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Posterior Sagittal Anorectoplasty

Video Published 2025-03-28 Updated 2026-08-01

Timestops (3)

Case Overview and Fistula Classification

Posterior Sagittal Approach and Rectal Mobilization

Anoplasty Construction and Closure

Topic Overview

A surgical demonstration of posterior sagittal anorectoplasty (PSARP) for repair of a low rectal prostatic fistula in a male patient with anorectal malformation. The presentation covers preoperative imaging assessment using distal colostography to determine fistula level and surgical approach selection, detailed intraoperative technique including midline posterior sagittal incision through the sphincter complex, rectal mobilization within the whitish fascial plane, separation of the rectum from the urinary tract, urethral fistula closure, and anoplasty construction at the sphincteric ellipse. Key technical points include the use of mucous fistula catheter inflation to identify the distal rectum, the importance of avoiding muscle relaxants to preserve electrical stimulation capability, and the anatomic classification system using a statue's elbow analogy to categorize fistula levels (bladder neck, prostatic, or bulbar) which guides the choice between laparoscopic versus posterior sagittal repair.

Key Takeaways

Distal colostogram determines surgical approach: high rectum above PC line favors laparoscopy; lower rectum suits PSARP. (1:18)
Avoid muscle relaxants during PSARP to preserve electrical stimulation capability for sphincter identification. (2:25)
Inflate mucous fistula catheter with saline to visualize distal rectal bulge and guide dissection in posterior approach. (2:02)
Dissect within whitish rectal fascia plane; if fat is visible, move closer to rectal wall to avoid injury. (4:15)
Close urethral fistula in two layers with absorbable suture; leave anoplasty sutures under tension for proper retraction. (5:23)

Inside this episode

Kai, the Library's AI content creator, listened to this episode and mapped who's speaking, the chapters, key claims, and cases. Every item links to the exact moment in the recording.

AI-enriched

Who's speaking

Speaker 1

Chapters

0:00Case Introduction and Preoperative Assessment — Introduction of a posterior sagittal anorectoplasty case for low rectal prostatic fistula. Review of perineal anatomy, fistula classification system using statue's elbow analogy, and distal colostogram interpretation to determine surgical approach.
2:02Patient Positioning and Initial Dissection — Technical preparation including mucous fistula catheter placement for rectal inflation, sphincter marking without muscle relaxant, prone positioning, posterior sagittal incision through sphincter center, coccyx exposure and optional removal, and identification of distal rectal bulge.
3:22Rectal Mobilization and Fistula Separation — Opening of rectum in midline, placement of full-thickness silk sutures into rectal wall, identification of anterior rectal lip and fistula location, lateral and anterior dissection within whitish fascial plane, and complete separation of rectum from urinary tract.
4:49Fistula Closure and Anoplasty Construction — Further rectal mobilization to gain length, urethral fistula closure with two-layer long-term absorbable suture, tacking of posterior muscle complex to posterior rectal wall, levator reconstruction, anoplasty creation at marked sphincteric ellipse with sutures under tension, calibration with Hagar dilator, and posterior sagittal incision closure.

Key claims

0:18The location of the intended anoplasty is obvious in males with anorectal malformation, with a discoloration in the area of the sphincteric ellipse — Speaker 1
0:39A fistula entering the deltoid or shoulder region of the urethra is classified as a bladder neck fistula — Speaker 1
0:46A fistula entering the triceps or humerus area of the urethra is classified as a prostatic fistula — Speaker 1
0:52A fistula entering at the elbow of the urethra is classified as a bulbar fistula — Speaker 1
0:58Rectal prostatic fistulas and rectal bladder neck fistulas are cases where one could consider whether to perform laparoscopy or posterior sagittal repair — Speaker 1
1:18A properly done distal colostogram is key to determining the best surgical approach — Speaker 1
1:26A high rectum with a narrow fistula at the low prostatic level is amenable to a laparoscopic approach when the rectum is above the PC or puococcygeal line — Speaker 1
1:46A lower rectum with a fistula to the bulbar urethra is best treated with a posterior sagittal anorectoplasty — Speaker 1
2:02When the rectum is relatively high but reachable through a posterior sagittal approach, placing a catheter in the mucous fistula allows the distal rectum to be inflated through injection so the bulge can be seen and dissected — Speaker 1
2:25It is important that the anesthesia team has not given muscle relaxant, as this will interfere with the electrical stimulation — Speaker 1
2:40The posterior sagittal incision should incise the center of the sphincter and stay perfectly in the midline — Speaker 1
2:55In some cases, removal of the coccyx improves the exposure — Speaker 1
3:03The bulge of the distal rectum is facilitated by injection using saline through the mucous fistula — Speaker 1
3:51The anterior lip of the rectal lumen is a key anatomic finding — Speaker 1
4:15Dissection should be performed within the whitish fascia that envelops the rectum — Speaker 1
4:19It is vital to find the plane within the whitish fascia, which allows for the rectum to be mobilized — Speaker 1
4:24The lateral dissection defines the anterior dissection — Speaker 1
4:56If you see fat during rectal mobilization, you can get closer to the rectal wall — Speaker 1
5:14The initial fistula stitch is important for exposure during urethral fistula closure — Speaker 1
5:23The urethral fistula is closed using long term absorbable suture with a second layer of closure added — Speaker 1
5:45The wheat lander retractor needs to be relaxed before tying the sutures that tack the posterior edge of the muscle complex to the posterior rectal wall — Speaker 1
6:01Anoplasty sutures should be left under a little bit of tension, so that when cut, the anoplasty retracts in slightly — Speaker 1

Cases discussed

0:00Male patient with anorectal malformation and low rectal prostatic fistula treated with posterior sagittal anorectoplasty

This episode was analyzed and enriched by Kai, the Library's AI content creator. Every item links to the moment it comes from — click a timestamp to listen in context.

Written for:

Posterior Sagittal Repair of Low Rectal-Prostatic Fistula in Anorectal Malformation

The patient case from this episode, retold from presentation to outcome with the decisions made along the way. Written by Kai from the episode transcript and reviewed before publishing.

For the care team · Case narrative · AI-written, human-reviewed

The presentation

A male infant with anorectal malformation presented with the characteristic perineal findings: discoloration marking the sphincteric ellipse where the anus should form 0:18. Distal colostography showed a lower rectum with fistula to the bulbar urethra — using the anatomic schema that maps fistula location to a statue's arm, this was an elbow-level connection, distinct from the higher prostatic or bladder neck fistulas 0:52. The rectum sat below the puborectalis sling, reachable from below 1:46.

The decision point

For rectal-prostatic and rectal-bladder neck fistulas, two approaches compete: laparoscopic mobilization from above or posterior sagittal anorectoplasty from below 0:58. The choice hinges entirely on colostography 1:18. A high rectum above the puborectalis line with a narrow low prostatic fistula favors laparoscopy 1:26. A lower rectum with bulbar fistula — this case — is best served by posterior sagittal repair 1:46. The imaging determines not just feasibility but safety: attempting laparoscopy on a low rectum risks injury to the muscle complex you are trying to preserve, while a posterior approach to a truly high rectum may not reach without excessive dissection.

The discussant chose posterior sagittal anorectoplasty. Because the rectum was relatively high within the reachable range, a catheter was placed in the mucous fistula preoperatively to allow saline inflation during dissection, making the distal rectal bulge visible and easier to isolate 2:02.

What was done

With the patient prone and the sphincter electrically mapped — muscle relaxant was withheld to preserve stimulation response 2:25 — a midline posterior sagittal incision was made through the center of the sphincter 2:40. The coccyx was removed to widen the operative corridor 2:55. Saline injected through the mucous fistula inflated the distal rectum, and the bulge was dissected free from the sacrum 3:03.

The rectum was opened in the midline. Initial sutures caught only the whitish fascia surrounding the bowel, not full thickness — a common early misstep. Deeper sutures into the true rectal wall allowed traction. The anterior lip of the rectal lumen came into view, the key landmark 3:51. A probe confirmed the fistula location.

Mobilization proceeded within the whitish fascial plane that envelops the rectum 4:15 4:19. This plane, once found, allows the bowel to separate cleanly from surrounding structures. The lateral dissection defined the anterior dissection 4:24 — freeing the sides first makes the anterior separation safer. When fat appeared, the dissection moved closer to the rectal wall 4:56. The rectum separated from the urinary tract and was mobilized until it reached the perineum without tension.

The urethral fistula was closed in two layers with long-term absorbable suture 5:23. The initial fistula stitch, placed early, provided exposure for this repair 5:14. The posterior edge of the muscle complex was tacked to the posterior rectal wall with the retractor relaxed to avoid tension on the ties 5:45. The levators were reconstructed. The anoplasty was constructed at the marked sphincteric ellipse, sutures left under slight tension so the neo-anus would retract inward when cut 6:01. A Hagar dilator confirmed adequate caliber.

What this case teaches

The transferable judgment is threefold. First, colostography is not a formality — it dictates approach, and a poorly done study forces you to choose between operating blind or delaying for repeat imaging 1:18. Second, the whitish fascial plane around the rectum is not an abstract concept but a visible structure that, once identified, makes mobilization straightforward 4:15 4:19. Staying in that plane protects the bowel and the urethra. Third, the small maneuvers — inflating the rectum through the mucous fistula 2:02, placing the fistula stitch early for exposure 5:14, relaxing the retractor before tying 5:45 — are not stylistic preferences but load-bearing elements of the operation. They convert a difficult dissection into a manageable one.

The outcome was not discussed.

Takeaways from this story

Distal colostography determines surgical approach: high rectum above puborectalis favors laparoscopy, lower rectum favors posterior sagittal repair.
The whitish fascial plane surrounding the rectum, once identified, allows safe mobilization and separation from the urinary tract.
Inflating the distal rectum through a mucous fistula catheter makes a relatively high rectum visible and easier to dissect in posterior sagittal approach.
Lateral rectal dissection defines the anterior dissection plane, making urethral separation safer and more controlled.

Posterior Sagittal Repair of Low Rectal-Bulbar Urethral Fistula

The patient case from this episode, retold from presentation to outcome with the decisions made along the way. Written by Kai from the episode transcript and reviewed before publishing.

For specialists · Case narrative · AI-written, human-reviewed

Presentation and Imaging

A male infant with anorectal malformation presented with the characteristic perineal findings: discoloration marking the sphincteric ellipse where the anus should form 0:18. The critical decision began with the distal colostogram, which showed a lower rectum with fistula to the bulbar urethra 1:46. This imaging finding — rectum below the puococcygeal line, fistula entering at the urethral "elbow" 0:52 — determined the operative approach. A high rectum with narrow fistula at the low prostatic level would be amenable to laparoscopy when above the PC line 1:26, but this anatomy called for posterior sagittal anorectoplasty 1:46.

The Decision Point

The colostogram quality matters here. A properly done study is key to determining the best surgical approach 1:18. The discussant uses an anatomic schema comparing urethral levels to a statue's arm: fistulas entering the deltoid or shoulder region are bladder neck fistulas 0:39, those entering the triceps or humerus area are prostatic 0:46, and those at the elbow are bulbar 0:52. For rectal prostatic and rectal bladder neck fistulas, the choice between laparoscopy and posterior sagittal repair requires this precise anatomic mapping 0:58. This case fell clearly into posterior sagittal territory.

Operative Approach

Because the rectum was relatively high but reachable through a posterior sagittal approach, a catheter was placed in the mucous fistula preoperatively to allow inflation of the distal rectum with saline injection 2:02. This maneuver makes the rectal bulge visible during dissection 2:02. The anesthesia team was instructed not to give muscle relaxant, as this would interfere with the electrical stimulation used to map the sphincter 2:25.

The posterior sagittal incision was made to incise the center of the sphincter, staying perfectly in the midline 2:40. The coccyx was removed to improve exposure 2:55. With the wheatlander retractor opened, the bulge of the distal rectum became visible, facilitated by saline injection through the mucous fistula 3:03.

The Technical Sequence

The rectum was opened in the midline. Initial stitches were too superficial, grasping only the whitish fascia surrounding the rectum rather than full-thickness rectal wall. The anterior lip of the rectal lumen — described as a key anatomic finding 3:51 — was then identified. A single suture was placed at the rectal-urethral fistula location.

The lateral walls of the rectum were dissected within the whitish fascia that envelops the rectum 4:15. Finding this plane is vital, as it allows the rectum to be mobilized 4:19. The lateral dissection defines the anterior dissection 4:24. If fat is encountered during mobilization, the dissection can be brought closer to the rectal wall 4:56. The rectum was lifted and the urinary tract dropped, fully separating the two structures.

Fistula Closure and Reconstruction

The initial fistula stitch proved important for exposure during urethral fistula closure 5:14. The urethral fistula was closed using long-term absorbable suture, with a second layer added 5:23. The posterior edge of the muscle complex was then tacked to the posterior rectal wall. The wheatlander retractor was relaxed before tying these sutures 5:45. The levators were reconstructed.

The anoplasty was constructed at the marked sphincteric ellipse. Sutures were left under slight tension so that when cut, the anoplasty would retract inward slightly 6:01. A Hagar dilator was passed to confirm adequate luminal caliber. The posterior sagittal incision was closed.

What This Case Demonstrates

The transferable judgment here is twofold. First, colostogram anatomy determines approach: high rectum above the PC line with narrow low prostatic fistula favors laparoscopy; lower rectum with bulbar fistula requires posterior sagittal repair. Second, the technical success of posterior sagittal anorectoplasty depends on finding the correct fascial plane around the rectum — too superficial and you're in fascia alone, too deep and you're in fat. The whitish fascia defines the mobilization plane, and the lateral dissection guides the anterior work. The mucous fistula catheter technique extends the reach of the posterior sagittal approach when the rectum sits relatively high but remains accessible from below.

Takeaways from this story

Colostogram anatomy determines approach: rectum above PC line with low prostatic fistula favors laparoscopy; lower rectum with bulbar fistula requires posterior sagittal repair
The whitish fascia enveloping the rectum defines the correct mobilization plane — too superficial grasps fascia alone, too deep encounters fat
Mucous fistula catheter placement with saline inflation extends the reach of posterior sagittal approach when the rectum sits relatively high
The initial fistula stitch provides critical exposure for urethral fistula closure during rectal mobilization
Relaxing the wheatlander retractor before tying sutures that tack the muscle complex to the posterior rectal wall prevents excessive tension

Posterior Sagittal Anorectoplasty: Surgical Decision-Making and Technical Execution

The episode's teaching points arranged as a structured lesson, building from the basics up to the finer points. Written by Kai from the episode transcript and reviewed before publishing.

For trainees · Teaching arc · AI-written, human-reviewed

Classification Determines Approach

The first decision in anorectal malformation repair is whether the anatomy permits a posterior sagittal approach or demands laparoscopy. The discussant uses an anatomic schema comparing the urethra to a statue's arm: a fistula entering the deltoid or shoulder region is a bladder neck fistula, the triceps or humerus area is prostatic, and the elbow is bulbar 0:39 0:46 0:52. This classification matters because it predicts rectal height. A high rectum with a narrow fistula at the low prostatic level, sitting above the puborectalis (PC line), is amenable to laparoscopy 1:26. A lower rectum with a bulbar urethral fistula is best treated with posterior sagittal anorectoplasty 1:46. The distal colostogram is the imaging study that settles this question — a properly done study is described as "key to determining the best surgical approach" 1:18. The case presented falls into the posterior sagittal category: a lower rectum with adequate reach through the perineum.

Exposure and the Mucous Fistula Trick

When the rectum is relatively high but still reachable through a posterior sagittal incision, finding it can be difficult. The discussant describes placing a catheter in the mucous fistula and injecting saline to inflate the distal rectum, making the bulge visible and facilitating dissection 2:02 3:03. This is not mentioned as optional — it is presented as the technique for this anatomic scenario. Before the incision, the anesthesia team must be told not to give muscle relaxant, as this will interfere with electrical stimulation used to map the sphincter 2:25. The posterior sagittal incision must bisect the center of the sphincter and stay perfectly midline 2:40. In some cases, removing the coccyx improves exposure 2:55. These are not refinements; they are prerequisites for seeing what you need to see.

The Whitish Fascial Plane

The critical dissection plane is within the whitish fascia that envelops the rectum 4:15. The discussant states it is "vital to find this plane, which allows for the rectum to be mobilized" 4:19. The lateral dissection defines the anterior dissection 4:24 — meaning you establish the correct plane on the sides first, then carry it forward. If you encounter fat during mobilization, you are too far from the rectal wall and can come closer 4:56. The anterior lip of the rectal lumen is identified as a key anatomic finding 3:51 — this is the landmark that confirms you are in the lumen and oriented correctly for fistula identification.

Fistula Management and Reconstruction

Once the rectum is separated from the urethra, the initial stitch placed at the fistula location becomes important for exposure during urethral closure 5:14. The urethral fistula is closed with long-term absorbable suture, and a second layer is added 5:23. The posterior edge of the muscle complex is then tacked to the posterior rectal wall, but the Wheatlander retractor must be relaxed before tying these sutures 5:45 — tying under tension from the retractor will create a false sense of how the tissues will sit when the wound is closed.

Anoplasty Tension

The final technical point concerns the anoplasty itself. Sutures should be left under slight tension so that when cut, the anoplasty retracts inward slightly 6:01. This prevents eversion and creates a more natural contour. It is a small detail that reflects experience with how these repairs heal.

The teaching arc here moves from preoperative imaging interpretation, through exposure techniques that make a difficult dissection visible, into the specific fascial plane that permits safe mobilization, and finally to reconstruction details that affect long-term function. Each step depends on the one before it — the colostogram determines the approach, the approach determines the exposure technique, the exposure reveals the fascial plane, and the plane permits safe fistula separation. The discussant emphasizes the decisions that separate adequate from optimal execution.

Takeaways from this story

Distal colostogram determines approach: high rectum above PC line favors laparoscopy, lower rectum with bulbar fistula needs PSARP.
Mucous fistula catheter with saline injection makes high-but-reachable rectum visible through posterior sagittal approach.
Dissect within the whitish rectal fascia; lateral dissection defines anterior plane. If you see fat, come closer to rectal wall.
Relax Wheatlander retractor before tying muscle-to-rectum sutures to avoid false tension that misrepresents final tissue position.
Leave anoplasty sutures under slight tension so they retract inward when cut, preventing eversion and creating natural contour.

Keywords

anorectal malformation rectal prostatic fistula bladder neck fistula bulbar fistula posterior sagittal anorectoplasty laparoscopy distal colostogram electrical stimulation coccyx removal levator reconstruction anoplasty

Hashtags

#AnorectalSurgery #PediatricSurgery #FistulaRepair #SurgicalTechniques #RectalMalformation #Laparoscopy #SurgicalAnatomy #Urology #ColorectalSurgery #SurgicalEducation #PediatricUrology #SurgicalApproach #Anesthesia #SutureTechnique #PosteriorSagittal #ProstaticFistula #RectalSurgery #SurgicalInnovation #MedicalEducation #SurgicalSkills #AnorectalMalformation #CongenitalAnomaly

Transcript

We present a case of a posterior sagittal anorectoplasty for a low rectal prostatic fistula. Here is a typical perineum of a male with an anorectal malformation. The location of the intended anoplasty is obvious, with a discoloration in the area of the sphincteric ellipse. Remember the schema that we use of determining the location of the distal rectum relative to the urinary tract using a statue's elbow. If the fistula enters the deltoid or shoulder region of the urethra, it is a bladder neck fistula. If it enters the triceps or humerus area, it is a prostatic fistula. And if it enters at the elbow of the urethra, it is a bulbar fistula. Here are representative distal cholostrograms of a recoprostatic fistula on the left and a rectal bladder neck fistula on the right. These are the ones one could consider whether to perform laparoscopy or via a posterior sagittal repair. A properly done distalcholostogram is key to determining the best surgical approach. The image on the top right shows a high rectum with a narrow fistula at the low prostatic level. This is amenable to a laparoscopic approach, as the rectum is above the PC or puococcygeal line. The image on the bottom right shows a lower rectum with a fistula to the bulbar urethra. For this case, a posterior sagittal anorectoplasty is best, and here is the case we are showing in today's video. When the rectum is relatively high but reachable through a posterior sagittal approach, a nice trick is to place a catheter in the mucous fistula so that the distal rectum can be inflated through injection. One can then see the bulge and dissect the distal rectum. The legs are lifted up and the sphincter marked. It is important that the anesthesia team has not given muscle relaxant, as this will interfere with the electrical stimulation. The patient is then placed in prone position. Here you see me palpating the coccyx. We begin the posterior sagittal incision, incising the center of the sphincter and staying perfectly in the midline. And dissect on either side of the coccyx to allow for the wheatlander retractor to be opened widely. In some cases, removal of the coccyx improves further the exposure, as you can see being done here. You now start to see the bulge of the distal rectum. This is facilitated by injection using saline through the mucous fistula. A silk suture is placed into the rectum, and then we dissect out the distal rectum. This releases the rectum from its adherence to the sacrum. The rectum is now opened in the midline. You note that the first stitches were not quite deep enough and only grasped the whitish fascia that surrounds the rectum. Now we can place another silk suture this time into the true rectal lumen and continue placing these silks into the full thickness rectal wall. And now we place a single suture at the rectal urethral fistula location. You can now see the anterior lip of the rectal lumen, a key anatomic finding. And I am placing a probe to show the fistula. I now place stitches across the anterior lip of the rectum. We start dissecting the lateral walls of the rectum. We dissect within the whitish fascia that envelops the rectum. It is vital to find this plane, which allows for the rectum to be mobilized. The lateral dissection defines the anterior dissection. And now we start to come across the anterior wall, lifting the rectum up and dropping the urinary tract down. A mixer right angle clamp is passed to demonstrate the separation of the anteriorectal wall from the fistula, and now the rectum is fully separated from the urinary tract. The rectum is now further mobilized. We take the attachment bands holding the rectum to gain length. If you see fat, you can get closer to the rectal wall. The rectum now easily reaches the perineum to the desired location of the anoplasty, which was previously marked, and now I turn my attention to closing the urethral fistula location. Note how important that initial fistula stitch is for your exposure to this part of the case. The fistula is now closed using long term absorbable suture on the urinary tract. And I have added a second layer of closure. Here you see me marking the posterior edge of the muscle complex, and now I am tacking the posterior edge of the muscle complex to the posterior rectal wall. The wheat lander retractor needs to be relaxed before tying these sutures, and now we place sutures to reconstruct the levators. And here you see me setting up the anoplasty. And now completing the anoplasty with sutures left under a little bit of tension, so that when cut, the anoplasty retracts in slightly. I pass a Hagar to be certain I have not narrowed the lumen. And finally, we close the posterior sagit incision.

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