, and upon closure the fragments are trapped within the basket. Opening the basket repeatedly will permit the entrapment of several fragments while retaining the original fragments within a slight redundancy of the net which forms a pouch. This basket may also be employed for removal of large rectal polyps when it is not possible to bring them through the anal canal since it permits a large amount of tension on the basket during removal of polyps through the anal canal.

Safety and complications

Removal of polyps using SIP is an extremely safe and effective method for polypectomy. I have never encountered a perforation utilizing this procedure. One of the obvious problems with piecemeal polypectomy of large colon polyps is the polyp with invasive carcinoma. If any fragment contains cancerous cells, it is not possible to tell which portion was at the base of the polyp, and therefore a decision should be made as for any patient having invasive carcinoma in an adenoma.

Most of the patients who have large right colon polyps are elderly, and decisions should be made based on the probability of recurrent tumor, the risk of nodal metastasis or distant metastases. Even with a large sessile polyp, where carcinoma invades down to the resection margin, the incidence of residual nodal or distant metastasis is less than 100%, and is probably closer to 15% [26]. Therefore, in the patient who is elderly and/or a poor operative risk, the risk of a surgical resection must be balanced against the probability of that patient dying from metastatic cancer. This decision must be based on the patient's general condition, the extent of carcinoma, and whether the endoscopist felt that the entire tumor was removed at the time of polypectomy.

A complication which has been seen following colonoscopic polypectomy of large colon polyps is bleeding. It has been reported [31] that there is a higher risk of bleeding following SIP than standard polypectomy but use of this technique results in a complete adenoma resection in a majority of patients. A recent paper [32] discussed the advantages of superselective transcatheter embolization of uncontrollable acute lower GI hemorrhage following SIP. Three cases were described, and all occurred immediately following SIP and controlled with microcoil embolization.

SIP is a safe and effective method for removal of sessile polyps. By paying attention to detail, raising a sufficient submucosal bleb of fluid, and following accepted piecemeal polypectomy techniques, removal of large sessile polyps throughout the colon is possible in a high percentage of patients.

This "Personal View" was published as part of the syllabus for the New York Society for Gastrointestinal Endoscopy 27th Annual Postgraduate Course - Endoscopic Decision Making 2003, held in New York, NY. 15 and 16 December 2003. See the NYSGE website.

References

  1. American Society for Gastrointestinal Endoscopy. Endoscopic mucosal resection. In press. Technology status evaluation.
  2. Binmoeller KF, Bohnacker S, Seifert H, et al. Endoscopic snare excision of "giant" colorectal polyps. Gastrointest Endosc 1996; 43: 183-8.
  3. Christie JP. Polypectomy or colectomy? Management of 106 consecutively encountered colorectal polyps. Am Surg 1988; 54: 93-9.
  4. Cranley JP, Petras RE, Carey WD, et al. When is endoscopic polypectomy adequate therapy for colonic polyps containing invasive carcinoma? Gastroenterology 1987; 91: 419-27.
  5. Deyhle H, Largiader F, Jenny S, et al. A method for endoscopic electroresection of sessile colonic polyps. Endoscopy 1973; 5: 36-40.
  6. Farin G, Grund K E. Technology of argon plasma coagulation with particular regard to endoscopic applications. Endosc Surg Allied Technol 1994; 2: 71-7.
  7. Fleischer D. Endoscopic mucosal resection: (not) made in the USA (so commonly). A dissection of the definition, technique, use and controversies. Gastrointest Endosc 2000; 52: 440-4.
  8. Grund K E, Storek D, Farin G. Endoscopic argon plasma coagulation (APC) first clinical experiences in flexible endoscopy. Endosc Surg Allied Technol 1994; 2: 42-6.
  9. Johanns W, Luis W, Janssen J, et al. Argon plasma coagulation (APC) in gastroenterology: experimental and clinical experiences. Eur J Gastroenterol Hepatol 1997; 9: 581-7.
  10. Kanamori T, Itoh M, Yokoyama Y, et al. Injection-incision - assisted snare resection of large sessile colorectal polyps. Gastrointest Endosc 1996; 43: 189-95.
  11. Morson BC, Whiteway JE, Jones EA, et al. Histopathology and prognosis of malignant colorectal polyps treated by endoscopic polypectomy. Gut 1984; 25: 437-44.
  12. Rosenberg N. Submucosal saline wheal as a safety factor in fulguration of rectal and sigmoid polyps. Arch Surg 1955; 70: 120.
  13. Rossini FP, Ferrari A, Coverlizza S, et al. Large bowel adenomas containing carcinoma--a diagnostic and therapeutic approach. Int J Colorect Dis 1988; 3: 47-52.
  14. Schiano TD, Pfister D, Harrison L, et al. Neoplastic seeding as a complication of percutaneous endoscopic gastrostomy. Am J Gastroenterol 1994; 89: 131-3.
  15. Slivka A, Parsons WG, Carr-Locke DL. Endoscopic band ligation for treatment of post-polypectomy hemorrhage: Case report. Gastrointest Endosc 1994; 40: 230-2.
  16. Storek D, Grund K E, Gronbach G, et al. [Endoscopic argon gas coagulation--initial clinical experiences]. Z Gastroenterol 1993; 31: 675-9.
  17. Sugihara K, Muto T, Morioka Y. Management of patients with invasive carcinoma removed by colonoscopic polypectomy. Dis Colon Rectum 1989; 32: 829-34.
  18. Tada M, Karita M, Yassai H, et al. Treatment of early gastric cancer using strip biopsy, a new technique for jumbo biopsy. In: Takemoto T, Kawai K, eds. Recent Topics of Digestive Endoscopy. Tokyo: Excerpta Medica, 1987: 137-42.
  19. Tsuga K, Haruma K, Fujimura J, et al. Evaluation of the colorectal wall in normal subjects and patients with ulcerative colitis using an ultrasonic catheter probe. Gastrointest Endosc 1998; 48: 477-84.
  20. Uno Y, Munakata A. The non-lifting sign of invasive colon cancer. Gastrointest Endosc 1994; 40: 485-9.
  21. Walsh RM, Ackroyd FW, Shelito PC. Endoscopic resection of large sessile colorectal polyps. Gastrointest Endosc 1992; 38: 303-9.
  22. Waye JD. Endoscopic treatment of adenomas. World J Surg 1991; 15: 14-19.
  23. Waye JD. How big is too big? Gastrointest Endosc 1996; 43: 256-7.
  24. Waye JD. New methods of polypectomy. Gastrointest Endosc Clin N Am 1997; 7: 413-22.
  25. Waye JD, Lewis BS, Yessayan S. Colonoscopy: a prospective report of complications. J Clin Gastroenterol 1992; 15: 347-51.
  26. Waye JD, O'Brien MJ. Cancer in Polyps. In: Cancer of the Colon, Rectum, and Anus. Eds. Alfred M. Cohen and Sidney J. Winawer, McGraw-Hill, New York, 1995.
  27. Williams CB, Whiteway JE, Jass JR. Practical aspects of endoscopic management of malignant polyps. Endoscopy 1987; 19: 31-7.
  28. Yamamoto H, Yube T, Isoda N, et al. A novel method of endoscopic mucosal resection using sodium hyaluronate. Gastrointest Endosc 1999; 50: 251-6.
  29. Zarchy T. Risk of submucosal saline injection for colonic polypectomy. Gastrointest Endosc 1997; 46: 89-90.
  30. Zlatanic J, Waye JD, Kim PS, et al. Large sessile colonic adenomas: use of argon plasma coagulator to supplement piecemeal snare polypectomy. Gastrointest Endosc 1999; 49: 731-5.
  31. Ahmad NA, Kochman ML, Long WB, et al. Efficacy, safety, and clinical outcomes of endoscopic mucosal resection: a study of 101 cases. Gastrointest Endosc 2002; 55: 390-6.
  32. Mezawa S, Homma H, Murase K, et al. Superselective trancatheter embolization for acute lower gastrointestinal hemorrhage after endoscopic mucosal resection: a report of 3 cases. Hepatogastroenterology 2003; 50: 735-7.
Go to top of page

YourComments

 

Removal of colon polyps in babies and children is no different from polypectomy in adults. Although the adult colon is quite thin, varying in size from 17-23mm throughout, the infant colon is considerably smaller in thickness. Most polyps in children will be juvenile polyps, and the vast majority of these are pedunculated, rendering polypectomy safer and easier than sessile polyps. However, for sessile polyps of any size I suggest submucosal injection of saline prior to polypectomy to increase the thickness of the submucosa prior to polypectomy. I do not believe that any changes in electrocoagulation settings are necessary for children.

fiogf49gjkf05

Jerome D. Waye, M.D. , 15 February 2004

 

Does Dr Waye make any changes in coagulation settings or technique while removing polyps in babies and children?

fiogf49gjkf05

Mani Veeraraghavan, Madras, India , 12 February 2004

Go to top of page Email this page Email this page to a colleague

Close folder Gastroenterology
Mouth
Esophagus
Stomach & duodenum
Helicobacter pylori
Small intestine
Colo-rectum and anus
Pancreas
Inflammatory bowel disease
Functional bowel disorders
Nutrition
Symptoms/signs of gastrointestinal disease
Basic science
Open folder Hepatology
Close folder Endoscopy
Upper endoscopy
ERCP
  Colonoscopy
Endoscopic ultrasound
Technology
Practice issues

Blackwell Publishing


GastroHep.com is a Blackwell Publishing registered trademark
© 2017 Wiley-Blackwell and GastroHep.com and contributors
Privacy Statement
Disclaimer
About Us