A purse string suture is a running stitch placed in a circle around an opening, so that when the thread is pulled tight, the tissue gathers inward like the drawstring on a cloth pouch. Surgeons use this technique across a surprisingly wide range of specialties, from closing skin wounds after tumor removal to shrinking a dilated pupil inside the eye. The concept is ancient and intuitive, but its modern applications keep expanding, particularly in endoscopic and minimally invasive procedures where conventional stitching is difficult or impossible.
How the Suture Actually Works
Picture the top of a fabric drawstring bag. A single thread runs around the rim in a circle. Pull both ends of the thread, and the opening cinches shut. A purse string suture does exactly that in living tissue. The surgeon passes a needle in and out around the perimeter of a wound or opening, creating a ring of thread. When tension is applied and the suture is tied, the surrounding tissue is drawn inward from all directions toward the center. This circumferential advancement is what makes the technique distinctive: instead of pulling two edges together in a straight line, it gathers tissue evenly from every side.
Because of that geometry, the final scar is always smaller than the original defect. One study of cutaneous surgical defects found the average scar measured about 79% the size of the initial wound.1PubMed Central. Various Applications of Purse-String Suture and Its Cosmetic Outcome in Cutaneous Surgical Defects And because the tissue moves inward symmetrically, nearby structures like the eyelid, nostril, or lip are less likely to be pulled out of position compared with a linear closure that tugs in one direction.2PubMed Central. Surgical refinement of the purse-string suture for skin and soft tissue defects of the head and neck
Closing Skin Wounds After Tumor Removal
Dermatologic surgeons often face a particular dilemma: after cutting out a skin cancer, they are left with a round or irregularly shaped defect that does not lend itself to a neat linear stitch. The standard options include a skin graft, a local flap (rotating a nearby patch of skin), or simply leaving the wound open to heal on its own (called second intention healing). A purse string suture offers an alternative that can shrink the wound dramatically without borrowing tissue from another site.
In head and neck surgery, where cosmetic outcomes matter a great deal and the anatomy is crowded, the purse string approach avoids distorting the eyes, nose, or mouth. Multi-layered versions of the suture, where stitches are placed at different tissue depths, can reduce wound size enough that a much smaller graft or flap finishes the job days later. In one series, a multi-layered purse string alone closed defects in an average of about three and a half days, while cases that needed a delayed graft or flap took closer to ten days.3PubMed Central. Various Applications of Purse-String Suture and Its Cosmetic Outcome in Cutaneous Surgical Defects
A fair question is whether the purse string actually looks better than letting the wound heal on its own. A randomized trial compared the two approaches directly and found no statistically significant difference in scar quality as rated by both patients and blinded observers. The scar-to-defect ratio was slightly lower in the purse string group (0.39 versus 0.43), and wounds trended toward faster healing (roughly five and a half weeks versus seven and a half), but neither difference reached significance. The one notable downside was spitting sutures, where buried stitch material works its way to the skin surface, which occurred more often in the purse string group.4JAMA Dermatology. Purse-String Suture vs Second Intention Healing: Results of a Randomized, Blind Clinical Trial The takeaway is that the purse string is not dramatically superior to leaving a wound alone in terms of final appearance, but it does shrink the wound upfront and may be worth the tradeoff when the defect is large or in a cosmetically sensitive spot.
Stoma Reversal Sites
One of the most well-studied uses of the purse string suture has nothing to do with internal organs. It involves the skin wound left behind when a stoma (an intestinal diversion that empties through the abdominal wall) is reversed. After the bowel is reconnected inside the abdomen, the surgeon still has to deal with the circular hole in the skin where the stoma used to be. The traditional approach is to close it with a straight line of stitches, but that site is notoriously prone to infection. The stoma opening has been exposed to bowel contents, and the wound is essentially contaminated.
A Cochrane systematic review pooling nine trials with over 750 patients found that purse string closure cut the risk of surgical site infection dramatically: roughly 5 in 100 patients developed an infection after purse string closure compared with about 24 in 100 after linear closure.5PubMed Central. Purse-string skin closure versus linear skin closure in people undergoing stoma reversal The mechanism makes intuitive sense. A purse string closure leaves a small central opening that can drain any fluid that accumulates beneath the skin, while a fully sealed linear closure traps contamination underneath. Patient satisfaction was also higher in the purse string group, though the evidence for that was less certain. The two techniques appeared similar for incisional hernia risk and operative time.
This is one of the clearest wins for the purse string in the surgical literature. The infection-rate difference is large enough and consistent enough across studies that many colorectal surgeons now use it as their default approach for stoma site skin closure.
The Appendiceal Stump Debate
For much of the twentieth century, surgeons were taught to bury the stump of a removed appendix by inverting it into the cecum (the pouch where the large intestine begins) and securing it with a purse string suture. The idea was that an exposed stump might leak, form adhesions, or serve as a starting point for infection. Inversion felt tidy and safe.
Multiple studies eventually challenged that assumption. A review of 886 appendectomies found that patients with gangrenous appendicitis who had their stumps inverted actually developed bowel obstructions from adhesions at a higher rate than those who had simple ligation, where the stump is just tied off and left alone.6JAMA Surgery. Simple Ligation vs Stump Inversion in Appendectomy A prospective randomized study of 200 patients reached the same conclusion: complication rates were equal between the two techniques, but simple ligation was faster, simpler, and preserved the normal anatomy of the cecal wall.7PubMed Central. Simple ligation vs stump inversion in appendicectomy A separate prospective trial agreed, recommending simple ligation as the standard procedure on the grounds that it avoids deforming the cecum and may reduce the risk of adhesion-related problems.8PubMed. Simple ligation superior to inversion of the appendiceal stump; a prospective randomized study
The purse string stump inversion has not disappeared entirely, but it is no longer considered necessary for routine appendectomy. In laparoscopic surgery, where the appendix is typically divided with a stapler or a loop ligature, stump inversion would add complexity for no proven benefit. This is a useful example of how a surgical tradition built around a purse string suture was eventually overturned by evidence.
Closing Holes During Endoscopy
Some of the most inventive recent uses of the purse string suture happen inside the gastrointestinal tract during endoscopic procedures. When an endoscopist removes a tumor from the stomach or intestinal wall, the resection can create a full-thickness hole. Historically, that meant open surgery to close the perforation. Endoscopic purse string suturing now offers a way to seal these defects without an operation.
The approach typically involves threading a suture through the working channel of an endoscope and placing it around the rim of the defect using small clips as anchoring points. The suture is then tightened, drawing the tissue edges inward to close the hole. A multicenter study of 42 patients who developed wall defects during endoscopic resection found that the technique worked as well through a standard single-channel endoscope as through the more specialized double-channel version, with no significant difference in suturing time (about 10 to 15 minutes) or complication rates.9PubMed Central. Therapeutic application of purse-string sutures with nylon loops and metal clips under single-channel endoscopy for repair of gastrointestinal wall defects A separate study confirmed that endoscopic purse string suturing achieved secure, complete closure of mucosal defects, and a pre-looped version of the technique shortened procedure time further.10PubMed Central. Feasibility and efficacy of endoscopic purse-string suture-assisted closure for mucosal defects induced by endoscopic manipulations For larger perforations in the duodenum, purse string sutures using novel endoloops and repositionable clips through a single-channel endoscope have also proven feasible and effective.11PubMed. Purse-string sutures using novel endoloops and repositionable clips for the closure of large iatrogenic duodenal perforations with single-channel endoscope: a multicenter study
There are limits, however. In ex vivo testing that compared different closure methods head-to-head, endoscopic purse string sutures provided lower burst pressures than over-the-scope clips or hand-sewn surgical sutures. The mean leak pressure for the endoscopic purse string approach was about 14 mmHg, compared with about 25 mmHg for over-the-scope clips.12PubMed Central. Comparison of purse-string suture versus over-the-scope clip for gastric endoscopic full-thickness closure: traction and leak pressure testing in ex vivo porcine model These are lab-bench numbers rather than clinical outcomes, but they suggest that for larger or higher-stress defects, clip-based closure or traditional surgery may still hold an advantage.
Hemorrhoid Surgery
Stapled hemorrhoidopexy, sometimes called the procedure for prolapse and hemorrhoids, relies heavily on a well-placed purse string suture. The surgeon places a running stitch in a ring around the rectal mucosa above the hemorrhoid cushions, then fires a circular stapler that excises a band of tissue and re-staples the edges. The purse string determines exactly where that tissue band sits: too high and you miss the prolapsing tissue, too low and you risk damaging the sensitive skin below the dentate line.
Getting this suture right is the most technically demanding part of the operation. Large prolapsing hemorrhoids can obscure the view and make precise placement difficult. Techniques have been developed to make the step more reliable for both experienced and novice surgeons, including methods that improve visibility by systematically retracting the hemorrhoidal tissue before placing the stitch.13Surgical Laparoscopy, Endoscopy & Percutaneous Techniques. Stapled Hemorrhoidopexy: A Technique for Applying the Crucial Purse String Suture (MAMC Technique) The purse string here is not closing a wound; it is positioning tissue for a stapler. But the underlying geometry is the same: a circular stitch, cinched tight, gathering tissue inward.
Cervical Cerclage in Pregnancy
In obstetrics, a purse string suture placed around the cervix is used to help prevent preterm birth in women with a weakened or shortened cervix. The procedure, called cervical cerclage, involves stitching the cervix closed during pregnancy and removing the suture near the due date. The technique dates back to the 1950s and remains one of the few mechanical interventions available for cervical insufficiency.
The evidence for cerclage is nuanced. A Cochrane review of nine trials involving nearly 2,900 women found that cerclage reduced preterm births by about 20% compared with no treatment. However, there was no statistically significant reduction in perinatal deaths or neonatal illness.14Cochrane Database of Systematic Reviews. Cervical stitch for preventing preterm birth in singleton pregnancy That gap between “fewer preterm births” and “not clearly fewer deaths” has kept the debate alive about which patients benefit most. Current practice generally reserves cerclage for women with a documented history of cervical insufficiency or a very short cervix on ultrasound, rather than using it broadly.
Reshaping the Pupil
One of the more unexpected places a purse string suture shows up is in ophthalmic surgery. When the iris (the colored part of the eye that controls the pupil) is damaged by trauma, prior surgery, or neurological conditions, the pupil can become permanently dilated and unable to constrict. This causes debilitating glare and light sensitivity. A purse string suture placed through the iris can cinch the pupil back down to a functional size.
A recent report on eight patients who underwent this technique found that average pupil diameter dropped from about 7.4 mm to about 3.1 mm. At follow-up of at least six months, all treated pupils remained centered and roughly round.15PubMed Central. Thirty-gauge needle-guided purse-string suture pupilloplasty: a new technique The procedure used an extremely fine suture (10-0 prolene, a thread barely visible to the naked eye) guided by a needle inserted through the cornea. The elegance of the approach lies in its simplicity: rather than cutting and restructuring the iris, the surgeon essentially tightens it like a drawstring.
Chest Drain Sites
After chest surgery, a drain tube is placed through the chest wall to remove air and fluid. When the tube comes out, the hole needs to close immediately or air can leak back in and collapse the lung. The conventional approach uses a pre-placed suture that is tied down when the tube is removed. A variant using a knotless barbed suture in a purse string pattern has been tested as an alternative. In a comparison study, the knotless method produced a low pneumothorax rate after tube removal, though the difference from the conventional method was not statistically significant.16PubMed Central. Feasibility and Safety of a New Chest Drain Wound Closure Method with Knotless Sutures The appeal of the purse string here is speed and simplicity at the bedside: cinch, tie (or let the barbs self-anchor), done.
Pediatric Hernia Repair
In children, laparoscopic inguinal hernia repair often uses a purse string suture to close the internal inguinal ring, the natural opening through which the hernia protrudes. The surgeon passes a suture around the ring under direct camera visualization and tightens it to seal the defect. One series combining inguinal and umbilical hernia repair in children reported mean operative times of about 30 minutes for unilateral cases and 40 minutes for bilateral, with no recurrences or complications during follow-up periods ranging from 8 to 32 months.17PubMed. Preliminary experience with laparoscopic repair of associated inguinal and umbilical hernias in children The purse string is well suited to this anatomy because the inguinal ring is essentially a round opening that needs to be narrowed, which is precisely the geometry the suture was designed for.
The Learning Curve for Endoscopic Purse Strings
Placing a purse string suture with your hands is a basic surgical skill. Placing one through a flexible endoscope, working with long instruments inside a hollow organ while watching a screen, is a different challenge entirely. The learning curve has historically been steep and poorly defined, which limits how widely the technique can spread.
Simulation-based training appears to help dramatically. A study evaluating a novel endoscopic suturing simulator found that trainees who practiced on the simulator could independently complete an entire purse string after an average of just 5 clinical cases, while those without simulator training needed about 38 cases to reach the same level of independence.18PubMed Central. Development of a novel endoscopic suturing simulator: validation and impact on clinical learning curve (with video) That is a sevenfold difference in the number of real patients needed before a trainee is competent. A separate effort to build a simulator specifically for transanal endoscopic purse string suturing confirmed that performance on the model tracked with prior laparoscopic suturing experience, suggesting the simulator meaningfully measures skill.19PubMed. Development and validation of a transanal endoscopic rectal purse string simulator
As endoscopic suturing expands into more complex procedures, from bariatric outlet reduction to defect closure to leak management, the ability to train surgeons and gastroenterologists efficiently becomes a bottleneck. The purse string is central to many of these procedures, and making it teachable outside of the operating room could be what determines how widely the techniques are adopted.
Where the Technique Falls Short
For all its versatility, the purse string suture is not universally the best option. In dermatologic surgery, as noted earlier, randomized data show it performs comparably to second intention healing rather than clearly outperforming it, and spitting sutures are a real nuisance for patients. In appendectomy, the purse string stump inversion turned out to be unnecessary and possibly harmful. And in bench testing of endoscopic closures, the purse string achieved lower burst pressures than some clip-based alternatives, raising questions about its reliability for high-stress closures.
In colorectal stapled anastomosis, the purse string serves a purely mechanical role: it secures the anvil of a circular stapler inside the bowel lumen so the stapler can fire properly.20Scientific Reports. Assessment of reinforcing sutures of double-stapling anastomosis with manual and powered circular staplers in Porcine models If the suture is placed unevenly, the staple line will be uneven, which increases the risk of leaking. The technique is only as good as the execution, and in tight spaces deep in the pelvis, getting an even circumferential bite of tissue can be genuinely difficult.
The common thread in these limitations is that the purse string works best when the opening is relatively small, the tissue is forgiving, and a slight residual gap (for drainage or secondary healing) is acceptable. When you need a watertight seal under pressure, a high-tension closure, or precise edge-to-edge alignment, other approaches often win. Surgeons who understand where the technique fits, and where it does not, get the best results from a stitch that has been around for centuries and is nowhere close to retirement.