Hinchey Classification for Diverticulitis
The Hinchey classification is a four-stage system that categorizes acute colonic diverticulitis based on the extent of infection and inflammation beyond the colon, guiding treatment decisions from conservative management to urgent surgical intervention. 1, 2
Original Hinchey Classification Stages
The original Hinchey classification consists of four progressive stages 1, 2:
Stage 1 (Hinchey I): Pericolic abscess or phlegmon - localized infection confined to the area immediately surrounding the colon 2
Stage 2 (Hinchey II): Pelvic, intra-abdominal, or retroperitoneal abscess - infection that has spread beyond the immediate pericolic area but remains contained 2
Stage 3 (Hinchey III): Generalized purulent peritonitis - rupture with pus throughout the abdominal cavity 1, 2
Stage 4 (Hinchey IV): Fecal peritonitis - rupture with fecal contamination throughout the abdominal cavity, representing the most severe form 1, 2
Modified Hinchey Classification
The Modified Hinchey Classification incorporates CT imaging findings for more precise diagnosis and includes additional substages 1, 2, 3:
Stage 0: Mild clinical diverticulitis without CT evidence of complications 2
Stage 1a: Confined pericolic inflammation or phlegmon 1
Stage 2: Pelvic, distant intra-abdominal, or retroperitoneal abscess (typically >4 cm) 1, 2
Clinical Management Based on Hinchey Stage
CT imaging is essential for accurate classification and management planning - relying solely on clinical examination is not recommended due to poor accuracy 2.
Treatment Algorithm by Stage:
Hinchey 0 and 1a: Conservative management with bowel rest and antibiotics; selected patients without comorbidities or systemic inflammatory response syndrome may be managed as outpatients 4
Hinchey 1b (abscess <4 cm): Non-operative management with bowel rest and antibiotics is recommended 1, 2
Hinchey 2 (abscess >4 cm): Percutaneous CT-guided drainage is recommended 1, 2; however, these patients have a 22.2% failure rate requiring urgent resection and a 41.2% recurrence rate, so elective surgery should be strongly considered after initial treatment 5
Hinchey 3 and 4: Surgical intervention is required; resection with primary anastomosis can be achieved in 73.6% of cases with perioperative mortality of 1.1% 5; laparoscopic lavage may be considered in select Hinchey III patients but carries higher rates of postoperative abscess and early reintervention 6
Important Clinical Considerations
CT evidence of a diverticular abscess has significant prognostic impact - it correlates with high risk of failure from nonoperative management (22.2% requiring urgent resection) regardless of patient age 5. The presence of an abscess on CT should prompt strong consideration for elective surgery after initial treatment to prevent recurrent diverticulitis, which occurs in 41.2% of stage II patients treated conservatively 5.
The Hinchey classification remains the most widely used system despite being originally designed for operative findings, as it effectively predicts the need for procedural intervention and complications 7, 3.