Practice of colorectal surgery opens numerous vulnerabilities for lawsuits:
- • Failure to timely diagnose disease: eg, colorectal cancer is the second most common type of cancer cited in malpractice lawsuits.
- • Sphincter injury with fecal incontinence after anorectal surgery or midline episiotomy.
- • Failure to offer continence-preserving procedure.
- • Iatrogenic medical complications/death during diagnosis or treatment.
- • Sponges/instruments left in the patient.
- • Iatrogenic organ injury of nontarget structures (eg, colon, small bowel, ureter, major vessels, spleen, vagina).
- • Lack of informed consent regarding extent or risks of procedures/endoscopies.
Specific challenges to physicians cited in malpractice cases arise from:
- • Type or sequence of diagnostic procedures, eg, failure to recommend colonoscopy.
- • Missing or insufficient documentation for medical rationale to recommended treatment, patient education, follow-up.
- • Lack of follow-up on test results, initiation of follow-up tests (eg, after incomplete colonoscopy).
- • Lack of communication.
Risk of lawsuit can never be completely eliminated but can be dramatically reduced, if the outlook of success for the plaintiff is lower, due to the fact that systematic preventive steps are undertaken:
- 1. To reduce misconceptions, miscommunications.
- 2. To follow recommended medical guidelines.
- 3. To adhere to excellent documentation in the chart, informed consenting process, and documentation of refusal to undergo recommended test/procedure.
- • Routine screening not recommended.
- • Routine screening recommended but not scheduled.
- • Diagnostic test recommended but not scheduled.
- • Diagnostic test scheduled but not performed.
- • Ordering or follow-up of screening or diagnostic procedures not documented.
- • Inadequate evaluation of abnormal findings.
- • Failure to convey to patient the importance of keeping test and follow-up appointments.
- • Multiple providers for the same patient fail to properly communicate important information.
- • Patient not notified of test results.
- • Informed refusal not documented.
- • Important clinical information missing from clinical note.
- • Adequate documentation of current history elements; clarification of patient’s vague terminology (eg, “occasional,” “frequent”) → reduce misinterpretation of self-reported symptoms.
- • Key statements must be documented by selected outside medical records, eg, pathology report (cancer, IBD), colonoscopy report (clearance of rest of the colon), operative notes (definition of anatomy, problems/adhesions during previous surgeries), medical clearance.
- • Amendments to existing chart/medical record: if an addendum is absolutely necessary, it should be made after the last entry, noting current date and time, with both entries cross-referenced. Inappropriately amended medical records render a case indefensible if plaintiff’s attorneys demonstrate in court that the note was written or typed after the fact. No addendum in anticipation of claim or legal action.
- • Medical record: “what is not documented has not happened” → record should reflect in appropriate detail what was done for patient and demonstrate quality of care given → provide defense against allegations of inadequate care.
- • Document all phone conversations, including those in which compliance issues are stressed.
- • To ensure that screening tests are performed: schedule before patient leaves office, or at least document discussion with patient of the recommendation for the test.
- • Document all follow-up efforts to reach patient or to reschedule a test/procedure.
- • Document discussions/conversations with patient and witnesses about recommended action, risks and benefits of proposed testing, as well as alternatives.
- • Document patient’s refusal to undergo recommended test or lifesaving procedure, preferably on a specific informed refusal form signed by patient.
- • Make it a routine for high-risk patients who fail to keep appointments or when responding to phone calls to reschedule:
- – To use a form for tracking details.
- – To contact them by registered mail (with return receipt).
- – To use a form for tracking details.
Obtaining the patient’s accurate and detailed history is the most important tool to direct the subsequent examination, to create a list of possible differential diagnoses, and eventually to establish the final diagnosis without wasting valuable resources. It is further crucial in tailoring the best choice among various treatment options to the patient’s individual situation. Preferably, the history is taken from the patient, often from accompanying individuals (family, translators, referring physicians): risk of “loss in translation.”
Particularly in colorectal surgery, it is a high art to take a patient’s history in an unprejudiced, sensitive, but nonetheless thorough manner. Efficient questioning consists of a problem-oriented focus and systematic expansion of areas, depending on the responses. It is advantageous to start by letting the patient describe the key symptoms in an open end–type narration, which is subsequently complemented with specific problem-oriented questions. Even in “simple” cases, a systematic checklist of relevant background information should be followed to ensure a complete context and hence avoid legal glitches.
- • Rectal bleeding: amount, color (bright red vs dark red), onset, pattern, mixed into the stool, triggering factors, etc.
- • Discharge: quality, associated symptoms, etc.
- • Pain: location, onset, pattern, triggering factors, etc.
- • Itching: hygiene habits, incontinence, discharge, medications applied, etc.
- • Prolapse: what, how much, where? Spontaneous or manual reduction, nonreducible?
- • Lump/mass: always there or protruding with bowel movements, pain?
- • Bowel movements: stool quality, sudden change in bowel habits, complete/ incomplete evacuation, necessary counterpressure/digital maneuvers.
- • Incontinence: stool, gas, urine.
- • Nausea/vomiting, weight loss, fevers/chills.
- • Associated symptoms.
- • Baseline bowel and anorectal function (prior to onset of presenting symptom).
- • History of IBD, IBS, cancer (abdominal/extraabdominal), etc.
- • Previous abdominal surgeries.
- • Previous anorectal/pelvic surgeries or radiation treatment.
- • Previous vaginal deliveries, obstetric injuries.
- • Previous colonic evaluations (colonoscopy, etc).
- • HIV status (if relevant for disease).
- • General medical history: cardiopulmonary, vascular, diabetes, cancer, liver, neurologic, kidney.
- • Documentation of preexisting symptoms (incontinence to stool/gas, sexual dysfunction, rectovaginal fistula, etc).
- • Particularly risk of polyps/cancer and IBD.
- • Medications (current and recent past).
- • Allergies.
- • Review of systems.
- • Profession/disability, socioeconomic environment, habits, caregivers.
Adequate documentation of current history elements is absolutely necessary. Key statements in a patient’s history must be documented by selected outside medical records, eg, pathology report (cancer, IBD), colonoscopy report (clearance of rest of the colon), operative notes (definition of anatomy, problems/adhesions during previous surgeries), medical clearance.
The clinical examination is the cornerstone and the most distinguishing skill for the initial and follow-up assessments of an overwhelming part of colorectal patients, particularly patients with anorectal problems. Nothing should be taken for granted even if there are respective statements in outside records. It is an art and special privilege to examine a patient in the most intimate area of the body and requires an unprejudiced, sensitive, but nonetheless thorough manner. To optimize the exam, it is important in the short time between the history taking and the actual exam to digest the information and prepare a working array of possible, likely or unlikely findings.
- • Habitus including weight and height → calculation of body mass index as weight (in kg) divided by square height (in m).
- • Vital signs: heart rate, blood pressure, respiratory rate, temperature.
- • Mobility and performance status.
- • Mental/intellectual status: eg, inquisitive vs passive vs manipulative nature; anxiety, mood.
- • Nutritional and hydration status.
- • Inspection:
- – Presence/absence of external/internal stool, blood, mucus, secretions (eg, pus).
- – Anal configuration: appearance/location/asymmetries of anus, perineal body, vagina. Circumferential presence of radial folding, or absence in area of sphincter defect?
- – Perianal skin: intact, irritation (symmetric, asymmetric), erythema, discoloration, focal pathology.
- – Visible evidence of pelvic floor dysfunction: perineal descent, flattened anal verge, patulous anus, gapping of anus to lateral traction.
- – Spreading of buttocks to the anal verge: search for visible pathologic openings, eg, fistula, fissure, ulcer.
- – Visible “tissue addition”: lumps, bumps, prolapse (posterior vs anterior/vaginal).
- – Visible “tissue diminution”: weakened/absent perineal body.
- – Presence/absence of external/internal stool, blood, mucus, secretions (eg, pus).
- • Palpation, including digital rectal exam:
- – Focal external tenderness to palpation.
- – Bidigital palpation (index finger inside, external counterpressure with thumb): focal induration, eg, perirectal or ischioanal fat, deep postanal space.
- – Focal tenderness: exact location, including coccyx, prostate, levator muscles, cervical motion.
- – Sacrum palpable: if not → suspect presacral mass/abscess/hematoma/scar!
- – Palpable mass (endorectal, prostate, extraluminal).
- – Sphincter tone at rest/squeeze, intersphincteric groove, focal defects, use of auxiliary muscles for squeezing.
- – Length of anal canal.
- – Anastomosis, anastomotic leak.
- – Stricture, stenosis: length, angulation, passable?
- – Presence/absence of stool, assessment of stool quality.
- – Palpable defect (eg, rectovaginal fistula).
- – Focal external tenderness to palpation.
- • Vaginal exam:
- – Palpable defect or mass.
- – Assessment of strength of rectovaginal septum.
- – Palpable defect or mass.
- • Anoscopy:
- – Evaluation of anal canal: internal hemorrhoids, dentate line, distal defect or mass.
- • Rigid sigmoidoscopy:
- – Evaluation of distal rectum and anal canal.
- – Characterization of visible stool.
- – Evaluation of distal rectum and anal canal.
- • Abdominal shape: scaphoid, flat, distended, obese.
- • Pannus, including location of body folds.
- • Distention: soft, tympanitic, mass, organomegaly.
- • Presence/absence of defects, wounds, ostomy, skin abnormality.
- • Presence/absence of fresh surgical wounds (incisions).
- • Presence/absence and location of scars.
- • Hernias: groin, umbilical, incisional hernias.
- • Tenderness to palpation: location, severity.
- • Peritoneal signs: guarding (involuntary), rebound tenderness, percussion tenderness.
- • Bowel sounds: normo-active, hyperactive, tympanitic, absent.
- • Lymph node regions: particularly groin, but also supraclavicular, axillary.
- • Hernia: former incisions, groin.
Symptoms are not reliable for early detection of colorectal cancer (CRC). There is therefore a need for risk-adjusted screening programs for asymptomatic individuals to start no later than age 50, earlier in increased or high-risk individuals. No definite guidance available about criteria to discontinue screening.
Effective screening has to be:
- • Based on understanding of the adenoma-carcinoma sequence: it takes 5–10 years from the first molecular change to a clinically manifest cancer (caveat: shorter sequence in HNPCC).
- • Based on individual’s genetic, disease- or age-dependent risk for the development of CRC.
- • Highly sensitive.
- • Practical, easy to do, cost-effective.
The term screening is only applicable to asymptomatic people; a test in the presence of symptoms should not be called “screening” but instead, “diagnostic” evaluation.
Prevalence of polyps: 20–30% in average-risk persons ≥ 50 years of age.
First colonoscopy responsible for largest benefit of polypectomy; risk for subsequent CRC in patients with small adenoma is not greater than average risk.
Current screening rates among average-risk population are unacceptably low: 20–50%. Contrast: > 50% of gastroenterologists and colorectal surgeons perform colonoscopy at intervals shorter than recommended by the guidelines → not cost-effective and diverting resources from higher yielding primary screening.
- • Low or average risk (65–75%): no risk factors, no CRC in any first-degree relatives.
- • Moderate risk (20–30%): CRC in one first-degree relative with age ≤ 60 years or ≥ two first-degree relatives of any ages, personal history of curative resection of colorectal malignancy or large polyp (> 1 cm) or multiple colorectal polyps of any size.
- • High risk (6–8%): FAP, HNPCC, IBD.
- • Pros: noninvasive, easy, convenient, safe.
- • Cons: colon not visualized, low to moderate sensitivity/specificity, positive tests require colonoscopy and other testing. Lack of specificity: only 2% of patients with positive FOBT have a CRC, ie, 50 colonoscopies needed to identify 1 patient with CRC, 100 colonoscopies needed to save 1 patient.
- • Precautions: should be repeated annually, dietary restrictions (no red meat, horseradish, vitamin C, etc).
- • Data: annual FOBT associated with decrease in CRC mortality of 20–33%; sensitivity for advanced adenomas or CRC only 24%.
- • Pros: safer than colonoscopy, more convenient, no bowel prep, most commonly no need for sedation.
- • Cons: does not visualize entire colon, positive findings require full colonoscopy.
- • Precautions: should be repeated every 5 years.
- • Data: decrease in CRC mortality = 60% overall, 70% distal CRC; 2% of patients with normal flexible sigmoidoscopy have a significant lesion proximal to splenic flexure.
Data: even though offering a theoretical advantage, the benefit of combining the 2 tests remains uncertain: higher detection rate, but no proven incremental decrease in CRC mortality compared to flexible sigmoidoscopy alone (see above).
- • Pros: gold standard with full colonic visualization, therapeutic capability.
- • Cons: higher risk than flexible sigmoidoscopy, need for bowel prep, need for sedation.
- • Precautions: should be repeated every 10 years.
- • Data: National Polyp Study found 76–90% decreased CRC incidence with colonoscopy and removal of all visualized polyps compared with historical controls.
- • Pros: full colonic visualization even in presence of nearly obstructing lesion, no need for sedation, better tolerated.
- • Cons: no therapeutic capability, lower sensitivity than colonoscopy, positive or uncertain findings need colonoscopic evaluation, still needs bowel prep.
- • Precautions: should be repeated every 5 years.
- • Data: sensitivity 80–85% for colorectal cancer and 50% for large polyps (> 1 cm).
- • Pros: full colonic visualization, no need for sedation.
- • Cons: no therapeutic capability, still needs bowel prep, higher discomfort (insufflation of air, no sedation given), unnecessary evaluations/surgeries for incidental findings.
- • Precautions: interpretation and recommendations not clarified.
- • Data: awaiting further confirmation. Current data controversial with reports of similar sensitivity vs only moderate sensitivity/specificity for larger lesions compared to colonoscopy. Sensitivity for smaller polyps definitely lower.
- • Pros: noninvasive, convenient, safe.
- • Cons: colon not visualized, low to moderate sensitivity/specificity, positive tests require colonoscopy and other testing.
- • Precautions: should be repeated every year.
- • Data: Sensitivity better than FOBT; 50% for detecting invasive CRC, 15–20% for significant adenomas.
Goal: Detection and elimination of precursor lesions, identification of patients at risk to stratify for frequency of future screening/surveillance.
- 1. Average-risk individuals, asymptomatic, non–African-American → start at age 50:
- a. Colonoscopy every 10 years (method of choice).
- b. Annual FOBT; if positive → colonoscopy.
- c. Screening sigmoidoscopy every 5 years.
- d. Double-contrast barium enema every 5 years.
- a. Colonoscopy every 10 years (method of choice).
- 2. Increased or high-risk individuals → specific guidelines:
- a. African-American ethnicity: start screening at age of 45.
- b. Positive family history (increased risk group): start at age of 40 or 10–15 years before youngest family member (whichever comes first).
- c. Ulcerative colitis: start 7 years post onset: (bi-)annual colonoscopy with multiple biopsies.
- d. FAP: start in early/mid teens (vs genetic testing).
- e. HNPCC: start around age of 25 (vs genetic testing); thereafter repeat colonoscopy every 1–3 years because of shorter adenoma-carcinoma sequence!
- a. African-American ethnicity: start screening at age of 45.
Goal: Detect and remove adenomata missed on the initial exam (miss rate: 10–20% of polyps = 6 mm); assess patient’s tendency to form new adenomas with advanced pathologic features.
- 1. Short interval (based on clinical judgment):
- a. Numerous adenomata.
- b. Malignant adenoma (cancerous polyp).
- c. Large sessile polyp.
- d. Incomplete colonoscopy or incomplete removal.
- a. Numerous adenomata.
- 2. Three-year interval:
- a. Advanced or multiple polyps (≥ 3).
- 3. Five-year interval:
- a. One to two small polyps (tubular adenoma).
- 4. No surveillance needed:
- a. Hyperplastic polyps (exception: patients with hyperplastic polyposis syndrome).
Goals: rule out synchronous/metachronous CRC; rule out true anastomotic recurrence (< 2% risk); detect and remove adenomata missed on the initial examination; assess patient’s tendency to form new adenomas with advanced pathologic stage.
- 1. Around time of resection ± 6 months:
- a. Full colonoscopy before resection.
- b. If colon perforated/obstructed and cannot be evaluated at the time of the resection → full colonoscopy to be performed within 6 months.
- a. Full colonoscopy before resection.
- 2. One-year interval:
- a. After the resection.
- 3. Three-year interval:
- a. If perioperative or first postoperative colonoscopy negative.
- 4. Five-year interval:
- a. Thereafter if normal.
HNPCC/AFAP: annual surveillance of residual colorectum.
Pathology results.
Clinical side effects of polypectomy: postpolypectomy syndrome, perforation, bleeding.
Surgery for larger polyps or cancer. Prophylactic surgery?
Secondary prophylaxis?
Limited colonic evaluation: justification dependent on patient’s young age (< 40 years), lack of individual risk factors for colorectal cancer, status post complete colonoscopy within acceptable interval, status post subtotal colectomy.
One to two working ports allow for intervention, manipulation, suction/irrigation. Cold biopsy: using forceps. Hot biopsies are generally contraindicated because of inadequate gas elimination with enemas which carries a risk of explosion!
Sedation and analgesia are commonly not needed as major flexures do not have to be passed. Success and detection rate depend on the endoscopist’s skill, time spent thoroughly inspecting the colon, and adequacy of cleansing enemas.
Diagnostic evaluation of symptomatic low-risk individuals (< 40 years old, negative personal/family history) with symptoms of likely distal origin, eg, bright red blood per rectum.
Intervention: biopsy, polypectomy, stenting, tattooing, to stop bleeding, for focal decompression.
Screening: in conjunction with Hemoccult test.
Surveillance of residual colon and rectum after total or subtotal colectomy.
Two Fleet enemas right before test.
Office procedure: commonly no sedation needed.
Caveat: enemas insufficient to remove explosive gases → snare/cautery contraindicated!
- • Pathologic lesion not in reach of flexible sigmoidoscope (eg, proximal polyps and neoplasms, 20% of C difficile colitis, etc).
- • Miss rate: up to 20–25% for polyps up to 1 cm.
- • Perforation: low risk for diagnostic endoscopy, higher in interventional endoscopy and/or preexisting bowel weakness, eg, acute diverticulitis.
- • Bleeding: depending on pathology/intervention, minimal for diagnostic endoscopy.
- • Explosion of intestinal gas (hydrogen, methane): use of cautery in inadequately prepped colon contraindicated in flexible sigmoidoscopy.
- • Size of lesions generally overestimated (magnification) → need to correlate size of lesion with diameter of inserted instruments.
- • Exact orientation difficult/impossible; only absolute landmark is dentate line; if location needs specification (eg, for later surgery): tattooing of the area with India ink (1 mL in 3 separate areas on the circumference).
Pathology: melanosis coli, friability, ulcerations, edema (disappearance of vascular pattern), granular reflections (“star sky”), polyps (diminutive, sessile, pedunculated, extramucosal), mass (mucosal/extramucosal), lipoma (extramucosal, soft impressibility: pillow sign), diverticula, stricture, fistula, hemorrhoids.
Complete evaluation of entire colon (and terminal ileum) with option of biopsy and intervention. Intended extent of examination is dependent on individual circumstances (eg, previous surgeries), expected findings, patient’s age, etc.
One to two working ports allow for intervention, manipulation, suction/irrigation. Cold biopsy: using forceps. Hot biopsies: using snare and electrocautery (contraindicated with inadequate cleansing, eg, enemas only).
As the instrument has to be negotiated around angles and flexures, monitored IV sedation and analgesia are commonly administered (even though not mandatory). Success and detection rate depend on endoscopist’s skills, time spent thoroughly inspecting the colon (withdrawal time > 6 minutes), and adequacy of bowel cleansing.
Advanced techniques:
- • High-resolution colonoscopy with chromoendoscopy (spraying of colon with 0.4% indigo carmine dye) is associated with a higher detection rate for polyps and flat adenomas.
- • Combination with endoscopic ultrasound.
Limited colonic evaluation: flexible sigmoidoscopy.
Single-column contrast enema: gives a road map but does not allow biopsy, intervention.
Double-contrast enema: if colon is clean and good radiologic technique is used → similar screening sensitivity as colonoscopy.
CT colonography (“virtual colonoscopy”): also needs bowel prep. Typically done without sedation → discomfort. Findings inside/outside colon precipitate further (unnecessary?) interventions.
Screening and surveillance per guidelines (asymptomatic individuals), clearing rest of colon before segmental intervention.
Diagnostic evaluation of specific symptoms (bleeding, distention, altered bowel habits, etc) in patient > 40 years of age or presence of additional risk factors. Evaluation of patients with altered bowel habits and suspicion for Crohn disease (→ intubation of ileocecal valve).
Intervention: biopsy, polypectomy, stenting, tattooing, to stop bleeding, for detorsion or decompression.
Contraindication: suspected perforation, acute diverticulitis (< 4–6 weeks after onset), fulminant colitis, unstable patient.
Colonoscopy: full bowel cleansing the day before.
Conscious sedation and monitoring.
If intervention anticipated: discontinuation of anticoagulation (if possible) or switch to heparin with perioperative short-term pausing; discontinuation of ASA/NSAIDs not mandatory but recommended if possible.
Combination of evaluation, biopsy, treatment, and intervention (gold standard).
Better tolerability under sedation.
- • Ten percent incomplete colonoscopy: inability to reach cecum due to technical, anatomic, or patient-related issues (pain tolerance), equipment failure: → barium enema: safe on same day unless biopsy or polypectomy performed → wait 5–7 days.
- • Miss rate: 20–25% for polyps < 1 cm, 6–12% for polyps > 1 cm: more likely in insufficient prep, spastic colon.
- • Bleeding: 0.1–0.5% (diagnostic), 1–2.5% (polypectomy).
- • Colon perforation: 0.1% in diagnostic endoscopy, up to 1–3% in interventional endoscopy, particularly in preexisting bowel wall weakness; perforation requires surgical intervention unless very favorable conditions allow for conservative management; 4 perforation mechanisms:
- – With the instrument tip → often relatively small perforation.
- – Bowing injury from instrument looping and overstretching of colon wall → commonly very large tears.
- – Diffuse overinsufflation in weakened colon wall (eg, diverticulum).
- – As result of intervention (biopsy, snare, stent).
- – With the instrument tip → often relatively small perforation.
- • Postpolypectomy syndrome: caused by cautery injury to colon wall → pain, abdominal tenderness, often starting 1–3 days after procedure; most commonly manageable with antibiotics but perforation needs to be ruled out.
- • Explosion of intestinal gases (hydrogen, methane): use of cautery in inadequately prepped colon, high risk with mannitol cleansing (sugar degradation through bacteria → increased intestinal gas production).
- • Size of lesions generally overestimated (magnification): → need to correlate size of lesion with diameter of inserted instruments.
- • Exact orientation difficult/impossible; only absolute landmarks are dentate line, terminal ileum.
Normal structures: ileum with carpet-like mucosa (small bowel villi), Peyer plaques. Appendiceal orifice. Ileocecal valve. Cecum/ascending colon: often less clean despite otherwise good cleansing. Hepatic flexure with transparency of bluish liver. Transverse colon (triangular shape typical but not specific). Descending/sigmoid colon. Rectum with reticular vascular pattern. Retroflex view for distal rectum and hemorrhoids.
Most common pathologies:
- • Degenerative: melanosis coli, diverticula, hemorrhoids, dolichocolon (too long, tortuous), megacolon (too wide), volvulus.
- • Inflammation: edema (disappearance of vascular pattern), granular reflections (“star sky”), friability, ulcerations (diffuse vs skip and bear claw), cobblestoning, pseudomembranes, mucosal necrosis.
- • Growth: polyps (diminutive, sessile, pedunculated, extramucosal), mass (mucosal/extramucosal), lipoma (extramucosal, soft impressibility: pillow sign).
- • Anastomosis, stricture, fistula.
Instrumentation (rigid or flexible) of existing pouch (ileoanal pouch, continent ileostomy) for evaluation or treatment (eg, dilation of stricture, decompression, tube insertion, etc).
Indication based on symptoms (ie, pouch dysfunction, pouchitis) or for routine surveillance of pouch and ATZ for dysplasia, polyps, or cancer (particularly in FAP).
Circumstances dictate whether flexible or rigid instrument preferable. Sedation and analgesia are commonly not needed but occasionally preferable in very sensitive patient (eg, traumatized perianal skin, etc).
- • IBD: every 1–3 years or when symptomatic and not responding to conservative treatment, surveillance of ATZ cuff every 1–3 years.
- • FAP: every year.
- • Pathology missed (inadequate visibility, pocket).
- • Perforation: low risk.
- • Bleeding: depending on pathology/intervention, minimal for diagnostic.
- • Exact orientation difficult/impossible.
Pathology: pouchitis, lymphoid hyperplasia (Peyer plaques), dysplasia, formation of polyps/tumor, mass (more likely in posterior area), acute and chronic inflammation, ulcerations (→ suggestive of Crohn disease if ulcerations in afferent limb), length of efferent limb (eg, S-pouch), friability of ATZ, length and configuration of valve segment (continent ileostomy), fistula opening.
Although the colon and upper GI tract are accessible for direct endoscopy, the small bowel in between is not. Overall, the small bowel only rarely is the primary site of disease. Concern that the test is often overused, eg, missing indication or low yield indication.
- • Obscure bleeding while EGD and colonoscopy negative.
- • Evaluation of small bowel Crohn disease.
- • Suspicion for small bowel tumor.
- • Relative contraindication: stricture (particularly first-generation device may get trapped; newer development: biodegradable capsules).
- • Pathology missed (inadequate visibility).
- • Obstruction.
- • Technique is time-consuming, expensive, and not universally available.
Pathology: varices, portal hypertension, erosions, areas of Crohn disease, small bowel tumors/polyps.
Series of elective tests to assess the function and morphology of the anorectum. Common indications are workup of fecal incontinence, obstructed defecation, complex perianal fistulae, assessment and staging, as well as surveillance of anorectal tumors. Test results are not absolute, but always require correlation with patient’s individual history, severity of complaints, clinical findings, and unrelated test results.
Typical test combinations:
- • Fecal incontinence: “triple studies”—PNTML, manometry/anorectal sensation, ultrasound.
- • Obstructed defecation: EMG, manometry/anorectal sensation, balloon expulsion test.
- • Anal/rectal tumor: ultrasound, potentially with ultrasound-guided biopsy; rarely triple studies are needed if anorectal function is an important parameter for decision-making.
- • Ruling out Hirschsprung disease: RAIR.
Obtain objective and reproducible evaluation of anorectal function for assessment and documentation (liability) of patient’s symptoms, patient counseling, assessment of treatment effect.
Patient cooperation required → false pathologic results possible.
Lack of 1:1 correlation of test results and symptoms → test interpretation and correlation within context of other elements of information necessary.
Latex allergy.
Assessment of transmission time within pudendal nerve from site of stimulus to site of sphincter contraction.
Evaluation of fecal incontinence: evidence for neuromuscular component of sphincter dysfunction?
Evaluation of possible preexisting autonomic nerve damage prior to pelvic or sphincter-reconstructive surgery.
Medtronic Duet Encompass (or comparable) machine with integrated/compatible software component. St. Marks Electrode.
A grounding probe is attached to the patient’s leg, and the test electrode connected and attached to the gloved finger. Insertion into posterolateral quadrants. Sequential stimulation with 50 mA until an adequate curve is reproducible.
Discomfort from electrical stimulus.
Electrical shock if improper setup (eg, too high mA, lack of grounding).
Normal PNTML ≤ 2.5 ms (Figure 2–1A).
Prolonged PNTML (if reading and stimulation curve adequate) is evidence of pudendal neuropathy.
Normal PNTML: can either be true normal, or false normal if significant nerve damage present is masked by sufficient number of intact and transmitting nerve fibers.
Absent PNTML reading: either related to complete absence of pudendal nerve function, or false negative (see below).
False negative: related to inadequate technique or stimulation, scar tissue, extraluminal pathology.
False positive: direct electrical stimulation of the sphincter muscle.
Majority of patients with idiopathic fecal incontinence have prolonged PNTML.
Controversy in literature about value of PNTML in predicting success of overlapping sphincteroplasty: half the reports show correlation and the other half, no relationship. Nonetheless, PNTML test is recommended prior to sphincteroplasty to protect surgeon in case of insufficient success or recurrent incontinence.
Objective (reproducible?) assessment of sphincter strength and sphincter tone at rest and squeeze (ie, obtain numbers for subjective impression on digital rectal exam). Definition of high-pressure zone.
Evaluation of fecal incontinence, pelvic floor and levator ani spasms, outlet obstruction, rarely in setting of anal fissure (before/after sphincterotomy).
Objective evaluation of treatment success after nonsurgical and surgical management.
Medtronic Duet Encompass (or comparable) machine with integrated/compatible data recording and analysis software. Multichannel catheter with a defined and oriented number of water-perfused channels. Pressure-sensitive pizo-electrodes are arranged around a central channel which is connected to the balloon at the catheter’s end. These pressure sensors measure the pressure needed to overcome the outflow resistance. Calibration of catheter to room air pressure with probe held externally at the level of the anus. Correct orientation of the catheter with separate recording of 4–8 positional pressures: anterior, posterior, R lateral, L lateral.
- • Stationary pull-through method: sequential recording of alternating 10 second periods of resting/squeeze at 6 static levels of 1-cm intervals.
- • Continuous pull-through method: motor-driven extraction of the probe and continuous pressure recording: two separate drive-throughs with one at rest and one during maximal squeeze.
Discomfort from probe/balloon placement.
Variation of normal anal canal pressures according to gender, age, measurement technique.
- • Radial pressures: more commonly reported pressure values, recorded with circumferential measuring ports: resting pressure 50–100 mm Hg, squeeze pressure 100–350 mm Hg.
- • Axial pressures: less frequently reported pressure values, recorded along longitudinal spiral of the catheter lumina.
- • Volume manometry:
- –High-pressure zone: length and maximal amplitude, defining the physiologic anal canal.
- –Area under the curve: integration of pressure values of the pressure profile over the length of the anal canal; better summative information of the total outlet resistance than just a single maximal resting and squeeze pressure.
- –High-pressure zone: length and maximal amplitude, defining the physiologic anal canal.
False normal pressures (despite sphincter weakness): compensatory use of gluteal muscles → this pitfall can be avoided/reduced by repeat testing after period of lasting gluteal contraction: while skeletal muscles become tired, sphincter muscle function is relatively resistant to fatigue.
Ongoing controversy about value and best interpretation of manometry in predicting severity of fecal incontinence. Single values likely are insufficient; pressure profile potentially is more meaningful. Continued lack of an incontinence score that incorporates physiologic data.
The RAIR is a physiologic relaxation of the internal sphincter muscle upon sudden distention of the rectum. Believed to play a role in anorectal sampling. Reflex may be absent in Hirschsprung disease, Chagas disease, 50% of ileoanal or coloanal anastomoses (ie, RAIR can recover in up to 50% after colo-anal or ileo-anal pullthrough procedure). Presence of RAIR reliably rules out Hirschsprung disease.
Evaluation of fecal incontinence: neurogenic component?
Evaluation of constipation → rule out Hirschsprung disease.
Same as before → continuation after previous test.
Catheter advanced such that pressure sensors in anal canal and balloon in the rectum. Await steady state pressure undulations > 0. Short insufflation of 15–40 mL of room air.
Discomfort, otherwise negligible.
RAIR present at 15–40 mL insufflation (Figure 2–1B).
RAIR present: normal → high negative predictive value, ie, if RAIR present → Hirschsprung disease ruled out.
RAIR absent: consistent with Hirschsprung disease, Chagas disease, 50% of ileoanal or coloanal anastomoses → further evaluation depending on context.
RAIR falsely absent: due to inadequate technique, large rectocele, megarectum, or underlying neuromuscular disease.
Evaluation of somatic and visceral anorectal sensation.
Evaluation of fecal incontinence.
Evaluation of IBS.
Evaluation of constipation.
- • Somatic sensation: perianal wiping with Q-tip to assess sensation (symmetry?) and to trigger anocutaneous reflex, ie, reflectory sphincter contraction.
- • Visceral sensation: manometry equipment as before, but exchange of balloon into one with high material compliance: catheter advanced into rectum, followed by slow instillation of body-temperature water (maximum 450 mL) with continuous pressure measurement → recording of the following steps:
- – First sensation: patient feels balloon in the rectum (not just at the anal verge).
- – First urge: patient notices first urge to move bowels.
- – Maximally tolerable volume: patient starts to feel discomfort/pain.
- – Rectal compliance = Δvolume/Δpressure.
- – First sensation: patient feels balloon in the rectum (not just at the anal verge).
Discomfort, balloon rupture, internal balloon loss (→ always secure balloon edge externally).
- • First sensation: 10–50 mL.
- • First urge: 50–100 mL.
- • Maximally tolerable volume: 140–320 mL (F), 170–440 mL (M).
- • Rectal compliance: 2–6 mL/mm Hg.
- • Normal: normal sensation and compliance.
- • IBS: reduced volume tolerance, normal compliance.
- • IBD or rectal stricture: reduced volume tolerance, reduced compliance.
- • Neurologic dysfunction: reduced sensation, increased volume tolerance, normal (or increased) compliance.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
