Ca Rectum

Rectum Anatomy and Landmarks

• Length: 12 cm - 15 cm from the anal verge
• Rectosigmoid Junction:
  • Taenia coalesce to anorectal ring
  • Operative: Taeniae coli splay and become indistinct
  • Radiological: Sacral promontory marks the junction
  • Endoscopic: 15 cm from anal verge
• Peritoneal Coverage:
  • Upper third: Covered anteriorly and laterally
  • Middle third: Covered only anteriorly
  • Lower third: Extraperitoneal (no peritoneal coverage)

Fascia’s of Rectum

Mesorectal fascia = Fascia propria

Mesorectum Anatomy

• Posteriorly: Contains associated vessels and lymphatics.
• Fascia Propria:
  • Envelops the mesorectum and separates it from the presacral fascia.
• Anteriorly:
  • Fascia of Denonvilliers: Separates the mesorectum from:
    • Males: Seminal vesicle and prostate.
    • Females: Uterus and vagina.
• Laterally:
  • Fascia propria condenses to form lateral stalks.
  • Note: The middle rectal artery and nerves do not run in the lateral stalks.[ but they are present just below it so chance of injury is present.]

Semilunar Valves and Anal Canal Anatomy

• Three Semilunar Valves of Houston:
  • Arrangement: Left, right, left (from below).
  • Middle Valve (Valve of Kohlrausch):
    • Corresponds to the anterior peritoneal reflection.
• Anal Canal:
  • Surgical Anal Canal: From the puborectalis ring to the anal verge.
  • Anatomical Anal Canal: From the dentate line to the anal verge.

Lymphatic Drainage of the Rectum and Anal Canal

• Below Dentate Line:
  • Drains into superficial inguinal nodes.
• Above Dentate Line:
  • Distal One Third:
    • Drains laterally into internal iliac nodes. [ via middle and inferior rectal[pudendal] artery]
    • Drains superiorly into inferior mesenteric and superior rectal nodes.
  • Proximal Third:
    • Drains into inferior mesenteric nodes.

Sites of Nerve Injury During Rectal Surgery

1. Most Common Site:
   • Origin of Inferior Mesenteric Artery (IMA):
     • Affects sympathetic nerves.
     • Leads to retrograde ejaculation or urinary incontinence.
2. Second Site:
   • Pelvic Brim/inlet:
     • Affects sympathetic nerves.
     • Injury to either right or left hypogastric nerve.
3. Third Site:
   • Presacral - Pelvic splanchnic nerves [Lateral Pelvic Wall]:
     • Affects parasympathetic nerves.
     • Results in atony of the bladder and impotence.
4. Fourth Site:
   • Anterolateral Aspect of Seminal Vesicles [Denonvilliers Fascia]:
     • Affects both sympathetic and parasympathetic nerves.

Rectal Cancer Diagnosis Flowchart

1. DRE (Digital Rectal Examination)
   • → Endoscopy
     • → Biopsy for histopathological confirmation
       • If distal extension > 15 cm from anal margin → Colon cancer
       • If distal extension ≤ 15 cm from anal margin → Rectal cancer
         • If up to 5 cm from anal margin → Low rectal cancer
         • If > 5 to 10 cm from anal margin → Middle rectal cancer
         • If > 10 to 15 cm from anal margin → High rectal cancer

Rectal Cancer Staging

1. Initial Assessments:
   • History, physical examination (including DRE), full blood count, liver and renal function tests, serum CEA.
   • CT scan of thorax and abdomen to define functional status and presence of metastases.
   • → M Stage.
   • RAS and BRAF mutational status testing upon diagnosis of metastases.
2. For patients over 70 years old:
   • Undergo geriatric assessments for frailty.
3. Rigid Rectoscopy.
4. Preoperative Colonoscopy:
   • To the cecal pole to exclude synchronous colonic tumors (in case of obstruction, virtual colonoscopy may be used).
   • Completion colonoscopy recommended within 6 months of surgery if no preoperative (virtual) colonoscopy performed.
5. Early Tumors:
   • ERUS (Endorectal Ultrasound) may be used to determine which lesions are appropriate for TEM (e.g., T1 tumors limited to the mucosa or submucosa).
   • → T Stage.
   • → N Stage.
6. Pelvic MRI:
   • For locoregional clinical staging, to detect EMVI (Extramural Vascular Invasion), predict the risk of synchronous/metachronous distant metastases, and define preoperative management and extent of surgery.
7. PET-CT:
   • May be used to rule out distant metastases in cases of patients with extensive EMVI on MRI, high levels of CEA at presentation, or when potential liver metastases are suspected on CT.
   • not present in routine preop staging.

MRI for Rectal Cancer

• Non-contrast MRI (rectal protocol).
• Axial, oblique, T2, coronal, sagittal views.
• CRM, T staging, N staging.
• Post NACRT response assessment.
• Extramural vascular invasion.
• MERCURY trial.

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Magnetic Resonance Tumor Regression Grade = by Diffusion weighted MRI

• Grade: Proportion of Tumor With Fibrotic Low Signal Intensity Compared to Remaining Residual Intermediate Signal:
  1. Predominance of fibrosis with no residual intermediate signal.
  2. Predominance of fibrosis with minimal residual intermediate signal.
  3. Substantial tumor signal present, but does not predominate the fibrosis.
  4. Predominance of tumor with minimal low-signal fibrosis.
  5. Tumor appears unchanged from baseline.

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Involved Margin Assessment

• Assessed by:
  • Primary tumor.
  • Lymph node.
  • Tumor deposit.
  • Extramural vascular invasion (EMVI).
• Key Measurements:
  • Within 1mm of mesorectal fascia: Considered involved.
  • Within 2mm of mesorectal fascia: Considered threatened.
  • Violation of intersphincteric plane: Critical involvement affecting surgical approach.

Advantages of MRI in Rectal Cancer

• CRM (Circumferential Resection Margin) Involvement:
  • Accurately assesses the risk of margin involvement, crucial for surgical planning.
• Nodal Involvement:
  • Provides detailed imaging to evaluate lymph node status.
• Wait and Watch Approach:
  • Helps monitor tumor response for patients under non-operative management strategies.
• Response to NACRT (Neoadjuvant Chemoradiotherapy):
  • Assesses tumor regression after treatment, aiding in decision-making for further management.
• Sphincter Involvement:
  • Identifies sphincter invasion, critical for determining the possibility of sphincter-sparing surgery.

Table 146.1: Low Rectal Cancer Staging (MCQ)

Stage 1:

• Confined to bowel wall but does not extend through full thickness; intact outer muscle coat.

Stage 2:

• Replaces muscle coat but does not extend into intersphincteric plane.

Stage 3:

• Invades intersphincteric plane or lies within 1 mm of levator muscle.

Stage 4:

• Invades external anal sphincter and is within 1 mm and beyond levators with or without invading adjacent organs.

Note: Stage 3 needs NACRT and Stage 4 only APR is an option

Conventional Transanal Excision Criteria

• T1N0: Tumor confined to the first layer of the rectum, no nodal involvement.
• Location: Within 10 cm from the anal verge.
• Tumor Characteristics:
  • Mobile and polypoid in nature.
  • Involves less than 1/3rd of the rectal circumference.
  • Tumor size: Less than 3 cm.
• Tumor Grade:
  • G1-G2: Well to moderately differentiated.
• No Evidence of Lymph Node Involvement (LNI): Absence of lymphatic spread.

Extended Criteria for Transanal Excision

• T2N0 Lesion: Tumor invading the muscularis propria without nodal involvement.
• Response to Chemoradiotherapy (CRT): Lesions that have shown a positive response to preoperative treatment.
• Location: Involves the higher and mid rectum, beyond the standard 10 cm range from the anal verge.

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Table 167B.1: Definitions of Early Rectal Cancer

Haggitt Classification (Pedunculated T1 cancers):

• Level 1: Invasion of submucosa limited to polyp head.
• Level 2: Invasion of submucosa of the polyp neck.
• Level 3: Invasion of submucosa of the polyp stalk.
• Level 4: Invasion of submucosa beyond the stalk.

Kikuchi Classification (Nonpedunculated T1 cancers):

• sm1: Invasion less than 1 mm.
• sm2: Intermediate between sm1 and sm3.
• sm3: Invasion near to the muscularis propria.

The Paris Classification of superficial neoplastic lesions and its revised edition:

• Polypoid Lesions:
  • Pedunculated (0-Ip).
  • Sessile (0-Is).
  • Mixed pattern (0-Isp).
• Nonpolypoid Lesions:
  • Slightly elevated (0-IIa), with elevation less than 2.5 mm above the level of the mucosa.
  • Completely flat (0-IIb).
  • Slightly depressed (0-IIc).
• Mixed Types:
  • Elevated and depressed lesions (0-IIa + IIc).
  • Depressed and elevated (0-IIc + IIa).
  • Sessile and depressed (0-Is + IIc).

EAES Consensus Conference:

• Early rectal cancer is a rectal cancer with good prognostic features that might be safely removed preserving the rectum and that will have a very limited risk of relapse after local excision.

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Lymph Node Involvement by Tumor Stage

• T1-sm1: Lymph node involvement risk is 0-3%.
• T1-sm2, sm3: Lymph node involvement risk is 15%.
• T2: Lymph node involvement risk is 25%.

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TEM (Transanal Endoscopic Microsurgery)

• Developed by: Dr. Gerhard Buess.
• Indications:
  • T1N0: Tumor within 10 cm from the anal verge.
  • T2N0: After CRT (Chemoradiotherapy), for patients not willing for surgery.
  • Involves tumors located in the higher and mid rectum.
• Positioning:
  • Depends on the location of the tumor.
  • Patient can be placed in prone or supine position.
• System: Utilizes a rigid system.
• Most Common Complication:
  • Rectal bleeding.

  • Suture line dehiscence.

    

TAMIS (Transanal Minimally Invasive Surgery)

• Patient Position:
  • Dorsal lithotomy regardless of tumor location.
• Indications:
  • Early rectal cancer (T1N0M0).
  • T1b: With SM1 involvement.
  • T2: Local resection in high-risk elderly patients.
  • T2: After NACRT (Neoadjuvant Chemoradiotherapy) for organ preservation.
• Tumor Size Consideration:
  • Lesions within 3 cm: Neither TAMIS nor TEM is indicated; instead, transanal excision is performed.

Complications of TAMIS/TEM Procedures

• Most Common:
  • Bleeding
• Other Complications:
  • Wound infection
  • Pelvic sepsis
  • Urinary retention
  • Transient fecal incontinence

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Summary for Early Rectal Lesion Management

• cT1N0 (No high-risk features):
  • TEM or TAMIS is appropriate.
• Adverse Risk Factors (e.g., lymphovascular invasion, poor differentiation):
  • TME (Total Mesorectal Excision) should be performed.
  • Alternatively, consider local RT (Radiotherapy).
• cT2 or Higher:
  • TME or Tumor-specific TME (with 5 cm mesorectal margin) for high rectal cancer.
• T2N0, T3a/T3bN0:
  • TME can be performed if the MRF (Mesorectal Fascia) is free of involvement.

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History of TME (Total Mesorectal Excision)

• Proposed by: Bill Heald.
• Technique:
  • Sharp dissection between the fascia propria and pelvic fascia, known as the Holy Plane of Healds.
• Key Features:
  • Preservation of autonomic nerves to maintain bladder and sexual function.
  • Sphincter preservation, when feasible.
  • Ensures the mesorectum remains intact during excision.

• Outcomes:

  • Local recurrence rate: 4-5%, demonstrating a significant improvement in cancer control.

  

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Indications for Neoadjuvant Therapy

• Absolute Indications:
  • T4 tumors.
  • Lymph node positive.
  • EMVI (Extramural Vascular Invasion) – predicts local/systemic recurrence.
• T3 Tumors:
  • T3c, T3d: >5mm from the muscular layer (can avoid neoadjuvant therapy in T3a, T3b, not absolute).
  • Threatened or involved mesorectal fascia.
• Preoperative NACRT:
  • With local excision if there is a good response to therapy.
• T3N0 (Distal):
  • For sphincter preservation: Can convert a planned APR (Abdominoperineal Resection) into LAR (Low Anterior Resection).
• T1N0/T2N0 (Distal):
  • No consensus on neoadjuvant therapy, TME can be done upfront.

Note: Tumors above peritoneal reflection- do not require neoadjuvant therapy

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German Rectal Cancer Study Group

• Comparison:
  • Preoperative CRT vs Postoperative CRT.
• Findings:
  • Local recurrence:
    • Preoperative CRT: 7%.
    • Postoperative CRT: 13%.
  • Overall survival (OS): Same between both groups.
• Treatment Protocols:
  • Long Course CRT:
    • 5FU/LV (5-Fluorouracil/Leucovorin) + 50.4 Gy (in 25-28 fractions).
    • Followed by delayed surgery. [6-8weeks]
  • Short Course RT (Swedish protocol):
    • 25 Gy (5 fractions of 5 Gy each).
    • Followed by immediate surgery. [within 7 days]

Short Course Therapy and Total Neoadjuvant Therapy

• Stockholm III Trial:
  • Short course radiotherapy followed by delayed surgery was evaluated.
• Total Neoadjuvant Therapy (TNT): [ T4;N2 ; EMVI+]
  • FOLFOX (4 cycles) followed by CRT (either short course or long course).
  • Benefits:
    • Improved local control.
    • Improved systemic control.
    • Downstaging of the tumor, enhancing the likelihood of successful resection and better outcomes.
  • Rapido Trial: A kind of TNT
    • The EXP treatment consisted of 5x5 Gy radiotherapy followed by six cycles of CAPOX or nine cycles of FOLFOX4 and surgery according to total mesorectal excision (TME) principles 2–4 weeks after the last chemotherapy. The STD treatment entailed long-course radiotherapy (28–25 × 1.8–2.0 Gy) and concurrent capecitabine followed by surgery after eight ± two weeks.

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Indications for Neoadjuvant Chemoradiotherapy (NACRT)

• Complete Pathological Response:
  • Achieved in 20% of cases.
• Criteria for CRT:
  • Only for tumors at high risk of local recurrence.
• Tumor Staging:
  • cT3b-d.
  • cT4, cN1 (positive nodes).
• Other Indications:
  • EMVI (Extramural Vascular Invasion).
  • Infiltration of internal or external sphincter.
  • Tumor involving the intersphincteric space.
• Benefits:
  • Reduces the rate of local recurrence.
• Applicable Tumor Types:
  • Mid/Low Stage II/III rectal cancer.
• Not Beneficial For:
  • Upper rectal cancer (>12 cm from the anal verge, above the peritoneal reflection).

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ESMO Guidelines:

Rectal Cancer Treatment

Very Early Disease

• cT1, sm1 (N0):
  • Local RT may be used as an alternative to local surgery (+/- CRT).
  • TEM if cT1 and no adverse features.
  • TEM plus perioperative CRT if adverse features present.
  • TME if adverse histopathology (pN ≥ 2, G3, VI, LI).

Early Disease

• cT1-cT2, cT3a-b if middle or high rectum, cN0 (sm1, MRF clear, no EMVI):
  • TEM, CRT, or "watch-and-wait" for frail, high-risk patients or those rejecting radical surgery.
  • MRI to re-evaluate the tumor.

Intermediate Disease

• cT3a-b, low rectum, clear MRF, no EMVI:
  • TME alone or SC-RT/CRT if good-quality mesorectal excision cannot be assured.
  • MRI to re-evaluate the tumor.
  • Watch-and-wait may be considered in high-risk patients if cCR achieved with CRT.
  • TME in most cases (photographic record of specimen and assessment of TME quality).

Locally Advanced Disease

• cT3c/d or very low, levators clear, MRF clear, cT3b mid-rectum, cN1-2 juxtaextramesorectal, EMVI+:
  • SC-RT or CRT.
  • MRI to re-evaluate the tumor.
  • Watch-and-wait may be considered in high-risk patients if cCR achieved with CRT.
  • TME (photographic record of specimen and assessment of TME quality).

Advanced Disease

• cT3 with any MRF involved, cT4a, levators threatened, lateral nodes+:
  • CRT.
  • SC-RT plus FOLFOX and delay to surgery.
  • MRI to re-evaluate the tumor.
  • TME (photographic record of specimen and assessment of TME quality).
  • Further surgery if needed due to tumor overgrowth.

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Timing of Surgery After Neoadjuvant Therapy

• Traditional Timing:
  • 6-8 weeks (based on the German Rectal Cancer Study).
• Extended Waiting Period:
  • Longer waiting time increases the probability of achieving pCR (pathological complete response).
  • Can wait up to 12 weeks if necessary.
• NCCN Guidelines:
  • Surgery can be performed between 5-12 weeks after completing neoadjuvant chemoradiotherapy.

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Low Anterior Resection (LAR)

• Patient Position:
  • Lloyd Davis position with steep Trendelenburg.
• Surgical Approach:
  • Open: Lateral to medial approach.
  • Laparoscopic: Medial to lateral approach.
• Ligation of IMA:
  • High ligation: At the base.
  • Low ligation: After the takeoff of the Left Colic Artery (LCA).
• Dissection Plane:
  • Holy Plane: Between fascia propria and presacral fascia (Waldeyer’s fascia) and Denonvilliers fascia.
• Rectal Transection:
  • Achieved during the procedure.
• Anastomosis:
  • Performed with stapled anastomosis.

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Reconstructive Options for Coloanal Anastomosis:

1. Types of Anastomosis:
   • End-to-End.
   • J-pouch.
   • Transverse Coloplasty.
   • End-to-Side.

2. Illustrated Reconstructive Options After Low Anterior Resection:

   • A: End-to-End Anastomosis.
   • B: End-to-Side Anastomosis.
   • C: J-pouch Anastomosis.

   

   No difference in the outcomes of different types of reconstruction.

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   Low Anterior Resection (LAR) Syndrome

   • Prevalence:
     • Affects 80% of patients after low anterior resection.
   • Symptoms:
     • Increased bowel frequency.
     • Incomplete emptying.
     • Incontinence (fecal urgency or leakage).
   • Risk Factors:
     • TME with coloanal anastomosis.
     • Neoadjuvant Chemoradiotherapy (NACRT).
     • Anastomotic leak post-surgery.
   • Preventive Measures:
     • J-pouch and transverse coloplasty are reconstructive options to help prevent severe symptoms.
   • Management:
     • Diet control.
     • Loperamide (anti-diarrheal medication).
     • Biofeedback therapy.
     • Transanal irrigation for better bowel management.
   • Score to assess severity: Wexner Score

Anastomotic Leak

• Incidence:
  • Higher in colorectal/coloanal anastomosis (up to 20%).
  • Lower in ileocolic anastomosis (1-3%).
• Risk Factors:
  • Male gender.
  • Obesity.
  • Extraperitoneal anastomosis.
  • Emergency operations.
  • Oral anticoagulation.
  • Poor nutrition.
• Diverting Stoma:
  • Does not decrease the incidence of leaks.
  • Decreases complications after a leak occurs.

• Imaging of Choice (IOC):

  • CECT scan.

  Key Points in Diagnosing Anastomotic Leaks:

  • Water-soluble contrast: Has fallen out of favor for detecting anastomotic leaks due to its limited accuracy.
  • CT with rectal contrast:
    • Performed at 10°C to help identify leaks.
  • Limitations:
    • Sensitivity: Approximately 70%.
    • Contrast extravasation is seen in only 15-17% of cases, making it a less reliable indicator.
  • Most Reliable Finding:
    • Perianastomotic air or fluid levels are considered the most reliable imaging signs, next to direct contrast extravasation.
  • Management:
  • Subclinical leaks:
    • Managed conservatively with antibiotics and drainage of collection.
  • Peritonitis:
    • Requires surgery, including lavage, drain placement, and creation of an ileostomy (ileostomy is typically not performed during the initial procedure).
  • If the anastomotic leak involves more than one-third of the circumference:
    • Dismantling of the anastomosis and creation of a stoma is necessary.

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Open vs Laparoscopic vs Robotic Surgery

Trials Comparing Laparoscopic and Open Surgery:

• CLASSIC, COLOR II, COREAN Trials:
  • Showed laparoscopic surgery had better short-term outcomes compared to open surgery.
  • No significant difference in oncologic outcomes (non-inferior results for cancer control).
• Australian ALa CaRT & American ACOSOG Trials:
  • Failed to show non-inferior oncologic outcomes for laparoscopic surgery compared to open surgery.
  • CRM involvement was higher in laparoscopy (12% vs 10%).
  • High conversion rates from laparoscopy to open surgery.

Morbidity: similar in Lap vs open

• Urinary dysfunction: 5-12%.
• Sexual dysfunction: 10-35%.
• Fecal incontinence: 20-30%.

Robotic Surgery:

• ROLARR & COLRAR Trials:
  • Long-term oncologic outcomes are still awaited.
  • No decrease in conversion rates when comparing robotic surgery to laparoscopic surgery.

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TaTME (Transanal Total Mesorectal Excision)

• Approaches:
  • Hybrid: Combination of transabdominal and transanal approaches.
  • Pure: Transanal approach only.
• Surgical Technique:
  • Dissection proceeds from below upwards.
  • Distal transection is clearly defined, aiding in sphincter preservation.
• Indications:
  • Particularly useful for male patients, those with obesity, narrow pelvis, or bulky tumors where conventional approaches are challenging.
• Clinical Trials:
  • No randomized trials comparing standard TME and TaTME (ongoing GRECCAR & COLORIII trials).
• Outcomes:
  • Rate of positive CRM: 2.4%.
  • Postoperative morbidity: 33%.
  • Increased risk of urethral injury and local recurrence.

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Ligation of Inferior Mesenteric Artery (IMA)

• High Ligation:
  • Performed 1 cm distal to the origin of the IMA.
  • Provides a more complete lymphadenectomy.
  • Associated with a higher risk of nerve injury (impacting autonomic function).
• Low Ligation:
  • Performed distal to the takeoff of the left colic artery.
  • Lower risk of anastomotic failure due to preserved blood supply.
• Oncological Outcome:
  • No significant difference in oncological outcomes between high and low ligation.

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Abdominoperineal Resection (APR) vs Low Anterior Resection (LAR)

• High Recurrence Rate in APR:
  • Traditionally, APR has a higher recurrence rate (up to 33%) compared to LAR.
• Factors Contributing to High Recurrence in APR:
  • Low bulky tumor.
  • Biologically aggressive tumors.
  • Poor differentiation of the tumor.
  • Increased number of lymph nodes involved.
  • Tumor perforation during surgery, leading to increased risk of recurrence.

Steps in Abdominoperineal Resection (APR):

1. Start Posterior Dissection:
   • The surgeon begins the dissection posteriorly, aiming to expose the required anatomical structures.
2. Anococcygeal Raphe is Divided:
   • The anococcygeal raphe is a key structure that must be divided during the procedure to provide access to the deeper tissues.

3. Presacral Plane is Entered:

   • After dividing the raphe, the surgeon enters the presacral plane, allowing further dissection and mobilization of the rectum.

   

Instrument Highlight:

• Lonestar Retractor:
  • This retractor system is commonly used in APR procedures to maintain exposure and improve visibility, particularly in narrow or deep anatomical regions. It helps hold back tissues, allowing for more precise and stable dissection.

Key Steps in Anterior Dissection During APR:

1. Levators are Cut Close to Their Origin:
   • The levator ani muscle is transected near its origin to allow further mobilization of the rectum and provide space for dissection.
2. Anterior Dissection:
   • The rectourethralis muscle is divided during anterior dissection. This is a critical step to allow the complete mobilization of the rectum.
3. Risk of Injury:
   • There is a risk of injury to the membranous urethra during this phase of the procedure due to its close anatomical proximity.

Indications for Total Neoadjuvant Therapy (TNT)

• Locally Advanced Rectal Cancer
• T4, N2 staging (high-risk features).
• EMVI (Extramural Vascular Invasion) or MRF (+) (Mesorectal Fascia involvement).
• Non-operative management in patients who are unsuitable for surgery or prefer a non-surgical approach.
• Aims for:
  • Local control of the tumor.
  • Distant control to prevent metastasis or recurrence.

TNT is increasingly being utilized to optimize treatment outcomes, particularly in high-risk rectal cancer cases.

Extended Surgeries in Rectal Cancer

• Total Pelvic Exenteration:
  • Complete removal of pelvic organs (bladder, rectum, and reproductive organs).
• Modified Exenteration Types:
  • Anterior Type:
    • Rectum is spared while other pelvic organs are removed.
  • Posterior Type:
    • Bladder is conserved, while the rectum and other posterior pelvic organs are removed.
• Composite Exenteration:
  • Involves bony resection (sacrum or pelvic bones) in addition to pelvic organs, usually in advanced cases with bone invasion.

These surgeries are performed in advanced or recurrent rectal cancers to achieve clear margins and control local disease spread.

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Colorectal Liver Metastases (CRLM)

• Incidence:
  • 20-34% of patients present with synchronous metastases at the time of colorectal cancer diagnosis.
• Classification:
  • Early Metachronous Metastases: Occur within 12 months after primary cancer treatment.
  • Late Metachronous Metastases: Occur after 12 months.
• Prognosis:
  • Synchronous metastases generally have a poorer prognosis compared to metachronous metastases.
• Treatment:
  • Surgery for CRLM combined with chemotherapy significantly improves survival outcomes.
• Survival:
  • 5-year survival rate after surgery and chemotherapy is approximately 50%.

Contraindications to Resection of Colorectal Liver Metastases (CRLM)

• Extensive Extrahepatic Disease. [ lung can be resected with pneumonectomy]
• Peritoneal Metastases.
• Extrabdominal Lymph Node Involvement.
• Unresectable Pulmonary Metastases.

These factors indicate a poor prognosis and typically preclude liver resection, as surgery would not provide a survival benefit due to widespread disease.

Preoperative Evaluation for CRLM Resection

• Tumor Response to Chemotherapy:
  • The most important prognostic factor for assessing resectability and potential outcomes.
• Mutational Status:
  • Helps guide treatment strategy, particularly in determining eligibility for targeted therapies.
  • KRas, BRAF
• Extrahepatic Disease:
  • Preoperative imaging should assess for any extrahepatic spread, which may contraindicate surgery.
• Survival After Downstaging:
  • Patients who undergo downstaging with chemotherapy and later surgery have survival rates similar to those who are eligible for upfront surgery.

Chemotherapy Toxicity in CRLM Treatment

• Irinotecan:
  • Associated with steatohepatitis in approximately 20% of patients.
• Oxaliplatin:
  • Causes sinusoidal injury in around 20% of patients.
• Bevacizumab:
  • Known to reduce oxaliplatin-induced sinusoidal injury, helping to mitigate this specific side effect.

Fong's Clinical Risk Score (CRS) for Colorectal Liver Metastases (CRLM)

• Nodal Status of Primary Tumor: Positive lymph node involvement increases risk.
• Disease-Free Interval: Less than 12 months from primary cancer treatment indicates higher risk.
• Number of Tumors: More than 1 tumor present in the liver.
• Size of Largest Tumor: Greater than 5 cm in diameter.
• Preoperative CEA: Levels greater than 200 ng/mL.

These factors are used to assess the prognosis and guide treatment strategies for patients with CRLM.

Imaging Modalities for Colorectal Liver Metastases (CRLM)

• CECT (Contrast-Enhanced CT Scan):
  • Phases: Arterial, venous, and delayed phases help visualize vascular supply, liver anatomy, and lesion characteristics.
• MRI:
  • Eovist MRI (Gadoxetic Acid-Enhanced MRI):
    • Provides high sensitivity for detecting liver metastases, especially small lesions and for assessing liver function.
• PET Scan:
  • Useful for identifying occult extrahepatic disease, which may alter the treatment plan by revealing metastases not visible on other imaging modalities.

Disappearing Liver Metastases

• Complete Radiographic Response:
  • Does not always indicate a complete pathologic response. Even if metastases are no longer visible on imaging, residual cancer may still be present.
• MRI Sensitivity:
  • MRI is more sensitive than CT for detecting liver metastases, especially in identifying residual disease after chemotherapy.
• Localization:
  • The use of pretreatment markers such as fiducial markers can help accurately localize lesions for surgical resection even if they "disappear" radiographically.

Strategies to Improve Resectability of Liver Metastases

• Neoadjuvant Chemotherapy:
  • Shrinks liver metastases, making previously unresectable tumors operable.
• Portal Vein Embolization (PVE):
  • Promotes hypertrophy of the future liver remnant (FLR), increasing the likelihood of safe resection.
• Two-Stage Hepatectomy:
  • Indication: Used for patients with bilobar liver metastases.
  • Procedure:
    • Neoadjuvant chemotherapy administered first to shrink the tumors.
    • Initial resection of metastases in the planned FLR (future liver remnant).
    • PVE is performed to increase the volume of the unaffected lobe.
    • Second resection: The affected lobe is resected after sufficient hypertrophy of the FLR.

These strategies aim to optimize liver function and volume, enabling curative resection in patients with complex or widespread metastases.

Hepatic Artery Infusional Therapy (HAI)

• Drug Used:
  • 5-FUDR: A deoxyribonucleoside derivative of 5-FU, specifically used for hepatic artery infusion.
• Indication:
  • Used in patients with absence of extrahepatic metastases, focusing on treating liver-only disease.
• Procedure:
  • A pump is inserted into the gastroduodenal artery (GDA) to deliver the chemotherapy directly to the liver.
• Most Common Complication:
  • Gastroduodenal ulceration due to high concentrations of the drug in the arterial supply.
• Other Complication:
  • Biliary toxicity, including bile duct damage, which can occur due to prolonged exposure to the chemotherapeutic agent.

Irreversible Electroporation (IRE)

• Mechanism:
  • High voltage direct current is delivered through electrodes placed around the tumor.
  • Causes cellular membrane disruption, leading to cell death.
• Characteristics:
  • Non-thermal: Does not rely on heat, which preserves surrounding tissues, particularly important near sensitive structures.
• Indications:
  • Used for unresectable small tumors that are close to major vessels, where other treatments may cause damage.
• Common Application:
  • Generally used for pancreatic cancers, though it may be applied to other tumor types under similar conditions.

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Table 171.3: Relative Contraindications to Resection of Locally Recurrent Rectal Cancer

• Extrapelvic disease: Exception may be patients with resectable oligometastasis.
• Predicted R2 resection margin.
• Sciatic pain.
• Bilateral ureteral obstruction: Exception may be involvement of the trigone.
• Circumferential or extensive pelvic sidewall involvement.
• Tumor extension through the greater sciatic notch.
• Tumor encasement of the common or external iliac vessels.
• S1 or S2 involvement: Bony and/or neural involvement.
• Poor patient fitness and surgical risk: ASA classifications IV or V, rare ASA III.

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Question:

Investigation of choice for Ca rectum:

• A) CECT pelvis with rectal protocol
• B) Contrast MRI pelvis with rectal protocol
• C) Non-contrast MRI pelvis with rectal protocol
• D) TRUS

Answer:

C) Non-contrast MRI pelvis with rectal protocol

Explanation:

Non-contrast MRI with rectal protocol is considered the investigation of choice for rectal cancer staging. It provides excellent soft tissue resolution without the need for contrast, effectively evaluating local tumor extension, involvement of the mesorectal fascia, and lymph node status, which are crucial for planning treatment strategies.

Question:

Distance of tumor from the anal verge is best assessed by:

• A) MRI
• B) TRUS
• C) CECT
• D) Rigid proctoscopy

Answer:

D) Rigid proctoscopy

Explanation:

Rigid proctoscopy is the best method to accurately measure the distance of the tumor from the anal verge. While digital rectal examination (DRE) using fingers is the simplest and often most effective initial assessment tool, rigid proctoscopy provides a more precise and standardized measurement for planning treatment.

Question:

Advantage of TAMIS over TEM are all except:

• A) Shorter learning curve
• B) Greater luminal access
• C) Patient position has to be changed according to lesion location
• D) None of the above

Answer:

C) Patient position has to be changed according to lesion location

Explanation:

In TAMIS (Transanal Minimally Invasive Surgery), the patient is typically positioned in dorsal lithotomy, regardless of the tumor location, providing flexibility and ease of access. This is an advantage over TEM (Transanal Endoscopic Microsurgery), where patient positioning must often be adjusted according to lesion location. Therefore, option C is not an advantage of TAMIS over TEM.

Question:

Which of the following lesions is least appropriate for TEM (Transanal Endoscopic Microsurgery)?

• A) Lesions within 3 cm from the anal verge
• B) Lesion within 10 cm of the anal verge
• C) T1/2 less than 3 cm in diameter
• D) Occupying less than 1/3 of the circumference

Answer:

A) Lesions within 3 cm from the anal verge

Explanation:

TEM is not appropriate for lesions located within 3 cm from the anal verge due to the limitations in accessing the area with the equipment, as the port length for TEM is typically around 3 cm. In such cases, Transanal Excision (TAE) is preferred for better accessibility and ease of removal.

Question:

All of the following are definitions of early rectal cancer except:

• A) T2N0
• B) T1N1
• C) Haggitt's Level 2
• D) Kikuchi sm3 involvement

Answer:

B) T1N1

Explanation:

T1N1 is not considered early rectal cancer because it involves positive lymph node involvement (N1), which indicates more advanced disease. Early rectal cancer typically refers to lesions without nodal involvement (N0), such as T1-T2N0 or specific classifications like Haggitt's Level 2 and Kikuchi sm3 involvement.

Question 1:

Risk of lymph node metastases for T2 rectal cancer:

• A) 0-3%
• B) 15%
• C) 25%
• D) 5-10%

Answer:

C) 25%

Explanation:

The risk of lymph node metastases for T2 rectal cancer is approximately 25%, indicating the potential for nodal involvement in T2 stage tumors.

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Question 2:

False statement about nerve supply of rectum:

• A) Superior hypogastric plexus has both sympathetic and parasympathetic fibers.
• B) Nervi erigentes are parasympathetic preganglionic fibers from S2, S3, S4.
• C) Sympathetic innervation of rectum is via L1, L2, L3.
• D) Inferior hypogastric plexus is formed in lateral pelvic wall by both superior hypogastric plexus and nervi erigentes.

Answer:

A) Superior hypogastric plexus has both sympathetic and parasympathetic fibers.

Explanation:

The superior hypogastric plexus contains only sympathetic fibers, not parasympathetic fibers. The parasympathetic supply to the rectum comes from the nervi erigentes.

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Question 3:

Concept of TME (Total Mesorectal Excision) was given by:

• A) Bill Heald
• B) Phil Quirke
• C) Victor Fazio
• D) Sam Atallah

Answer:

A) Bill Heald

Explanation:

Bill Heald pioneered the concept of TME, a crucial surgical technique for rectal cancer resection. Phil Quirke is known for assessing TME specimen quality, while Sam Atallah developed TaTME (Transanal TME).

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Question 4:

Indications for neoadjuvant therapy:

• A) 5 cm tumor at 12 cm from the anal verge involving muscularis propria.
• B) 8 cm tumor 4 cm from the anal verge involving perimuscular tissue with no lymph nodes.
• C) 4 cm tumor 3 cm from the anal verge involving internal sphincter muscle.
• D) 3 cm tumor 4 cm from the anal verge involving muscularis propria.

Answer:

C) 4 cm tumor 3 cm from the anal verge involving internal sphincter muscle.

Explanation:

C) Involvement of the internal sphincter muscle (IAS) is an absolute indication for neoadjuvant therapy due to its location and risk factors.

• A) is in the upper rectum, which typically does not require neoadjuvant therapy.
• B) is a T3N0 tumor, a relative indication for neoadjuvant therapy.
• D) is T2N0, which may not necessarily require neoadjuvant therapy.

Question 1:

A 70-year-old male with a history of hypertension presents with rectal pain and intermittent bleeding. Colonoscopy identifies a rectal mass, and biopsy confirms adenocarcinoma. MRI staging reveals a T4N2M0 tumor with invasion into the prostate. According to the latest guidelines, what is the recommended treatment approach for this patient?

• A) Immediate abdominoperineal resection
• B) Neoadjuvant chemoradiotherapy followed by pelvic exenteration
• C) Palliative chemotherapy
• D) Radiotherapy alone

Answer:

B) Neoadjuvant chemoradiotherapy followed by pelvic exenteration

Explanation:

For a T4N2M0 rectal tumor with prostate invasion, the standard of care involves neoadjuvant chemoradiotherapy (CRT) to downstage the tumor, followed by pelvic exenteration for complete tumor resection. Immediate surgery without neoadjuvant therapy would not achieve optimal results due to the advanced tumor stage.

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Question 2:

RAPIDO trial involved:

• A) Short-course RT followed by 9 cycles of FOLFOX
• B) Long-course RT followed by 6 cycles of FOLFOX
• C) 6 cycles of FOLFOX followed by short-course RT
• D) Long-course RT followed by 6 cycles of FOLFOX

Answer:

A) Short-course RT followed by 9 cycles of FOLFOX

Explanation:

The RAPIDO trial tested a total neoadjuvant therapy (TNT) approach using short-course radiotherapy (25 Gy over 5 daily fractions), followed by 9 cycles of FOLFOX or 6 cycles of CAPOX chemotherapy, followed by surgery. This regimen was designed to improve oncologic outcomes by maximizing preoperative treatment.

Question:

A 62-year-old female undergoes low anterior resection (LAR) with total mesorectal excision (TME) for rectal cancer. She presents 3 weeks postoperatively with fever, abdominal pain, and leukocytosis. A CT scan reveals a pelvic fluid collection. What is the most likely complication, and how should it be managed?

• A) Anastomotic leak; managed with antibiotics and percutaneous drainage
• B) Small bowel obstruction; managed with nasogastric decompression
• C) Pelvic abscess; managed with intravenous antibiotics alone
• D) Urinary tract infection; managed with oral antibiotics

Answer:

A) Anastomotic leak; managed with antibiotics and percutaneous drainage

Explanation:

The patient’s presentation of fever, abdominal pain, leukocytosis, and a pelvic fluid collection 3 weeks after LAR with TME is most suggestive of an anastomotic leak. The standard management includes antibiotics and percutaneous drainage of the fluid collection. This is a serious complication that requires prompt treatment to prevent further septic complications.

Question:

TaTME is an upcoming oncologic approach to rectal cancer. Which of the following statements is not true?

• A) Done only in a hybrid fashion with transabdominal & transanal route
• B) Helpful in sphincter preservation
• C) Unusual high rate of urethral injuries
• D) Lower morbidity compared to laparoscopic TME

Answer:

A) Done only in a hybrid fashion with transabdominal & transanal route

D) Lower morbidity compared to laparoscopic TME

Explanation:

• A is incorrect because TaTME can be performed in a pure transanal approach, without the need for a hybrid transabdominal route.
• D is also incorrect as the morbidity rates of TaTME are comparable or sometimes higher due to complications like urethral injuries, especially in male patients.

Question: ? ? ?

All of the following decrease the incidence of anastomotic leak after colorectal surgery except:

• A) Diversion stoma
• B) Preoperative nutritional rehabilitation
• C) Mechanical bowel preparation
• D) Staple line reinforcement

Answer:

D) Staple line reinforcement

Explanation:

• Staple line reinforcement does not have a significant impact on reducing the incidence of anastomotic leaks.
• While diversion stomas may not directly decrease the incidence, they reduce the severity of complications associated with a leak.
• Preoperative nutritional rehabilitation and mechanical bowel preparation are aimed at improving overall surgical outcomes and reducing complications, including leaks.

Question:

Two months following LAR, a patient complains of frequent and urgent bowel movements after every meal. Which of the following statements is false regarding his complaints?

• A) Patients with diverting ileostomy have decreased risk
• B) Evaluated with Wexner score
• C) More common in patients undergoing preoperative radiation
• D) Typically have increased resting and squeeze pressure

Answer:

D) Typically have increased resting and squeeze pressure

Explanation:

After LAR, patients often develop symptoms of Low Anterior Resection Syndrome (LARS), which includes frequent, urgent bowel movements. These patients generally have decreased resting and squeeze pressures due to disruption of the anal sphincter and pelvic nerve supply.

Question:

CT scan shows leaks of contrast into the pelvic cavity with a 4 cm pelvic collection. The next line of management includes all except:

• A) Conservative management with IV antibiotics and PCD drain
• B) Laparotomy with diversion ileostomy and drainage
• C) Laparotomy with dismantling of stoma and end colostomy
• D) Laparotomy with primary repair of the leak

Answer:

A) Conservative management with IV antibiotics and PCD drain

D) Laparotomy with primary repair of the leak

Explanation:

• Conservative management alone (IV antibiotics and percutaneous drainage) is insufficient due to the significant size of the collection and active leak.
• Primary repair of the anastomotic leak is also generally not recommended, especially with contamination.
• Appropriate options include laparotomy with diversion ileostomy or, in severe cases, dismantling the anastomosis with creation of an end colostomy, particularly if the anastomosis cannot be salvaged.

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General Approach to Anastomotic Leak Management:

• Resuscitation
• Antimicrobial therapy
• Source control:
  • Image-guided drainage for small, localized leaks.
  • Operative management for larger leaks.
• Anastomotic Salvage:
  • Possible if there is no fecal contamination and the defect involves less than 1/4 of the circumference.
• Extraperitoneal anastomosis:
  • Can be salvaged with diversion to manage the leak effectively.

Non-Operative Interventions for Anastomotic Leaks

• Criteria for Non-Operative Management:
  • No signs of diffuse peritonitis.
  • Hemodynamically stable.
  • Late leaks (occurring after the initial postoperative period).
  • Controlled fistula or abscess that is manageable with non-surgical approaches.
• Clinical Indicators:
  • Patient is passing stool and flatus, indicating some bowel function.
• Therapies:
  • Endoluminal vacuum therapy: A non-operative technique used to help control anastomotic leaks and promote healing by applying negative pressure. This method is especially useful for controlled leaks and fistulas.

These criteria are typically applied when the leak is contained, and there is no immediate life-threatening situation that requires surgical intervention.

Question:

Contraindications for resection of locally recurrent rectal cancer include:

• A) Bladder involvement
• B) Unilateral hydronephrosis
• C) Para-aortic lymph node involvement
• D) S1 bony involvement

Answer:

D) S1 bony involvement

Explanation:

S1 bony involvement is considered a contraindication for resection in locally recurrent rectal cancer due to the complex anatomy and high risk of poor surgical outcomes. Other factors like bladder involvement, unilateral hydronephrosis, and para-aortic lymph node involvement are not absolute contraindications and may still be surgically addressed depending on the overall condition and operability of the tumor.